61 results on '"Wong GR"'
Search Results
2. A comparison of the electrophysiologic and electroanatomic characteristics between the right and left atrium in persistent atrial fibrillation: Is the right atrium a window into the left?
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Prabhu, S, Voskoboinik, A, McLellan, AJA, Peck, KY, Pathik, B, Nalliah, CJ, Wong, GR, Azzopardi, SM, Lee, G, Mariani, J, Ling, L-H, Taylor, AJ, Kalman, JM, Kistler, PM, Prabhu, S, Voskoboinik, A, McLellan, AJA, Peck, KY, Pathik, B, Nalliah, CJ, Wong, GR, Azzopardi, SM, Lee, G, Mariani, J, Ling, L-H, Taylor, AJ, Kalman, JM, and Kistler, PM
- Abstract
INTRODUCTION: The right atrium (RA) is readily accessible; however, it is unclear whether changes in the RA are representative of the LA. We performed detailed biatrial electroanatomic mapping to determine the electrophysiological relationship between the atria. METHODS AND RESULTS: Consecutive patients with persistent AF underwent biatrial electroanatomical mapping with a contact force catheter acquiring points with a CF >10 g prior to ablation. Points were analyzed for tissue voltage, complex electrograms, low voltage (<0.5 mV), scar (<0.05 mV), and conduction velocity (CV). Forty patients (mean age 59 ± 9.2 years, AF duration 12.9 ± 9.2 months, LA area: 28 ± 5.2, RA area: 25 ± 6.4 mm2 , LVEF: 44 ± 15%) underwent mapping during CS pacing. Bipolar voltage (R = 0.57, P <0.001), unipolar voltage (R = 0.68, P <0.001), low voltage (<0.5 nV) (R = 0.48, P = 0.002), fractionation (R = 0.73, P <0.001), and CV (R = 0.49, P = 0.001) correlated well between atria. There was no difference in global bipolar voltage (LA 1.89 ± 0.77 vs. RA 1.77 ± 0.57 mV, P = 0.57); complex electrograms (LA 20% vs. RA 20%, P = 0.99) or low voltage (LA 15% vs. RA 16%, P = 0.84). Global unipolar voltage was significantly higher in the LA compared to the RA (2.95 ± 1.14 vs. 2.28 ± 0.65 mV, P = 0.002) and CV was significantly slower in the RA compared to the LA (0.93 ± 0.15 m/s vs. 1.01 ± 0.19 m/s, P = 0.001). CONCLUSION: AF is associated with remodeling processes affecting both atria. The more accessible RA provides an insight into the biatrial process associated with AF in various disease states without trans-septal access.
- Published
- 2017
3. Seropositivity of HPV 16 E6 and E7 and the risk of oral cancer
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Wong, GR, primary, Ha, KO, additional, Himratul‐Aznita, WH, additional, Yang, YH, additional, Wan Mustafa, WM, additional, Yuen, KM, additional, Abraham, MT, additional, Tay, KK, additional, Karen‐Ng, LP, additional, Cheong, SC, additional, and Zain, RB, additional
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- 2014
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4. Porcine reproductive and respiratory syndrome virus (PRRSV) infection spreads by cell-to-cell transfer in cultured MARC-145 cells, is dependent on an intact cytoskeleton, and is suppressed by drug-targeting of cell permissiveness to virus infection
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Rowland Raymond RR, Ward-Demo Pam, Said Suleman, Wong Grace HW, Duman Richard G, Cafruny William A, and Nelson Eric A
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Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Porcine reproductive and respiratory syndrome virus (PRRSV) is the etiologic agent of PRRS, causing widespread chronic infections which are largely uncontrolled by currently available vaccines or other antiviral measures. Cultured monkey kidney (MARC-145) cells provide an important tool for the study of PRRSV replication. For the present study, flow cytometric and fluorescence antibody (FA) analyses of PRRSV infection of cultured MARC-145 cells were carried out in experiments designed to clarify viral dynamics and the mechanism of viral spread. The roles of viral permissiveness and the cytoskeleton in PRRSV infection and transmission were examined in conjunction with antiviral and cytotoxic drugs. Results Flow cytometric and FA analyses of PRRSV antigen expression revealed distinct primary and secondary phases of MARC-145 cell infection. PRRSV antigen was randomly expressed in a few percent of cells during the primary phase of infection (up to about 20–22 h p.i.), but the logarithmic infection phase (days 2–3 p.i.), was characterized by secondary spread to clusters of infected cells. The formation of secondary clusters of PRRSV-infected cells preceded the development of CPE in MARC-145 cells, and both primary and secondary PRRSV infection were inhibited by colchicine and cytochalasin D, demonstrating a critical role of the cytoskeleton in viral permissiveness as well as cell-to-cell transmission from a subpopulation of cells permissive for free virus to secondary targets. Cellular expression of actin also appeared to correlate with PRRSV resistance, suggesting a second role of the actin cytoskeleton as a potential barrier to cell-to-cell transmission. PRRSV infection and cell-to-cell transmission were efficiently suppressed by interferon-γ (IFN-γ), as well as the more-potent experimental antiviral agent AK-2. Conclusion The results demonstrate two distinct mechanisms of PRRSV infection: primary infection of a relatively small subpopulation of innately PRRSV-permissive cells, and secondary cell-to-cell transmission to contiguous cells which appear non-permissive to free virus. The results also indicate that an intact cytoskeleton is critical for PRRSV infection, and that viral permissiveness is a highly efficient drug target to control PRRSV infection. The data from this experimental system have important implications for the mechanisms of PRRSV persistence and pathology, as well as for a better understanding of arterivirus regulation.
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- 2006
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5. Gastrointestinal: Esophageal complications of cardiac interventions.
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Sarraf, B, Apostolov, R, Yeoh, J, and Wong, GR
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- 2024
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6. SABA prescriptions and asthma management practices in Singapore: results from a cross-sectional, observational SABINA III study.
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Tan DHY, Tan TL, Tan WH, Choong C, Beekman MJHI, Khor JH, Kumar SS, Wong GR, and Lim HF
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- Humans, Female, Cross-Sectional Studies, Singapore, Male, Middle Aged, Adult, Aged, Severity of Illness Index, Primary Health Care statistics & numerical data, Asthma drug therapy, Adrenergic beta-2 Receptor Agonists therapeutic use, Practice Patterns, Physicians' statistics & numerical data, Anti-Asthmatic Agents therapeutic use
- Abstract
Objectives: To evaluate asthma characteristics and treatment patterns, including short-acting β
2 -agonist (SABA) prescriptions, in primary and specialist care in the Singapore cohort of the SABA use IN Asthma (SABINA III) study., Design: Cross-sectional, observational study., Setting: Multicentre study conducted at five sites across Singapore., Methods: In patients with asthma (aged ≥12 years), data on demographics, disease characteristics and asthma treatment prescriptions were collected using electronic case report forms. Patients were classified by investigator-defined asthma severity (guided by 2017 Global Initiative for Asthma recommendations) and practice type (primary/specialist care)., Results: Of the 205 patients analysed (mean (SD) age, 53.6 (16.8) years; female, 62%), 55.9% were enrolled by specialists and 44.1% by primary care physicians. Most study patients (80.5%) had moderate-to-severe asthma (86.0% in specialist care and 74.4% in primary care). In the 12 months before study enrolment, 18.0% of patients experienced ≥1 severe exacerbation. Asthma was well or partly controlled in 78.0% of patients. Overall, 17.1% of all patients were overprescribed SABA (≥3 SABA canisters/year) in the preceding 12 months, and overprescription was greater in specialist versus primary care (26.3% vs 5.6%). Only 2.9% of patients were prescribed SABA monotherapy, while 41.0% received SABA in addition to maintenance therapy. Among the latter, 40.5% were overprescribed SABA. Overall, a higher percentage of patients prescribed ≥3 SABA canisters (vs 0-2 SABA canisters) were assessed as having uncontrolled asthma during the study visit (42.9% vs 17.6%). Maintenance therapy in the form of inhaled corticosteroids (ICS) or ICS/long-acting β2 agonist fixed-dose combinations were prescribed to 14.1% and 84.9% of patients, respectively, in the 12 months before enrolment., Conclusions: In this Singapore cohort, ~17% of all patients and more than 40% of patients prescribed SABA in addition to maintenance therapy were overprescribed SABA. These findings emphasise the need to align clinical practices with the latest evidence-based treatment recommendations., Trial Registration: NCT03857178., Competing Interests: Competing interests: DHYT has received honorarium from AstraZeneca as well as consultation fees from GSK in the past. TLT has received honorarium from AstraZeneca in the past. CC was an employee of AstraZeneca at the time of manuscript development. MJHIB was an employee of AstraZeneca at the time of the study conduct. WHT, JHK, SSK, GRW and HFL have no conflicts of interest to declare., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)- Published
- 2024
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7. Evaluating the efficacy of OralDETECT training: Face-to-face versus online delivery in dental education.
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Ramanathan A, Zaini ZM, Ghani WMN, Wong GR, Zainuddin NI, Yang YH, and Zain RB
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Objective: This study evaluated the effectiveness of face-to-face (F2F) and online OralDETECT training programme in enhancing early detection skills for oral cancer., Methods: A total of 328 final-year dental students were trained across six cohorts. Three cohorts (175 students) received F2F training from the academic years 2016/2017 to 2018/2019, and the remaining three (153 students) underwent online training during the Covid-19 pandemic from 2019/2020 to 2021/2022. Participant scores were analysed using the Wilcoxon signed rank test, the Mann-Whitney test, Cohen's d effect size, and multiple linear regression., Results: Both F2F and online training showed increases in mean scores from pre-test to post-test 3: from 67.66 ± 11.81 to 92.06 ± 5.27 and 75.89 ± 11.03 to 90.95 ± 5.22, respectively. Comparison between F2F and online methods revealed significant differences in mean scores with large effect sizes at the pre-test stage (p < 0.001), while significant differences with small effect sizes were noted for post-test 1 (p = 0.002) and post-test 3 (p = 0.041). Regression analysis indicated that the delivery method is associated with the participants' final scores., Conclusion: F2F and online versions of the OralDETECT training programme significantly enhance participants' knowledge and skills in oral cancer detection. Although F2F appeared to be more effective, the difference was not substantial enough to be considered educationally meaningful., (© 2024 Wiley Periodicals LLC.)
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- 2024
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8. Changing the view: Preventing pneumothorax during transvenous pacemaker implantation.
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Loudon BL and Wong GR
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- Humans, Prosthesis Implantation, Axillary Vein, Pneumothorax etiology, Pneumothorax prevention & control, Pacemaker, Artificial adverse effects, Defibrillators, Implantable
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- 2024
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9. High spinal cord injury precipitating syncope: a rare indication for pacemaker insertion.
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Khan I, Scully TG, Teh AW, and Wong GR
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- Humans, Bradycardia etiology, Bradycardia therapy, Cardiac Pacing, Artificial adverse effects, Syncope therapy, Syncope complications, Male, Middle Aged, Pacemaker, Artificial adverse effects, Spinal Cord Injuries complications, Syncope, Vasovagal etiology, Syncope, Vasovagal therapy
- Abstract
The current evidence for vasovagal syncope management is that cardiac pacing is only indicated in a highly select group of patients where symptoms can be linked to bradycardic episodes. High spinal cord injury can lead to autonomic dysfunction and sympathetic nervous system hypoactivity. A high spinal cord injury can theoretically precipitate profound bradycardia leading to haemodynamic instability and syncope. A patient in his 50s with a history of C2 spinal injury was admitted to our tertiary centre for management of what was initially thought to be septic shock causing hypotension and syncope. With evidence to suggest this patient's presentation may be profound reflex syncope in the context of unopposed parasympathetic signalling, consensus was reached to implant a permanent pacemaker. Remarkably, the patient's haemodynamics stabilised and there were no further episodes of syncope., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2023. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2023
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10. Atrial Fibrillation Catheter Ablation vs Medical Therapy and Psychological Distress: A Randomized Clinical Trial.
