The measurement of systolic time intervals. A microprocessor based system for long-term registration of the impedance cardiogram and the systolic time intervals.

The systolic time intervals (STI) are reliable parameters for the characterization of left ventricular heart function. The non-invasive methods for the determination of STI are here introduced and compared. The disadvantage of all these methods is their manual evaluation of time intervals which makes a continuous monitoring of STI impossible. Therefore, a microprocessor based system was developed for the automatic registration of STI, stroke time volume (SV) and heart rate from the impedance cardiogram (ICG) and the electrocardiogram (ECG). In this article the preliminary results are discussed of the long-term monitoring of these parameters with the help of this device.