Cardiac arrhythmias are changes in the heart rhythm in terms of frequency, regularity, origin, and/or conduction of excitation. A distinction is made between bradyarrhythmias (e.g., sick sinus syndrome, AV blocks; usually <60/min) and tachyrrhythmias (e.g., atrial fibrillation, ventricular tachycardia; usually>100/min, ventricular fibrillation). Furthermore, arrhythmias are classified according to their anatomical site of origin into supraventricular and ventricular rhythm disturbances. Various antiarrhythmic medications, catheter ablation, pacemakers, and implntable cardioverter defibrillators (ICD) as well as, if necessary, anticoagulation to prevent peripheral embolisms and stroke are used for the treatment of rhythm disturbances.