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Al-Kaisey AM, Parameswaran R, Bryant C, Anderson RD, Hawson J, Chieng D, Segan L, Voskoboinik A, Sugumar H, Wong GR, Finch S, Joseph SA, McLellan A, Ling LH, Morton J, Sparks P, Sanders P, Lee G, Kistler PM, and Kalman JM
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- Female, Humans, Male, Middle Aged, Anxiety etiology, Anxiety therapy, Anxiety Disorders etiology, Aged, Depression etiology, Depression therapy, Atrial Fibrillation complications, Atrial Fibrillation psychology, Atrial Fibrillation surgery, Atrial Fibrillation therapy, Catheter Ablation adverse effects, Catheter Ablation methods, Catheter Ablation psychology, Psychological Distress, Anti-Arrhythmia Agents therapeutic use
- Abstract
Importance: The impact of atrial fibrillation (AF) catheter ablation on mental health outcomes is not well understood., Objective: To determine whether AF catheter ablation is associated with greater improvements in markers of psychological distress compared with medical therapy alone., Design, Setting, and Participants: The Randomized Evaluation of the Impact of Catheter Ablation on Psychological Distress in Atrial Fibrillation (REMEDIAL) study was a randomized trial of symptomatic participants conducted in 2 AF centers in Australia between June 2018 and March 2021., Interventions: Participants were randomized to receive AF catheter ablation (n = 52) or medical therapy (n = 48)., Main Outcomes and Measures: The primary outcome was Hospital Anxiety and Depression Scale (HADS) score at 12 months. Secondary outcomes included follow-up assessments of prevalence of severe psychological distress (HADS score >15), anxiety HADS score, depression HADS score, and Beck Depression Inventory-II (BDI-II) score. Arrhythmia recurrence and AF burden data were also analyzed., Results: A total of 100 participants were randomized (mean age, 59 [12] years; 31 [32%] women; 54% with paroxysmal AF). Successful pulmonary vein isolation was achieved in all participants in the ablation group. The combined HADS score was lower in the ablation group vs the medical group at 6 months (8.2 [5.4] vs 11.9 [7.2]; P = .006) and at 12 months (7.6 [5.3] vs 11.8 [8.6]; between-group difference, -4.17 [95% CI, -7.04 to -1.31]; P = .005). Similarly, the prevalence of severe psychological distress was lower in the ablation group vs the medical therapy group at 6 months (14.2% vs 34%; P = .02) and at 12 months (10.2% vs 31.9%; P = .01), as was the anxiety HADS score at 6 months (4.7 [3.2] vs 6.4 [3.9]; P = .02) and 12 months (4.5 [3.3] vs 6.6 [4.8]; P = .02); the depression HADS score at 3 months (3.7 [2.6] vs 5.2 [4.0]; P = .047), 6 months (3.4 [2.7] vs 5.5 [3.9]; P = .004), and 12 months (3.1 [2.6] vs 5.2 [3.9]; P = .004); and the BDI-II score at 6 months (7.2 [6.1] vs 11.5 [9.0]; P = .01) and 12 months (6.6 [7.2] vs 10.9 [8.2]; P = .01). The median (IQR) AF burden in the ablation group was lower than in the medical therapy group (0% [0%-3.22%] vs 15.5% [1.0%-45.9%]; P < .001)., Conclusion and Relevance: In this trial of participants with symptomatic AF, improvement in psychological symptoms of anxiety and depression was observed with catheter ablation, but not medical therapy., Trial Registration: ANZCTR Identifier: ACTRN12618000062224.
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- 2023
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11. First Report of Pectobacterium carotovorum and Pectobacterium aroidearum Causing Bacterial Soft Rot on Curly Dwarf Pak Choy ( Brassica rapa var. Chinensis ) in Malaysia.
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Teoh SH, Wong GR, Teo WFA, and Mazumdar P
- Abstract
Brassica rapa var. Chinensis (curly dwarf pak choy) is commonly grown in large-scale vertical farming aquaponic systems. In October 2022, soft rot symptoms and dark brown lesions were observed on B. rapa grown in a commercial aquaponic farm located in Perak, Malaysia. The infected stem appeared brown and water soaked. Severely infected plants produced creamy white ooze on the surface before collapsing entirely (Fig. 1A and B). Infected leaves displayed yellow-brown symptoms and eventually rotted (Fig. 1C); the healthy plants were symptomless (Fig. 1D). About 20 % of the 20,000 B. rapa plants on the farm exhibited symptoms. Ten randomly selected symptomatic plants, five with infected stems and five with infected leaves, were surface sterilized. Each tissue (1.0 cm
2) was homogenized and suspended in a saline solution. The suspensions were then serially diluted and plated separately on Luria-Bertani agar. After a 16-h incubation period, stem tissue yielded 12 isolated colonies, while leaf tissue produced 8 colonies. These isolates were subjected to dereplication using RAPD-PCR (Krzewinski et al., 2001), revealing two distinct RAPD patterns. The cultures, named Pathogen Stem 2 (PS2, obtained from the stem) and Pathogen Leaf 2 (PL2, obtained from the leaf), were initially identified as Pectobacterium sp. through 16S rRNA sequence analysis (Frank et al., 2008) on the EzBioCloud 16S database (Yoon et al., 2017). Further identification of the Pectobacterium species was conducted using multilocus sequence analysis (MLSA) of the icdA , mdh , proA , and mltD genes (Ma et al., 2007). The sequences were deposited in GenBank (OQ660180, OQ660181, and OR206482-OR206489). Based on MLSA phylogeny, PS2 and PL2 were identified as Pectobacterium carotovorum and Pectobacterium aroidearum , respectively (Fig. 2A). Anaerobic assays confirmed their facultative anaerobic nature, while Gram staining revealed Gram-negative, rod-shaped morphology consistent with Pectobacterium (Fig. 2B and C). For the re-inoculation study, one-month-old healthy B. rapa plants were used. PS2 was inoculated into petioles, while PL2 was inoculated into leaves separately (3 biological replicates × 3 leaves for each replicate) using the prick inoculation method (Wei et al., 2019). Sterile needles were used to prick the plant tissues, and 10 µL of bacterial suspensions (2.40×109 CFU/mL) in saline were inoculated onto the pricked spots. Negative control using sterile saline was included. The inoculated plants were maintained in a controlled growth chamber (25 ± 1°C, relative humidity 80 ± 5%). After 48 hpi, the petiole tissue inoculated with PS2 showed bacterial soft rot symptoms (Fig. 1F) and leaves inoculated with PL2 appeared dark brown around the wound (Fig. 1G), similar to the symptoms observed in the commercial farm (Fig. 1B, C); while control plants remained asymptomatic (Fig. 1E). Bacteria were re-isolated from the inoculated petiole and leaf tissue and their identities were confirmed by RAPD-PCR. The RAPD profiles of the bacteria reisolated from the petiole and leaf tissues were the same as those of PS2 and PL2 respectively (Fig. 1H). The pathogenicity of PS2 and PL2 was thus confirmed. To our knowledge, this is the first report of bacterial soft rot on B. rapa in aquaponic systems caused by P. carotovorum and P. aroidearum in Malaysia. The identification of these pathogens is crucial for the prevention of disease outbreaks and to develop an effective disease management strategy.- Published
- 2023
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12. Improved outcomes of conduction system pacing in heart failure with reduced ejection fraction: A systematic review and meta-analysis.
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Gin J, Chow CL, Voskoboinik A, Nalliah C, Wong C, Van Gaal W, Farouque O, Mohamed U, Lim HS, Kalman JM, and Wong GR
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- Humans, Bundle of His, Electrocardiography methods, Treatment Outcome, Heart Conduction System, Cardiac Conduction System Disease, Ventricular Function, Left, Stroke Volume, Cardiac Resynchronization Therapy methods, Heart Failure therapy
- Abstract
Conduction system pacing (CSP)-His bundle pacing (HBP) and left bundle branch area pacing (LBBAP)-are emerging alternatives to biventricular pacing (BVP) for cardiac resynchronization therapy (CRT) in heart failure. However, evidence is largely limited to small and observational studies. We conducted a meta-analysis including a total of 15 randomized controlled trials (RCTs) and non-RCTs that compare CSP (HBP and LBBAP) with BVP in patients with CRT indications. We assessed the mean differences in QRS duration (QRSd), pacing threshold, left ventricular ejection fraction (LVEF), and New York Heart Association (NYHA) class score. CSP resulted in a pooled mean QRSd improvement of -20.3 ms (95% confidence interval [CI] -26.1 to -14.5 ms; P < .05; I
2 = 87.1%) vs BVP. For LVEF, a weighted mean increase of 5.2% (95% CI 3.5%-6.9%; P < .05; I2 = 55.6) was observed after CSP vs BVP. The mean NYHA score was reduced by -0.40 (95% CI -0.6 to -0.2; P < .05; I2 = 61.7) after CSP vs BVP. A subgroup analysis of outcomes stratified by LBBAP and HBP demonstrated statistically significant weighted mean improvements of QRSd and LVEF with both CSP modalities compared with BVP. LBBAP resulted in NYHA improvement compared with BVP, without differences between CSP subgroups. LBBAP is associated with a significantly lowered mean pacing threshold of -0.51 V (95% CI -0.68 to -0.38 V) while HBP had increased the mean threshold (0.62 V; 95% CI -0.03 to 1.26 V) compared with BVP; however, this was associated with significant heterogeneity. Overall, both CSP techniques are feasible and effective CRT alternatives for heart failure. Further RCTs are needed to establish long-term efficacy and safety., (Copyright © 2023 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)- Published
- 2023
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13. Polygenic risk scores are associated with atrial electrophysiologic substrate abnormalities and outcomes after atrial fibrillation catheter ablation.
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Al-Kaisey A, Wong GR, Young P, Chieng D, Hawson J, Anderson R, Sugumar H, Nalliah C, Prabhu M, Johnson R, Soka M, Tarr I, Bakshi A, Yu C, Lacaze P, Giannoulatou E, McLellan A, Lee G, Kistler PM, Fatkin D, and Kalman JM
- Subjects
- Humans, Heart Atria, Cardiac Electrophysiology, Risk Factors, Treatment Outcome, Atrial Fibrillation genetics, Atrial Fibrillation surgery, Catheter Ablation adverse effects
- Published
- 2023
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14. 'Let's Pause A Minute…And Think' - Syncope Due to Prolonged Atrioventricular Block.
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Gin JH and Wong GR
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- Humans, Syncope etiology, Electrocardiography, Data Collection, Atrioventricular Block diagnosis
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- 2023
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15. Homeobox Genes in Odontogenic Lesions: A Scoping Review.
