Programmed electrical stimulation and long-term follow-up in asymptomatic, nonsustained ventricular tachycardia

Thirty-three patients with ventricular tachycardia (VT) (3 or more beats, less than 30 seconds in duration, rate more than 100 per minute) on 24-hour Holter monitoring and no history of clinical arrhythmia (presyncope, syncope or sudden death) were studied using programmed electrical stimulation (PES). PES induced VT in 14 patients (42%), sustained VT in 7 (21%) and nonsustained VT in 7 (21%). Inducible VT was associated with underlying heart disease in 9 of 19 patients with coronary artery disease, 3 of 6 patients with idiopathic dilated cardiomyopathy and 2 of 4 patients with mitral valve prolapse. Patients without structural heart disease did not have inducible VT. Ejection fraction (EF) was not significantly different in patients with or without inducible VT. Twenty-three patients were discharged with drug therapy and 10 patients without therapy. At 23 ± 16 months (mean ± standard deviation) follow-up, 28 patients (85%) were alive, 4 (12%) had died from a cardiac cause (EF 49 ± 17% vs 28 ± 20%, p < 0.03). Another patient died from cerebrovascular accident. Twenty-six patients (79%) were free of clinical arrhythmia and 7 patients (21%) had arrhythmic events (EF 49 ± 18% vs 31 ± 17%, p < 0.04). Two of 8 patients with noninducible VT who were discharged without drug treatment had clinical arrhythmic events and neither of 2 patients with inducible VT discharged off drugs had such events. Thus, in asymptomatic, nonsustained VT, underlying heart disease makes inducible VT more likely, an incidence of progression to clinical arrhythmic events is apparent and EF appears predictive of subsequent cardiac death and clinical arrhythmic events but not ability to induce VT.