Alternative diastolic function models of ventricular longitudinal filling velocity are mathematically identical.

ALTERNATIVE DIASTOLIC FUNCTION MODELS OF VENTRICULAR LONGITUDINAL FILLING VELOCITY ARE MATHEMATICALLY IDENTICAL.
Am J Physiol Heart Circ Physiol. 2020 Mar 06;:
Authors: Bhagavan D, Padovano WM, Kovacs SJ
Abstract
Noninvasive imaging has established the spatiotemporal features of normal, in-vivo cardiac motion. Long-axis cardiac motion has become a focus of Diastolic Function (DF) characterization, especially the Tissue Doppler e'-wave, which occurs in early diastole when the LV is a mechanical suction pump (dP/dV<0). To characterize DF and elucidate mechanistic features, several models have been proposed and have been previously compared algebraically, numerically and in their ability to fit physiologic velocity data. We analyze two previously uncompared models of early, rapid-filling lengthening velocity (Doppler e'-wave): parametrized diastolic filling (PDF) Kovács (8) and force balance model (FBM) Remme (18). Our initial numerical experiments sampled FBM generated e'(t) contours as input to determine PDF model (8) predicted fit. The resulting exact numerical agreement [Standard Error of Regression (SER)= 9.06x10-16] was not anticipated. We further analyzed all published FBM generated e'(t) contours and observed identical agreement. We re-expressed FBM's algebraic expressions for velocity and observed for the first time that both models' expressions are identical: e'(t) = g e- at sinh(bt). We also provide exact algebraic relati...

Source: American Journal of Physiology. Heart and Circulatory Physiology - March 5, 2020 Category: Physiology Authors: Bhagavan D, Padovano WM, Kovacs SJ Tags: Am J Physiol Heart Circ Physiol Source Type: research