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Hii EPW, Ramanathan A, Pandarathodiyil AK, Wong GR, Sekhar EVS, Binti Talib R, Zaini ZM, and Zain RB
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- Humans, Genes, Homeobox genetics, Homeodomain Proteins genetics, Transcription Factors genetics, Ameloblastoma, Odontogenic Tumors genetics, Carcinoma genetics, Odontogenic Cysts
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Background: Homeobox genes play crucial roles in tooth morphogenesis and development and thus mutations in homeobox genes cause developmental disorders such as odontogenic lesions. The aim of this scoping review is to identify and compile available data from the literatures on the topic of homeobox gene expression in odontogenic lesions., Method: An electronic search to collate all the information on studies on homeobox gene expression in odontogenic lesions was carried out in four databases (PubMed, EBSCO host, Web of Science and Cochrane Library) with selected keywords. All papers which reported expression of homeobox genes in odontogenic lesions were considered., Results: A total of eleven (11) papers describing expression of homeobox genes in odontogenic lesions were identified. Methods of studies included next generation sequencing, microarray analysis, RT-PCR, Western blotting, in situ hybridization, and immunohistochemistry. The homeobox reported in odontogenic lesions includes LHX8 and DLX3 in odontoma; PITX2, MSX1, MSX2, DLX, DLX2, DLX3, DLX4, DLX5, DLX6, ISL1, OCT4 and HOX C in ameloblastoma; OCT4 in adenomatoid odontogenic tumour; PITX2 and MSX2 in primordial odontogenic tumour; PAX9 and BARX1 in odontogenic keratocyst; PITX2, ZEB1 and MEIS2 in ameloblastic carcinoma while there is absence of DLX2, DLX3 and MSX2 in clear cell odontogenic carcinoma., Conclusions: This paper summarized and reviews the possible link between homeobox gene expression in odontogenic lesions. Based on the current available data, there are insufficient evidence to support any definite role of homeobox gene in odontogenic lesions., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)
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- 2023
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16. Impact of CPAP on the Atrial Fibrillation Substrate in Obstructive Sleep Apnea: The SLEEP-AF Study.
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Nalliah CJ, Wong GR, Lee G, Voskoboinik A, Kee K, Goldin J, Watts T, Linz D, Parameswaran R, Sugumar H, Prabhu S, McLellan A, Ling LH, Joseph SA, Morton JB, Kistler P, Sanders P, and Kalman JM
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- Continuous Positive Airway Pressure methods, Humans, Polysomnography, Sleep, Atrial Fibrillation, Sleep Apnea, Obstructive complications, Sleep Apnea, Obstructive therapy
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Background: Observational studies report that obstructive sleep apnea (OSA) is associated with an increasingly remodeled atrial substrate in atrial fibrillation (AF). However, the impact of OSA management on the electrophysiologic substrate has not been evaluated., Objectives: In this study, the authors sought to determine the impact of OSA management on the atrial substrate in AF., Methods: We recruited 24 consecutive patients referred for AF management with at least moderate OSA (apnea-hypopnea index [AHI] ≥15). Participants were randomized in a 1:1 ratio to commence continuous positive airway pressure (CPAP) or no therapy (n = 12 CPAP; n = 12 no CPAP). All participants underwent invasive electrophysiologic study (high-density right atrial mapping) at baseline and after a minimum of 6 months. Outcome variables were atrial voltage (mV), conduction velocity (m/s), atrial surface area <0.5 mV (%), proportion of complex points (%), and atrial effective refractory periods (ms). Change between groups over time was compared., Results: Clinical characteristics and electrophysiologic parameters were similar between groups at baseline. Compliance with CPAP therapy was high (device usage: 79% ± 19%; mean usage/day: 268 ± 91 min) and resulted in significant AHI reduction (mean reduction: 31 ± 23 events/h). There were no differences in blood pressure or body mass index between groups over time. At follow-up, the CPAP group had faster conduction velocity (0.86 ± 0.16 m/s vs 0.69 ± 0.12 m/s; P (time × group) = 0.034), significantly higher voltages (2.30 ± 0.57 mV vs 1.94 ± 0.72 mV; P < 0.05), and lower proportion of complex points (8.87% ± 3.61% vs 11.93% ± 4.94%; P = 0.011) compared with the control group. CPAP therapy also resulted in a trend toward lower proportion of atrial surface area <0.5 mV (1.04% ± 1.41% vs 4.80% ± 5.12%; P = 0.065)., Conclusions: CPAP therapy results in reversal of atrial remodeling in AF and provides mechanistic evidence advocating for management of OSA in AF., Competing Interests: Funding Support and Author Disclosures For this work, Dr Nalliah received the Eric Prystowsky Fellows Clinical Research Award, Heart Rhythm Society, May 2020, and the Ralph Reader Young Investigator Prize of the Cardiac Society of Australia and New Zealand, December 2020; and he is supported also by the National Heart Foundation and a Viertel Charitable Foundation Clinical Investigator Award. Dr Voskoboinik is supported by an NHMRC EL1 Investigator Grant and an NHF Early Career Fellowship. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2022 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)
- Published
- 2022
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17. Effectiveness of "OralDETECT": a Repetitive Test-enhanced, Corrective Feedback Method Competency Assessment Tool for Early Detection of Oral Cancer.
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Zain RB, Pateel DGS, Ramanathan A, Kallarakkal TG, Wong GR, Yang YH, Zaini ZM, Ibrahim N, Kohli S, and Durward C
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- Early Detection of Cancer methods, Feedback, Humans, Quality of Life, Mouth Diseases, Mouth Neoplasms diagnosis
- Abstract
Early diagnosis of oral cancer results in less aggressive treatment and improves the quality of life and overall 5-year survival rate. Well-trained dental professionals can play a crucial role in the early detection of oral cancers. The present study aims to determine the effectiveness of the training program "OralDETECT", a spaced repetitive, test-enhanced learning tool with a corrective feedback mechanism for early detection of oral cancer. Thirty-two dentists and 259 dental students from three Malaysian dental schools were involved in this study. All participants were trained and calibrated to recognize oral potentially malignant disorders (OPMD) and oral cancer using "OralDETECT", which is comprised of a series of pre-test, lecture, post-tests and review sessions. The percentage of correct answers (scores) for each test given by the participants was calculated and analysed using a paired t test. It was found that the overall percentage of diagnostic accuracy for both dental professionals and student groups increased to above 80% from the pre-tests to the final post-tests. There was a significant improvement in overall scores between the pre-tests and all three post-tests for the dental professional groups and the student groups. The diagnostic accuracy for individual OPMD and lesions suspicious of oral cancer also increased to above 80% for both groups. The results of our study demonstrate that the "OralDETECT" is an efficient and effective competency tool which can be used to train dental professionals and students for the early detection of OPMD and oral cancer., (© 2020. American Association for Cancer Education.)
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- 2022
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18. Sex-Related Differences in Atrial Remodeling in Patients With Atrial Fibrillation: Relationship to Ablation Outcomes.
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Wong GR, Nalliah CJ, Lee G, Voskoboinik A, Chieng D, Prabhu S, Parameswaran R, Sugumar H, Al-Kaisey A, McLellan A, Ling LH, Sanders P, Kistler PM, and Kalman JM
- Subjects
- Action Potentials, Aged, Atrial Fibrillation diagnosis, Atrial Fibrillation surgery, Catheter Ablation, Electrophysiologic Techniques, Cardiac, Female, Humans, Male, Middle Aged, Prospective Studies, Recurrence, Risk Assessment, Risk Factors, Sex Factors, Time Factors, Treatment Outcome, Atrial Fibrillation physiopathology, Atrial Remodeling, Heart Rate
- Abstract
Background: Population studies have demonstrated a range of sex differences including a higher prevalence of atrial fibrillation (AF) in men and a higher risk of AF recurrence in women. However, the underlying reasons for this higher recurrence are unknown. This study evaluated whether sex-based electrophysiological substrate differences exist to account for worse AF ablation outcomes in women., Methods: High-density electroanatomic mapping of the left atrium was performed in 116 consecutive patients with AF. Regional analysis was performed across 6 left atrium segments. High-density maps were created using a multipolar catheter (Biosense Webster) during distal coronary sinus pacing at 600 and 300 ms. Mean voltage and conduction velocity was determined. Complex fractionated signals and double potentials were manually annotated., Results: Overall, 42 (36%) were female, mean age was 61±8 years and AF was persistent in 52%. Global mean voltage was significantly lower in females compared with males at 600 ms (1.46±0.17 versus 1.84±0.15 mV, P <0.001) and 300 ms (1.27±0.18 versus 1.57±0.18 mV, P =0.013) pacing. These differences were seen uniformly across the left atrium. Females demonstrated significant conduction velocity slowing (34.9±6.1 versus 44.1±6.9 cm/s, P =0.002) and greater proportion of complex fractionated signals (9.9±1.7% versus 6.0±1.7%, P =0.014). After a median follow-up of 22 months (Q1-Q3: 15-29), females had significantly lower single-procedure (22 [54%] versus 54 [75%], P =0.029) and multiprocedure (24 [59%] versus 60 [83%], P =0.005) arrhythmia-free survival. Female sex and persistent AF were independent predictors of single and multiprocedure arrhythmia recurrence., Conclusions: Female patients demonstrated more advanced atrial remodeling on high-density electroanatomic mapping and greater post-AF ablation arrhythmia recurrence compared with males. These changes may contribute to sex-based differences in the clinical course of females with AF and in part explain the higher risk of recurrence. Graphic Abstract: A graphic abstract is available for this article.
- Published
- 2022
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19. Percutaneous Balloon-Assisted Suprapubic Cystostomy Tube Placement: A Novel Technique.
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Patel T, Wong GR, Commander CW, Kim KR, and Bream PR Jr
- Published
- 2021
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20. Severe hyperkalaemia in the setting of tumour lysis syndrome.
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Scully TG, Wong GR, Teh AW, and Lim HS
- Subjects
- Humans, Hyperkalemia diagnosis, Hyperkalemia etiology, Tumor Lysis Syndrome diagnosis, Tumor Lysis Syndrome etiology
- Abstract
Competing Interests: Competing interests: None declared.
- Published
- 2021
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21. Pregnancy in patients with implantable cardiac defibrillators.
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Wong GR, Ang M, Jayarajan J, Walker F, and Lambiase PD
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- Arrhythmias, Cardiac, Death, Sudden, Cardiac prevention & control, Female, Humans, Pregnancy, Defibrillators, Implantable, Heart Defects, Congenital
- Abstract
The number of patients of reproductive age with inherited and congenital heart disease receiving implantable cardiac defibrillators (ICD) is steadily increasing. Safely and effectively coordinating pregnancy in this high-risk cohort is important to optimise maternal-foetal outcomes. As members of the multidisciplinary team caring for pregnant patients with indications for ICD, cardiologists and electrophysiologists should be aware of the considerations and nuances involved in managing these patients. This article reviews the pathophysiology of arrhythmias, ICD implantation considerations, novel minimal fluoroscopy techniques and subcutaneous ICD. In addition, antenatal and device management during pregnancy and delivery are discussed.
- Published
- 2021
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22. Sleep apnoea has a dose-dependent effect on atrial remodelling in paroxysmal but not persistent atrial fibrillation: a high-density mapping study.
