Systolic Time Intervals Detection and Analysis of Polyphysiographic Signals

The newly developed computer program allows the continuous measurement of the following systolic time intervals (STI): PEP – preejection period, Q − S2 - time between trough of Q wave and aortic valve closure, Q − D - time between trough of Q wave and dicrotic notch, S2 − D - time between aortic valve closure and dicrotic notch, as well as QQ interval. The program was tested on the recordings obtained in 30 young, healthy subjects remaining in supine position who performed twice two-minute isometric handgrip (HG). First HG was followed by four-minute rest, second HG by two-minute occlusion of the working arm. Since there were distinct oscillation in the time course of Q − S2 intervals and the time course of Q − D intervals was relatively smooth, we suggested that S2 and D might reflect different events which is in contrary to common notation.