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BACKGROUND The Singapore Cardiac Databank was designed to monitor the performance and outcomes of catheter ablation. We investigated the outcomes of paroxysmal supraventricular tachycardia (PSVT)-ablation in a prospective, nationwide, cohort study. METHODS Atrioventricular nodal re-entrant tachycardia (AVNRT), atrioventricular re-entry tachycardia (AVRT) or atrial tachycardia (AT)-ablations in Singapore from 2010 to 2018 were studied. Outcomes include acute success, periprocedural-complications, post-operative pacing requirement, arrhythmic recurrence and one-year all-cause mortality. RESULTS Among 2,260 patients (mean age 45±18years, 50% female, 57% AVNRT, 37% AVRT, 6% AT), overall acute success rates of PSVT-ablation was 98.4% and increased in order of AT, AVRT and AVNRT (p

Aims This study aims to determine procedural characteristics, acute success rates, and medium-term outcomes of consecutive patients undergoing His bundle pacing (HBP); and learning curves of experienced electrophysiologists adopting HBP. Methods and results Consecutive HBP patients at three hospitals were recruited. Clinical characteristics, acute procedural details, and medium-term outcomes were extracted from electronic medical records. Two hundred and thirty-three patients [mean age 74.6 ± 10.1 years, 48% female, 68% narrow QRS, 71% normal left ventricular ejection fraction (LVEF), 55.8% atrioventricular block] underwent HBP. Acute procedural success was 81.1% (mean procedural and fluoroscopic times of 105.5 ± 36.5 and 13.8 ± 9.3 min). Broad QRS was associated with lower HBP success (odds ratio 0.39, P = 0.02). Fluoroscopic and procedural times decreased and plateaued after 30–40 cases per operator. Implant HBP threshold was 1.3 ± 0.7 V at 1.0 ± 0.2 ms and R wave was 5.0 ± 3.9 mV. During follow-up, loss of HBP occurred in a further 12.4% and 11.3% of patients experienced a ≥1 V increase in HBP threshold. Five (2.6%) patients required HBP revision for pacing difficulties. About 8.6% of patients had a >50% decrease in R wave but lead revision for sensing issues was not necessary. On an intention to treat basis, 56.7% of patients in whom HBP was attempted had persisting HBP capture and thresholds of Conclusion Physicians adopting HBP should be cognizant of the learning curve and preferentially select non-dependent patients with normal QRS and LVEF, to minimize risk of lead revision. Further rises in HBP threshold may increase battery drain and need for reoperations, important considerations when choosing HBP for cardiac resynchronization therapy.

Pacing leads with extendable-retractable helix (EHL) are alternatives to fixed-helix leads (FHL) for conduction system pacing (CSP), but data on handling characteristics are limited. This study evaluated a dual-center experience of lead handling and performance during CSP.Consecutive patients with His-bundle pacing (HBP) or left bundle branch pacing (LBBP) were evaluated for the primary outcome of lead failure, defined as structural damage to the lead necessitating lead replacement. Differences in pacing characteristics were compared. Among 280 patients (mean age 74 ± 11 years, 44% male, 50% LBBP), 246 (88%) received FHL and 34 (12%) received EHL. Of 299 leads used, lead failure occurred more frequently among patients with EHL than FHL (29% vs. 2%, p .001), regardless of CSP modality. Majority of damaged leads (89%) in the form of helix deformation were successfully removed, with failure occurring in only two patients, both EHL, leading to helix fracture and retention within the septal myocardium. EHL, compared to FHL, was associated with 25-fold increased odds of lead failure (odds ratio: 25.21, 95% confidence interval: 7.35-86.51), and persisted after adjustment in turn for age, pacing modality and indication. CSP implant success rates did not differ by lead design (FHL 80% vs. EHL 71%, p = .18), with similar pacing thresholds at implant and follow-up.Helix deformation and fracture were more frequent with EHL in CSP despite similar implant success. These findings have significant implications for lead selection during CSP and raises concerns about the long-term extractability of EHL in CSP.

Introduction: Patients with migraines, particularly those with auras, may present with stroke. Atrial fibrillation is a known risk factor for stroke. With common pathophysiological factors between migraines and atrial fibrillation, we aimed to clarify the association between migraine and atrial fibrillation in this systematic review and meta-analysis. Materials and Methods: A literature search was conducted in EMBASE, PubMed, Scopus and Cochrane electronic bibliographic databases from inception to 14th June 2021 with the following inclusion criteria: (1) cohort or cross-sectional studies, (2) patients ≥ 18-years-old, (3) studies examining association between atrial fibrillation and migraines. Exclusion criteria were case-control studies, studies including patients with prior diagnosis of atrial fibrillation or non-migrainous headache. The Newcastle Ottawa Scale was used to assess the quality of studies. Results: 6 studies were included, demonstrating a 1.61% (95% CI 0.51, 3.29) pooled prevalence of atrial fibrillation in migraine with aura and 1.32% (95% CI 0.17, 3.41) in migraine without aura. The total prevalence of atrial fibrillation in migraine was 1.39% (95% CI 0.24, 3.46) overall. Conclusion: Overall, there was a higher prevalence of atrial fibrillation in migraine with aura compared to migraine without aura. Prevalence of atrial fibrillation in migraine patients was low.

