Sudden cardiac death is still the largest cause of natural death in western countries, especially in patients with coronary artery disease and in those who have already experienced an episode of resuscitated out-of-hospital cardiac arrest or ventricular tachycardia. Prevention of arrhythmia recurrences (i.e. secondary prevention) in these patients remains a challenge for the cardiologist. To date no studies have demonstrated that drug therapy can be of some value in preventing arrhythmia recurrences or sudden death in these patients, and only cardioverter-defibrillator (ICD) implantation resulted effective in reducing mortality rate. It remains, however, to be defined which patients who survived an out-of-hospital cardiac arrest or who already experienced a sustained ventricular tachycardia could benefit the most from an ICD, but to date no invasive or non-invasive tests have proven to be effective for this stratification. Vaughan-Williams class II and III drugs could be of some value in reducing tachycardia cycle length thus increasing antitachycardia pacing efficacy and reducing ICD shocks.