Electrical energy requirements for ventricular defibrillation.

Deaths from coronary attacks constitute one of the major problems in medicine in the western world. The majority of such deaths are sudden and occur outside hospital (Bainton and Peterson, 1963; Gordon and Kannel, 1971). More than 90 per cent of sudden coronary deaths result from ventricular fibrillation (Adgey et al., 1969). The prevention of ventricular fibrillation is associated with many problems. No ideal long-term oral antiarrhythmic agent is available for the patient with known coronary artery disease. Furthermore, ventricular fibrillation may be the first manifestation of ischaemic heart disease. However, in 1966, it was shown for the first time that the correction of ventricular fibrillation outside hospital is possible (Pantridge and This led to an explosive proliferation of mobile coronary care units, particularly in the USA. Paramedical personnel operating these units concentrate on resuscitation of patients with cardiac arrest. It has become clear that involvement of the public in the technique of cardiopulmonary resuscitation is a necessary part of any pre-hospital coronary care scheme (Thompson et al., 1977). Unfortunately, the limitations of cardio- pulmonary resuscitation have not been sufficiently recognised. External cardiac massage and ventilation will maintain the viability of the cerebrum for 20