Epicardial ventricular tachycardia ablation a multicenter safety study

The aim of this study was to perform a systematic evaluation of safety and midterm complications after epicardial ventricular tachycardia (VT) ablation.

Elimination of local abnormal ventricular activities: a new end point for substrate modification in patients with scar-related ventricular tachycardia

Catheter ablation of ventricular tachycardia (VT) is effective and particularly useful in patients with frequent defibrillator interventions. Various substrate modification techniques have been described for unmappable or hemodynamically intolerable VT. Noninducibility is the most frequently used end point but is associated with significant limitations, so the optimal end point remains unclear. We hypothesized that elimination of local abnormal ventricular activities (LAVAs) during sinus rhythm or ventricular pacing would be a useful and effective end point for substrate-based VT ablation. As an adjunct to this strategy, we used a new high-density mapping catheter and frequently used epicardial mapping.

Role of electrophysiological studies in predicting risk of ventricular arrhythmia in early repolarization syndrome.

BACKGROUND The early repolarization (ER) pattern is associated with an increased risk of arrhythmogenic sudden death. However, strategies for risk stratification of patients with the ER pattern are not fully defined. OBJECTIVES This study sought to determine the role of electrophysiology studies (EPS) in risk stratification of patients with ER syndrome. METHODS In a multicenter study, 81 patients with ER syndrome (age 36 ± 13 years, 60 males) and aborted sudden death due to ventricular fibrillation (VF) were included. EPS were performed following the index VF episode using a standard protocol. Inducibility was defined by the provocation of sustained VF. Patients were followed up by serial implantable cardioverter-defibrillator interrogations. RESULTS Despite a recent history of aborted sudden death, VF was inducible in only 18 of 81 (22%) patients. During follow-up of 7.0 ± 4.9 years, 6 of 18 (33%) patients with inducible VF during EPS experienced VF recurrences, whereas 21 of 63 (33%) patients who were noninducible experienced recurrent VF (p = 0.93). VF storm occurred in 3 patients from the inducible VF group and in 4 patients in the noninducible group. VF inducibility was not associated with maximum J-wave amplitude (VF inducible vs. VF noninducible; 0.23 ± 0.11 mV vs. 0.21 ± 0.11 mV; p = 0.42) or J-wave distribution (inferior, odds ratio [OR]: 0.96 [95% confidence interval (CI): 0.33 to 2.81]; p = 0.95; lateral, OR: 1.57 [95% CI: 0.35 to 7.04]; p = 0.56; inferior and lateral, OR: 0.83 [95% CI: 0.27 to 2.55]; p = 0.74), which have previously been demonstrated to predict outcome in patients with an ER pattern. CONCLUSIONS Our findings indicate that current programmed stimulation protocols do not enhance risk stratification in ER syndrome.

Benign vs malignant inferolateral early repolarization: Focus on the T wave.

BACKGROUND Inferolateral early repolarization (ER) is highly prevalent and is associated with idiopathic ventricular fibrillation (VF). OBJECTIVE The purpose of this study was to evaluate the potential role of T-wave parameters to differentiate between malignant and benign ER. METHODS We compared the ECGs of patients with ER and VF (n = 92) with control subjects with asymptomatic ER (n = 247). We assessed J-wave amplitude, QTc interval, T-wave/R-wave (T/R) ratio in leads II and V5, and presence of low-amplitude T waves (T-wave amplitude <0.1 mV and <10% of R-wave amplitude in lead I, II, or V4-V6). RESULTS Compared to controls, the VF group had longer QTc intervals (388 ms vs 377 ms, P = .001), higher J-wave amplitudes (0.23 mV vs 0.17 mV, P <.001), higher prevalence of low-amplitude T waves (29% vs 3%, P <.001), and lower T/R ratio (0.18 vs 0.30, P <.001). Logistic regression analysis demonstrated that QTc interval (odds ratio [OR] per 10 ms: 1.15, 95% confidence interval [CI} 1.02-1.30), maximal J-wave amplitude (OR per 0.1 mV: 1.68, 95% CI 1.23-2.31), lower T/R ratio (OR per 0.1 unit: 0.62, 95% CI 0.47-0.81), presence of low-amplitude T waves (OR 3.53, 95% CI 1.26-9.88). and presence of J waves in the inferior leads (OR 2.58, 95% CI 1.18-5.65) were associated with malignant ER. CONCLUSION Patients with malignant ER have a higher prevalence of low-amplitude T waves, lower T/R ratio (lead II or V5), and longer QTc interval. The combination of these parameters with J-wave amplitude and distribution of J waves may allow for improved identification of malignant ER.