A brief history of sudden cardiac death and its therapy.

At the end of the 19th century, there was both experimental and clinical evidence that coronary artery obstruction causes ventricular fibrillation and sudden death and that fibrillation could be terminated by electric shocks. The dominant figure at that time was McWilliam, who in 1923 complained that "little attention was given to the new view for many years." This remained so for many decades. It was not until the 1960s that the medical profession became aware of the magnitude of the problem of sudden death and began to install coronary care units where arrhythmias could be monitored and prompt defibrillation could be delivered. This approach was pioneered by Julian in 1961. Milestones that allowed this development were open-chest defibrillation by Beck, closed-chest defibrillation by Zoll, cardiac massage by Kouwenhoven et al., and development of the DC defibrillator by Lown. In 1980, Mirowski et al. implanted the first implantable cardioverter defibrillator (ICD) in a patient. Thereafter, the use of the ICD increased exponentially. Several randomized trials, largely in patients with coronary artery disease and left ventricular dysfunction or in patients with documented lethal arrhythmias, showed beyond doubt that the ICD is superior to antiarrhythmic drug therapy in preventing sudden death, although a number of trials showed no effect. Trials on antiarrhythmic drugs were disappointing. Sodium channel blockers and "pure" potassium channel blockers actually increase mortality, calcium channel blockers have no effect, and, although amiodarone reduces arrhythmic death, it had no effect on total mortality in the 2 largest trials. Only the beta-blockers have been proven to reduce the incidence of sudden death, but their effect appears not to be related to the suppression of arrhythmias but rather to the reduction in sinus rate. Drugs that prevent ischemic events, or lessen their impact, such as anticoagulants, statins, angiotensin-converting enzyme inhibitors, and aldosteron antagonists, all reduce the incidence of sudden death.