Implantable cardioverter-defibrillator (ICD) indications in 1996: have they changed?

The recent progress in the technology of the implantable cardioverter-defibrillator (ICD) and the excellent clinical results achieved with ICD treatment in the prevention of sudden death have facilitated the wide-spread acceptance and diffusion of this therapeutic modality. However, ICD implantation is a costly therapy and its use is still associated with some important unresolved issues. In particular, owing to the absence of randomized controlled clinical trials, it is not yet known whether ICD really reduces overall mortality. Thus, at the present time, it appears logical to exercise restraint in expanding the use of ICDs as first-choice therapy in patients with life-threatening ventricular arrhythmias. ICD treatment should be restricted to those well-defined categories of high-risk patients who are most likely to benefit from device implantation in terms of life prolongation. Basically, this means patients with hemodynamically poorly tolerated ventricular tachycardia or ventricular fibrillation that are not inducible at electrophysiologic study and those who do not respond to, or do not tolerate, drug therapy with amiodarone, sotalol, or beta blockers. Patients with idiopathic ventricular fibrillation also seem to be suitable candidates for ICD implantation. Other indications for ICD therapy are, as yet, more controversial and should be carefully evaluated on a case-by-case basis.