[Prevention of sudden cardiac death].

The problem of sudden cardiac death (SCD) is complex and many questions concerning the pathophysiologic mechanism are still unanswered. At present the only reliable way of recognizing high risk patients is by means of left ventricular dysfunction, measured as LV-EF<or=35%. The positive predictive accuracy for other non-invasive risk markers is too low. So far, antiarrhythmic drugs have failed to successfully prevent SCD. More than 25 years of clinical experience with the implantable defibrillator (ICD) with its continuous technical improvement has made the ICD the most effective weapon against SCD. Its effectiveness has been demonstrated in many prospective trials and the use of the ICD is fully enclosed within the current guidelines for the prevention of SCD. Guidelines do not, however, replace the physician's judgement and experience to correctly evaluate the patient's status. ICD therapy in the primary and secondary prevention of heart failure, which is often accompanied by a high risk of SCD is, however, not justified without guideline-adjusted therapy.