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Background Premature ventricular contractions (PVCs) induced by subtle cardiac dysfunction are missed by echocardiography. We evaluated acoustic cardiography for detection of early electromechanical dysfunction in patients with idiopathic PVCs and normal left ventricular ejection fraction (LVEF), and investigated the impact of radiofrequency ablation (RFA) in reversing this adverse effect. Methods Eighty-six patients with PVCs and 33 normal controls having normal LVEF were studied. Fifty PVC patients were in the ablation group and 36 in the nonablation group. %Electromechanical activation time (%EMAT), %left ventricular systolic time (%LVST), third (S3) and fourth heart sound (S4), and systolic dysfunction index (SDI) during sinus rhythm (SR) were measured by acoustic cardiography (Audicor, Inovise Medical, Inc., Beaverton, OR, USA) pre- and postablation. In 28 patients, acoustic parameters were compared during SR without PVCs, and SR with single PVC, ≥ 2 PVCs, or ventricular tachycardia over 10-second Audicor recording in a single patient at different times. Twenty-four-hour acoustic cardiographic and acoustic cardiographic Holter recording were used to assess the impact of PVC burden on electromechanical function in 41 patients. Results %EMAT, S3, S4, and SDI showed significant worsening in the PVC versus control group. %EMAT and SDI were worsened with increasing PVC number in a 10-second strip. %EMAT showed significant linear increment with increasing PVC burden. There was a significant improvement in %EMAT, %LVST, S3, S4, and SDI postablation in patients with PVCs. Conclusion Acoustic cardiography can detect PVC-induced minor electromechanical dysfunction in patients with normal LVEF. RFA can reverse this adverse effect.

Background Alcohol consumption is known to increase the risk of atrial fibrillation (AF). Whether the genotypes of alcohol-metabolizing genes (alcohol dehydrogenase [ADH1B]) are associated with the risk of AF recurrence after catheter ablation remains unclear. Methods and results The ADH1B genotypes of 281 patients who received catheter ablation for AF were examined. We followed this group of patients to monitor their AF recurrence. Alcohol consumption levels of this cohort were evaluated before and after catheter ablation. There was no difference in the underlying diseases presented by the patients with different ADH1B genotypes. Regardless of the ADH1B genotypes, the amount of alcohol consumption was the only factor associated with left atrial dilatation. The ADH1B*2 alleles (hazard ratio: ADH1B*1/*2 vs *1/*1: 2.64; ADH1B*2/*2 vs *1/*1: 1.80, P = 0.02) and the levels of alcohol consumption were independently associated with AF recurrence in the patients with paroxysmal AF after catheter ablation. ADH1B polymorphisms were not associated with AF recurrence in the patients with nonparoxysmal AF. We also found that the association of increased AF recurrence with alcohol consumption and the ADH1B genotypes cannot be explained by mechanisms of systemic inflammation. Conclusions ADH1B*2/*2 genotype and amount of alcohol consumption increase the risk of AF recurrence after catheter ablation.

Predictors of AF Progression After AblationIntroduction Although rare, some paroxysmal atrial fibrillations (AF) still progress despite radiofrequency (RF) ablation. In the study, we evaluated the long-term efficacy of RF ablation and the predictors of AF progression. Methods A total of 589 paroxysmal AF patients (404 men and 185 women; aged 54 ± 12 years) who received 3-dimensional mapping and ablation were enrolled. Their clinical parameters and electrophysiological characteristics were collected. They were divided into Group 1 (N = 13, with AF progression) and Group 2 (N = 576, no AF progression). AF progression was defined as recurrence of persistent AF. Results Group 1 patients had larger left atrial (LA) diameter, larger left ventricle (LV) end-systolic and end-diastolic diameters, poorer LV systolic function, and more amiodarone use at baseline. After 1.2 ± 0.5 procedures, 123 (21%) patients experienced recurrence during 56 ± 29 months’ follow-up. In the multivariate analysis, LA diameter (P = 0.018, HR = 1.12, 95% CI = 1.02–1.24) and LV end-systolic diameter (P = 0.005, HR = 1.10, 95% CI = 1.03–1.17) independently predicted AF progression. LA diameter >43 mm and LV end-systolic diameter >31 mm were the best cut-off values for predicting AF progression by ROC analysis. AF progression rate achieved 19% if they had both larger LA diameter (>43 mm) and LV end-systolic diameter (>31 mm). Conclusion RF ablation prevents the progression of paroxysmal AF effectively, except in patients with increased LA diameter and LV end-systolic diameter on echocardiogram, suggesting more aggressive rhythm control therapies should be considered in these patients.

Non-ischemic cardiomyopathies (NICMs) are composed of variable disease entities, including primary and secondary cardiomyopathies. Determining the etiology of NICM provides pivotal roles of not only the understanding of the individual pathogenesis, but also the clinical management, such as risk stratification, pharmacological treatment, and intervention therapies. Despite the diverse causes of NICM, these cases mostly require clinical attention owing to progressive myocardial injury, resulting in ventricular dysfunction and heart failure. The interaction between the diseased ventricular substrates and systemic/neurophysiological factors contributes to the cornerstones responsible for ventricular arrhythmogenesis and sudden cardiac death (SCD). Prevention of SCD and diminishing ventricular tachyarrhythmias are the important mainstays for the management of NICM patients. Given the understanding of the abnormal ventricular substrates and advancement of navigation systems, radiofrequency catheter ablation (RFCA) has become an adjunctive or alternative strategy for NICM patients who experience drug-refractory ventricular tachycardias (VTs). Successful ablation can frequently be achieved at the expense of an epicardial intervention. A recent study has proven the survival benefits for NICM patients who are free from recurrent VTs after a successful RFCA, regardless of the New York Heart Association (NYHA) functional class status or left ventricular ejection fraction. Additionally, recent evidence has highlighted the better delineation of a diseased myocardium through the incorporation of cardiovascular magnetic resonance imaging (CMRI) and 3-D mapping systems, which can facilitate the identification of critical ventricular arrhythmogenic substrates in NICM patients.