Optimal left ventricular (LV) lead placement improves response to cardiac resynchronization therapy (CRT) but can be hindered by unfavorable venous anatomy. Interventional procedures in the coronary veins have been described with promising short-term outcomes.The purpose of this study was to establish the safety and efficacy of percutaneous coronary venoplasty (PCV) during CRT implantation and assess medium-term lead performances and clinical outcomes against matched controls not requiring PCV.Each consecutive PCV case was matched according to age, gender, and bundle branch morphology to 2 controls from a large prospective registry of CRT recipients. Demographics, procedural success, lead performance, and response to CRT were tracked using a comprehensive electronic medical records system.Of 422 consecutive CRT recipients treated between 2012 to 2018, 29 patients (6.9%; mean age 65.7 ± 10.7 years; 7 female; 17 ischemic cardiomyopathy; 22 left bundle branch block) required PCV, which was successful in 21 cases (72%). Target veins measuring 1.1 ± 0.6 mm were dilated by noncompliant balloons with mean diameter 2.8 ± 0.5 mm. No complications occurred. Fluoroscopic and procedural durations were longer in the PCV group (P.01) Over mean follow-up of 33.0 ± 25.0 months, no differences in lead performance, CRT response, or 2-year survival were observed compared to the control group.PCV during CRT device implant is typically successful, safe and associated with long-term clinical outcomes comparable to patients who did not need PCV. This is an important technique to optimize LV lead placement and maximize CRT response.

We describe the unique phenomenon of occlusive venogram-induced suppression of premature ventricular complexes (PVC) arising from the epicardial left ventricular summit (LVS). Prior to ablation through the coronary sinus, routine occlusive venogram performed at the focus of PVC origin led to localized myocardial staining and simultaneous, sustained PVC suppression. Pace-mapping adjacent to the area of myocardial staining revealed near-identical PVC morphology match (98%). Routine occlusive venogram prior to ablation within the coronary venous system is safe and contributed to localization of the PVC focus.

The association of diabetes mellitus (DM) with cardiac resynchronization therapy (CRT) response and cardiovascular outcomes in Asian patients with heart failure (HF) is unclear. This study aims to investigate the effects of DM on CRT response and cardiovascular outcomes in Asian HF patients. Consecutive Asian HF patients receiving CRT were enrolled in the Prospective Evaluation of Asian with CRT for Heart Failure (PEACH) study from 2011 to 2017. CRT response and super-response were defined as decrease in end-systolic volume index ≥15% and ≥30%, respectively. Primary endpoint was time to composite of HF-hospitalization and all-cause mortality. Among 161 patients followed for 3.3 ± 1.5 years (age 66.7 ± 11.2 years, 22% females, mean QRS duration 154.3 ± 22.4 ms, 83% left bundle branch block), 84 (52%) were CRT responders and 57 (35%) were super-responders. Of 82 (51%) patients with DM (100% type 2, mean HbA1c 7.3 ± 1.9%), 35 (43%) were responders. DM attenuated reverse remodeling (CRT response: AOR 0.44, 95% confidence interval [CI] 0.20 to 0.98, p 0.05; super-response: AOR 0.42, 95% CI 0.18 to 0.97, p0.05), and DM increased HF-hospitalization and all-cause mortality (AHR 1.68, 95% CI 1.00 to 2.82, p = 0.05). The extent of CRT-response correlates with higher event-free survival (CRT response: AHR 0.5, 95% CI 0.30 to 0.81, p = 0.005; super-response: AHR 0.27, 95% CI 0.14 to 0.52, p 0.001). In conclusion, the extent of reverse remodeling post-CRT is the strongest predictor of event free survival. However, DM is detrimental to the CRT recipient by attenuating reverse remodeling, inducing end organ dysfunction and is independently associated with worsened clinical outcomes among Asian HF patients.

The disease burden of AF is greater in Asia-Pacific than other areas of the world. Direct oral anticoagulants (DOACs) have emerged as effective alternatives to vitamin K antagonists (VKA) for preventing thromboembolic events in patients with AF. The Asian Pacific Society of Cardiology developed this consensus statement to guide physicians in the management of AF in Asian populations. Statements were developed by an expert consensus panel who reviewed the available data from patients in Asia-Pacific. Consensus statements were developed then put to an online vote. The resulting 17 statements provide guidance on the assessment of stroke risk of AF patients in the region, the appropriate use of DOACs in these patients, as well as the concomitant use of DOACs and antiplatelets, and the transition to DOACs from VKAs and vice versa. The periprocedural management of patients on DOAC therapy and the management of patients with bleeding while on DOACs are also discussed. ispartof: EUROPEAN CARDIOLOGY REVIEW vol:16 ispartof: location:England status: published