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Nalliah CJ, Wong GR, Lee G, Voskoboinik A, Kee K, Goldin J, Watts T, Linz D, Wirth D, Parameswaran R, Sugumar H, Prabhu S, McLellan A, Ling H, Joseph S, Morton JB, Kistler P, Sanders P, and Kalman JM
- Subjects
- Aged, Heart Atria diagnostic imaging, Heart Atria surgery, Humans, Male, Middle Aged, Atrial Fibrillation diagnosis, Atrial Fibrillation surgery, Atrial Remodeling, Catheter Ablation, Sleep Apnea, Obstructive diagnosis
- Abstract
Aims: Obstructive sleep apnoea (OSA) associates with atrial fibrillation (AF), but the relationship of OSA severity and AF phenotype with the atrial substrate remains poorly defined. We sought to define the atrial substrate across the spectrum of OSA severity utilizing high-density mapping., Methods and Results: Sixty-six consecutive patients (male 71%, age 61 ± 9) having AF ablation (paroxysmal AF 36, persistent AF 30) were recruited. All patents underwent formal overnight polysomnography and high-density left atrial (LA) mapping (mean 2351 ± 1244 points) in paced rhythm. Apnoea-hypopnoea index (AHI) (mean 21 ± 18) associated with lower voltage (-0.34, P = 0.005), increased complex points (r = 0.43, P < 0.001), more low-voltage areas (r = 0.42, P < 0.001), and greater voltage heterogeneity (r = 0.39, P = 0.001), and persisted after multivariable adjustment. Atrial conduction heterogeneity (r = 0.24, P = 0.025) but not conduction velocity (r = -0.09, P = 0.50) associated with AHI. Patchy regions of low voltage that co-localized with slowed conduction defined the atrial substrate in paroxysmal AF, while a diffuse atrial substrate predominated in persistent AF. The association of AHI with remodelling was most apparent among paroxysmal AF [LA voltage: paroxysmal AF -0.015 (-0.025, -0.005), P = 0.004 vs. persistent AF -0.006 (-0.017, 0.005), P = 0.30]. Furthermore, in paroxysmal AF an AHI ≥ 30 defined a threshold at which atrial remodelling became most evident (nil-mild vs. moderate vs. severe: 1.92 ± 0.42 mV vs. 1.84 ± 0.28 mV vs. 1.34 ± 0.41 mV, P = 0.006). In contrast, significant remodelling was observed across all OSA categories in persistent AF (1.67 ± 0.55 mV vs. 1.50 ± 0.66 mV vs. 1.55 ± 0.67 mV, P = 0.82)., Conclusion: High-density mapping observed that OSA associates with marked atrial remodelling, predominantly among paroxysmal AF cohorts with severe OSA. This may facilitate the identification of AF patients that stand to derive the greatest benefit from OSA management., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2021. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2021
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23. Comparison of Cost and Efficacy of Trufill® vs Histoacryl® n-Butyl Cyanoacrylate for Translumbar Type 2 Endoleak Embolization.
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Wong GR, Yu H, and Isaacson AJ
- Subjects
- Aged, Aged, 80 and over, Aortic Aneurysm, Abdominal surgery, Blood Vessel Prosthesis Implantation adverse effects, Cost Savings, Cost-Benefit Analysis, Embolization, Therapeutic adverse effects, Enbucrilate adverse effects, Endoleak etiology, Endovascular Procedures adverse effects, Female, Humans, Male, Middle Aged, Retrospective Studies, Treatment Outcome, Embolization, Therapeutic economics, Enbucrilate administration & dosage, Enbucrilate economics, Endoleak economics, Endoleak therapy, Health Care Costs
- Abstract
Purpose: The study aimed to compare the cost and efficacy of translumbar approach type 2 endoleak repairs using either Trufill® or Histoacryl® n-BCA liquid embolic., Method and Materials: This was a retrospective review of patients who had translumbar approach type 2 endoleak repairs using either Trufill® or Histoacryl®. Patients were included if they underwent a technically successful type 2 endoleak repair via a translumbar approach with Trufill® or Histoacryl® n-BCA. A multivariable analysis was performed with the primary clinical outcome of percent change in aneurysm diameter per month compared. Procedure cost was calculated based on typical materials used., Results: 20 Trufill® and 14 Histoacryl® patients were included. The mean procedure cost was higher for Trufill® ($5,757.30 vs. $1,586.09, p ≤ 0.001). There was no significant difference between Trufill® or Histoacryl® patients for age at first embolization, gender, total number of embolizations, number of feeding branches, aneurysm sac size prior to embolization, or residual endoleak at first follow-up. Trufill® patients had more coils used (12.0 vs. 4.3, p = 0.0007), less glue used (0.9 vs. 2.1 mL, p < 0.001), longer follow-up duration (33.5 vs. 13.2 months, p = 0.002), more follow-up CT angiograms (CTA) (3.7 vs. 1.9, p = 0.01), and larger excluded aneurysm sac size at most recent CTA (7.1 cm vs. 5.9 cm, p = 0.04). Percent change in sac diameter per month was not significantly different between Trufill® and Histoacryl® (0.21% vs. -0.25%/month, p = 0.06, respectively). There were no complications., Conclusion: Use of Histoacryl® over Trufill® n-BCA resulted in significantly less procedural cost while maintaining safety and efficacy.
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- 2021
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24. Catheter Ablation Versus Medication in Atrial Fibrillation and Systolic Dysfunction: Late Outcomes of CAMERA-MRI Study.
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Sugumar H, Prabhu S, Costello B, Chieng D, Azzopardi S, Voskoboinik A, Parameswaran R, Wong GR, Anderson R, Al-Kaisey AM, Ling LH, Kotschet E, Taylor AJ, Kalman JM, and Kistler PM
- Subjects
- Contrast Media, Gadolinium, Heart Atria, Humans, Magnetic Resonance Imaging, Middle Aged, Stroke Volume, Ventricular Function, Left, Atrial Fibrillation diagnostic imaging, Atrial Fibrillation drug therapy, Atrial Fibrillation surgery, Catheter Ablation, Ventricular Dysfunction, Left diagnostic imaging
- Abstract
Objectives: This study sought to determine the long-term outcomes of restoring sinus rhythm with catheter ablation (CA)., Background: The CAMERA-MRI (Catheter Ablation Versus Medical Rate Control in Atrial Fibrillation and Heart Failure-An MRI-Guided Multicenter Randomized Controlled Trial) study demonstrated that restoration of sinus rhythm with CA significantly improved left ventricular ejection fraction (LVEF) compared with medical rate control (MRC) at 6 months in persistent atrial fibrillation and otherwise unexplained systolic heart failure. However, the long-term outcomes have not been reported., Methods: Patients enrolled in the CAMERA-MRI study were followed for 4 years with echocardiogram and cardiac magnetic resonance. CA involved pulmonary vein isolation and posterior left atrial wall isolation in 94%. Patients crossed over to CA after 6-month study duration. Arrhythmia burden was determined with implanted cardiac monitors or cardiac devices., Results: Sixty-six patients (age 62 ± 10 years, atrial fibrillation duration of 22 ± 16 months, and LVEF 33 ± 9%) were randomized 1:1 to CA versus MRC. Eighteen of 33 patients crossed over from MRC group to CA group. At 4.0 ± 0.9 years, atrial fibrillation recurred in 27 patients (57%) in the CA group with a mean burden of 10.6 ± 21.2% after 1.4 ± 0.6 procedures. There was an absolute increase in LVEF with CA of 16.4 ± 13.3% compared with 8.6 ± 7.6% in MRC (p = 0.001). In the CA group, the absence of ventricular late gadolinium enhancement was associated with a greater improvement in absolute LVEF (19 ± 13% vs. 10 ± 11% in the late gadolinium enhancement-positive group; p = 0.04) and LVEF normalization in 19 patients (58%) versus 4 patients (18%) in the late gadolinium enhancement-positive group (p = 0.008) at 4.0 ± 0.9 years follow-up., Conclusions: CA is superior to MRC in improving LVEF in the long term in patients with atrial fibrillation and systolic heart failure. The greatest recovery in systolic function was demonstrated in the absence of ventricular fibrosis on cardiac magnetic resonance., Competing Interests: Author Disclosures Dr. Sugumar has received support from a co-funded National Health and Medical Research Committee/National Health Foundation post-graduate scholarships and Royal Australian College of Physicians J.J. Billings and Centre of Research Excellence in Cardiovascular Outcomes Improvement scholarships. Prof. Jonathan M. Kalman has received a National Health and Medical Research Committee practitioner fellowship; and research and fellowship support from Medtronic and Biosense Webster, all outside the submitted work. Prof. Kistler has received funding from Abbott Medical for consultancy and speaking engagements, outside the submitted work. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2020 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
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25. Genetic Susceptibility to Atrial Fibrillation Is Associated With Atrial Electrical Remodeling and Adverse Post-Ablation Outcome.
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Wong GR, Nalliah CJ, Lee G, Voskoboinik A, Prabhu S, Parameswaran R, Sugumar H, Anderson RD, Ling LH, McLellan A, Johnson R, Sanders P, Kistler PM, Fatkin D, and Kalman JM
- Subjects
- Female, Genetic Predisposition to Disease, Heart Atria, Humans, Male, Middle Aged, Atrial Fibrillation genetics, Atrial Fibrillation surgery, Atrial Remodeling, Catheter Ablation
- Abstract
Objectives: This study sought to assess the atrial electrophysiological properties and post-ablation outcomes in patients with atrial fibrillation (AF) with and without the rs2200733 single nucleotide variant., Background: The phenotype associated with chromosome 4q25 of the AF-susceptibility locus remains unknown., Methods: In this study, 102 consecutive patients (ages 61 ± 9 years, 64% male) with paroxysmal or persistent AF were prospectively recruited prior to ablation. Patients were genotyped for rs2200733 and high-density left atrial (LA) electroanatomic maps were created using a multipolar catheter during distal coronary sinus (CS) pacing at 600 ms. Voltage, conduction velocity (CV), CV heterogeneity, and fractionated signals of 6 LA segments were determined. Arrhythmia recurrence was assessed by continuous device (51%) and Holter monitoring., Results: Overall, 41 patients (40%) were single nucleotide variant carriers (38 heterozygous, 3 homozygous). A mean of 2,239 ± 852 points per patient were collected. Carriers had relatively increased CV heterogeneity (45.7 ± 7.5% vs. 35.9 ± 2.3%; p < 0.001), complex signals (9.4 ± 2.9% vs 6.0 ± 1.2%; p = 0.008), regional LA slowing, or conduction block (31.7 ± 8.2% vs. 17.9 ± 1.9%; p = 0.013) particularly in the posterior and lateral walls. There were no differences in CV, voltage, atrial refractoriness, or sinus node function. At follow-up (median: 27 months; range 19 to 31 months), carriers had lower arrhythmia-free survival (51% vs. 80%; p = 0.003). On multivariable analysis, carrier status was independently associated with CV heterogeneity (p = 0.001), complex signals (p = 0.002), and arrhythmia recurrence (p = 0.019)., Conclusions: These data provide the first evidence that the rs2200733-tagged haplotype alters LA electrical remodeling and is a determinant of long-term outcome following AF ablation. The molecular mechanisms underpinning these changes warrant further investigation., Competing Interests: Author Relationship With Industry Dr. Wong has received support from co-funded National Health and Medical Research Council (NHMRC)/Heart Foundation post-graduate scholarships. Dr. Fatkin has received support from the NHMRC, Victor Chang Cardiac Research Institute, Estate of the Late RT Hall, and Simon Lee Foundation. Prof. Kalman has received support from an NHMRC practitioner fellowship; and has received research and fellowship support from Biosense Webster, Boston Scientific, St. Jude Medical, and Medtronic. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2020. Published by Elsevier Inc.)
- Published
- 2020
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26. Arrhythmia recurrence is more common in females undergoing multiple catheter ablation procedures for persistent atrial fibrillation: Time to close the gender gap.
