The subject of cardiac arrhythmias is of practical relevance. Various arrhythmias are found in different clinical situations, such as premature complexes in healthy individuals, supraventricular tachyarrhythmias in patients with Wolff-Parkinson-White snydrome, atrioventricular block, and ventricular fibrillation in cardiopathic conditions, especially in patients with ischemic disease. Topics of major interest are discussed in this volume: malignant ventricular arrhythmias, sudden death, automatic implantable cardioverter defibrillators, syncope, current indications for pacing therapy, radiofrequency catheter ablation, flutter, and atrial fibrillation.