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Introduction: Inappropriate use of direct oral anticoagulants (DOACs) is common, affecting up to 30% of atrial fibrillation (AF) population receiving treatment for stroke prevention. This study assessed appropriateness of anticoagulation in anticoagulation-naive AF patients treated with DOACs during a 12-month prospective follow-up. Methods: This prospective cohort study included all anticoagulation-naive AF patients referred for anticoagulation for stroke prevention at a tertiary cardiovascular center. Participants were prospectively followed through phone call interviews by a dedicated nurse at 1, 3, 6, 9, and 12 months after enrollment. Results: Of 403 anticoagulation-naive AF patients, rivaroxaban was prescribed for 325 patients (80.7%) and apixaban for 78 (19.3%). Inappropriate therapy was observed in 23% (76/325) and 46% (36/78) of patients treated with rivaroxaban and apixaban, respectively. Undertreatment was predominant scenario for both drugs, detected in 78.5% (78/112) of patients treated inappropriately, and was more frequently observed with apixaban versus rivaroxaban (44.8% vs 16.3%). During 12 months, inappropriate treatment was corrected in only 13% of all patients. The multivariate regression model identified creatinine clearance ≤ 49 mL/min (odds ratio [OR], 2.17; 95% confidence interval [CI], 1.12 to 4.21), female sex (OR, 1.81; 95% CI, 1.11 to 2.97), and age ≥ 80 years (OR, 1.85; 95% CI, 1.22 to 2.83) as independent covariates associated with inappropriate dosing. Conclusions: Inappropriate therapy with DOACs for stroke prevention in patients with AF is common, and the dosage were corrected in few patients during the 12-month follow-up. Our findings highlight the persistent lack of knowledge regarding appropriate DOAC dosage and need for continuous education. [ABSTRACT FROM AUTHOR]

Background: Catheter ablation is a common treatment for atrial fibrillation (AF), but recurrence rates remain variable. Predicting the success of catheter ablation is crucial for patient selection and management. This research seeks to create a machine learning model to forecast the early recurrence of atrial fibrillation following catheter ablation. Methods: A prospective longitudinal study was conducted using data from the Iranian AF registry. The dataset included 402 consecutive AF patients who underwent radiofrequency catheter ablation. The primary outcome was early recurrence of AF within 3 months' post-ablation. Data preprocessing and feature selection were performed, followed by the development and evaluation of various machine learning models. The CatBoost model was selected as the best-performing model. Results: The study population had a mean age of 57.30 ± 14.05 years, and 61.4% were male. AF recurrence occurred in 26.1% of patients. The CatBoost model, utilizing 35 features, achieved an accuracy of 92.5% in predicting AF recurrence. The model demonstrated high sensitivity (88.6%) and specificity (94.0%), with an area under the ROC curve of 0.96. Paroxysmal AF, BUN, Cr, age, mitral regurgitation, LA velocity, and mild valvular heart disease were among the most important predictive features. Conclusion: Machine learning methods, particularly the CatBoost model, demonstrate high accuracy in predicting early catheter ablation outcomes in AF patients. The developed model has the potential to improve patient care and decision-making by identifying patients most likely to benefit from the procedure. Further studies with larger sample sizes and external validation are warranted to assess the generalizability of this method for catheter ablation outcome prediction in AF patients. [ABSTRACT FROM AUTHOR]

Background: Pulsed‐field ablation (PFA) is a cutting‐edge technique that employs non‐thermal energy to cause cell death by inducing irreversible electroporation of cell membranes. This systematic review evaluates the PFA effectiveness as a potential alternative to radiofrequency and cryo‐ablation for treating ventricular tachycardia. Methods: PubMed, Embase, Scopus, and Web of Science were systematically searched using keywords related to ventricular tachycardia and pulsed‐field ablation. Eligible Studies evaluating this therapeutic approach for ventricular tachycardia were included in the final analysis. Results: We included six studies (five case reports and one case series) in our systematic review. Eight (88.8%) of procedures were successful with 100% long‐term efficacy. No procedural complications or ventricular tachycardia (VT) recurrence were observed in the cases. Conclusion: The absence of complications, high effectiveness, and long‐term success rate make PFAs a good VT treatment option. However, PFA safety and efficacy studies for VT treatment are scarce. Thus, larger investigations on this topic are urgently needed. [ABSTRACT FROM AUTHOR]

In this systematic review and meta-analysis, we aim to evaluate the efficacy and safety of catheter ablation as the first-line treatment of ventricular tachycardia (VT) in patients with structural heart disease (SHD) and preserved left ventricular ejection fraction (LVEF). Patients with SHD are particularly susceptible to VT, a condition that increases the risk of sudden cardiac death (SCD). Implantable cardioverter-defibrillators (ICDs) can terminate VT and prevent SCD but do not prevent VT recurrence. The efficacy and safety of CA as a first-line treatment in SHD patients with preserved LVEF remain unclear. We searched PubMed/Medline, EMBASE, Web of Science, and Cochrane CENTRAL for studies reporting the outcomes of CA therapy in patients with VT and preserved LVEF, published up to January 19, 2023. The primary outcome was the incidence of SCD following catheter ablation as the first-line treatment of VT in patients with SHD and preserved LVEF. Secondary outcomes included all-cause mortality, VT recurrence, procedural complications, CA success rate, and ICD implantation after catheter ablation. We included seven studies in the meta-analysis, encompassing a total of 920 patients. The pooled success rate of catheter ablation was 84.6% (95% CI 67.2–93.6). Complications occurred in 6.4% (95% CI 4.0–9.9) of patients, and 13.9% (95% CI 10.1–18.8) required ICD implantation after ablation. VT recurrence was observed in 23.2% (95% CI 14.8–34.6) of patients, while the rate of sudden cardiac death (SCD) was 3.1% (95% CI 1.7–5.6). The overall prevalence of all-cause mortality in this population was 5% (95% CI 1.8–13). CA appears promising as a first-line VT treatment in patients with SHD and preserved LVEF, especially for monomorphic hemodynamically tolerated VT. However, due to the lack of direct comparisons with ICDs and anti-arrhythmic drugs, further research is needed to confirm these findings. [ABSTRACT FROM AUTHOR]

Background: Postoperative atrial fibrillation (POAF) is one of the most common types of acute AF and can complicate the treatment course of approximately one third of patients undergoing cardiac surgery. Sodium‐glucose cotransporter‐2 (SGLT2) inhibitors are among the newest antidiabetic drugs which can be therapeutic options for preventing POAF by different mechanisms. Methods: Empagliflozin to Prevent POAF (EMPOAF) is an interventional, investigator‐initiated, double‐blind, placebo‐controlled, multicenter, randomized controlled trial which will be conducted in two referral teaching cardiology hospitals in Tehran. Four‐hundred ninety‐two adult patients who are scheduled for elective isolated coronary artery bypass graft (CABG) surgery will be randomly assigned to one of the groups of intervention (empagliflozin 10 mg daily) or placebo starting at least 3 days before surgery until discharge. Key exclusion criteria are a history of diabetes mellitus, AF, ketoacidosis, or recurrent urinary tract infections along with severe renal or hepatic impairment, unstable hemodynamics, and patients receiving SGLT2 inhibitors for another indication. The primary outcome will be the incidence of POAF. Key secondary endpoints will be the composite rate of life‐threatening arrhythmias, postoperative acute kidney injury, hospitalization length, in‐hospital mortality, stroke, and systemic embolization. Key safety endpoints will be the rate of life‐threatening and/or genitourinary tract infections, hypoglycemia, and ketoacidosis. Conclusions: EMPOAF will prospectively evaluate whether empagliflozin 10 mg daily can reduce the rate of POAF in patients undergoing elective CABG. Enrolment into this study has started by November 2023 and is expected to be ended before the end of 2025. [ABSTRACT FROM AUTHOR]