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Sugumar H, Nanayakkara S, Chieng D, Wong GR, Parameswaran R, Anderson RD, Al-Kaisey A, Nalliah CJ, Azzopardi S, Prabhu S, Voskoboinik A, Lee G, McLellan AJ, Ling LH, Morton JB, Kalman JM, and Kistler PM
- Subjects
- Atrial Fibrillation epidemiology, Atrial Fibrillation physiopathology, Australia epidemiology, Female, Follow-Up Studies, Humans, Incidence, Male, Middle Aged, Recurrence, Sex Distribution, Sex Factors, Time Factors, Treatment Outcome, Atrial Fibrillation surgery, Catheter Ablation methods, Pulmonary Veins surgery
- Abstract
Background: Female gender is associated with an increased recurrence of atrial fibrillation (AF) after catheter ablation (CA). Although AF is more common in men, women constitute a significant proportion with persistent atrial fibrillation (PsAF)., Objective: The purpose of this study was to determine whether multiple ablation procedures improves arrhythmia outcomes in females with PsAF compared to men., Methods: We performed a multicenter observational study to determine long-term arrhythmia outcomes in patients undergoing >1 CA for PsAF. CA involved pulmonary vein (PV) isolation with additional ablation including linear, posterior wall isolation, electrogram-guided, or a combination of these., Results: A total of 281 patients had >1 ablation procedure for PsAF and were included in this analysis (mean age 58.7 ± 9.3 years; 86 [30.6%] female; left atrial [LA] area 27.0 ± 5.3 cm
2 ; PsAF duration 1.7 ± 1.7 years). At mean follow-up of 45.5 ± 31.8 months, freedom from recurrent AF was present in 148 patients(52.7%) after 2.2 ± 0.5 procedures. After multivariate analysis, female gender (hazard ratio [HR] 2.10; P <.001) and enduring PV isolation (HR 1.64; P = .01) were independently associated with AF recurrence. Enduring PV isolation was significantly higher in women than in men (33.7% vs 19.5%; P = .01)., Conclusion: Female gender was independently and strongly associated with arrhythmia recurrence in patients undergoing multiple procedures for PsAF. PV reconnection was less likely, and fewer reconnected PVs occurred in women. Further studies are required to better understand the mechanisms responsible for AF in females to assist in closing the gender gap in the success of CA., (Copyright © 2019 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)- Published
- 2020
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27. Dynamic Atrial Substrate During High-Density Mapping of Paroxysmal and Persistent AF: Implications for Substrate Ablation.
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Wong GR, Nalliah CJ, Lee G, Voskoboinik A, Prabhu S, Parameswaran R, Sugumar H, Anderson RD, McLellan A, Ling LH, Morton JB, Sanders P, Kistler PM, and Kalman JM
- Subjects
- Aged, Atrial Fibrillation diagnosis, Atrial Fibrillation surgery, Cardiac Pacing, Artificial, Catheter Ablation, Coronary Sinus, Female, Heart Conduction System physiopathology, Humans, Male, Middle Aged, Pulmonary Veins surgery, Atrial Fibrillation physiopathology, Electrophysiologic Techniques, Cardiac methods, Heart Atria physiopathology
- Abstract
Objectives: This study sought to determine the impact of rate and direction on left atrial (LA) substrate., Background: The extent to which substrate mapped in sinus rhythm varies according to cycle length and direction of wave front propagation is unknown., Methods: A total of 73 consecutive patients with atrial fibrillation (AF) underwent electroanatomic LA mapping before pulmonary vein isolation using multipolar catheter during distal coronary sinus (CS) pacing at 600 ms and 300 ms. Additional maps were created during left superior pulmonary vein pacing at 300 ms. Bipolar voltage, conduction velocity (CV), and complex signals were determined., Results: Mean age was 61 ± 9 years, 67% were men, and 53% had persistent AF. Global mean voltage was lower with CS pacing at 300 ms compared with 600 ms (1.56 ± 0.47 mV vs. 1.74 ± 0.48 mV; p < 0.001). This was seen in all LA segments. Global CV was reduced (30.4 ± 13.0 cm/s vs. 38.6 ± 14.0 cm/s; p < 0.001) with greater complex signals at 300 ms (8.9% vs. 5.3%; p < 0.005). Compared with CS pacing, left superior pulmonary vein pacing demonstrated highly regional changes with decreased voltage (1.04 ± 0.43 mV vs. 1.47 ± 0.53 mV; p = 0.01) and CV (24.4 ± 13.0 cm/s vs. 39.9 ± 16.6 cm/s; p = 0.008), and greater complex signals posteriorly. Longer AF duration in paroxysmal AF (p = 0.02) and shorter duration in persistent AF (p = 0.015) and left ventricular ejection fraction (p = 0.016) were independent predictors of voltage change., Conclusions: In patients with AF, variation in cycle length and direction of wave front activation produce both generalized and regional changes in voltage, CV, and complex fractionation, resulting in significant changes in substrate maps. This study highlights the potential limitations of static low-voltage maps to identify the AF ablation target zone., (Copyright © 2019. Published by Elsevier Inc.)
- Published
- 2019
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28. Diagnostic yield of computed tomography-guided biopsy and aspiration for vertebral osteomyelitis.
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Ang MT, Wong GR, Wong DR, Clements W, and Joseph T
- Subjects
- Female, Humans, Male, Middle Aged, Osteomyelitis diagnostic imaging, Retrospective Studies, Spinal Diseases diagnostic imaging, Suction, Image-Guided Biopsy, Osteomyelitis pathology, Spinal Diseases pathology, Tomography, X-Ray Computed
- Abstract
Introduction: The diagnostic yield of and best approaches for imaging-guided percutaneous biopsy for vertebral osteomyelitis is controversial. Early studies suggest yields of up to 90%; however, recent evidence shows lower yields of 30-40%. We aim to determine yield and predictors of yield in percutaneous CT-guided biopsies in vertebral osteomyelitis., Methods: We conducted a retrospective observational single-centre study cohort study of all patients presenting for vertebral biopsy or aspiration between 2014 and 2018. Only patients undergoing biopsy for suspected infection were included. Patients with malignant indications were excluded. Comprehensive review of medical records was performed for clinical presentation, comorbidities, imaging, biomarkers, microbiology and treatment., Results: Overall, 40 out of 88 biopsies were performed for suspected infection, in 36 patients. Mean age was 59 ± 18 years; 29 (81%) were male. Of the 40 samples, an organism was identified in 14 samples (35%). Gram-positive organisms were most commonly identified; Staphylococcus aureus was cultured in 7 (50%) of samples. Mean admission CRP was significantly higher in patients with identified organisms compared to those without (137 ± 106 vs 54 ± 78, P = 0.008). Aspiration was a strong independent predictor of positive microbiological growth on multivariate analysis (OR 6.52 [1.25-34.02], P = 0.026). Biopsy or aspiration aided clinical decision-making in half of cases., Conclusions: Percutaneous CT-guided biopsy has a modest yield for identifying the culprit organism in suspected cases of vertebral osteomyelitis. Elevated CRP and aspiration of fluid collections are associated with improved microbiological yield and should be considered in deciding when and where to biopsy., (© 2019 The Royal Australian and New Zealand College of Radiologists.)
- Published
- 2019
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29. Atrial Remodeling Following Catheter Ablation for Atrial Fibrillation-Mediated Cardiomyopathy: Long-Term Follow-Up of CAMERA-MRI Study.
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Sugumar H, Prabhu S, Voskoboinik A, Young S, Gutman SJ, Wong GR, Parameswaran R, Nalliah CJ, Lee G, McLellan AJ, Taylor AJ, Ling LH, Kalman JM, and Kistler PM
- Subjects
- Aged, Atrial Fibrillation complications, Cardiomyopathies diagnostic imaging, Cardiomyopathies etiology, Echocardiography, Electrophysiologic Techniques, Cardiac, Female, Heart Atria diagnostic imaging, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Stroke Volume, Treatment Outcome, Ventricular Dysfunction, Left diagnostic imaging, Ventricular Dysfunction, Left etiology, Ventricular Dysfunction, Left physiopathology, Atrial Fibrillation surgery, Atrial Remodeling, Cardiomyopathies physiopathology, Catheter Ablation, Heart Atria physiopathology, Heart Conduction System physiopathology
- Abstract
Objectives: This study sought to determine the long-term right atrial (RA) electrical and structural changes in a subgroup from the CAMERA-MRI (Catheter Ablation Versus Medical Rate Control in Atrial Fibrillation and Systolic Dysfunction-Magnetic Resonance Imaging) study., Background: Catheter ablation (CA) is successful in restoring ventricular function in patients with atrial fibrillation (AF) and otherwise unexplained cardiomyopathy, as demonstrated in the randomized study of CA versus rate control (CAMERA-MRI). It is unknown if this is associated with atrial remodeling., Methods: Detailed electroanatomical (EA) mapping of the RA using CARTO3 and a force sensing catheter was performed at initial CA and electively at least 12 months after CA in patients with >90% reduction in AF burden following ablation. Bipolar voltage, fractionation, and conduction velocity were collected in 4 segments together with echo and cardiac magnetic resonance imaging., Results: Fifteen patients (mean age 59.1 ± 6.8 years) underwent repeat RA EA mapping. At a mean follow-up of 23.4 ± 11.9 months, left ventricular (LV) ejection fraction improved from 33.6 ± 3.2% to 54.1 ± 3.2% (p = 0.001), RA area decreased from 28.4 ± 2.0 cm
2 to 20.8 ± 1.2 cm2 (p < 0.001), and left atrial area decreased from 32.9 ± 2.3 cm2 to 26.8 ± 1.4 cm2 (p = 0.007). On EA mapping, RA bipolar voltage increased from 1.6 ± 0.1 mV to 1.9 ± 0.1 mV (p = 0.04). Tissue voltage increased across all regions, which achieved statistical significance at the posterior (p = 0.002) and septal (p = 0.01) segments. There was a significant decrease in complex fractionated electrograms from 21.7 ± 3.5% to 8.3 ± 1.8% (p = 0.002); however, no significant change occurred in global or regional conduction velocities (p = 0.5)., Conclusions: Recovery of atrial electrical and structural changes was observed following restoration of sinus rhythm and recovery of LV function in patients who underwent CA for persistent AF and LV systolic dysfunction. The randomized CAMERA MRI study demonstrated significant improvement in LV systolic function with AF ablation compared with rate control. The present study demonstrated reverse electrical and structural atrial recovery in concert with recovery of LV systolic function at 2 years post-AF ablation. This may partially explain the long-term success of CA in patients with AF and otherwise unexplained cardiomyopathy., (Copyright © 2019 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)- Published
- 2019
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30. Oral Anticoagulation Therapy in Atrial Fibrillation Patients Managed in the Emergency Department Compared to Cardiology Outpatient: Opportunities for Improved Outcomes.
