Electrocardiographic characteristics for predicting idiopathic right ventricular outflow tract premature ventricular complex-induced cardiomyopathy.

PURPOSE

In spite of several proposed predictors for premature ventricular complex (PVC)-induced cardiomyopathy (PVC-CMP), the specific ECG features of idiopathic right ventricular outflow tract (RVOT) PVC-CMP remain unknown.

METHODS

A total of 130 patients (49 males, mean age 44 years) with symptomatic and drug-refractory idiopathic RVOT PVCs undergoing radiofrequency catheter ablation (RFCA) were enrolled. The patients were categorized into two groups, including those with and without RVOT PVC-CMP (left ventricular ejection fraction (LVEF) < 50%, n = 25 and LVEF ≥ 50%, n = 105, respectively). The 12-lead PVC morphologies were assessed.

RESULTS

Patients with RVOT PVC-CMP had a lower LVEF (42 ± 5% vs. 60 ± 7%, P < 0.01) and higher PVC burden (24 ± 14% vs. 15 ± 11%, P = 0.02) when compared to patients without RVOT PVC-CMP. The PVC features in those with PVC-CMP displayed a significantly wider QRS duration (143 ± 14 ms vs. 132 ± 17 ms, P < 0.01) and higher peak deflection index (PDI; 0.60 ± 0.07 vs. 0.55 ± 0.08, P < 0.01). A multivariate analysis demonstrated that the QRS duration (odds ratio (OR) 1.130, 95% confidence interval (CI) 1.020-1.253, P = 0.02) and PDI (OR 1.240, 95% CI 1.004-1.532, P = 0.04) were independently associated with RVOT PVC-CMP. Based on the receiver-operating characteristic analysis, a QRS duration > 139 ms and PDI > 0.57 could predict RVOT PVC-CMP (area under the curve (AUC) 0.710 and AUC 0.690, respectively). The elimination and suppression of PVCs by RFCA resulted in the recovery of the LVEF in RVOT PVC-CMP.

CONCLUSIONS

The ECG parameters, including a wider QRS duration and higher PDI, could predict the development of RVOT PVC-CMP, which could be effectively treated by RFCA.