Background: Due to the absence of differential guidelines for heart failure with tachyarrhythmia, it is difficult to diagnose tachycardia-induced cardiomyopathy (TIC) at the initial visit. Furthermore, clinical outcomes of rate versus rhythm control in TIC are unclear. Hypothesis: Because the etiology of TIC is different from dynamic cardiomyoplasty (DCMP), differential parameters may be present. Methods: We assessed 21 patients with TIC (15 men; mean age, 50 ± 14 years) and 21 control patients with idiopathic DCMP. We assessed clinical courses, echocardiographic parameters, as well as outcomes by treatment.Results: In the TIC group, the related tachyarrhythmias were atrial fibrillation (n = 12), atrial flutter (n = 5), atrial tachycardia (n = 3) and paroxysmal supraventricular tachycardia (n = 1). After treatment, all patients became asymptomatic and the ejection fraction (EF) improvement ( EF 15%) was observed in all patients (left ventricular ejection fraction [LVEF], 30 ± 11% initial versus 58 ± 6% last ). In the idiopathic DCMP group, no patient showed EF improvement (EF increase 5%), and 4 patients (19%) underwent heart transplantation. Left ventricle (LV) mass indices, volumes adjusted by BSA, and dimensions were smaller in the TIC group than in the idiopathic DCMP group. Of those, LV end-diastolic dimension was the only independent predictor of TIC in multiple regression analysis (odds ratio [OR] 0.742 per 1 mm, 95% confidence ratio [CI] 0.618 to 0.891, p = 0.001). The Association of University Cardiologists (AUC) was 0.908 on receiver-operating characteristic (ROC) curve analysis and LV end-diastolic dimension 61 mm could predict TIC with a sensitivity of 100% and a specificity of 71.4%. After restoration of sinus rhythm (n = 8), one experienced recurrent TIC after discontinuation of amiodarone. After control of heart rate (n = 13), one experienced recurrent TIC due to poor control of heart rate (log-rank test, p = 0.808). There were no differences in the echocardiographic parameters between the 2 groups before and after treatment except for the larger initial LV volumes in the rhythm control. Conclusions: In patients presented as heart failure with tachyarrhythmia, initial echocardiographic parameters, especially LV end-diastolic dimension, help to differentiate TIC from idiopathic DCMP. Rate control was as effective as rhythm control for EF improvement and prognosis.

The treatment effect of the hybrid procedure, consisting of a thoracoscopic ablation followed by an endocardial radiofrequency catheter ablation (RFCA), is unclear. A total of 117 ablation-naïve patients who underwent either the staged hybrid procedure (n = 72) or RFCA alone (n = 105) for drug-refractory, non-valvular persistent or long-standing persistent atrial fibrillation (AF) were enrolled. The primary outcome is occurrence of total atrial arrhythmia, defined as a composite of AF, sustained atrial tachycardia (AT), and atypical atrial flutter (AFL) after index procedure. The mean age was 52.7 years. Eighty-four percentage of the patients were male. Patients with prior history of stroke and long-standing persistent AF were more prevalent in the hybrid group than RFCA group. The left atrial volume index was larger in the hybrid group (P<0.001). During 2.1 years of median follow-up, the incidence of total atrial arrhythmia was not different between the two groups (32.5% vs. 35.7%; adjusted hazard ratio: 0.64; 95% confidence interval: 0.36–1.14; P = 0.13). The AF recurrence was significantly lower in the hybrid group than in the RFCA group (29.6% vs. 34.9%; adjusted HR: 0.53; 95% CI: 0.29–0.99; P = 0.046). The hospital stay was longer in the hybrid group than in the RFCA group (11 days vs. 4 days; P<0.001). A staged hybrid procedure may be an alternative choice for drug-refractory persistent AF, but it is no more effective than RFCA alone to eliminate atrial arrhythmias. Considering the long-length of stay and the morbidity, careful consideration should be given in selection of treatment strategy.

Background Recurrent atrial tachyarrhythmia (ATa) is a challenge in all ablation procedures for atrial fibrillation (AF). However, data on ATa after totally thoracoscopic ablation (TTA) is lacking. This study aimed to investigate the mechanisms and outcomes of recurrent ATa after TTA. Methods Eligible patients for the present study were those who underwent electrophysiologic study and catheter‐based radiofrequency ablation (RFA) at least 3 months after TTA for symptomatic recurrent ATa that was refractory to antiarrhythmic drugs and/or cardioversion. Follow‐up outcomes included recurrent ATa after first or repeated RFA. Results A consecutive 154 TTA patients were evaluated. A total of 24 patients showed symptomatic recurrent ATa after TTA, and 22 underwent RFA. Half of the patients (11/22, 50%) had AF as a form of recurrent ATa. Nonpulmonary vein (PV)‐related mechanisms of ATa were noted in half of patients. PV gaps showed a characteristic distribution: most gaps in right PVs were located at the posterior ridge (71.4%) with the posterior ridge of left PVs saved in all patients. Post‐RFA recurrence rate was 27.3% during a median follow‐up of 9.1 months, with all recurrences except for one occurring within 3 months after first RFA. Conclusions During a median of 17.8 months after TTA, 24 patients (24/154, 15.6%) developed symptomatic recurrent ATa, and 22 patients underwent RFA. Post‐RFA recurrence rate was 27.3%, which mostly occurred within 3 months after RFA. Catheter‐based ablation of recurrent arrhythmias may be effective, but challenging.