Background Calcium deposits in the heart have been associated with cardiovascular events, mortality, stroke, and atrial fibrillation (AF). However, there is no accepted standard method for scoring cardiac calcifications. Existing methods have also not been validated for the assessment of patients with embolic stroke of undetermined source (ESUS). The aim of this study was to evaluate the association of various cardiac calcification scores with new-onset AF and stroke recurrence in a cohort of patients with ESUS. Methods In this study, 181 consecutive patients with stroke diagnosed with ESUS were identified and evaluated. They were followed for new-onset AF and ischemic stroke recurrence for a median duration of 2.1 years. Various echocardiographic cardiac calcification scores were assessed on transthoracic echocardiography performed during the evaluation of ESUS and subsequently assessed for their relation to AF detection and recurrent stroke. The echocardiographic calcium scores assessed were the (1) global cardiac calcium score (GCCS), (2) echocardiographic calcium score (eCS), (3) echocardiographic calcification score, (4) echocardiographic composite cardiac calcium score, and (5) total heart calcification score. Only two of these scoring schemes, GCCS and eCS, quantified the cardiac calcium burden. Results Higher calcium scores as measured by GCCS and eCS were found to be significantly associated with subsequent AF detection as well as recurrent ischemic stroke in patients with ESUS. The association with recurrent stroke remained significant even after adjustment for comorbidities and AF. Conclusions Higher cardiac calcification measured using the GCCS and eCS is independently associated with AF detection and recurrent ischemic stroke in patients with ESUS, and these scores can be useful markers for further risk stratification in patients with ESUS.

Background: Several P-wave indices are thought to represent underlying atrial remodeling and have been associated with ischaemic stroke even in the absence of atrial fibrillation (AF). However, the utility of these P-wave indices in predicting outcomes in patients with embolic stroke of undetermined source (ESUS) has not been studied. The aim of this study is to examine these different P-wave indices towards predicting new-onset AF and stroke recurrence in a cohort of patients with ESUS, thereby demonstrating the value of these electrocardiographic markers for stroke risk stratification. Methods: Between October 2014 and October 2017, consecutive patients diagnosed with ESUS were followed for new-onset AF and ischaemic stroke recurrence. The various P-wave indices, namely, the P-terminal force in the precordial lead V1 (PTFV1), P-wave duration, P-wave dispersion, interatrial blocks, and P-wave axis, were assessed on the initial electrocardiogram on presentation and studied for their relation to eventual AF detection and recurrent stroke. Results: 181 ischaemic stroke patients with ESUS were recruited and followed up for a median duration of 2.1 years. An abnormal PTFV1 was associated with occult AF detection but not with recurrent ischaemic strokes. No significant association was observed between the other P-wave indices with either occult AF or stroke recurrence. Conclusion: PTFV1 is associated with AF detection but not recurrent strokes in ESUS patients and can be a useful electrocardiographic marker for further risk stratification in ESUS patients.

Introduction This study aimed to investigate the causes, clinical management and outcomes of clinically significant pericardial effusions, and evaluate the practice of pericardiocentesis within an academic medical centre in Singapore, a multiethnic country in Southeast Asia. Methods Consecutive patients undergoing pericardiocentesis at a single Asian academic medical centre were identified. Patient demographics, echocardiographic findings, investigations, pericardiocentesis procedural details and clinical progress were tracked using a comprehensive electronic medical records system. Results Of 149 patients who underwent pericardiocentesis, malignancy (46.3%) was the most common cause of pericardial effusions, followed by iatrogenic postsurgical complications (17.4%). 77.3% of effusions were large and 69.8% demonstrated tamponade physiology. Pericardiocentesis guided by echocardiography and fluoroscopy was successful in 99.3% of patients and had a complication rate of 2.0%. Likelihood of effusion recurrence and survival to discharge was determined by the aetiology of the pericardial effusion. 24.6% of malignant effusions recurred, and the survival rate 12 months after drainage of a malignant pericardial effusion was 45.0%. Short-term mortality was highest among patients presenting with tamponade due to acute aortic syndromes and those with myocardial rupture due to ischaemic heart disease. Conclusion Cancer and iatrogenic complications were the most common causes of pericardial effusion in this large cohort of Singapore patients. Pericardiocentesis has a high success rate and relatively low complication rate. Prognosis and clinical course after pericardiocentesis are determined by the underlying cause of the pericardial effusion.

