[ICD therapy for the primary prevention of sudden cardiac arrest. The patient after a myocardial infarction].

ICD therapy represents a major advance in the treatment of patients with severely impaired left ventricular function after myocardial infarction. While an ICD implantation also remains a valuable option late (>5 years) after myocardial infarction, patients early after this event are at a competitive risk of arrhythmogenic and nonarrhythmogenic cardiac death. Prevention of sudden cardiac death in patients early after myocardial infarction, therefore, just converts the mode of death in a significant number of patients from sudden to nonsudden cardiac death (conversion theory). In patients with a left ventricular ejection fraction (LVEF) of < or =30% after myocardial infarction, implantation of the ICD should, therefore, be postponed to at least 30-40 days after the event. It is, however, not clear how the risk of sudden cardiac death should be approached during this post infarction phase. Similarly, it is not clear if patients with a reduced LVEF post infarction and additional specific risks (nonsustained ventricular tachycardia, atrial fibrillation, bundle branch block, etc.) beyond this single criterion may also benefit from ICD implantation and which risk factors may be relevant. In any case, ICD therapy should avoid right ventricular pacing and shock discharges whenever possible.