Effect of age and gender on ventricular-arterial coupling estimated using a non-invasive technique

Background: Left ventricular-arterial coupling is assessed as the ratio of left ventricular end-systolic elastance (Ees) to arterial elastance (Ea). Previous studies have introduced non-invasive estimations of Ees/Ea. It requires only four variables, namely pre-ejection period, ejection time, end-systolic pressure and diastolic pressure. The aims of the present study were to clarify the reference values of Ees/Ea estimated using the noninvasive technique, and to investigate the effects of age and gender on Ees/Ea in healthy subjects. Methods: : This retrospective study utilized data from healthy, 30-79 year old subjects. We recorded electrocardiogram, phonocardiogram, and brachial arterial pulse waves simultaneously using the vascular screening system, and used the observed variables to calculate Ees/Ea. We separated subjects into five groups according to their age and compared Ees/Ea among the different age groups. Results: : The study included 2114 males and 2292 females. Ees/Ea ranged from 1.87 to 2.04 in males, and 1.97 to 2.32 in females. We observed no age-related differences in Ees/Ea in males (p=0.10), and significant differences in females (p<0.001). Ees/Ea in males was not different compared to those in females in 60-69 year old group. Whereas Ees/Ea was higher in females compared to those in males in the other age groups. Conclusions: : We clarified the reference values of Ees/Ea in healthy subjects. The effect of age on Ees/Ea is different in males and females, although Ees/Ea is maintained within a relatively narrow range in all subjects.