Introduction: It is unclear which surrogate of atrial cardiopathy best predicts the risk of developing a recurrent ischemic stroke in embolic stroke of undetermined source (ESUS). Left atrial diameter (LAD) and LAD index (LADi) are often used as markers of left atrial enlargement in current ESUS research, but left atrial volume index (LAVi) has been found to be a better predictor of cardiovascular outcomes in other patient populations. Objective: We aim to compare the performance of LAVi, LAD, and LADi in predicting the development of new-onset atrial fibrillation (AF) and stroke recurrence in ESUS. Methods: Between October 2014 and October 2017, consecutive patients diagnosed with ESUS were followed for new-onset AF, ischemic stroke recurrence, and a composite outcome of occult AF and stroke recurrence. LAVi and LADi were measured by transthoracic echocardiogram; “high” LAVi was defined as ≥35 mL/m2 in accordance with American Society of Echocardiography guidelines. Results: 185 ischemic stroke patients with ESUS were recruited and followed for a median duration of 2.1 years. Increased LAVi was associated with new-onset AF detection (aOR 1.08; 95% CI 1.03–1.14; p = 0.003) and stroke recurrence (aOR 1.05; 95% CI 1.01–1.10; p = 0.026). Patients with “high” LAVi had a higher likelihood of developing a composite of AF detection and stroke recurrence (HR 3.45; 95% CI 1.55–7.67; p = 0.002). No significant association was observed between LADi and either occult AF or stroke recurrence. Conclusions: LAVi is associated with new-onset AF and stroke recurrence in ESUS patients and may be a better surrogate of atrial cardiopathy.

INTRODUCTION Risk stratification in dilated cardiomyopathy (DCM) is imprecise, relying largely on echocardiographic left ventricular ejection fraction (LVEF) and severity of heart failure symptoms. Adverse cardiovascular events are increased by the presence of myocardial scarring. Late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) imaging is the gold standard for identifying myocardial scars. We examined the association between LGE on CMR imaging and adverse clinical outcomes during long-term follow-up of Asian patients with DCM. METHODS Consecutive patients with DCM undergoing CMR imaging at a single Asian academic medical centre between 2005 and 2015 were recruited. Clinical outcomes were tracked using comprehensive electronic medical records and mortality was determined by cross-linkages with national registries. Presence and distribution of LGE on CMR imaging were determined by investigators blinded to patient outcomes. Primary endpoint was a composite of heart failure hospitalisations, appropriate implantable cardioverter-defibrillator shocks and cardiovascular mortality. RESULTS Of 86 patients, 64.0% had LGE (80.2% male; mean LVEF 30.1% ± 12.7%). Mid-wall fibrosis (71.7%) was the most common pattern of LGE distribution. Over a mean follow-up period of 4.9 ± 3.2 years, 19 (34.5%) patients with LGE reached the composite endpoint compared to 4 (12.9%) patients without LGE (p = 0.01). Presence of LGE, but not echocardiographic LVEF, independently predicted the primary endpoint (hazard ratio 4.15 [95% confidence interval 1.28–13.50]; p = 0.02). CONCLUSION LGE presence independently predicted adverse clinical events in Asian patients with DCM. Routine use of CMR imaging to characterise the myocardial substrate is recommended for enhanced risk stratification and should strongly influence clinical management.

Background Conventional right ventricular (RV) pacing is increasingly recognised to cause tricuspid valve (TV) injury or dysfunction, in part due to the need to pass the lead through the valve. This may be especially problematic in patients with preexisting TV disease or prior TV surgery. An alternative in this situation is to implant a left ventricular (LV) lead instead of ventricular pacing. Methods We performed a single‐center retrospective analysis of 26 patients with tricuspid valve surgery/disease who received a LV pacing lead in the coronary veins to avoid crossing the tricuspid valve, with or without a right atrial lead. A matched control population was obtained from patients receiving conventional right ventricular pacing and outcomes were compared. Main outcomes of interest were lead stability, electrical lead parameters and change in echocardiographic parameters such as left ventricular ejection fraction (LVEF) during long‐term follow‐up. Results Successful left ventricular pacing was established in 25 out of the 26 cases with one case converted to a RV lead due to lead dislodgement. During the 2.96 ± 1.0 year follow‐up, 24 of 25 (96.0%) leads were functional with stable pacing and sensing parameters, and 1 of 25 (4.0%) was extracted for due to device infection following an episode of thrombophlebitis. Conclusion We conclude that in patients with existing tricuspid valve disease or surgery, ventricular pacing via the coronary veins is a feasible, safe, and reliable alternative to right ventricular pacing., We conducted a single center retrospective analysis of patients with tricuspid valve surgery or disease who received a LV pacing lead. Results show that in patients with existing tricuspid valve disease or surgery, ventricular pacing via the coronary veins is a feasible, safe and reliable alternative to right ventricular pacing.