The clinical safety and consequences of upgrade procedures compared with de novo cardiac resynchronisation therapy (CRT) implantation in heart failure remain unclear. The present study aimed to assess clinical and procedural consequences of patients undergoing CRT upgrade as compared to de novo CRT implantations. In this prospective cohort study, two subgroups were considered as the study population as (1) de novo group that CRT was considered on optimised medical treatment with heart failure of NYHA functional class from II to IV, left ventricular ejection fraction (LVEF) of ≤35%, and QRS width of >130 ms and (2) upgrade group including the patients with previously implantable cardioverter defibrillator (ICD) with the indications for upgrading to CRT. The two groups were compared regarding the changes in clinical outcome and echocardiography parameters. The procedure was successful in 95.9% of patients who underwent CRT upgrade and 100% of those who underwent de novo CRT implantation. It showed a significant improvement in LVEF, severity of mitral regurgitation and NYHA functional classification, without any difference between the two study groups. Overall procedural related complications were reported in 10.8% and 3.8% (p =.093) and cardiac death in 5.4% and 2.5% (p =.360), respectively, with no overall difference in postoperative outcome between the two groups. Upgrading to CRT is a safe and effective procedure regarding improvement of functional class, left ventricular function status and post-procedural outcome. [ABSTRACT FROM AUTHOR]

Background: Brugada syndrome (BrS) is characterized by ST‐segment elevation in the right precordial leads, which is not explained by ischemia, electrolyte disturbances, or obvious structural heart disease. Aim: In present study, we aim to evaluate presentation, long‐term outcome, genetic findings, and therapeutic interventions in patients with BrS. Methods: Between September 2001 and June 2022, all consecutive patients with diagnosis of BrS were enrolled in the present study. All patients gave written informed consent for the procedure, and the local ethical committee approved the study. Results: Of the 76 cases, 79% were proband and 21% were detected during screening after diagnosis of BrS in a family member. Thirty‐three (43%) patients had a typical spontaneous electrocardiogram (ECG) pattern. Thirty percent of the patients were symptomatic; symptomatic patients were more likely to have spontaneous type 1 Brugada ECG pattern in their ECGs (p =.01), longer PR interval (p =.03), and SCN5A mutation (p =.01) than asymptomatic patients. The mean PR interval was considerably longer in men than women (p =.034). SCN5A mutation was found in 9 out of 50 (18%) studied patients. Fifteen percent received appropriate implantable cardioverter‐defibrillator (ICD) therapy and inappropriate ICD interventions were observed in 17%. Presentation with aborted SCD or arrhythmic syncope was the only predictor of adverse outcome in follow‐up (odds ratio: 3.1, 95% confidence interval: 0.7–19.6, p =.001). Conclusions: Symptomatic patients with BrS are more likely to present with spontaneous type 1 Brugada ECG pattern, longer PR interval, and pathogenic mutation in SCN5A gene. Appropriate ICD interventions are more likely in symptomatic patients and those with SCN5A mutation. [ABSTRACT FROM AUTHOR]

BACKGROUND: Atrial fibrillation (AF) augments the risk of stroke by 4-5 times. Vitamin D is pivotal in numerous metabolic pathways. A handful of studies have explored the correlation between vitamin D deficiency (VDD) and AF outcomes. Hence, the authors sought to assess the relationship between VDD and AF outcomes. METHODS: From December 2021 to February 2023, 190 patients with AF were incorporated into the authors’ study. Given the seasonal fluctuation of vitamin D levels, these levels were examined from the start of December until the end of March. RESULTS: The final analysis comprised 190 patients (55.8% male) with an average age of 46.22±15.03. Vitamin D deficiency, insufficiency, and sufficiency were noted in 77 (40.5%), 46 (24.2%), and 67 (35.3%) patients, respectively. Fatigue and syncope were significantly more prevalent in the VDD group than in other groups. Three-vessel disease was more frequent in the VDD group (p-value=0.04). Mortality was more prevalent in patients with VDD (6.31%) compared to the VDI (2.10%) and VDS (0.05%) groups (p = 0.03). Successful cardioversion was significantly more prevalent in the VDS group (p = 0.03). CONCLUSION: A sufficient level of vitamin D was linked with a better response to cardioversion. However, low vitamin D levels are correlated with higher mortality in AF patients. [ABSTRACT FROM AUTHOR]

Background: The majority of cardiac disorders resulting from ventricular dysrhythmias are fatal. The Implantable Cardioverter Defibrillator (ICD) is one of the most common treatments of ventricular dysrhythmias. Despite the benefits of ICD in preserving life, patients with ICD experience adverse physical, psychological, and social consequences. This study investigated the effects of the continuous care program on self-efficacy in patients with ICD. Materials and Methods: The present study was a randomized clinical trial. Based on the inclusion criteria, 80 patients attending an educational cardiovascular center in Tehran during 2017-2018, were randomly assigned to two intervention and control groups (40 in each). The intervention included the continuous care program, an educational session, and a follow-up program undertaken for the patients receiving the ICD. The control group received routine care. Self-efficacy was then measured by ICD (SE-ICD and OE-ICD) questionnaires and compared between the two groups. Results: The results showed no difference between the two groups before the intervention (p > 0.05). However, there was a significant difference in the mean self-efficacy score between the two groups after the intervention, being significantly higher in the intervention group (t77 = 4.9, p < 0.001). Conclusions: The results of the present study indicated that providing a continuous care program can increase self-efficacy in patients with ICD and can be used as an effective model in the nursing care of patients with ICD. [ABSTRACT FROM AUTHOR]

Introduction: Dapagliflozin, a new treatment option for heart failure, leads to a significant reduction in the hospitalization of patients with heart failure. We aimed to review studies on the economic evaluation of adding dapagliflozin to standard care compared with standard care alone in heart failure patients with reduced ejection fraction (HFrEF). Methods: For this systematic review, the PubMed, EMBASE, Web of Science, Cochrane, Scopus, and CEA Registry scientific databases were searched from 1 January 2020 to 25 March 2022. Two of the present researchers screened titles and abstracts, extracted data from full-text articles, and evaluated their quality using the Quality of Health Economic Studies (QHES) checklist for the quality assessment of health economic studies. Results: Of the 456 abstracts screened, 19 studies met the inclusion criteria. The mean QHES score for the studies was 0.87 (high quality). Eight studies on cost-effectiveness analysis, ten studies on cost-utility analysis, and one study on cost-minimization analysis were conducted. Based on the available evidence and the present findings, the addition of dapagliflozin to standard care in patients with HFrEF was cost effective in most countries. Conclusions: Based on the results of the present study, the addition of dapagliflozin to standard care in patients with HFrEF was cost effective. More studies investigating the cost effectiveness of dapagliflozin in patients with HFrEF are required in light of the actual epidemiological data of countries in the relevant input parameters. It is also recommended to conduct cost-effectiveness studies of dapagliflozin taking into account costs and benefits from a societal perspective. [ABSTRACT FROM AUTHOR]

