Study of isovolumic relaxation in man.

Although isovolumic relaxation time is relatively short, occupying less than 10% of the total cardiac cycle, study of its duration and of pressure and wall movement changes occurring in it have shed considerable light on the normal synchronous pattern of left ventricular function and its loss in disease. These observations have indicated the importance of diastolic as well as systolic events in determining overall cardiac function, and have stressed the requirement for a more versatile intellectual framework for interpreting these observations than the conviction that all ventricular disease is simply the result of "depressed contractility".