Limited data exists about management of syncope in Asia. The American College of Emergency Physicians (ACEP) and European Society of Cardiology (ESC) guidelines have defined the high-risk syncope patient. This study aims to determine the effectiveness of managing syncope in an Asian healthcare system and whether strict adherence of international guidelines would reduce hospitalizations.Patients attending the Emergency Department of a Singaporean tertiary hospital with syncope were identified. Clinical journeys of all patients were meticulously mapped by interrogation of a comprehensive electronic medical record system and linkages with national datasets. Primary endpoint was hospitalization. Secondary endpoints were recurrent syncope within 1year and all-cause mortality. Expected admission rates based on application of ACEP/ESC guidelines were calculated.638 patients (43.8±22.4years, 49.0% male) presented with syncope. 48.9% were hospitalized for 2.9±3.2days. Yields of common investigations ranged from 0 to 11.5% and no diagnosis was reached in 51.5% of patients. Diuretics use (HR 5.1, p=0.01) and prior hospitalization for syncope (HR 6.9, p0.01) predicted recurrent syncope. Over 2.8 SD 0.3years of follow-up, 40 deaths occurred. 24 patients who died within 12months of presentation were admitted or had a firm diagnosis upon discharge. Application of guidelines did not significantly reduce hospitalisations, with limited agreement which patients warrant admission. (Actual 376, ACEP 354, ESC 391 admissions, p=NS).Unstructured management of syncope results in nearly half of patients being admitted and substantial healthcare expenditures, yet with limited diagnostic yield. Strict adoption of ACEP or ESC guidelines does not reduce admissions.

ObjectiveWe studied the optimal duration of ambulatory event monitors for symptomatic patients and the predictors of detected events.MethodsPatients with palpitations or dizziness received a patient-activated handheld event monitor which records 30 s single-lead ECG strips. Patients were monitored in an ambulatory setting for a range of 1–4 weeks and ECG strips interpreted by five independent electrophysiologists. Event pick-up rates and clinical covariates were analysed.ResultsOf 335 consecutive adults (age 50±16 years, 58% female) with palpitations (94%) and dizziness (25%) monitored, 286 patients (85%) reported events, and clinically significant events were detected in 86 (26%) patients. Of these 86 patients, 26% had ≥2 significant events, and 73% had events detected in the first 3 days. No significant events were detected after 12 days. The most common ECG abnormalities detected were premature ventricular ectopy (38%), premature atrial ectopy (37%) and atrial fibrillation (AF)/atrial flutter (34%). A history of AF (adjusted OR (AOR) 4.2, 95% CI 1.1 to 15.8), previous arrhythmia (AOR 2.8, 95% CI 2.3 to 5.9) and previous abnormal ambulatory monitoring (AOR 3.4, 95% CI 1.0 to 9.4) were associated with detection of clinically significant events. Patients older than 50 years were 82% more likely to have a clinically significant event (OR 1.8, 95% CI 1.3 to 3.6).ConclusionPatient-activated ambulatory event monitoring for 7 days may be sufficient in the diagnosis of symptomatic patients as significant events first detected beyond 10 days were rare. Patients with a history of AF, arrhythmia or previous abnormal ambulatory monitoring may require even shorter monitoring periods.

Background Occult atrial fibrillation (AF) is not uncommon in patients with stroke. In western cohorts, insertable loop recorders (ILRs) have been shown to be the gold-standard and are cost-effective for AF detection. Anticoagulation for secondary stroke prevention is indicated if AF is detected. The incidence of occult AF among Asian patients with cryptogenic stroke is unclear. Methods Patients with cryptogenic stroke referred between August 2014 and February 2017 had ILRs implanted. Episodes of AF >2 minutes duration were recorded using proprietary algorithms within the ILRs, whereupon clinicians and patients were alerted via remote monitoring. All AF episodes were adjudicated using recorded electrograms. Once AF was detected, patients were counseled for anticoagulation. Results Seventy-one patients with cryptogenic stroke, (age 61.9 ± 13.5 years, 77.5% male, mean CHA2DS2VASc score of 4.2 ± 1.3) had ILRs implanted. Time from stroke to the ILR implant was a median of 66 days. Duration of ILR monitoring was 345 ± 229 days. The primary endpoint of AF detection at 6 months was 12.9%; and at 12 months it was 15.2%. Median time to detection of AF was 50 days. The AF episodes were all asymptomatic and lasted a mean of 77 minutes (± 118.9). Anticoagulation was initiated in all but 1 patient found to have AF. Conclusions The incidence of occult AF is high in Asian patients with cryptogenic stroke and comparable to western cohorts. The combination of ILR and remote monitoring is a highly automated, technologically driven, and clinically effective technique to screen for AF.

A 44 year old male with idiopathic dilated cardiomyopathy was undergoing persistent atrial fibrillation (AF) ablation. Following antral ablation, AF terminated into a regular narrow complex rhythm. Earliest activation was mapped to a focus in the superior vena cava (SVC) which was conducted in a 2:1 ratio to the atria which in turn was conducted with 2:1 ratio to the ventricles, resulting in an unusual 4:2:1 conduction of the SVC tachycardia. 1:1 conduction of the SVC tachycardia to the atrium preceded initiation of AF. During AF, SVC tachycardia continued unperturbed. Sinus rhythm was restored following catheter ablation of the focus.

