The Control of Ventricular Function in Man

Since William Harvey's discovery of the prime function of the heart as a pump, clinicians and physiologists have marvelled at the extraordinary ability of this organ to adjust its performance almost instantaneously to meet the rapidly changing requirements of the peripheral tissues. Pro- bably no other aspect of cardiovascular research has received as much effort and attention as the attempts to gain an understanding of the systems that control the heart's ability to propel blood through the circulatory system. During the past century, this problem has been investigated at many levels; from isolated extracts of contractile proteins, to isolated atrial and papillary muscle preparations, to isolated hearts and heart-lung preparations, and anesthetized open-chest dogs, as well as closed-chest, unanxsthetized dogs.