INFLUENCE OF TIME (4 YEARS) ON THE RESULT S OF PROGRAMMED VENTRICULARSTIMULATION

The reproducibility of programmed ventricular stimulation has been pre viously demonstrated for periods of a few hours to several months. It has not been studied over longer intervals. The aim of this study was to assess the reproducibility of the method at long-term (> 2 years). Forty-six patients with underlying cardiac disease underwent two progr ammed ventricular stimulations in the absence of antiarrhythmic treatm ent at intervals of 2 to 6 years (mean 4 years). None of the patients had myocardial infarction or cardiac surgery during this period. The p rotocol was identical: up to 3 extrastimuli were delivered in the two right ventricular sites over 3 cycles. Twenty-eight patients had induc ible sustained monomorphic ventricular tachycardia during the first in vestigation (Group I): the investigation was negative in the remaining 18 patients (Group II). During the second investigation, 26 of the 28 patients in Group had inducible ventricular tachycardia, the rate of which decreased from 206 +/- SO bpm to 196 +/- 54 bpm. The induced ven tricular tachycardia was slower in 15 patients and faster in 5 patient s. The mode of induction was different in 12 cases. In Group II, 4 pat ients (22 %) had inducible sustained ventricular tachycardia at the se cond investigation. The authors conclude that the reproducibility of p rogrammed ventricular stimulation remains good in the long-term in sub jects whith inducible tachycardia, demonstrating the stability of the arrhythmogenic substrate; the frequency of this tachycardia is general ly slower. In subjects with an abnormal initial investigation who beca me symptomatic, it may be useful to repeat programmed ventricular stim ulation.