[Prognostic value of ventricular tachycardia induced by stimulation in patients without documented tachycardia]

In order to determine the cause of syncopes or disorders of conduction, 584 programmed stimulations using 2 ventricular extrastimuli delivered during an imposed rhythm were performed, between 1981 and 1985, in patients without ventricular tachycardia (VT) proven by Holter recordings. Eighty-seven non-sustained VT (NSVT) (15%), 8 ventricular fibrillations (VF) (1%), 16 ventricular flutters (VF1) (3%) and 23 sustained VT (SVT) (4%) were induced. To appraise the significance of these responses the patients were followed up for a mean period of 2 +/- 1 years. Among the NSVT patients the first 47 were followed up until 1984 and the others, less numerous, until 1985. Patients who responded to stimulation with NSVT had (4.4%) or did not have an underlying cardiopathy; their mean left ventricular ejection fraction (LVEF) was 53.5 +/- 17% (n = 10); 17% died of heart disease, but the disease was related to VT in only one case; 36% of these patients had cardiac symptoms, but only one presented with episodes of NSVT. Patients who responded with VF had a normal (50%) or abnormal heart; their mean LVEF was 52 +/- 19%; one died of heart failure, the others were asymptomatic. All but one of the patients who responded with VF1 had an underlying cardiopathy and a mean LVEF of 38 +/- 19%; 3 died, 2 of heart failure and 1 of sudden death; 13 were asymptomatic. All patients who responded with SVT had an underlying cardiopathy and a mean LVEF of 37 +/- 13%; 7 (30%) died, including 2 sudden deaths; 2 had episodes of VT and 12 were asymptomatic. In summary, an underlying cardiopathy was present in one-half of the patients who responded with NSVT or VF and in all patients who responded with VF1 or SVT. The risk of VT was low (5%) in patients who responded with NSVT, VF or VF1 and was higher (17%) in those who responded with SVT.