Of the patients who survive hospitalization after an acute myocardial infarction, ca. 10% die of sudden cardiac death in the following 2 years. The prognosis appears not improved by medication with antiarrhythmics (class I/III). A positive effect of beta-blockers (Metoprolol CR/Zok) on total mortality after myocardial infarction in patients with heart failure is well established. On the other hand, an implantable defibrillator (ICD) proved to be superior to medication when used for secondary prevention in patients after cardiac arrest. The question arises whether ICD therapy is also effective in primary prevention in high risk patients after acute myocardial infarction. This study determines if patients, who were defined as high risk patients in the early post infarction phase by means of noninvasive methods, benefit from primary prevention by means of an ICD. Special emphasis is put on an individual optimization of the infarction therapy, including beta-blockers.

Inclusion Criteria:

• acute myocardial infarction (5-31 days)

• fulfill requirement I and/or II :

  • I first ECG heart rate >= 90 bpm (within day 1-2 post MI) and LVEF <= 40 % (within day 5-31 post-MI)
  • II >= 1 episode of non-sustained ventricular tachycardia >= 150 bpm (on Holter, within 5-31 days post-MI)

Exclusion Criteria:

• Patients with ventricular arrhythmia, requiring clinical therapy, before the index infarction or more than 48 h later
• Patients with therapy refractory heart failure (NYHA IV)
• Myocardial infarction older than 31 days
• First-ECG not available or was recorded more than 48 h after the symptom onset.
• Patients with indication for CABG operation before inclusion
• Patients with cerebral organic psycho syndrome
• Secondary diseases which clearly limit life expectancy
• Patient with right sided artificial heart valve
• Patients with poor compliance
• Patients who are participating in another study
• Unstable clinical condition
• Pregnancy
• No consent from patient