Introduction: Epicardial pacemakers are known as an alternative for endocardial pacemakers in some cases such as heart block, and complex congenital heart diseases. Considering recent advances and improvement of epicardial lead subtypes, it is essential to investigate the long‐term function of them. In this study, we aimed to assess the sensing and pacing characteristics, and survival of bipolar steroid‐eluting and unipolar nonsteroid‐eluting epicardial pacemakers. Methods: We conducted an entirely concentrated search on the documents of all patients who had undergone epicardial lead implantation in the Shaheed Rajaie Cardiovascular, Medical & Research Center during 2015–2018. Implant, and follow‐up data were extracted. Kaplan–Meier analysis and Weibull regression hazards model were applied for the survival analysis. Results: Eighty‐nine leads were implanted for 77 patients. Of the total leads, 52.81%, 53.93%, and 47.19% were implanted in children (under 18‐year‐old), females, and patients with congenital heart diseases, respectively. Bipolar steroid‐eluting leads comprised 33.71% of 89 leads. The pacing threshold of unipolar nonsteroid‐eluting leads that were implanted on the left ventricle and right atrium increased significantly during the follow‐up to greater records than bipolar steroid‐eluting leads. Survival analysis also revealed that bipolar steroid‐eluting leads are significantly better in 48‐month survival (Weibull hazard ratio [HR]: 0.13 (95% confidence interval [CI]: 0.02–0.99), p =.049). Age, ventricular location of the lead, and acute pacing characteristics were not associated with survival. Conclusions: Bipolar steroid‐eluting epicardial leads have an acceptable survival compared with unipolar nonsteroid‐eluting, without a significant difference regarding patients age. Therefore, they could be an excellent alternative for endocardial ones. [ABSTRACT FROM AUTHOR]

Background: Electrocardiography (ECG), as an easily accessible modality, is usually helpful in hypertrophic cardiomyopathy (HCM) diagnosis. The purpose of this study was to evaluate the role of ECG in differentiating between obstructive (OHCM) and non-obstructive (NOHCM) HCM. Methods: The present study is a cross-sectional analysis of HCM patients referred to our center between 2008 and 2017. The study variables included age, sex, clinical presentation, medications, and ECG characteristics including PR interval, QRS width, QTc duration, Tpeak-Tend interval, QRS axis, QRS transition, ventricular hypertrophies, atrial abnormalities, ST-T abnormalities, and abnormal Q waves. Results: The HCM sample consisted of 200 patients (55% males; age 45.60±15.50 y) from our HCM database. We compared the clinical and ECG characteristics of 143 NOHCM patients with those of 57 OHCM patients. The OHCM group was significantly younger than the NOHCM group (age =41.7 vs 47.0 y; P=0.016). The initial clinical presentation was similar between the 2 forms (P>0.05), and palpitations were the dominant symptom. Baseline ECG intervals, including PR (155.6 vs 157.9 ms), QRS (82.5 vs 82.0 ms), and QTc (430.5 vs 433.0 ms), were similar (all Ps>0.050). There were no differences regarding baseline rhythm, atrial abnormalities, QRS transition, ventricular hypertrophies, axis changes, ST-T changes, and abnormal Q waves between the HCM groups (all Ps>0.05). Conclusion: The present study showed that standard 12-lead ECG had no role in distinguishing patients with the obstructive and non-obstructive forms of HCM. [ABSTRACT FROM AUTHOR]

The catheter ablation of idiopathic ventricular arrhythmias is accepted as a first-line treatment as it successfully eliminates about 90.0% of such arrhythmias. One of the most challenging ventricular arrhythmias originates from the left ventricular summit (LVS), a triangular epicardial space with the left main bifurcation as its apex. This area accounts for about 14.0% of LV arrhythmias. The complex anatomy of this region, accompanied by proximity to the major epicardial coronary arteries and the presence of a thick fat pad in this region, renders it a challenging area for catheter ablation. This article presents a review of the anatomy of the LVS and relevant regions and discusses novel mapping and ablation techniques for eliminating LVS ventricular arrhythmias. Additionally, we elaborate on the electrocardiographic (ECG) manifestations of arrhythmias from the LVS and their successful ablation via the direct approach and the adjacent structures. [ABSTRACT FROM AUTHOR]

Atrial fibrillation (AF) is a morbid and heritable irregular cardiac rhythm that affects about 2%-3% of the population. Patients with early-onset AF have a strong genetic association with the disease; nonetheless, the exact underlying mechanisms need clarification. We herein present our evaluation of a 2-generation Iranian pedigree with early-onset AF. Whole-exome sequencing was applied to elucidate the genetic predisposition. Direct DNA sequencing was utilized to confirm and screen the variants in the proband and his available family members. The pathogenicity of the identified nucleotide variations was scrutinized via either segregation analysis in the family or in silico predictive software. The comprehensive variant analysis revealed a missense variant (c.G681C, p.E227D, rs1477078144) in the human α-dystrobrevin gene (DTNA), which is rare in genetic databases. Most in silico analyses have predicted this variant as a disease-causing variant, and the variant is co-segregated with the disease phenotype in the family. Previous studies have demonstrated the association between the DTNA gene and left ventricular noncompaction cardiomyopathy. Taken together, we provide the first evidence of an association between a nucleotide variation in the DTNA gene and early-onset AF in an Iranian family. However, the genetic testing of AF in the Iranian population is still limited. This finding not only further confirms the significant role of genetics in the incidence of early-onset AF but also expands the spectrum of the gene variations that lead to AF. Additionally, it may have further implications for the treatment and prevention of AF. [ABSTRACT FROM AUTHOR]

Conventionally, patients have been admitted overnight after atrial fibrillation (AF) catheter ablation. Several centers have recently adopted a same‐day discharge (SDD) protocol for patients undergoing AF catheter ablation. We aimed to systematically review the current evidence for the safety and efficacy of SDD after AF catheter ablation. A systematic search was performed in PubMed, Embase, Scopus, Web of Science, and the Cochrane library until August 21, 2021. The risk of bias was assessed with the "Methodological Index for Non‐Randomized Studies" (MINORS). The pooled efficacy rate of SDD protocol (defined as the proportion of patients discharged the same day of ablation among the patients who were planned for SDD) was calculated. Meanwhile, pooled major complication rates and early readmission or emergency department (ED) visit rates were evaluated in successful and planned SDD groups separately. Overall, 12 observational studies consisting of 18,065 catheter ablations were included, among which 7320 (40.52%) were discharged the same‐day after ablation. The pooled efficacy was 90.3% (95% confidence interval [CI] [82.7–96.0]). The major complication rates were 1.1% (95%CI [0.5–1.9]), and 0.7% (95% CI [0.0–3.1]) in planned SDD and successful SDD groups, respectively. In addition, readmission/ED visit rate were 3.0% (95%CI [0.9–6.1]), and 3.1% (95% CI [0.8–6.5]) in the same groups. There were no significant differences between planned SDD and overnight groups with respect to major complication rate (risk ratio = 0.70, 95%CI [0.35–1.42], p‐value =.369). The available data indicates that SDD after AF ablation is safe and efficient. Further prospective and randomized studies are warranted to elucidate the safety of SDD after AF ablation and develop a standardized SDD protocol. [ABSTRACT FROM AUTHOR]

