Maintenance of the circulation in cardiac asystole by the mechanical pulsator.

Photograph of the case. (A) Rubber tube for supplying a pneumatic pulse to the bellows. (B) Rubber button on the bellows to provide fixed angular location. (C) Oblong orifice near the base through which the great vessels pass. CUTE MYOCARDIAL INSUFFICIENCY either as the result of vascular occlu-sion or surgical operation, can produce inadequate body perfusion. This may be of a self-limited duration, but the period remains unknown. The present status of poor cardiac output appears to be progressive and potentiating, with deterioration of many organ systems leading to the pa-tient's demise. If the circulation can be supported for a short period of time (six to eight hours) myocardial and extravas-cular organ circulation may permit their survival. This period of myocardial insuf-*Lnstrumentation and apparatus developed by E. F. Andrews Laboratories and project supported ficiency, supported by a mechanical aid, may be all that is needed for a patient's recovery. Various methods are now in study: 1) assisted circulatory support, 2) left heart bypass, or 3) a myocardial replacement mechanical heart. These methods at present have some disadvantages, viz., a large operative procedure or total body heparinization for prolonged periods. The problem of maintaining adequate systemic circulation during cardiac standstill by mechanical means has created interest among research workers. Bencini1 in 1956 employed mechanical pneumomas-sage of the heart in dogs. Vineberg1 in 1957 reported his experimental work on the canine heart. Difficulties arose because of resultant high venous and pulmonary artery pressure and impaired coronary circulation.