[Long-term results of implantable automatic defibrillator in 43 patients. Analysis of predictive factors of the first electric shock].

In order to identify patients who will receive an electric shock after implantation of an automatic fibrillator, the relationship between the time to the first shock and clinical and paraclinical characteristics were studied in 43 patients treated at the Lyon Cardiological Hospital between July 1987 and September 1991. The age of the patients was 49.5 +/- 16 years (mean + SD). Eighty two percent of patients were men and the average left ventricular ejection fraction was 38.5 +/- 16.8%. Four patients died in the peri-operative period. The average follow-up of the survivors was 22 months. During this period, 21 patients (53.8%) received an appropriate electric shock. Three patients died. The causal role of a malignant ventricular arrhythmia is discussed in one case. A second patient, who never had automatic fibrillation, died of cardiac failure. Finally, the third patient died of non-cardiac pathology. The 22 month actuarial survival rate was 86%. The probability of receiving an appropriate electric shock was 60%. Analysis of clinical and paraclinical features identified left ventricular dysfunction (ejection fraction less than 38%) and cardiac symptoms (Stage III dyspnoea of the NYHA classification) as being associated with earlier electric shocks. This association was even more clear cut in the group of patients with previous myocardial infarction. Therefore, patients with implantable automatic defibrillators for malignant ventricular arrhythmias receive appropriate electric shocks in over 50% of cases. Patients with symptoms of cardiac failure and low ejection fraction are particularly exposed especially when they have previous myocardial infarction.