ROLE OF THE UNDERLYING ETIOLOGY IN PATIEN TS WITH AN IMPLANTABLE CARDIOVERTER DIFIBRILLATOR

It is unclear whether the outcome of patients with implanted cardiover ter defibrillator (ICD) is influenced by the underlying etiology or no t. Therefore, we studied the follow-up of 271 patients who underwent I CD implantation for life-threatening ventricular tachyarrhythmias. Cor onary artery disease was present in 203 patients (75%) (G1), dilated c ardiomyopathy in 36 patients (18%) (G2), while 32 patients (12%) (G3) had an ''arrhythmogenic'' ventricle (dysplasia, valvular disease, idio pathic arrhythmias). Mean left ventricular ejection fraction was 30 +/ - 11% in G1, 33 +/- 13% in G2 and 48 +/- 13% in G3. Perioperatively, 1 2/271 patients (4%) died. During the mean follow-up of 21 +/- 17 (< 1 to 99) months, 52/259 patients (20%) died: 31% (11/36 patients) in G2, 19% (36/193 patients) in G1 and 17% (5/39 patients) in G3. There was a low incidence of sudden death (SD) (4%, 2% per year) without signifi cant differences between G1 (3%), G2 (8%) and G3 (3%). In addition, no significant differences were observed in cardiac mortality (CD) betwe en G1 (10%), G2 (14%) and G3 (3%) (p = n.s.). ICD discharges occurred in 188 patients (69%); ICD discharges occurred in G1 in 138 patients ( 68%), in G2 in 27 patients (75%) and in G3 in 23 patients (72%). The m ean incidence of ICD discharges per patient was 16 +/- 10 shocks in G1 , 24 +/- 8 shocks in G2 and 18 +/- 8 shocks in G3. After ICD implant, complications occurred in 67 patients (23%). Our data show that the IC D is highly effective in preventing sudden death independent on the un derlying etiology. Patients in G2 are at higher risk to die from cardi ac mortality than those in G1 or G3.