Background: Atrial fibrillation. (AF) is the most common sustained arrhythmia globally and its prevalence is likely to increase in the next decades as a result of increasing age and co-morbidities. There are no data on demographic features, clinical characteristics, associated comorbidities, and practice patterns of AF in Iran.Methods: The Iranian Registry of Atrial Fibrillation (IRAF) is a hospital-based prospective survey of AF patients with a 12-month follow-up. Data were collected on a standardized case report form and entered into a web-based electronic database. This paper reports the baseline characteristics of the IRAF cohort.Results: Between February 2018 and March 2020, a total of 1300 patients (57% Male, mean age, 60 ± 14 years) were enrolled. Palpitations were the most common presenting symptom (66%). The most common cardiac comorbidities were hypertension (52%), heart failure (23.7%), and valvular heart disease (21.8%). AF mainly presented as a paroxysmal pattern (44.6%). Seventy-eight percent of the patients with non-valvular AF had CHA2 DS2 -VASc score ≥1 and most (97%) were at low risk for bleeding (HAS-BLED score <3). Rhythm control was given to 55.1% of the patients. Anticoagulation for stroke prevention was provided to 69.5% of the eligible patients, while aspirin was used in 35%.Conclusion: The IRAF Registry has provided a systematic collection of contemporary data regarding the management and treatment of AF in Iran. Oral anticoagulant was used in 69.5%, but aspirin use was still common. [ABSTRACT FROM AUTHOR]

Background: There are some data showing that repurposed drugs used for the Coronavirus disease‐19 (COVID‐19) have potential to increase the risk of QTc prolongation and torsade de pointes (TdP), and these arrhythmic side effects have not been adequately addressed in COVID‐19 patients treated with these repurposed medications. Methods: This is the prospective study of 2403 patients hospitalised at 13 hospitals within the COVID‐19 epicentres of the Iran. These patients were treated with chloroquine, hydroxychloroquine, lopinavir/ritonavir, atazanavir/ritonavir, oseltamivir, favipiravir and remdesivir alone or in combination with azithromycin. The primary outcome of the study was incidence of critical QTc prolongation, and secondary outcomes were incidences of TdP and death. Results: Of the 2403 patients, 2365 met inclusion criteria. The primary outcome of QTc ≥ 500 ms and ∆QTc ≥ 60 ms was observed in 11.2% and 17.6% of the patients, respectively. The secondary outcomes of TdP and death were reported in 0.38% and 9.8% of the patients, respectively. The risk of critical QT prolongation increased in the presence of female gender, history of heart failure, treatment with hydroxychloroquine, azithromycin combination therapy, simultaneous furosemide or beta‐blocker therapy and acute renal or hepatic dysfunction. However, the risk of TdP was predicted by treatment with lopinavir‐ritonavir, simultaneous amiodarone or furosemide administration and hypokalaemia during treatment. Conclusion: This cohort showed significant QTc prolongation with all COVID‐19 medications studied, however, life‐threatening arrhythmia of TdP occurred rarely. Among the repurposed drugs studied, hydroxychloroquine or lopinavir‐ritonavir alone or in combination with azithromycin clearly demonstrated to increase the risk of critical QT prolongation and/or TdP. [ABSTRACT FROM AUTHOR]

Most of the information on the natural history and management of cardiomyopathies and myocarditis in Iran has been obtained from cohort studies in a small number of patients. The prevalence of patients with cardiomyopathies referred to Rajaei Cardiovascular medical and research centers from all over the country is remarkable. Rajaie Cardiomyopathy and myocarditis Registry (RCMR) study is an observational registry of patients with four subtype of cardiomyopathy include: hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), arrhythmogenic right ventricular cardiomyopathy (ARVC), and restrictive cardiomyopathy (RCM) as well as myocarditis designed to determine clinical characteristics, natural history, current therapeutic approaches, response to treatment and long-term outcomes of patients with cardiomyopathy and myocarditis. Prediction of mortality and response to different treatments in these patients using artificial intelligence is another aim of this Registry. COVID 19 Myocarditis and its sequence as cardiomyopathy seem a new challenge in forthcoming years. At the baseline visit, past medical history, clinical signs/symptoms, risk factors, physical examination and family history of cardiomyopathy, current standards for diagnostic workup and clinical follow-up, and relevant electrocardiogram echocardiography, cardiac magnetic resonance, Holter monitoring, or biomarker analyses will be checked. The outcome and results of various therapeutic approaches currently employed for patients, including implantable cardioverter defibrillator, cardiac resynchronization therapy, septal myomectomy, ablation, cardiac transplantation, and medications, will be assessed. Long-term outcomes, including the benefits and complications of therapeutic interventions, will be collected. A follow-up visit will be scheduled after 12 months for all patients, and survival status, hospitalizations, co-morbidities, medications will be assessed. [ABSTRACT FROM AUTHOR]

Postoperative atrial fibrillation (POAF) is a major complication after cardiac surgery which can lead to high rates of morbidity and mortality, an enhanced length of hospital stay, and an increased cost of care. POAF is postulated to be a multifactorial phenomenon; however, some major pathogeneses have been proposed, including inflammatory pathways, oxidative stress, and autonomic dysfunction. Genetic studies also showed that inflammatory pathways, beta-1 adrenoreceptor variants, G protein-coupled receptor kinase 5 gene variants, and non-coding single-nucleotide polymorphisms in the 4q25 chromosomal locus are involved in this phenomenon. Moreover, several predisposing factors lead to the development of POAF, consisting of pre-, intra-, and postoperative contributors. The main predisposing factors comprise age, prior history of major cardiovascular risk factors, and ischemia-reperfusion injury during surgery. The management of POAF is based on the usual therapies used for non-surgical AF, including medications for either rate control or rhythm control in hemodynamically unstable patients. The perioperative administration of β-blockers and some antiarrhythmic agents has been recommended in major international guidelines. In addition, upstream therapies consisting of colchicine, magnesium, statins, and antioxidants have attenuated the incidence of POAF; however, some uncomfortable side effects developed in large randomized trials. The use of anticoagulation has also resulted in less mortality in patients with POAF at higher risk of thromboembolic events. Despite these recommendations, the actual regimen for the prevention of POAF remains controversial. In this review, we highlight the pathogenesis, predisposing factors, and potential therapeutic options for the management of patients at risk for or with POAF following cardiac surgery. [ABSTRACT FROM AUTHOR]

In this study, we combine heat diffusion equation and modified Hodgkin-Huxley axonal model to investigate how an action potential is generated during infrared neural stimulation. The effects of temporal and spatial distribution of heat induced by infrared pulsed lasers on variation of electrical membrane capacitance are investigated. These variations can lead to depolarize the membrane and generate an action potential. We estimate the threshold values of laser light parameters such as energy density, pulse duration, and repetition rate are needed to trigger an action potential. In order to do it, we present an analytic solution to heat diffusion equation. Then, the analytic results are verified by experimental results. Furthermore, the modified Hodgkin-Huxley axonal model is applied to simulate the generation of action potential during infrared neural stimulation by taking into account the temperature dependence of electrical membrane capacitance. Results show that the threshold temperature increase induced by a train infrared pulse laser can be smaller if repetition rate is higher. These results also indicate that temperature rise time and axon diameter influence on threshold temperature increase. To verify threshold values estimated by the presented method, we use a train infrared pulsed laser (λ = 1450 nm with repetition rate of 3.8 Hz, pulse duration of 18 ms and energy density of 5 J/cm2) to optically pace an adult rat heart, and we are able to successfully pace the rat heart during an open-heart surgery. The presented method can be used to estimate threshold values of laser parameters required for generating an action potential, and it can provide an insight to how the temperature changes lead to neural stimulation during INS. [ABSTRACT FROM AUTHOR]

