Robert S. Sheldon, MD, PhD, FRCP(C) and Satish R. Raj, MD, FRCP(C), Cardiovascular Research Group, University of Calgary, Calgary, AB.

Implantable cardioverter-defibrillators are pacemaker-like devices that sense and treat ventricular tachycardia and ventricular fibrillation, and are generally used in an aging population. They have been proven in large randomized clinical trials to prevent death in patients who have already survived a life-threatening episode of ventricular arrhythmias. Recent studies have expanded their indications to the prevention of arrhythmic death in patients who have risk factors for this disorder. How widely they will be used, and at what cost, is unknown.
Key words: implanted defibrillator, arrhythmia, sudden death, anti-arrhythmic therapy, heart disease.