PROGRAMMED VENTRICULAR STIMULATION FOR ARRHYTHMIA RISK PREDICTION IN PATIENTS WITH IDIOPATHIC DILATED CARDIOMYOPATHY AND NONSUSTAINED VENTRICULAR-TACHYCARDIA

Objectives. This study investigated the role of programmed ventricular stimulation (PVS) for arrhythmia risk prediction in patients with idi opathic dilated cardiomyopathy (IDC) and spontaneous nonsustained vent ricular 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 ve ntricular (LV) ejection fraction less than or equal to 35%, and sponta neous nonsustained VT underwent PVS. All patients were prospectively f ollowed for 24 +/- 13 months. Results. Sustained ventricular arrhythmi as were induced in 13 patients (38%). Sustained monomorphic VT was ind uced in three patients (9%), and polymorphic VT or ventricular fibrill ation (VF) in another 10 patients (29%). No sustained ventricular arrh ythmia could be induced in 21 study patients (62%). Prophylactic impla ntation of third-generation defibrillators (ICDs) with electrogram sto rage capability was performed in all 13 patients with inducible sustai ned VT or VF, and in nine of 21 patients (43%) without inducible susta ined VT or VF. There were no significant differences between the addit ional 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 pat ients (26%) including sudden cardiac deaths in two patients and ICD sh ocks for rapid VT or VF in seven patients. Arrhythmic events during fo llow-up occurred in four of 13 patients with inducible ventricular arr hythmias compared with five of 21 patients without inducible ventricul ar arrhythmias at PVS (31% vs. 24%, p = NS). Conclusion. PVS does not appear to be helpful for arrhythmia risk stratification in patients wi th IDC, a left ventricular ejection fraction less than or equal to 35% , and spontaneous nonsustained VT. Due to the limited number of patien ts, however, the power of this study is too small to exclude moderatel y large differences in outcome between patients with IDC with and with out inducible VT or VF. (J Am Coll Cardiol 1998;32:739-45) (C)1998 by the American College of Cardiology.