Objective(s): Recent progress in understanding the pathogenesis of premature ventricular contraction (PVC)-induced cardiomyopathy (PIC) has suggested a key role for inflammation. The aim of this study was to evaluate the expression of messenger RNAs (mRNAs) and the protein production of interleukin-6 (IL-6), IL-10, tumor necrosis factor alpha (TNF-α) and interferon-γ (IFN-γ) and two circulating micro-RNAs related to inflammation and cardiovascular disease; miR-155 and miR-146. Materials and Methods: The study population was comprised 25 patients with PIC and 25 patients with normal left ventricular ejection fraction despite frequent PVCs. TNF-α, IL-6, IL10, and IFN-γ levels were evaluated in peripheral blood mononuclear cells (PBMCs) by flow cytometry and their mRNAs were assessed by real time PCR. We analyzed circulating levels of these cytokines by enzyme linked immunosorbent assay (ELISA). Two circulating micro-RNAs, miR-155 and miR-146a, were also investigated. Results: The flow cytometry findings showed that the median fluorescence intensity (MFI) of antibodies reacted with the IL-6 and TNF-α were higher in PIC group than the control group (P-value<0.001). In ELISA, the levels of IL-6 (P-value<0.001) and TNF-α (P-value <0.001) and in RT-PCR the relative expression levels of IL-6 (P-value<0.001) and TNF-α (P-value<0.001) were significantly higher in the PIC group. The relative expression levels of miR-155 and miR-146a were not significantly different between 2 groups (P-value>0.05). Conclusion: In our patients with PIC, there was an elevation in the expression levels of IL-6 and TNF-α in PBMCs. This finding may provide further insights into the inflammatory pathways involved in PIC. [ABSTRACT FROM AUTHOR]

Background: The aim of the present study was to determine whether postprocedural antibiotic reduces the risk of infection related to the cardiac implantable electronic device (CIED) implantations. Methods: The present investigation is a randomized, prospective, single‐blinded controlled trial. All consecutive patients who presented for new CIED implantation, generator replacement, or upgrade were randomized into the following three groups: (A) no antibiotic, (B) intravenous (IV) antibiotic for 1 day, (C) 1 day IV plus 7 days oral antibiotic. Follow‐up was performed on 10‐12 days; 1, 3, 6 months; and then every 6 months for 2 years. The primary endpoint was any evidence of infection at the generator pocket or systemic infection related to the procedure at short‐term (6‐month) and long‐term (2‐year) follow‐ups. Results: Of the 450 patients (72 patients with cardiac resynchronization device) included in the study, the primary endpoint of short‐term infection was reached in one patient (0.2%) in group A and no patients in groups B and C. The endpoint of long‐term infection was reached in nine patients (2%) with equal frequency between three randomized groups (three patients in each group). On multivariable analysis, the only independent predictor of infection was defibrillator implantation (odds ratio, 8.5; 95% confidence interval, 1.6‐45). Conclusions: The results of this prospective study showed no benefit for the postoperative antibiotic for the prevention of CIED infection. [ABSTRACT FROM AUTHOR]

Atrial fibrillation (AF) is the most commonly treated arrhythmia in clinical practice and is often found in association with an atrial septal defect (ASD). However, ASD closure rarely confers complete arrhythmia control. A 23-year-old man presented to our center with frequent episodes ofpalpitations. AF was documented in 12-lead electrocardiography, and echocardiography showed a secundum-type ASD, 14 mm in size, with a significant left-to-right shunt. ASD closure was performed successfully with an ASD occluder device with no residual shunting. During follow-up, the patient experienced several episodes of AF. Thirteen months after the ASD closure, cryoballoon pulmonary vein isolation was done successfully with no complications. During a 12-month follow-up, he had no symptoms or AF recurrences, and echocardiography showed no residual shunting. This study showed that cryoballoon pulmonary vein isolation could be performed successfully without residual shunts in patients with ASD closure devices. [ABSTRACT FROM AUTHOR]

BACKGROUND: Atrial fibrillation (AF) is the most common cardiac arrhythmia, and its prevalence increases with advancing age. Pulmonary vein isolation is a standard approach in drug refractory paroxysmal AF which could be performed by cryoballoon ablation (CBA). We tried to evaluate its efficacy and safety in Iranian patients with AF. METHODS: From 2015 to 2017, 97 patients with paroxysmal and persistent AF were enrolled in our observational historical cohort study. They were visited 1 and 6 months post-procedure in order to assess the efficacy (recurrence) and safety. Recurrence was defined as 30 seconds of arrhythmia on their 48-hours Holter monitoring. RESULTS: Ninety-seven patients enrolled in the study, 64 (66.0%) of them were men, and their mean age was 55 ± 12 years. Hypertension was reported in 41 patients (42.3%), as the most common cardiac risk factor. 71 patients (73.2%) patients with paroxysmal AF and 15 patients (15.5%) with persistent AF underwent the procedure. After 6 months, recurrence was documented in only 17 patients (17.5%), and 82.5% of the patients were free from the recurrence. Post-procedural complication was detected only in 3 patients (3.1%). CONCLUSION: In our study, the mid-term success and safety of CBA in patients with paroxysmal AF was showed. CBA is a safe and effective method in paroxysmal AF, and even in some cases with persistent AF. [ABSTRACT FROM AUTHOR]

Introduction: Myocardial perfusion imaging using gated SPECT and phase analysis is an effective tool in evaluation of mechanical dyssynchrony. The purpose of this study was to determine the normal ranges of global and regional phase parameters. Methods: A total of 100 patients with normal resting and stress electrocardiograms, low pretest likelihood for coronary artery disease and a normal gated MPI study were recruited in the study. All of the patients underwent a standard 2-day stress/rest gated MPI study according to standard protocols. The reconstructed images were further analyzed by Cedar-Sinai's quantitative gated SPECT. Left ventricular phase indices were provided both globally and regionally for both genders and the normal interquartile range of these parameters were defined. Results: Normal ranges of global and wall-based regional phase parameters are presented both in unisex and in gender-specific formats. Both global (P<0.001) and major LV regional phase parameters (P<0.05) are found to be significantly different between the two genders with a significant positive association between end-diastolic volume with phase global indices (P<0.01). There is also more synchronized phase distribution in phase analysis results of post-exercise gated MPI as compared to the phase analysis of the same patients at resting state. Conclusion: Normal ranges of phase indices are defined in this article by using Cedar-Sinai's QGS software. As normal ranges of phase dyssynchrony parameters are gender-specific and are related to LV volume, stress or resting state and stress type, the need for careful incorporation of these data is indicated in interpretation of phase studies. [ABSTRACT FROM AUTHOR]

Introduction: Congenital long QT syndrome (LQTS) is a cardiac disorder characterized by QT interval prolongation at basal ECG. Different LQTS genes encode ion channel subunits or proteins involved in regulating cardiac ionic currents. Long QT syndrome type 6 (LQT6) is caused by mutation in the KCNE2 gene. Our research aimed to analyze genetic variants of KCNE2 gene causing the disease in Iranian population. Methods: Twenty nine patients consented for participation in the study. They were diagnosed based on Schwartz's criteria. After DNA extraction from peripheral blood cells, two exons of the KCNE2 gene were amplified. Afterwards, PCR-SSCP was carried out for screening the possible mutated gene variants. As the last verification step, direct sequencing was done to determine the sequence. Results: All samples were detected by PCR-SSCP and sequenced. None of the patients had the mutation in the KCNE2 gene. Conclusion: Investigating a genetic variant associated with LQTS, in Iranian patients clinically diagnosed with LQT6, no association was found between the disease and KCNE2 gene. Other previously identified genes, especially the major genes, should be considered for further investigation. [ABSTRACT FROM AUTHOR]