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Rangnekar G, Gallagher C, Wong GR, Rocheleau S, Brooks AG, Hendriks JML, Middeldorp ME, Elliott AD, Mahajan R, Sanders P, and Lau DH
- Subjects
- Administration, Oral, Aged, Atrial Fibrillation complications, Australia epidemiology, Female, Follow-Up Studies, Humans, Incidence, Male, Registries, Retrospective Studies, Risk Factors, Stroke epidemiology, Stroke etiology, Anticoagulants administration & dosage, Atrial Fibrillation drug therapy, Emergency Service, Hospital trends, Outpatients, Quality Improvement, Stroke prevention & control, Thrombolytic Therapy methods
- Abstract
Introduction: Recent registry data suggests oral anticoagulation (OAC) usage remains suboptimal in atrial fibrillation (AF) patients. The aim of our study was to determine if rates of appropriate use of OAC in individuals with AF differs between the emergency department (ED) and cardiac outpatient clinic (CO)., Methods: This was a retrospective study of consecutive AF patients over a 12-month period. Data from clinical records, discharge summaries and outpatient letters were independently reviewed by two investigators. Appropriateness of OAC was assessed according to the CHA
2 DS2 -VASc score., Results: Of 455 unique ED presentations with AF as a primary diagnosis, 115 patients who were treated and discharged from the ED were included. These were compared to 259 consecutively managed AF patients from the CO. Inappropriate OAC was significantly higher in the ED compared to the CO group (65 vs. 18%, p<0.001). Treatment in the ED was a significant multivariate predictor of inappropriate OAC (odds ratio 8.2 [4.8-17.7], p<0.001)., Conclusions: This patient level data highlights that significant opportunity exists to improve disparities in the use of guideline adherent therapy in the ED compared to CO. There is an urgent need for protocol-driven treatment in the ED or streamlined early follow-up in a specialised AF clinic to address this treatment gap., (Copyright © 2018 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.)- Published
- 2019
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31. Association of Interleukin-10 Genotypes and Oral Cancer Susceptibility in Selected Malaysian Population: A Case- Control Study
- Author
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Goud EVSS, Malleedi S, Ramanathan A, Wong GR, Hwei Ern BT, Yean GY, Ann HH, Syan TY, and Zain RM
- Subjects
- Carcinoma, Squamous Cell epidemiology, Carcinoma, Squamous Cell secondary, Case-Control Studies, Female, Follow-Up Studies, Genetic Predisposition to Disease, Genotype, Humans, Lymphatic Metastasis, Malaysia epidemiology, Male, Middle Aged, Mouth Neoplasms epidemiology, Mouth Neoplasms pathology, Prevalence, Prognosis, Survival Rate, Carcinoma, Squamous Cell genetics, Interleukin-10 genetics, Mouth Neoplasms genetics, Polymorphism, Single Nucleotide
- Abstract
Background: Interleukin-10 (IL10) genotypes have been closely correlated to the susceptibility for oral squamous cell carcinoma. More than half of oral cancers in the world occur in Asia with estimated 168,850 new cases were diagnosed in this geographical region alone. Considering the rising numbers of oral cancer cases in Malaysia, association of IL10 A1082G gene polymorphism was correlated. Methodology: 41 oral squamous cell carcinoma (OSCC) cases and 48 healthy controls of comparable age, gender, and with habits like smoking, alcohol consumption and betel quid chewing were selected. In this case-control study, samples were collected from the Oral Cancer Research and Coordinating Centre (OCRCC), Faculty of Dentistry, University of Malaya, Malaysia. Genotyping conditions were evaluated by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). The PCR products were subjected to digestion by MnlI enzyme (NEB, UK) to screen for the IL10 A-1082G. Digested DNA products were analyzed by electrophoresis on 4% (w/v) agarose gel, stained with ethidium bromide and imaged under UV illumination. Chi-square test and Fisher’s Exact test were used in statistical analysis. Results: AG genotypes were present in 81.3% and 86.0% of healthy control and OSCC cases respectively (OR=0.468, 95% CI=0.133-1.653). No significant association was found between IL10 A1082G polymorphism with risk habits, clinico-pathological parameters and 5-years overall survival. The findings also show no significant correlation between the IL10 genotype and features of OSCC within the case group as measured by tumor size, lymph node involvement, stage, invasive front, grading, depth, pattern of invasion. Conclusion: This study suggests that functional polymorphism AG of IL10 A1082G may have no influence with OSCC susceptibility. However, further investigation with larger sample sizes can be conducted to provide additional evidence to support the lack of association of IL10 A1082G polymorphism in oral cancer., (Creative Commons Attribution License)
- Published
- 2019
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32. Ectopic expression of a Musa acuminata root hair defective 3 (MaRHD3) in Arabidopsis enhances drought tolerance.
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Wong GR, Mazumdar P, Lau SE, and Harikrishna JA
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- Abscisic Acid metabolism, Arabidopsis, Chlorophyll metabolism, Dehydration, Musa genetics, Musa physiology, Plant Growth Regulators metabolism, Plant Proteins genetics, Plant Proteins metabolism, Plant Proteins physiology, Plant Roots genetics, Plant Roots metabolism, Plants, Genetically Modified, Reactive Oxygen Species metabolism, Real-Time Polymerase Chain Reaction, Musa metabolism
- Abstract
Genetic improvement is an important approach for crop improvement towards yield stability in stress-prone areas. Functional analysis of candidate stress response genes can provide key information to allow the selection and modification of improved crop varieties. In this study, the constitutive expression of a banana cDNA, MaRHD3 in Arabidopsis improved the ability of transgenic lines to adapt to drought conditions. Transgenic Arabidopsis plants expressing MaRHD3 had roots with enhanced branching and more root hairs when challenged with drought stress. The MaRHD3 plants had higher biomass accumulation, higher relative water content, higher chlorophyll content and an increase in activity of reactive oxygen species (ROS) scavenging enzymes; SOD, CAT, GR, POD and APX with reduced water loss rates compared to control plants. The analysis of oxidative damage indicated lower cell membrane damage in transgenic lines compared to control plants. These findings, together with data from higher expression of ABF-3 and higher ABA content of drought-stressed transgenic MaRHD3 expressing plants, support the involvement of the ABA signal pathway and ROS scavenging enzyme systems in MaRHD3 mediated drought tolerance., (Copyright © 2018 Elsevier GmbH. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
33. Predicted longevity of contemporary cardiac implantable electronic devices: A call for industry-wide "standardized" reporting.
- Author
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Munawar DA, Mahajan R, Linz D, Wong GR, Khokhar KB, Thiyagarajah A, Kadhim K, Emami M, Mishima R, Elliott AD, Middeldorp ME, Roberts-Thompson KC, Young GD, Sanders P, and Lau DH
- Subjects
- Electric Power Supplies standards, Equipment Design, Humans, Defibrillators, Implantable standards, Electric Countershock instrumentation, Health Care Sector standards, Heart Failure therapy
- Abstract
Background: Battery longevity is an important factor that may influence the selection of cardiac implantable electronic devices (CIEDs). However, there remains a lack of industry-wide standardized reporting of predicted CIED longevity to facilitate informed decision-making for implanting physicians and payers., Objective: The purpose of this study was to compare the predicted longevity of current generation CIEDs using best-matched CIEDs settings to assess differences between brands and models., Methods: Data were extracted for current model pacemakers, implantable cardioverter-defibrillators (ICDs), and cardiac resynchronization therapy-defibrillators (CRT-Ds) from product manuals and, where absent, by communication with the manufacturers. Pacemaker longevity estimations were based on standardized pacing outputs (2.5V, 0.40-ms pulse width, 500-Ω impedance) and pacing loads of 50% or 100% at 60 bpm. ICD and CRT-D longevity were estimated at 0% pacing and 15% atrial plus 100% biventricular pacing, with essential capacitor reforms and zero clinical shocks., Results: Mean maximum predicted longevity of single- and dual-chamber pacemakers was 12.0 ± 2.1 and 9.8 ± 1.9 years, respectively. Use of advanced features such as remote monitoring, prearrhythmia electrogram storage, and rate response can result in ∼1.4 years of reduction in longevity. Mean maximum predicted longevity of ICDs and CRT-Ds was 12.4 ± 3.0 and 8.8 ± 2.1 years, respectively. Of note, there were significant variations in predicted CIED longevity according to device manufacturers, with up to 44%, 42%, and 44% difference for pacemakers, ICDs, and CRT-Ds, respectively., Conclusion: Contemporary CIEDs demonstrate highly variable predicted longevity according to device manufacturers. This may impact on health care costs and long-term clinical outcomes., (Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
34. Regression of Diffuse Ventricular Fibrosis Following Restoration of Sinus Rhythm With Catheter Ablation in Patients With Atrial Fibrillation and Systolic Dysfunction: A Substudy of the CAMERA MRI Trial.
- Author
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Prabhu S, Costello BT, Taylor AJ, Gutman SJ, Voskoboinik A, McLellan AJA, Peck KY, Sugumar H, Iles L, Pathik B, Nalliah CJ, Wong GR, Azzopardi SM, Lee G, Mariani J, Kaye DM, Ling LH, Kalman JM, and Kistler PM
- Subjects
- Aged, Fibrosis, Humans, Magnetic Resonance Imaging, Middle Aged, Atrial Fibrillation complications, Atrial Fibrillation diagnostic imaging, Atrial Fibrillation surgery, Cardiomyopathies complications, Cardiomyopathies physiopathology, Catheter Ablation, Ventricular Dysfunction, Left complications, Ventricular Dysfunction, Left physiopathology
- Abstract
Objectives: This study sought to determine if diffuse ventricular fibrosis improves in patients with atrial fibrillation (AF)-mediated cardiomyopathy following the restoration of sinus rhythm., Background: AF coexists in 30% of heart failure (HF) patients and may be an underrecognized reversible cause of left ventricular systolic dysfunction. Myocardial fibrosis is the hallmark of adverse cardiac remodeling in HF, yet its reversibility is unclear., Methods: Patients with persistent AF and an idiopathic cardiomyopathy (left ventricular ejection fraction [LVEF] ≤45%) were randomized to catheter ablation (CA) or ongoing medical rate control as a pre-specified substudy of the CAMERA-MRI (Catheter Ablation versus Medical Rate Control in Atrial Fibrillation and Systolic Dysfunction-an MRI-Guided Multi-centre Randomised Controlled Trial) trial. All patients had cardiac magnetic resonance imaging scans (including myocardial T1 time), serum B-type natriuretic peptide, 6-min walk tests, and Short Form-36 questionnaires performed at baseline and 6 months. Sixteen patients with no history of AF or left ventricular systolic dysfunction were enrolled as normal controls for T1 time., Results: Thirty-six patients (18 in each treatment arm) were included in this substudy. Demographics, comorbidities, and myocardial T1 times were well matched at baseline. At 6 months, patients in the CA group had a significant reduction in myocardial T1 time from baseline compared with the medical rate control group (-124 ms; 95% confidence interval [CI]: -23 to -225 ms; p = 0.0176), although it remained higher than that of normal controls at 6 months (p = 0.0017). Improvements in myocardial T1 time with CA were associated with significant improvements in absolute LVEF (+12.5%; 95% CI: 5.9% to 19.0%; p = 0.0004), left ventricular end-systolic volume (p = 0.0019), and serum B-type natriuretic peptide (-216 ng/l; 95% CI: -23 to -225 ng/l; p = 0.0125)., Conclusions: The improvement in LVEF and reverse ventricular remodeling following successful CA of AF-mediated cardiomyopathy is accompanied by a regression of diffuse fibrosis. This suggests timely treatment of arrhythmia-mediated cardiomyopathy may minimize irreversible ventricular remodeling., (Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
35. Pulmonary vein activity does not predict the outcome of catheter ablation for persistent atrial fibrillation: A long-term multicenter prospective study.