Aims Brugada syndrome (BrS) is a rare heritable ventricular arrhythmia. Genetic defects in SCN5A , a gene that encodes the α-subunit of the sodium ion channel Nav1.5, are present in 15–30% of BrS cases. SCN5A remains by far, the highest yielding gene for BrS. We studied a young male who presented with syncope at age 11. This proband was screened for possible disease causing SCN5A mutations. The inheritance pattern was also examined amongst his first-degree family members. Methods and results The proband had a baseline electrocardiogram that showed Type 2 BrS changes, which escalated to a characteristic Type I BrS pattern during a treadmill test before polymorphic ventricular tachycardia onset at a cycle length of 250 ms. Mutational analysis across all 29 exons in SCN5A of the proband and first-degree relatives of the family revealed that the proband inherited a compound heterozygote mutation in SCN5A , specifically p.A226V and p.R1629X from each parent. To further elucidate the functional changes arising through these mutations, patch-clamp electrophysiology was performed in TSA201 cells expressing the mutated SCN5A channels. The p.A226V mutation significantly reduced peak sodium current ( I Na) to 24% of wild type (WT) whereas the p.R1629X mutation abolished the current. To mimic the functional state in our proband, functional expression of the compound variants A226V + R1629X resulted in overall peak I Na of only 13% of WT ( P < 0.01). Conclusion Our study is the first to report a SCN5A compound heterozygote in a Singaporean Chinese family. Only the proband carrying both mutations displayed the BrS phenotype, thus providing insights into the expression and penetrance of BrS in an Asian setting.

Diagnostic errors can occur when physicians rely solely on computer electrocardiogram interpretation. Cardiologists often receive referrals for computer misdiagnoses of atrial fibrillation. Patients may have been inappropriately anticoagulated for pseudo atrial fibrillation. Anticoagulation carries significant risks, and such errors may carry a high cost. Have we become overreliant on machines and technology? In this article, we illustrate three such cases and briefly discuss how we can reduce these errors.

Introduction A middle-aged male developed right-sided endocarditis from an infection of an implantable cardiac defibrillator (ICD) system. Following percutaneous device and lead explantation, a very large pedunculated vegetation (19 mm × 14 mm) was found on the Eustachian valve. We decided to remove the vegetation percutaneously using a wire snare instead of open heart surgery. Case report Real-time three-dimensional transesophageal echocardiography and fluoroscopy were used to guide the procedure. Access was from the right femoral vein. Using a triple-loop wire snare through a deflectable sheath, the vegetation was successfully removed in its entirety without complications. Conclusion Percutaneous snare vegetectomy is feasible and may be a viable option in place of open heart surgery in selected patients. © 2013 Wiley Periodicals, Inc.

Aims Persistent left superior vena cava (PLSVC) is found in 0.3–2% of the population. Pacemaker implant in PLSVC can be technically challenging. Most operators have hitherto manipulated ventricular leads through the coronary sinus (CS) into the right ventricle (RV). In this case series, we describe the use of standard passive tined ventricular leads implanted into the left ventricular (LV) epicardial veins in PLSVC. Methods and results Three patients with PLSVC underwent pacemaker implantation for bradycardia. Contrast injection in the dilated CS identified LV coronary veins. Standard passive tined pacing leads were manoeuvred into these branches using hand-shaped stylets without need for additional equipment. Atrial leads were actively fixed to the anterolateral right atrial wall. There were no procedural complications. Chronic ventricular capture threshold at 6 months of follow-up was 1.0 mV@ 0.4 ms. Conclusion Implanting standard leads into the LV veins in PLSVC is safe, effective, and simple without the need for special tools. This is easier than manipulating leads into the RV in PLSVC. Longer-term follow-up and dedicated clinical trials are needed to evaluate the efficacy and safety of this approach.

Background— Electric isolation of the pulmonary veins and posterior left atrium with a single ring of radiofrequency lesions (single-ring isolation [SRI]) may result in fewer atrial fibrillation (AF) recurrences than wide antral pulmonary vein isolation (wide antral isolation [WAI]) by abolishing extravenous AF triggers. The effect of mitral isthmus line (MIL) ablation on outcomes after SRI has not previously been assessed. Methods and Results— We randomly assigned 220 consecutive patients (58±10 years old; 82% men) with highly symptomatic AF (61% paroxysmal, 39% persistent/longstanding persistent) to undergo either SRI or WAI. Half of each cohort was also randomly allocated to have left lateral MIL ablation (2×2 factorial study design). Patients were followed clinically and with 7-day Holter studies for arrhythmia recurrences. The primary end points were recurrence of AF and organized atrial tachyarrhythmias. AF-free survival at 2 years was better after SRI (74% [95% CI, 65%–82%]) than WAI (61% [51%–70%]; P =0.031). Organized atrial tachyarrhythmia–free survival was similar after SRI and WAI (67% [57%–75%] ersus 64% [54%–72%], respectively, at 2 years; P =0.988). MIL ablation resulted in better 2-year organized atrial tachyarrhythmia–free survival (71% [62%–79%] versus 60% [50%–69%]; P =0.07), which approached statistical significance. Survival free of any atrial arrhythmia after one procedure was not significantly affected by isolation technique or MIL ablation. Conclusions— SRI resulted in fewer AF recurrences compared with WAI on long-term follow-up but did not reduce the recurrence of all atrial arrhythmias. MIL ablation may reduce organized atrial tachyarrhythmia recurrences. Clinical Trial Registration— http://www.anzctr.org.au ; ACTRN12606000467538.