Background: Statin therapy has been thought to improve outcomes in cardiac surgeries. We aimed to determine the statin effects on the development of postoperative atrial fibrillation (AF), hospital length of stay (LOS), and inflammatory status in patients undergoing cardiac surgeries.Methods: A systematic literature search in databases was performed, until January 2015. Randomized clinical trial (RCT) studies evaluating statin effect on statin-naive patients with sinus rhythm undergoing cardiac surgeries were eligible to be analyzed.Results: Twelve RCTs involving 1116 patients, 559 receiving statin and 557 receiving control regimen, were analyzed. Postoperative AF occurred in 17.9% and 36.1% of patients in the statin and control groups, respectively. The statin therapy was associated with decreases in the postoperative AF (risk ratio [RR] 0.50, 95% confidence interval [CI] 0.41-0.61, P < .000010), hospital LOS (mean difference in days, RR -0.44, 95% CI -0.67 to -0.20, P = .0002), and postoperative C-reactive protein (CRP) compared with control (mean difference in mg/L, RR -12.37, 95% CI -23.87 to -0.87, P = .04). The beneficial effects on AF and CRP were more marked in patients receiving atorvastatin compared to other statins. Decrease in postoperative AF was greater in coronary artery bypass graft surgery compared to that in isolated valvular surgery.Conclusion: Perioperative statin therapy in statin-naive patients with sinus rhythm undergoing cardiac surgeries was associated with decreases in the development of postoperative AF, the hospital LOS, and the CRP level. However, there were insufficient data to provide evidences regarding statin impacts in patients undergoing isolated valvular surgery. [ABSTRACT FROM AUTHOR]

Residual fibrous structures, referred as "ghosts", are occasionally encountered following lead extraction. Though typically detected in patients with cardiac device infections, their prognostic and therapeutic implications remain speculative. We describe a 62‐year‐old gentleman with history of sick sinus syndrome who presented atrial fibrillation with rapid ventricular response. The patient had history of transvenous lead extraction following pacemaker pocket infection 6 months earlier. In echocardiography, an echo‐dense tubular lead‐like structure was seen that followed the route of a pacer lead from superior vena cava to right atrium and then passing through the tricuspid valve into right ventricle. [ABSTRACT FROM AUTHOR]

Background: Recently, the phase analysis of gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) has become feasible via several software packages for the evaluation of left ventricular mechanical dyssynchrony. We compared two quantitative software packages, quantitative gated SPECT (QGS) and Emory cardiac toolbox (ECTb), with tissue Doppler imaging (TDI) as the conventional method for the evaluation of left ventricular mechanical dyssynchrony. Methods and Results: Thirty-one patients with severe heart failure (ejection fraction ≤35%) and regular heart rhythm, who referred for gated-SPECT MPI, were enrolled. TDI was performed within 3 days after MPI. Dyssynchrony parameters derived from gated-SPECT MPI were analyzed by QGS and ECTb and were compared with the Yu index and septal-lateral wall delay measured by TDI. QGS and ECTb showed a good correlation for assessment of phase histogram bandwidth (PHB) and phase standard deviation (PSD) ( r = 0.664 and r = 0.731, P < .001, respectively). However, the mean value of PHB and PSD by ECTb was significantly higher than that of QGS. No significant correlation was found between ECTb and QGS and the Yu index. Nevertheless, PHB, PSD, and entropy derived from QGS revealed a significant ( r = 0.424, r = 0.478, r = 0.543, respectively; P < .02) correlation with septal-lateral wall delay. Conclusion: Despite a good correlation between QGS and ECTb software packages, different normal cut-off values of PSD and PHB should be defined for each software package. There was only a modest correlation between phase analysis of gated-SPECT MPI and TDI data, especially in the population of heart failure patients with both narrow and wide QRS complex. [ABSTRACT FROM AUTHOR]

Background There are only limited prospective data on the clinical relevance of current of injury (COI) as a predictor of the midterm performance of active-fixation leads. This study sought to investigate whether it is possible to predict the midterm performance of active-fixation leads using COI recorded at the time of implantation. Methods and results One hundred fifty patients (78 men; mean age, 63 ± 19 years) who received active-fixation pacing (n = 201) and defibrillator (n = 51) leads were studied. COI was measured from the intracardiac bipolar electrogram recorded at the time of lead implantation. The study outcome was good lead performance at 6 months, defined as P wave ≥ 1.5 mV, threshold <1.5 V for atrial lead, R-wave ≥ 5 mV, and threshold <1 V for ventricular lead. A total of 102 active-fixation atrial and 150 ventricular leads were implanted. During a 6-month follow-up, invasive intervention was required for seven atrial and seven ventricular leads. In multivariate analysis, COI was the only independent predictor of good outcome for the active-fixation atrial (odds ratio [OR]: 5.67, 95% confidence interval [CI]: 2.18-14.76, P = 0.001) and ventricular leads (OR: 3.99, 95% CI: 1.08-21.26, P = 0.002). Receiver-operating characteristic analysis identified ST-segment elevation ≥2.0 mV for the atrial leads (sensitivity, 75%; specificity, 89%) and ≥10.0 mV for the ventricular leads (sensitivity, 70%; specificity, 87%) as optimal cutoffs for good midterm performance. Conclusions Midterm performance of active-fixation leads is predictable using COI recorded at the time of lead implantation. A ST-segment elevation ≥2.0 mV in the atrial leads and ≥10.0 mV in the ventricular leads are recommended to improve the lead performance at 6 months. [ABSTRACT FROM AUTHOR]

BACKGROUND: Reperfusion ventricular fibrillation after aortic cross clamp is one of the important complications of open cardiac surgery and its prevention could reduce myocardial injuries. This study aimed to evaluate the efficacy of single dose of amiodarone or lidocaine by the way of pump circuit three minutes before aortic cross clamp release and compare the results with normal saline as placebo in a randomized double blinded controlled trial. METHODS: One hundred fifty patients scheduled for first time elective coronary artery bypass graft surgery were randomly assigned to receive either single dose of amiodarone (150 mg), lidocaine (100 mg), or normal saline (5 ml) three minutes before aortic cross clamp release. The incidence of ventricular fibrillation and the need for reuse of drug were compared between these groups by chi-square, Student's t-test, Mann-Whitney test, and One-way ANOVA. SPSS software was used for statistical analysis. RESULTS: The incidence of ventricular fibrillation is higher in the placebo group (15.9%) compare to lidocaine (11.8%) and amiodarone (8.9%) groups; however, there was no statistical difference among the three groups (P = 0.41). Moreover, the reuse of amiodarone (22.7%) was statistically higher (P < 0.05) than lidocaine (5.9%). CONCLUSION: This study showed no difference among lidocaine, amiodarone, and placebo in preventing ventricular fibrillation after aortic cross clamp release. [ABSTRACT FROM AUTHOR]

