NONINVASIVE ESTIMATIONS OF VENTRICULAR EJECTION TIME AND STROKE VOLUME - COMPARISON OF IMPEDANCE CARDIOGRAPHY AND THE PORTAPRES-2

Stroke volume estimates and left ventricular ejection time (1) derived from calibrated finger pulse pressure recordings (Portapres 2, TNO-BM I, Amsterdam) based on the Model Flow method and (2) derived from impe dance cardiography were compared in 20 students subjects. The recordin gs were made for seven conditions: supine rest, standing, mental arith metic, ergometer exercise 50 W, motor performance test, reading aloud, and walking. Finding indicated that caution is required in assuming c oncurrent validity for both methods in tracking haemodynamic changes. Within-subject correlations were low or even negligible. Basic discrep ancies were evident regarding the estimation of left ventricular eject ion time but obviously more sources of measurement error exist which n ecessitate further research.