[Implantable cardioverter-defibrillators in patients resuscitated from sudden death and in patients with sustained refractory ventricular tachycardia].

OBJECTIVE: The aim of this study was to evaluate the results of our experience with implantable cardioverter-defibrillator therapy.

PATIENT SELECTION: We treated with implantable cardioverter-defibrillator (ICD) 18 patients, 15 male and 3 female, mean age 51 years, ranging from 12 to 76 years, with life threatening ventricular arrhythmias. Eleven patients were resuscitated from cardiac arrest and seven had refractory ventricular tachycardia. The underlying condition was coronary artery disease in 12 patients, dilated cardiomyopathy in two, congenital long QT syndrome in one, mitral regurgitation in one and idiopathic in two patients.

METHODS: All patients underwent cardiac catheterization and electrophysiological study before ICD implantation. In the first patient epicardial leads were used, but a transvenous approach was used in the remaining 17 patients. The device was implanted in an abdominal position in all patients. Defibrillation and pacing threshold tests were performed during the implantation procedure and whenever necessary. After implantation, patients were followed up in an outpatient basis, with evaluation of therapy efficacy and reprogramming of the device if required. The mean follow-up time was 16 months, ranging from 1 to 40 months.

RESULTS: The implantation was successful and without complications in all patients. Defibrillation threshold was considered within normal range, with an electrode impedance ranging from 40 to 65 Ohms. During the follow-up period no deaths occurred, 8 patients (44%) had episodes of VT or VF that were successfully treated, with shock in six patients, with antitachycardia pacing in one and with both modalities in another patient. Inappropriate shocks were observed in three patients (16%). The device was reprogrammed in five patients.

CONCLUSIONS: Our experience with implantable ICD in patients who survived cardiac arrest or with refractory VT has shown a low surgical risk with no mortality. The incidence of ICD discharges was high, with a satisfactory efficacy rate and the number of inappropriate shocks was acceptable. The careful patient selection made possible a good cost/benefit relation.