Background: Noninvasive techniques for the localization of the accessory pathways (APs) might help guide mapping procedures and ablation techniques. We sought to examine the diagnostic accuracy of strain imaging for the localization of the APs in Wolff-Parkinson-White syndrome. Methods: We prospectively studied 25 patients (mean age = 32 ± 17 years, 58.3% men) with evidence of pre-excitation on electrocardiography (ECG). Electromechanical interval was defined as the time difference between the onset of delta wave and the onset of regional myocardial contraction. Time differences between the onset of delta wave (δ) and the onset of regional myocardial contraction (δ-So), peak systolic motion (δ-Sm), regional strain (δ-ε), peak strain (δ-εp), and peak strain rate (δ-SRp) were measured. Results: There was a significant difference between time to onset of delta wave to onset of peak systolic motion (mean ± SD) in the AP location (A) and normal segments (B) versus that in the normal volunteers (C) [A: (57.08 ± 23.88 msec) vs. B: (75.20 ± 14.75) vs. C: (72.9 0 ± 11.16); p value (A vs. B) = 0.004 and p value (A vs. C) = 0.18] and [A: (49.17 ± 35.79) vs. B: (67.60 ± 14.51) vs. C: (67.40 ± 6.06 msec); p value ( A vs. B) < 0.001 and p value (A vs. C) = 0.12, respectively]. Conclusion: Our study showed that strain imaging parameters [(δ-So) and (δ-Strain)] are superior to the ECG in the localization of the APs (84% vs. 76%). [ABSTRACT FROM AUTHOR]

A 37-year-old man, known case of mitral valve replacement, was referred for ablation. Meticulous mapping showed the earliest signal in the distal coronary sinus (CS). Endocardial ablation via transseptal approach failed to permanently ablate the accessory pathway. Similarly, ablation within the CS was unsuccessful. Finally, the mapping catheter was introduced into the vein of Marshall (VoM) and a very early signal was obtained. In the first 3 seconds of the radiofrequency energy application within the VoM, delta wave disappeared. During 1-year follow-up, the patient had no recurrence of the palpitations and electrocardiogram showed no delta wave. (PACE 2013; 36:e132-e135) [ABSTRACT FROM AUTHOR]

Aims Despite the several electrocardiographic (ECG) criteria, misclassification may still occur in differential diagnosis of the regular paroxysmal supraventricular tachycardia (PSVT). The aim of the present study was to evaluate the diagnostic accuracy of the aVR lead in ECG differentiation of atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reciprocating tachycardia (AVRT). Methods and results A 12-lead ECG was recorded in 150 consecutive patients (96 women, mean age, 45 ± 13.5 years) with drug-refractory regular PSVT during both sinus rhythm and tachycardia. All ECGs were reviewed by two experienced electrophysiologists who had no knowledge of the tachycardia mechanism. The ECG recordings were evaluated for standard criteria as well as our newly proposed criterion of pseudo-r′ in the lead aVR. Mechanism of arrhythmia was confirmed by the electrophysiological study and the successful catheter ablation. Patients with AVNRT were older (50 ± 10 vs. 37 ± 15 years, P = 0.001), predominantly female (71 vs. 53%, P = 0.03), and presented with slower tachycardia (175 ± 25 vs. 186 ± 26 b.p.m., P = 0.01). Among the ECG criteria of the AVRT diagnosis, visible P-wave with RP interval ≥100 ms had highest diagnostic accuracy (sensitivity 79%, specificity 87%, and positive predictive value 79%). For AVNRT diagnosis, pseudo-r′ in aVR had a higher sensitivity, specificity, and predictive values compared with the conventional criteria of the pseudo-r′ in V1 and pseudo-s in inferior leads (all P < 0.05). Conclusions New criterion of pseudo-r′ in lead aVR appears to be more accurate than the standard ECG criteria for ECG diagnosis of AVNRT. [ABSTRACT FROM PUBLISHER]

Atrial fibrillation (AF) is the most common complication of coronary artery bypass graft surgery (CABG). The reported incidence of AF after CABG varies from 20% to 40%. Postoperative AF (POAF) is associated with increased incidence of hemodynamic instability, thromboembolic events, longer hospital stays, and increased health care costs. A variety of pharmacological and nonpharmacological strategies have been employed to prevent AF after CABG. Preoperative and postoperative beta blockers are recommended in all cardiac surgery patients as the first-line medication to prevent POAF. Sotalol and amiodarone are also effective and can be regarded as appropriate alternatives in high-risk patients. Corticosteroids and biatrial pacing may be considered in selected CABG patients but are associated with risk. Magnesium supplementation should be considered in patients with hypomagnesemia. There are no definitive data to support the treatment with nonsteroidal anti-inflammatory drugs, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, procainamide, and propafenone, or anterior fat pad preservation to reduce POAF. [ABSTRACT FROM AUTHOR]

Atrial fibrillation (AF) is a commonly encountered cardiac arrhythmia. Predicting the conditions under which AF terminates spontaneously is an important task that would bring great benefit to both patients and clinicians. In this study, a new method was proposed to predict spontaneous AF termination by employing the points of section (POS) coordinates along a Poincare section in the electrocardiogram (ECG) phase space.The AF Termination Database provided by PhysioNet for the Computers in Cardiology Challenge 2004 was applied in the present study. It includes one training dataset and two testing datasets, A and B. The present investigation was initiated by producing a two-dimensional reconstructed phase space (RPS) of the ECG. Then, a Poincare line was drawn in a direction that included the maximum point distribution in the RPS and also passed through the origin of the RPS coordinate system. Afterward, the coordinates of the RPS trajectory intersections with this Poincare line were extracted to capture the local behavior related to the arrhythmia under investigation. The POS corresponding to atrial activity were selected with regard to the fact that similar ECG morphologies such as P waves, which are corresponding to atrial activity, distribute in a specific region of the RPS. Thirteen features were extracted from the selected intersection points to quantify their distributions. To select the best feature subset, a genetic algorithm (GA), in combination with a support vector machine (SVM), was applied to the training dataset. Based on the selected features and trained SVM, the performance of the proposed method was evaluated using the testing datasets.The results showed that 86.67% of dataset A and 80% of dataset B were correctly classified. This classification accuracy is in the same range as or higher than that of recent studies in this area. These results show that the proposed method, in which no complicated QRST cancelation algorithm was used, has the potential to predict AF termination. [ABSTRACT FROM PUBLISHER]

Aims: Valvular regurgitation, especially on the right side of the heart, is a common finding even in patients without endocardial pacing leads. The severity of valvular regurgitation can change after permanent pacemaker (PPM) implantation. Ventricular pacing has been shown to cause ventricular dysfunction. The purpose of this study was to evaluate the mid-term effects of right ventricular (RV) apical pacing on atrioventricular (AV) valvular regurgitation in patients with a normal left ventricular function before PPM implantation. Methods and Results: Patients who required dual-chamber pacemakers due to a high-degree AV block were enrolled in the study. Initial echocardiography was performed before PPM implantation and re-evaluation by echocardiography was performed every 24 months thereafter. A total of 125 patients (61 male; mean age: 66.57 ± 6.45 years) were included in the study, and 115 pacemaker-dependent patients were followed up (mean ± SD; 4.08 ± 0.8 years). Echocardiography demonstrated mild tricuspid regurgitation (TR) and mitral regurgitation (MR) in 70 (60.1%) and 34 (29.6%) patients before PPM implantation, respectively. Moderate TR and MR were detected in 10 (8.7%) and 1 (0.9%) patients, respectively. Thirty-six (31.6%) patients showed moderate-to-severe TR at long-term follow-up, compared with the 10 (8.7%) patients, who had the same degree of TR before RV apical pacing (P < 0.001). Mild and moderate MR were detected in 54 (47%) and 8 (7%) patients after PPM implantation on the last echocardiography(P < 0.001). Baseline systolic pulmonary artery pressure (PAP) was 29.24 ± 8.45 mmHg, which increased to 36 ± 11 mmHg on the last echocardiography (P < 0.001). Conclusion: Considering the haemodynamic effects at mid-term follow-up, left ventricular dysfunction is rare in patients with RV apical pacing and normal baseline left ventricular function. Right ventricular apical pacing is associated with a significant increase in the prevalence and severity of TR and MR. [ABSTRACT FROM AUTHOR]

