RESULTS OF ROUTINE PROGRAMMED VENTRICULAR STIMULATION AFTER MYOCARDIAL-INFARCTION - WHICH PROTOCOL SHOULD BE USED

The authors report the prognostic value of ventricular arrhythmias ind uced by routine programmed ventricular stimulation after the acute pha se of myocardial infarction. The protocol consisted of two extrastimul i in the first 185 patients and 3 extrastimuli in 308 patients. The us e of 3 extrastimuli increased the incidence of inducible sustained mon omorphic ventricular tachycardia (VT) < 270/mn, from 17 to 22 % and, m ore importantly, that of ventricular fibrillation from 4 to 17 %. Indu ction of ventricular flutter (monomorphic VT > 270/mn) was not increas ed. A long follow-up period (average 4 +/- 2 years) showed that the ri sk of VT was increased during the first months after infarction (n = 1 4), and that, 4 years later, other patients develop VT (n = 6). The ri sk of serious arrhythmias (VT and sudden death) was significantly high er in patients with inducible VT < 270/mn (20 %) than in patients with out inducible VT, but it was also higher in patients with inducible ve ntricular flutter (12,5 %). The use of a third extrastimulus has a low positive predictive value for arrhythmic events (10 %). This study co nfirms that the induction of sustained monomorphic VT after myocardial infarction is associated with an increased risk of arrhythmic events but the positive predictive value is relatively low (17 %). In view of the risk of inducing non-specific ventricular fibrillation, the autho rs recommended using a stimulation protocol with only 2 ventricular ex trastimuli.