The underlying mechanism of inter-site discrepancies in ejection time measurements from arterial waveforms and its validation in the Framingham Heart Study

Am J Physiol Heart Circ Physiol. 2021 May 21. doi: 10.1152/ajpheart.00096.2021. Online ahead of print.ABSTRACTRadial applanation tonometry is a well-established method for clinical hemodynamic assessment and is also becoming popular in wrist-worn fitness trackers. The time difference between the foot and the dicrotic notch of the arterial pressure waveform is a well-accepted approximation for the left ventricular ejection time (ET). However, several clinical studies have shown that ET measured from the radial pressure waveform deviates from that measured centrally. In this work, we consider the systolic wave and the dicrotic wave as two independent traveling waves and hypothesize that their wave speed difference leads to the inter-site differences of measured ET (ΔET). Accordingly, we derived a mathematical dicrotic wave decomposition model and identified the most influential factors on ΔET via global sensitivity analysis. In our clinical validation on a heterogeneous cohort (N = 5742) from the Framingham Heart Study (FHS), the local sensitivity analysis results resembled the sensitivity variations patterns of ΔET from model simulations. A regression analysis on FHS data, using morphological features of radial pressure waveforms to estimate the Carotid ET, produced a root mean square error of 3.76 ms and R2 of 0.91. The proposed dicrotic wave decomposition model can explain the inter-site ET measurement discrepancies observed in the clinical data of FHS and can facilitate ...
Source: American Journal of Physiology. Heart and Circulatory Physiology - Category: Physiology Authors: Source Type: research