[Results of programmed ventricular stimulation in primary dilated cardiomyopathy]

Programmed ventricular stimulation (PVS) has been advocated as being capable of identifying patients with idiopathic non obstructive dilated cardiomyopathy (NOCM) and at high risk of sudden death. We have studied the results of that method in 56 patients aged from 29 to 69 years (mean 53 years) presenting with idiopathic NOCM. The patients were divided into two groups according to the presence or absence of ventricular tachycardia (VT). Group I (controls) comprised 23 patients without documented VT. Group II consisted of 33 patients with documented VT which was sustained in 5 cases. Finally, 7 patients from both groups experienced losses of consciousness. Ventricular stimulation was performed on 2 sites of the right ventricle, using 1 to 3 extrastimuli on 2 imposed cycles. It was repeated under isoprenaline on 25 occasions. PVS induced non sustained ventricular tachycardia (NSVT) in only 2 patients of group I; it reproduced the sustained ventricular tachycardia (SVT) observed in the 5 patients with spontaneous SVT. PVS was negative in 14 of the 28 patients with NSVT; it induced NSVT in 8/28 and SVT in 6/28 (including 4 with more than 280 beats/min). The isoprenaline test failed to induce SVT. 7 patients died suddenly: 3 presented with SVT and 4 had syncopes and NSVT; ventricular stimulation induced SVT in 3 of these 4 patients. It is concluded that induction of sustained VT is uncommon in NOCM, but a history of syncope should prompt a search for SVT. Patients with spontaneous symptomatic NSVT and inducible SVT must be considered at high risk of sudden death.