Abstract: A method and apparatus are provided for measuring selected patient heartbeat parameters such as heartrates and amplitude variations, for processing the measured parameters to place them in more usable form and for analyzing measured and processed heartbeat parameters to obtain certain useful information concerning the condition of the patient's cardiac function. Measurement preferably involves detection and storage of at least two of the P, R and T pulses for each heartbeat and the conversion of such information into time series for selective heartrates. Indicators .delta..sub.j are computed for selected ones of the time series for selected values of j and the computed .delta..sub.j 's are then compared against stored .delta..sub.j values to obtain a measure of the state of cardiac function. The time series are preferably notched, detrended and normalized prior to being analyzed.