The term ‘Arrhythmia’ simply means ‘abnormal heart rhythm’, and encompasses a large number of medical conditions. Some of these are benign and need no treatment at all. Others are common, chronic conditions requiring specialist management and follow up, including medicines or even medical devices or procedures for their effective treatment, and still others can be medical emergencies that can result in cardiac arrest and death. See the sections on palpitations and ventricular ectopics, atrial fibrillation, supraventricular tachycardia, slow heartbeat and pacemakers, and sudden cardiac death and defibrillators, for some common examples of arrhythmias and their treatment.