Noninvasive single-beat determination of left ventricular end-systolic elastance in humans

Abstract

The E(es) can be reliably estimated from simple noninvasive measurements. This approach should broaden the clinical applicability of this useful parameter for assessing systolic function, therapeutic response and ventricular-arterial interaction.

Effects of Cardiopulmonary Exercise Rehabilitation on Left Ventricular Mechanical Efficiency and Ventricular‐Arterial Coupling in Patients With Systolic Heart Failure

“…Briefly, single‐beat LV elastance (E es(sb) ) was calculated by:${\mathrm{normalE}}_{\mathrm{es}(\mathrm{sb})}=false[{\mathrm{P}}_{\mathrm{d}}-({\mathrm{normalE}}_{\mathrm{nd}(\mathrm{est})}\times \text{LVESP})false]/false[\text{SV}\times {\mathrm{E}}_{\mathrm{normalnd}false(\mathrm{normalest}false)}false]$where E nd(est) is the time and amplitude normalized estimated time varying elastance, P d is central aortic diastolic pressure, LVESP is the LV end‐systolic pressure, and SV is stroke volume. The E nd(est) was estimated form a regression model based on invasive PV data using a 7‐term polynomial function, LVEF, central aortic end‐systolic and diastolic pressures, and the ratio of pre‐ejection period to total systolic period, as described elsewhere 15. E a was estimated by dividing end‐systolic pressure to stroke volume.…”

“…A more powerful and largely load‐independent measure of contractile function is LV end‐systolic elastance (E es ), which can be defined as the stiffness of the left ventricle at the end of the systole. The arterial system can also be assessed in elastance terms; hence, ventricular‐arterial coupling (VAC) can be expressed by the comparison of ventricular and arterial elastances (E a ) 12, 13, 14, 15. Experimental models showed that LV EW is maximal when the VAC (E es /E a ) ratio is 1,12 whereas the mechanical efficiency is maximal when the ratio is 2 13, 14.…”

“…In the past, to obtain these parameters, invasive pressure and volume measurements were required to be measured under a wide range of loading conditions. Recently, with the introduction of noninvasive, single‐beat solutions for estimating E es ,15 it became possible to construct PV loop and assess VAC noninvasively. More important, it has been shown that VAC estimated by noninvasive methods is a strong predictor of prognosis in systolic heart failure 16.…”

Vascular ventricular coupling in patients with malignant phase hypertension: the West Birmingham malignant hypertension project

“…Measurements of arterialvascular interaction were made in accordance with previously validated methodologies. 11,12 To calculate effective EaI we calculated effective Ea from stroke volume (by 3D echocardiography) and systolic BP and adjusted by body area. Ees was calculated using systolic and diastolic BP, stroke volume, preejection and total-systolic times.…”

“…This echocardiographic approach has been validated by direct comparisons with invasive analysis of pressure-volume curves. 11,12 The non-invasive nature of the method makes it suitable for clinical use and for monitoring of treatment effectiveness, leading to its growing popularity among researchers.…”