Estimation of left ventricular end-diastolic volume by left ventricular arterial coupling and stroke volume: A prospective, observational study

Background: Left ventricular end-diastolic volume (Ved) is a major determinant of cardiac preload. However, its use in determination of fluid management is limited by lack of a simple means to measure it noninvasively. This study presents a new noninvasive method that was validated against simultaneously measured Ved by transthoracic echocardiography (TTE). The goal of this study was to develop and validate a method to estimate Ved in humans non-invasively from left ventricular arterial coupling (Ees/Ea) and stroke volume (SV). Methods Ees/Ea was approximated using four variables that can be measured noninvasively: end-systolic arterial pressure (Pes), diastolic arterial pressure (DBP), pre-ejection period (PEP), and ejection time (ET). A formula to derive Ved (Ved calc) using Ees/Ea was also devised. Ved measured using transthoracic echocardiography (Ved echo) was taken to be the actual value, and Ved calc and Ved echo were compared. The results are shown as mean values ± standard deviation. Results The 47 patients were 39 men and 8 women with a mean age of 24 ± 4 years, mean height of 169 ± 7 cm, and mean weight of 65 ± 12 kg. Ved echo was 91 ± 16 ml, and Ved calc was 102 ± 21 ml. There was a significant correlation between Ved echo and Ved calc (R 2  = 0.88, p < 0.01). A Bland–Altman plot between Ved echo and Ved calc showed that the bias was − 17.4 ml. Conclusions The results suggest that Ved can be measured non-invasively from Ees/Ea and SV.