Background: The signal-averaged electrocardiography is a noninvasive method to evaluate the presence of the potentials generated by tissues activated later than their usual timing in the cardiac cycle. The purpose of this study was to demonstrate the correlation between the filtered QRS duration obtained via the signal-averaged electrocardiography and left ventricular dimensions and volumes and then to compare it with the standard electrocardiography. Methods: We included patients with advanced systolic left ventricular dysfunction (ejection fraction ≤ 35%). All the patients underwent surface twelve-lead electrocardiography, signal-averaged electrocardiography, and echocardiography. Results: The study included 86 patients with a mean age of 54.66 ± 13.23 years. The mean left ventricular ejection fraction was 18.31 ± 5.49%; the mean QRS duration was 0.14 ± 0.02 sec; and 52% of the patients had left bundle branch block. The mean filtered QRS duration was 145.87 ± 24.89 ms. Our data showed a significant linear relation between the filtered QRS duration and left ventricular end-systolic volume, left ventricular end-diastolic volume, left ventricular end-systolic diameter, and left ventricular end-diastolic diameter; the correlation coefficient was, however, not good. There was no significant correlation between the QRS duration and left ventricular diameters and volumes. Conclusion: The filtered QRS duration has a better correlation with left ventricular dimensions and volumes than does the QRS duration in the standard electrocardiography. [ABSTRACT FROM AUTHOR]

Aims We sought to evaluate the efficacy and safety of different antitachycardia pacing (ATP) sites in heart failure (HF) patients with a biventricular implantable cardioverter-defibrillator (ICD). Methods and results Between January 2003 and December 2008, 89 consecutive patients with biventricular (BiV) ICDs (Medtronic Inc., St Paul, Minnesota, USA) were enrolled. In these patients, stored electrograms of the true spontaneous ventricular tachycardia (VT) episodes with at least one ATP therapy were analysed. Out of the 89 patients, 46 experienced 259 VT episodes. When we considered all VT forms, both left ventricular (LV)-ATP (91%) and BiV-ATP (89%) were significantly better than right ventricular (RV)-ATP (72%) in terminating VTs (P= 0.03 and 0.04, respectively). In the fastVT zone, there was a trend for higher efficacy of BiV-ATP compared with RV-ATP and LV-ATP (75 vs. 60 vs. 60%, P= 0.10). Fast VT acceleration occurred to a similar extent in all ATP groups (20% in RV-ATP vs. 20% in LV-ATP vs. 20% in BiV-ATP, P= NS). In the slow VT zone, RV-ATP was significantly less effective than LV-ATP (74 vs. 100%, P= 0.001) and BiV-ATP (74 vs. 100%, P= 0.014). Incidence of acceleration was lower with LV-ATP and BiV-ATP than RV-ATP (0 vs. 0 vs. 9%, P= 0.03) in the slow VT zone. Conclusions In HF patients treated with BiV ICD, overall ATP efficacy is higher when delivered from LV or BiV than from RV. Biventricular-ATP and LV-ATP are also safer than RV-ATP in the slow VT zone. [ABSTRACT FROM PUBLISHER]

Aims: To predict response to cardiac resynchronization therapy (CRT) in patients with heart failure (HF) and intraventricular conduction delay. [ABSTRACT FROM PUBLISHER]

Background: A remote magnetic navigation system (MNS) has been used with a nonirrigated magnetic catheter for ablation of some supraventricular and ventricular arrhythmias. However, the irrigated tip catheter has not been evaluated. Objective: To evaluate the feasibility and efficiency of the newly available irrigated tip magnetic catheter for radiofrequency ablation (RF) of electrical storm due to scar-related ventricular tachycardia (VT) in patients with ischemic heart disease. Methods: Between January and March 2008, a total of 4 consecutive patients (4 men, mean age 67.7 years) with electrical storm who had an implantable cardioverter defibrillator underwent radiofrequency ablation using a remote MNS and the new magnetic irrigated catheter. Results: Five ablation procedures were performed in study patients. Acute success, defined as noninducibility of any monomorphic VT, was obtained in 3 patients. In 1 patient, a nonclinical VT remained inducible. A monomorphic VT corresponding to clinical VT with the median (range) cycle length of 485 (440–580) ms was induced in all patients. The duration of ablation was 2,273 (985–3087) seconds, with median total procedure and fluoroscopy times of 135 (100–150) minutes and 6.5 (5–9) minutes, respectively. One recurrence occurred 1 week after ablation, which was ablated successfully in the second session. No complication was observed after ablation. During mean follow-up of 4.2 months, all patients were in sinus rhythm, they received no ICD therapy, and no mortality occurred. Conclusions: Irrigated ablation of scar-related ventricular tachycardia guided by remote MNS is a feasible and effective modality for management of the electrical storm in patients with ischemic cardiomyopathy with minimal radiation exposure. [ABSTRACT FROM AUTHOR]

Background: Approximately 30% of patients with hypertrophic cardiomyopathy (HCM) suffer syncope and syncope was the only symptom associated with sudden death. However, no systematic studies in large cohorts looking at predictors of syncope are available in the literature. Therefore, we sought to determine predictors of syncope in patients with HCM. Methods: One hundred and seventy-three consecutive patients with HCM and a mean age of 42 ± 18 years (range 10–78) underwent extensive clinical, electrocardiographic, and echocardiographic testing to identify predictors of syncope. Results: During the mean follow-up duration of 50 months, syncope occurred in 28% of the HCM patients. Univariate analysis showed male gender, age <40 years, family history of sudden death, PR interval, QRS width, ≥2 bursts of nonsustained ventricular tachycardia (NSVT), ≥3 bursts of nonsustained supraventricular tachycardia (NSSVT), maximum left ventricular wall thickness ≥30 mm, and abnormal blood pressure response, out of 24 demographic, clinical, hemodynamic, electrocardiographic, and echocardiographic features, to be significantly associated with syncope. Of these nine variables, the only independent predictors of syncope at multivariate analysis were age <40 years (odds ratio [OR]: 4.4, 95% confidence interval [CI]: 2.2–16, P = 0.003), ≥2 bursts of NSVT (OR: 9.9, 95% CI: 2.0–46, P = 0.0001), and ≥3 bursts of NSSVT (OR: 2.7, 95% CI: 0.38–8.25, P = 0.001). The concomitant occurrence of all three variables had a sensitivity of 87% and specificity of 73% in identifying the patients with syncopal events. Conclusions: The results of this study showed that age <40 years, bursts of NSVT, and NSSVT were independently associated with the risk of syncope in patients with HCM. Demographic data and ambulatory ECG findings could help in risk stratification of patients with HCM. [ABSTRACT FROM AUTHOR]

Aims: From the spectrum of electrocardiogram (ECG) changes that may occur in hypertrophic cardiomyopathy (HCM), there is no criterion reported to be useful for risk stratification. We sought to determine whether there was a relationship between the resting ECG findings and prognosis in patients with HCM. [ABSTRACT FROM PUBLISHER]

Aims: It is currently recommended to implant the left ventricular (LV) pacing lead at the lateral wall. However, the optimal right ventricular (RV) pacing lead location for cardiac resynchronization therapy (CRT) remains controversial. We sought to investigate whether optimizing the site for placement of the RV lead could further improve the long-term response to CRT in patients with advanced heart failure. [ABSTRACT FROM PUBLISHER]