Clinical introduction A 21-year-old male with a medical history of scoliosis was referred for an abnormal chest radiograph performed on screening (figure 1). He was asymptomatic with good exercise tolerance. Blood pressure and heart rate were normal. The heart sounds were normal. The pulmonary examination was unremarkable. A treadmill test performed 3 years prior for atypical chest pain was normal. An ECG performed was also normal. Question What abnormality is present in the chest radiograph? Dextrocardia Enlarged right heart border Mediastinal mass Prominent pulmonary vasculature Situs inversus

Aims Implantable cardioverter defibrillators (ICDs) reduce sudden death in patients at high risk. High defibrillation thresholds (DFTs) are not uncommon and may be the cause of failed defibrillation in patients with ICDs. Addition of a coil in the azygous vein posterior to the heart lowers the DFT in most patients by altering the electrical vector during defibrillation. This can be accomplished fairly easily and expeditiously using standard equipment in the laboratory. It also avoids the difficulties and complications associated with other methods such as the use of a subcutaneous array. Methods and results This series of three cases illustrates the type of patients who may benefit from this technique. The addition of an azygous coil successfully lowered the DFT to

Early recurrences of atrial arrhythmia after wide electrically isolating ablation for atrial fibrillation (AF) are well described, but the long-term risk of recurrence for patients with persistent and permanent AF has not been studied in detail. METHODS AND RESULTS Fifty-six consecutive patients [45 men (80.4%), age 55.9 +/- 8.7 years] with persistent [39(69.6%)] or permanent [17(30.4%)] AF were followed for 21.6 +/- 8.8 months after ablation. Atrial fibrillation duration prior to ablation was 6.4 +/- 5.6 years. Electrically isolating lesions encircling the left and right pulmonary veins (PVs) in pairs were created. After 1.5 +/- 0.7 procedures, 48 (85.7%) had sinus rhythm (SR) at 21.6 +/- 8.8 months of follow-up: achieved with 1 procedure in 27 (56.3%) and without anti-arrhythmics in 30 (62.5%). Atrial fibrillation recurrence was observed in 69.6% after the first and 46.4% after the last procedure. Of those with late recurrences (90 days) following the last procedure, most [18 (69.2%)] did not have early recurrences. Pre-procedural AF duration (P = 0.007) and female gender (P = 0.005) were independent predictors of recurrence following the last procedure.Circumferential PV isolation is effective in most patients with persistent or permanent AF. However, repeat procedures are frequently required. Late recurrences are common and not precluded by the absence of early post-procedural arrhythmias.

Prognostic indicators and mortality in multiethnic Southeast Asian patients with heart failure (HF) may be different.The study population comprised 225 inpatients with HF with a left ventricular ejection fraction of 40% or less who were discharged alive. Five years later, survival and causes of death were determined. Proportionally, more Malay and Indian patients were admitted compared with Chinese patients (P.001). There were 55.6% in New York Heart Association (NYHA) class III or IV. Ischemic heart disease was the most common cause (85.8%). At 5 years, 152 patients (67.5%) had died. Angiotensin-converting enzyme inhibitors were prescribed to 79.1% of patients on discharge. Cardiovascular causes accounted for 69.7% of deaths. Predictors of mortality include female gender (P = .046), age 70 years or more (P = .017), renal impairment (P = .008), NYHA class III or IV (P = .03), and non-use of angiotensin-converting enzyme inhibitors (P = .005). On multivariate analysis, increasing age (P = .001) and renal impairment (P = .019) were independent predictors of all-cause mortality. Cardiovascular death was more likely with NYHA class III or IV (P = .004) and renal impairment (P = .012).Mortality is unusually high in this group of patients despite treatment. Greater use of evidence-based therapies in HF-management programs may arrest this trend.

Background Wide electrical pulmonary vein isolation (PVI) with two separate rings of ablation requires extensive ablation on the posterior left atrial wall close to the esophagus. Objective The purpose of this study was to determine the feasibility of PVI using a single ring of radiofrequency ablation lesions. Methods Irrigated-tip ablation catheters, deflectable sheaths, and computerized tomographic image integration were used to isolate the pulmonary veins and posterior wall of the left atrium in 41 patients with a single ring of radiofrequency ablation lesions. The procedural details were compared with a consecutive series of 41 historical controls who underwent PVI with two separate rings around the ipsilateral vein pairs. Results Isolation with a single ring was possible in 39 of 41 cases. Ablation was required within the ring at the venous side of the ridge separating the left atrial appendage and left pulmonary veins (n = 17, 43%) or within the roofline (n = 16, 40%). The length of linear lesions adjacent to the esophagus was shorter in the single-ring group (19 ± 10 mm vs. 31 ± 14 mm; P = .01). The procedural times, number of ablation sites, duration of ablation required to achieve PVI, and rhythm outcomes at 6 months were similar in the two groups. Conclusions Radiofrequency ablation using an open irrigated-tip ablation catheter can be used to reliably electrically isolate the pulmonary veins with a single large circular lesion. PVI can be achieved with a similar procedural and ablation time. The major problem areas were identified as the roof of the left atrium and the ridge separating the left-sided veins from the left atrial appendage.

