Apex-cardiographic approaches applicable to incipient myocardial failure in preclinical periods.

A survey is made of present-day methods proving myocardial failure, and a new indirect method is set forth based on apex-cardiography. After consideration of the physiological variations of the 'a' wave and OF interval, they are checked in an after-exercise state. It is established that the slow normalization of 'a' wave, which follows the restoration of the pulse rate initial values, is an indication of incipient myocardial failure. This regularity is observed for all diseases involving some failure of the myocardial functions.