Objective: We compared the effectiveness of sotalol on mortality and the recurrence of ventricular tachyarrhythmia (VTA) between idiopathic dilated cardiomyopathy (IDCM) and coronary artery disease (CAD).
Patients: Forty patients with spontaneous VTA and induced VTA associated with CAD (n = 23) and IDCM (n = 17) were studied. In all patients, sotalol was prescribed and an electrophysiologic study (EPS) was performed to evaluate its effect on the induction of VTA. There were no significant differences in left ventricular ejection fraction (LVEF) between CAD and IDCM (35%+/- 10% vs. 35%+/- 12%).
Results: After sotalol, there were no significant differences in the QTc interval on electrocardiogram (ECG) or in the effective refractory period in the apex of the right ventricle between the two groups, but sotalol was more effective in preventing the induction of VTA in CAD than in IDCM (65% vs. 29%; P < 0.05). During a mean follow-up period of 47 +/- 27 months, the overall VTA recurrence rate was significantly lower in CAD than in IDCM (P < 0.01). The all-cause mortality rate tended to be lower in CAD than in IDCM, but the difference was not significant (P = 0.07). Electrical storm (ES) occurred more frequently in IDCM than in CAD, (41% vs. 13%; P < 0.05), and all patients with ES (n = 10) failed to respond to sotalol as assessed by EPS.
Conclusion: Sotalol reduced the overall VTA recurrence rate and all-cause mortality more in CAD than in IDCM.