Background Biopsy specimens of lesions with clinical features of urticarial vasculitis often show a predominantly lymphocytic infiltrate with eosinophils and red blood cell extravasation. Only occasionally is a leukocytoclastic vasculitis encountered, confirming a diagnosis of urticarial vasculitis. Objective The aim of this study was to assess the clinical presentation and histologic features of patients who meet the clinical criteria for urticarial vasculitis. Methods Patients were recruited who had persistent urticarial lesions individually lasting longer than 24 hours, associated with at least 2 of 3 of the following: pain or tenderness; purpura or dusky changes; and resolution with hyperpigmentation. Patients were interviewed based on a standard questionnaire with regard to their symptoms. Blood tests and chest radiographs were performed to exclude systemic involvement and hypocomplementemia. Skin biopsy specimens were sent for histology and direct immunofluorescence. Results Of 22 patients recruited, 19 (86.4%) showed a predominantly lymphocytic infiltrate on histology. Three cases (13.6%) had a neutrophil-predominant infiltrate associated with a leukocytoclastic vasculitis. Twenty (90.9%) had a superficial perivascular infiltrate, and two (9.1%) had a superficial and deep perivascular infiltrate. In all, 21 biopsy specimens (95.5%) showed inflammatory cells within dermal blood vessel walls, obscuring the vessel outline in some. Endothelial cell swelling was seen in 20 biopsy specimens (90.9%), erythrocyte extravasation in 17 (77.3%), nuclear dust in 5 (22.7%), and fibrin extravasation in 2 (9.1%). Multivariate analysis revealed the following features to be independently associated with neutrophil predominance: fulfillment of all 3 minor criteria for urticarial vasculitis-like lesions ( P = .007); presence of fibrin on histology ( P P = .001); hypocomplementemia ( P = .001); and anemia ( P = .015). There was a trend toward lesions not clearing as readily in the neutrophil-predominant group ( P = .071), even with two-modality treatment ( P = .089). Limitations Serum immunoelectrophoresis was not done to exclude Schnitzler's syndrome. Electronmicroscopy and cytokine profiling were not performed. Conclusion Biopsy specimens of lesions with clinical features of urticarial vasculitis reveal that only a minority of patients has leukocytoclastic vasculitis. The majority has a lymphocyte-predominant histology, associated with varying numbers of eosinophils. We favor a lymphocytic vasculitis as a causative explanation in the lymphocyte-predominant group.

Spontaneous coronary artery dissection is an uncommon cause of acute coronary syndrome. Diagnosis of coronary artery dissection is made on coronary angiogram and prompt revascularisation is the key in management. We present a case of coronary artery dissection with an atypical presentation of cardiac arrhythmia mimicking benign fascicular ventricular tachycardia. A high index of suspicion and early coronary angiogram allowed us to diagnose and treat this potentially life-threatening disease.

We sought to assess the hemodynamic significance of mitral stenosis (MS) using a new index.We studied 88 patients with MS. Maximum separation of mitral leaflet tips in diastole in parasternal long-axis and apical 4-chamber views was measured. These two parameters were averaged to yield the mitral leaflet separation index. The index was compared with mitral valve area by planimetry and pressure half-time.The mitral leaflet separation index was measurable in 76 (86.4%) patients. There was excellent correlation with mitral valve area by planimetry (r = 0.91, P.001) and pressure half-time (r = 0.86, P.001) across a wide range of mitral valve areas. Good correlation was found even in atrial fibrillation (r = 0.86 and r = 0.79, respectively). The index could discriminate between hemodynamically significant and insignificant MS (P.001). An index of 0.81 cm or less predicted severe MS with 92.3% sensitivity and 100% specificity whereas a value of 1.11 cm or more identified mild MS with 85.7% sensitivity and 100% specificity.The mitral leaflet separation index is an independent and reliable measure of MS severity that is easy to measure.

Objectives: To study sex differences in clinical characteristics and outcomes among multi-ethnic Southeast Asian patients with hospitalized heart failure (HHF). Background: HHF is an important public health problem affecting man and women globally. Reports from Western populations suggest striking sex differences in risk factors and outcomes in HHF. However, this has not been studied in a multi-ethnic Asian population. Methods: Using the population-based resources of the Singapore Cardiac Data Bank, we studied 5,703 consecutive cases of HHF admitted across hospitals in the Southeast Asian nation of Singapore from 1st January, 2008 through 31st December, 2009. Results: Women accounted for 46% of total admissions and were characterized by older age (73 vs. 67 years; p