- Author
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Prabhu S, Kalla M, Peck KY, Voskoboinik A, McLellan AJA, Pathik B, Nalliah CJ, Wong GR, Sugumar H, Azzopardi SM, Lee G, Ling LH, Kalman JM, and Kistler PM
- Subjects
- Atrial Fibrillation physiopathology, Catheter Ablation methods, Female, Follow-Up Studies, Heart Conduction System surgery, Humans, Male, Middle Aged, Prospective Studies, Recurrence, Tachycardia, Paroxysmal physiopathology, Time Factors, Treatment Outcome, Atrial Fibrillation surgery, Heart Atria physiopathology, Heart Conduction System physiopathology, Pulmonary Veins physiopathology, Tachycardia, Paroxysmal surgery
- Abstract
Background: Pulmonary vein (PV) isolation (PVI) remains the cornerstone of catheter ablation (CA) in persistent atrial fibrillation (AF) (PeAF), although less successful than for paroxysmal AF. Whether rapid or fibrillatory (PV AF) PV firing may identify patients with PeAF more likely to benefit from a PV-based ablation approach is unclear., Objective: The purpose of this study was to determine the relationship between the PV cycle length (PVCL) and the PV AF outcome after CA., Methods: Before ablation, the multipolar catheter was placed in each PV and the left atrial appendage (LAA) for 100 consecutive cycles. The presence of PV AF, the average PVCL of all 4 veins (PV
4VAverage ), the fastest vein average (PVFVAverage ), the fastest cycle length (PVFast ) both individually and relative to the average LAA cycle length were calculated. The ablation strategy included PVI and posterior wall isolation with a minimum of 12 months follow-up., Results: A total of 123 patients underwent CA (age 62 ± 9.1 years; CHA2 DS2 -VASC score 1.6 ± 1.1; left ventricular ejection fraction 48% ± 13%; left atrial area 31 ± 8.7 cm2 ; AF duration 16 ± 17 months). PVI was achieved in 100% of patients. Multiprocedure success (MPS; freedom from AF/atrial tachycardia episodes lasting >30 seconds) was achieved in 76% of patients at 24 ± 8.1 months of follow-up after 1.2 ± 0.4 procedures. PV activity was not associated with MPS either absolutely (PV4VAverage [MPS no vs yes: 178 ± 27 ms vs 177 ± 24 ms; P = .92], PVFVAverage [P = .69], or PVFast [P = .82]) or as a ratio relative to the LAA cycle length (PV4VAverage /LAA 1.05 ± 0.11 vs 1.06 ± 0.21; P = .87). The presence of PV AF (31% vs 47%; P = .13) did not predict MPS., Conclusion: The rapidity of PV firing or presence of fibrillation within the PV was not predictive of outcome of CA for PeAF. PV activity does not identify patients most likely to benefit from a PV-based ablation strategy., (Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)- Published
- 2018
- Full Text
- View/download PDF
36. A narrow QRS tachycardia with changing rate: What is the mechanism(s)?
- Author
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Prabhu MA, Wong GR, Anderson RD, and Kalman JM
- Published
- 2018
- Full Text
- View/download PDF
37. Biatrial Electrical and Structural Atrial Changes in Heart Failure: Electroanatomic Mapping in Persistent Atrial Fibrillation in Humans.
- Author
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Prabhu S, Voskoboinik A, McLellan AJA, Peck KY, Pathik B, Nalliah CJ, Wong GR, Azzopardi SM, Lee G, Mariani J, Ling LH, Taylor AJ, Kalman JM, and Kistler PM
- Subjects
- Aged, Cardiac Imaging Techniques, Cardiomyopathies, Female, Humans, Male, Middle Aged, Prospective Studies, Atrial Fibrillation diagnostic imaging, Atrial Fibrillation physiopathology, Electrophysiologic Techniques, Cardiac methods, Heart Atria diagnostic imaging, Heart Atria physiopathology, Heart Failure diagnostic imaging, Heart Failure physiopathology
- Abstract
Objectives: This study sought to characterize the biatrial substrate in heart failure (HF) and persistent atrial fibrillation (PeAF)., Background: Atrial fibrillation (AF) and HF frequently coexist; however, the contribution of HF to the biatrial substrate in PeAF is unclear., Methods: Consecutive patients with PeAF and normal left ventricular (NLV) systolic function (left ventricular ejection fraction [LVEF] >55%) or idiopathic cardiomyopathy (LVEF ≤45%) undergoing AF ablation were enrolled. In AF, pulmonary vein (PV) cycle length (PVCL) was recorded via a multipolar catheter in each PV and in the left atrial appendage for 100 consecutive cycles. After electrical cardioversion, biatrial electroanatomic mapping was performed. Complex electrograms, voltage, scarring, and conduction velocity were assessed., Results: Forty patients, 20 patients with HF (mean age: 62 ± 8.9 years; AF duration: 15 ± 11 months; LVEF: 33 ± 8.4%) and 20 with NLV (mean age: 59 ± 6.7 years; AF duration: 14 ± 9.1 months; p = 0.69; mean LVEF: 61 ± 3.6%; p < 0.001), were enrolled. HF reduced biatrial tissue voltage (p < 0.001) with greater voltage heterogeneity (p < 0.001). HF was associated with significantly more biatrial fractionation (left atrium [LA]: 30% vs. 9%; p < 0.001; right atrium [RA]: 28% vs. 11%; p < 0.001), low voltage (<0.5 mV) (LA: 23% vs. 6%; p = 0.002; RA: 20% vs 11%; p = 0.006), and scarring (<0.05 mV) in the LA (p = 0.005). HF was associated with a slower average PVCL (185 vs. 164 ms; p = 0.016), which correlated significantly with PV antral bipolar voltage (R = -0.62; p < 0.001) and fractionation (R = 0.46; p = 0.001)., Conclusions: HF is associated with significantly reduced biatrial tissue voltage, fractionation, and prolongation of PVCL. Advanced biatrial remodeling may have implications for invasive and noninvasive rhythm control strategies in patients with AF and HF., (Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
38. Catheter Ablation Versus Medical Rate Control in Atrial Fibrillation and Systolic Dysfunction: The CAMERA-MRI Study.
- Author
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Prabhu S, Taylor AJ, Costello BT, Kaye DM, McLellan AJA, Voskoboinik A, Sugumar H, Lockwood SM, Stokes MB, Pathik B, Nalliah CJ, Wong GR, Azzopardi SM, Gutman SJ, Lee G, Layland J, Mariani JA, Ling LH, Kalman JM, and Kistler PM
- Subjects
- Aged, Atrial Fibrillation epidemiology, Catheter Ablation methods, Electrocardiography, Ambulatory methods, Female, Gadolinium administration & dosage, Humans, Magnetic Resonance Imaging, Cine methods, Male, Middle Aged, Prospective Studies, Single-Blind Method, Ventricular Dysfunction, Left epidemiology, Atrial Fibrillation diagnostic imaging, Atrial Fibrillation therapy, Catheter Ablation trends, Electrocardiography, Ambulatory trends, Magnetic Resonance Imaging, Cine trends, Ventricular Dysfunction, Left diagnostic imaging, Ventricular Dysfunction, Left therapy
- Abstract
Background: Atrial fibrillation (AF) and left ventricular systolic dysfunction (LVSD) frequently co-exist despite adequate rate control. Existing randomized studies of AF and LVSD of varying etiologies have reported modest benefits with a rhythm control strategy., Objectives: The goal of this study was to determine whether catheter ablation (CA) for AF could improve LVSD compared with medical rate control (MRC) where the etiology of the LVSD was unexplained, apart from the presence of AF., Methods: This multicenter, randomized clinical trial enrolled patients with persistent AF and idiopathic cardiomyopathy (left ventricular ejection fraction [LVEF] ≤45%). After optimization of rate control, patients underwent cardiac magnetic resonance (CMR) to assess LVEF and late gadolinium enhancement, indicative of ventricular fibrosis, before randomization to either CA or ongoing MRC. CA included pulmonary vein isolation and posterior wall isolation. AF burden post-CA was assessed by using an implanted loop recorder, and adequacy of MRC was assessed by using serial Holter monitoring. The primary endpoint was change in LVEF on repeat CMR at 6 months., Results: A total of 301 patients were screened; 68 patients were enrolled between November 2013 and October 2016 and randomized with 33 in each arm (accounting for 2 dropouts). The average AF burden post-CA was 1.6 ± 5.0% at 6 months. In the intention-to-treat analysis, absolute LVEF improved by 18 ± 13% in the CA group compared with 4.4 ± 13% in the MRC group (p < 0.0001) and normalized (LVEF ≥50%) in 58% versus 9% (p = 0.0002). In those undergoing CA, the absence of late gadolinium enhancement predicted greater improvements in absolute LVEF (10.7%; p = 0.0069) and normalization at 6 months (73% vs. 29%; p = 0.0093)., Conclusions: AF is an underappreciated reversible cause of LVSD in this population despite adequate rate control. The restoration of sinus rhythm with CA results in significant improvements in ventricular function, particularly in the absence of ventricular fibrosis on CMR. This outcome challenges the current treatment paradigm that rate control is the appropriate strategy in patients with AF and LVSD. (Catheter Ablation Versus Medical Rate Control in Atrial Fibrillation and Systolic Dysfunction [CAMERA-MRI]; ACTRN12613000880741)., (Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
39. A comparison of the electrophysiologic and electroanatomic characteristics between the right and left atrium in persistent atrial fibrillation: Is the right atrium a window into the left?
- Author
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Prabhu S, Voskoboinik A, McLellan AJA, Peck KY, Pathik B, Nalliah CJ, Wong GR, Azzopardi SM, Lee G, Mariani J, Ling LH, Taylor AJ, Kalman JM, and Kistler PM
- Subjects
- Aged, Atrial Fibrillation therapy, Atrial Remodeling, Body Surface Potential Mapping, Cardiac Catheterization, Cardiac Electrophysiology, Catheter Ablation, Electrocardiography, Female, Heart Conduction System physiopathology, Humans, Male, Middle Aged, Prospective Studies, Atrial Fibrillation physiopathology, Electrophysiologic Techniques, Cardiac methods, Heart Atria physiopathology
- Abstract
Introduction: The right atrium (RA) is readily accessible; however, it is unclear whether changes in the RA are representative of the LA. We performed detailed biatrial electroanatomic mapping to determine the electrophysiological relationship between the atria., Methods and Results: Consecutive patients with persistent AF underwent biatrial electroanatomical mapping with a contact force catheter acquiring points with a CF >10 g prior to ablation. Points were analyzed for tissue voltage, complex electrograms, low voltage (<0.5 mV), scar (<0.05 mV), and conduction velocity (CV). Forty patients (mean age 59 ± 9.2 years, AF duration 12.9 ± 9.2 months, LA area: 28 ± 5.2, RA area: 25 ± 6.4 mm
2 , LVEF: 44 ± 15%) underwent mapping during CS pacing. Bipolar voltage (R = 0.57, P <0.001), unipolar voltage (R = 0.68, P <0.001), low voltage (<0.5 nV) (R = 0.48, P = 0.002), fractionation (R = 0.73, P <0.001), and CV (R = 0.49, P = 0.001) correlated well between atria. There was no difference in global bipolar voltage (LA 1.89 ± 0.77 vs. RA 1.77 ± 0.57 mV, P = 0.57); complex electrograms (LA 20% vs. RA 20%, P = 0.99) or low voltage (LA 15% vs. RA 16%, P = 0.84). Global unipolar voltage was significantly higher in the LA compared to the RA (2.95 ± 1.14 vs. 2.28 ± 0.65 mV, P = 0.002) and CV was significantly slower in the RA compared to the LA (0.93 ± 0.15 m/s vs. 1.01 ± 0.19 m/s, P = 0.001)., Conclusion: AF is associated with remodeling processes affecting both atria. The more accessible RA provides an insight into the biatrial process associated with AF in various disease states without trans-septal access., (© 2017 Wiley Periodicals, Inc.)- Published
- 2017
- Full Text
- View/download PDF
40. Paediatric chronic recurrent multifocal osteomyelitis.
- Author
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Wong DR, Wong GR, Moussa B, and Ang MT
- Subjects
- Adolescent, Anti-Inflammatory Agents therapeutic use, Anti-Inflammatory Agents, Non-Steroidal therapeutic use, Female, Humans, Low Back Pain etiology, Magnetic Resonance Imaging, Osteomyelitis drug therapy, Prednisolone therapeutic use, Radionuclide Imaging, Recurrence, Whole Body Imaging, Lumbar Vertebrae diagnostic imaging, Osteomyelitis diagnostic imaging
- Published
- 2017
- Full Text
- View/download PDF
41. Determining the Optimal Dose of Adenosine for Unmasking Dormant Pulmonary Vein Conduction Following Atrial Fibrillation Ablation: Electrophysiological and Hemodynamic Assessment. DORMANT-AF Study.
