Objectives: This study investigated the role of programmed ventricular stimulation (PVS) for arrhythmia risk prediction in patients with idiopathic dilated cardiomyopathy (IDC) and spontaneous nonsustained ventricular tachycardia (VT).
Background: Nonsustained VT in patients with IDC has been associated with a high incidence of sudden cardiac death.
Methods: Over the course of 4 years, 34 patients with IDC, a left ventricular (LV) ejection fraction < or = 35%, and spontaneous nonsustained VT underwent PVS. All patients were prospectively followed for 24+/-13 months.
Results: Sustained ventricular arrhythmias were induced in 13 patients (38%). Sustained monomorphic VT was induced in three patients (9%), and polymorphic VT or ventricular fibrillation (VF) in another 10 patients (29%). No sustained ventricular arrhythmia could be induced in 21 study patients (62%). Prophylactic implantation of third-generation defibrillators (ICDs) with electrogram storage capability was performed in all 13 patients with inducible sustained VT or VF, and in nine of 21 patients (43%) without inducible sustained VT or VF. There were no significant differences between the additional use of amiodarone, d,I-sotalol, and beta-blocker therapy during follow-up in patients with and without inducible VT or VF. During 24+/-13 months of follow-up, arrhythmic events were observed in nine patients (26%) including sudden cardiac deaths in two patients and ICD shocks for rapid VT or VF in seven patients. Arrhythmic events during follow-up occurred in four of 13 patients with inducible ventricular arrhythmias compared with five of 21 patients without inducible ventricular arrhythmias at PVS (31% vs. 24%, p=NS).
Conclusion: PVS does not appear to be helpful for arrhythmia risk stratification in patients with IDC, a left ventricular ejection fraction < or =35%, and spontaneous nonsustained VT. Due to the limited number of patients, however, the power of this study is too small to exclude moderately large differences in outcome between patients with IDC with and without inducible VT or VF.