- Author
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Prabhu S, Mackin V, McLellan AJ, Phan T, McGlade D, Ling LH, Peck KY, Voskoboinik A, Pathik B, Nalliah CJ, Wong GR, Azzopardi SM, Lee G, Mariani J, Taylor AJ, Kalman JM, and Kistler PM
- Subjects
- Action Potentials, Aged, Atrial Fibrillation diagnosis, Atrial Fibrillation physiopathology, Atrioventricular Block etiology, Atrioventricular Block physiopathology, Cardiac Pacing, Artificial, Female, Humans, Male, Middle Aged, Predictive Value of Tests, Pulmonary Veins physiopathology, Treatment Outcome, Victoria, Adenosine administration & dosage, Atrial Fibrillation surgery, Atrioventricular Block diagnosis, Blood Pressure, Catheter Ablation adverse effects, Electrophysiologic Techniques, Cardiac, Heart Rate, Pulmonary Veins surgery
- Abstract
Introduction: ELECTROPHYSIOLOGICAL AND HEMODYNAMIC ASSESSMENT., Dormant-Af Study: The significance of adenosine induced dormant pulmonary vein (PV) conduction in atrial fibrillation (AF) ablation remains controversial. The optimal dose of adenosine to determine dormant PV conduction is yet to be systematically explored., Methods and Results: ELECTROPHYSIOLOGICAL AND HEMODYNAMIC ASSESSMENT., Dormant-Af Study: Consecutive patients undergoing index AF ablation received 3 adenosine doses (12, 18, and 24 mg) in a randomized blinded order, immediately after pulmonary vein isolation (PVI). Electrophysiological (PR prolongation, AV block (AVB) and PV reconnection) and hemodynamic (BP) parameters were measured. A total, 339 doses (113/dose) assessed 191 PVs in 50 patients (66% male, 72% PAF, 52% hypertensive). Dormant PV conduction occurred in 28% of patients (16.5% [32] of PVs). All cases were associated with AVB (AVB: PV reconnection vs. no PV reconnection 100% vs. 83%, P = 0.007). AVB occurred more frequently at 24 mg versus 12 mg (92% vs. 82%, P = 0.019) but not versus 18 mg (91%, P = 0.62). AVB duration progressed between 12 mg (12.0 ± 8.9 seconds), 18 mg (16.1 ± 9.1 seconds, P = 0.001), and 24 mg (19.0 ± 9.3 seconds, P < 0.001) doses. MBP fell further at 24 mg (ΔMBP: 27 ± 12 mmHg) and 18 mg (26 ± 13 mmHg) doses compared to 12 mg (22 ± 10 mmHg vs., P < 0.001). A significant reduction in AVB in patients >110 kg (65% vs. 91% in 70-110 kg group, P < 0.001) in response to adenosine was seen., Conclusion: ELECTROPHYSIOLOGICAL AND HEMODYNAMIC ASSESSMENT., Dormant-Af Study: An adenosine dose producing AVB is required to unmask dormant PV conduction. AVB is significantly reduced in patients >110 kg. Weight and dosing variability may in part explain the conflicting results of studies evaluating the clinical utility of adenosine in PVI., (© 2016 Wiley Periodicals, Inc.)
- Published
- 2017
- Full Text
- View/download PDF
42. Feasibility and safety of Reveal LINQ insertion in a sterile procedure room versus electrophysiology laboratory.
- Author
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Wong GR, Lau DH, Middeldorp ME, Harrington JA, Stolcman S, Wilson L, Twomey DJ, Kumar S, Munawar DA, Khokhar KB, Mahajan R, and Sanders P
- Subjects
- Aged, Australia, Equipment Design, Feasibility Studies, Female, Humans, Male, Microelectrodes, Middle Aged, Patient Safety, Prospective Studies, Arrhythmias, Cardiac complications, Arrhythmias, Cardiac diagnosis, Electrocardiography, Ambulatory instrumentation, Electrocardiography, Ambulatory methods, Electrophysiologic Techniques, Cardiac instrumentation, Electrophysiologic Techniques, Cardiac methods, Prosthesis Implantation methods, Syncope diagnosis, Syncope etiology
- Abstract
Background: Insertable cardiac monitors (ICMs) are increasingly utilized for diagnosis of unexplained syncope and arrhythmia monitoring. The Reveal LINQ is a novel miniaturized ICM with improved algorithms. The feasibility and safety of insertion outside the traditional electrophysiology laboratory is unknown. Here we compare outcomes of Reveal LINQ insertion in different environments., Methods: We report on a prospective, single-centre, non-randomized, observational experience of consecutive Reveal LINQ implantation in the electrophysiology laboratory or a procedure room between October 2013 and October 2015., Results: Of 178 consecutive patients who underwent LINQ device insertion, 80 were implanted in the electrophysiology laboratory and 98 in a procedure room. There were no significant differences in baseline patient characteristics. All implants were performed in the recommended manufacturer method with the exception of 1 which required suture closure. Only a minority received peri-procedural antibiotics with a greater number in the electrophysiology laboratory group (11 [14%] versus 1 [1%], p=0.007). Overall, there were 3 (1.7%) complications with no significant difference between the electrophysiology laboratory and the procedure room groups (2 [3%] versus 1 [1%], p=0.45). There was 1 superficial infection in the procedure room group and 1 superficial infection with device extrusion and 1 traumatic extrusion in the electrophysiology laboratory group. Procedure room implantation subjectively improved laboratory efficiency and patient flow., Conclusion: Reveal LINQ insertion can be safely performed outside of the cardiac laboratory provided a sterile technique is followed by the operator using manufacturer recommendations for insertion. These findings have significant resource implications for hospitals undertaking such procedures., (Crown Copyright © 2016. Published by Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
43. Cor Medusae: Giant Coronary Arteriovenous Fistula.
- Author
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Wong GR, Nelson AJ, and Rajwani A
- Subjects
- Aged, 80 and over, Coronary Angiography, Echocardiography, Humans, Magnetic Resonance Angiography, Male, Multimodal Imaging, Arteriovenous Fistula diagnosis, Coronary Sinus abnormalities, Coronary Vessel Anomalies diagnosis
- Published
- 2016
- Full Text
- View/download PDF
44. Catheter ablation for atrial fibrillation in congestive heart failure: consider the upside, consider the downside.
- Author
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Wong GR and Kalman JM
- Subjects
- Cardiovascular Diseases surgery, Heart Failure, Humans, Atrial Fibrillation, Catheter Ablation
- Published
- 2016
- Full Text
- View/download PDF
45. Audit of Turnaround Time for a Training Oral Histopathology Laboratory in Malaysia.
- Author
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Chan SW, Liew LH, Wong GR, Kallarakkal TG, Abraham MT, Ramanathan A, and Zain RB
- Subjects
- Biopsy, Humans, Laboratories, Malaysia, Mouth Diseases diagnosis, Time Factors, Pathology, Surgical standards
- Abstract
Background: Turnaround time (TAT) is the benchmark to assess the performance of a laboratory, pathologists, and pathology services, but there are few articles on TAT of surgical pathology, particularly in relation to oral or head and neck specimens. This study investigates the TAT for oral histopathology reporting in an academic institution's training laboratory and offers recommendations to achieve better overall quality of diagnostic services., Methods: This study examined data obtained from biopsy request forms for specimens received from the Oro-Maxillofacial Surgery Department of Hospital Tengku Ampuan Rahimah Klang in the Oral Pathology Diagnostic Laboratory of the Faculty of Dentistry, University of Malaya, over a period of 3 years between January 2012 and October 2014., Results: TAT for surgical and decalcified specimens were increased significantly compared to biopsies. Additional special handling did not influence TAT, but increased specimen volume resulted in greater TAT. Slide interpretation was the most time-consuming stage during histopathology reporting. Overall, mean TAT was acceptable for most specimens, but the TAT goals were less than satisfactory., Conclusion: A TAT goal appropriate for this laboratory may hence be established based on this study. Collective efforts to improve the TAT for various specimens are essential for better laboratory performance in the future., (© The Author(s) 2016.)
- Published
- 2016
- Full Text
- View/download PDF
46. Massive pulmonary embolism with acute cor pulmonale.
- Author
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Nelson AJ, Wong GR, Roberts-Thomson R, and Parvar SL
- Subjects
- Humans, Immobilization, Male, Middle Aged, Pulmonary Embolism drug therapy, Pulmonary Embolism physiopathology, Pulmonary Heart Disease drug therapy, Pulmonary Heart Disease physiopathology, Stroke Volume, Treatment Outcome, Angiography, Anticoagulants therapeutic use, Echocardiography, Transesophageal, Pulmonary Embolism diagnostic imaging, Pulmonary Heart Disease diagnostic imaging, Tomography, X-Ray Computed, Warfarin therapeutic use
- Published
- 2016
- Full Text
- View/download PDF
47. Cardiac metastatic melanoma.
- Author
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Ramchand J, Wong GR, Yudi MB, and Sylivris S
- Subjects
- Early Detection of Cancer, Female, Heart Neoplasms surgery, Humans, Middle Aged, Positron-Emission Tomography methods, Treatment Outcome, Heart Neoplasms diagnostic imaging, Heart Neoplasms secondary, Melanoma drug therapy
- Published
- 2016
- Full Text
- View/download PDF
48. Non-traumatic spinal intradural haematoma: a rare case of paralysis following abciximab for ST elevation acute coronary syndrome.
- Author
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Wong GR, Scherer DJ, Nelson AJ, and Worthley MI
- Subjects
- Abciximab, Acute Coronary Syndrome complications, Antibodies, Monoclonal administration & dosage, Hematoma diagnostic imaging, Hematoma rehabilitation, Hematoma surgery, Humans, Immunoglobulin Fab Fragments administration & dosage, Laminectomy, Magnetic Resonance Imaging, Male, Middle Aged, Spinal Cord Compression diagnostic imaging, Spinal Cord Compression rehabilitation, Spinal Cord Compression surgery, Treatment Outcome, Acute Coronary Syndrome drug therapy, Antibodies, Monoclonal adverse effects, Hematoma chemically induced, Immunoglobulin Fab Fragments adverse effects, Spinal Cord Compression chemically induced
- Published
- 2016
- Full Text
- View/download PDF
49. Large apical thrombus due to Takotsubo cardiomyopathy.
- Author
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Wong GR, Roberts-Thomson R, Parvar SL, and Nelson AJ
- Subjects
- Echocardiography, Electrocardiography, Female, Humans, Magnetic Resonance Imaging, Middle Aged, Takotsubo Cardiomyopathy complications, Thrombosis complications, Heart Ventricles diagnostic imaging, Takotsubo Cardiomyopathy diagnosis, Thrombosis diagnostic imaging
- Published
- 2016
- Full Text
- View/download PDF
50. Defibrillator lead endocarditis.
- Author
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Wong GR, Roberts-Thomson RL, and Nelson AJ
- Subjects
- Device Removal, Diagnostic Imaging, Female, Humans, Middle Aged, Defibrillators, Implantable adverse effects, Electrodes, Implanted adverse effects, Endocarditis etiology, Endocarditis surgery, Prosthesis-Related Infections etiology, Prosthesis-Related Infections surgery
- Published
- 2015
- Full Text
- View/download PDF
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