Echocardiographic Estimation of Ventricular and Systolic Elastance in Fetuses during Mid-Gestation compared to Neonates

Echocardiographic measurement of ventricular elastance is essential for evaluating cardiac function. With the technological advancements in echocardiography devices, assessing fetal heart function has become more accurate. Ventricular elastance reflects ventricular function, while arterial elastance measures ventricular afterload. Ventricular-arterial coupling demonstrates the interaction between the ventricle and artery. This study aimed to estimate ventricular end-systolic elastance, arterial elastance, and ventricular-arterial coupling using a non-invasive echocardiographic method.

This descriptive-analytical study was conducted on 67 fetuses with a gestational age of 19-24 weeks (38 female fetuses and 29 male fetuses) and 43 infants aged 10-60 days (25 female and 18 male) referred to the cardiac echocardiography clinic of the Children's Medical Center over a period of 14 months. Mothers and infants were healthy, and there was no structural heart disease in the fetuses and infants. Those with abnormal rhythm, a vague view, and an unfavorable quality of Doppler signal were excluded. Ventricular end-systolic elastance (Ea), arterial elastance (Ees), and ventricular-arterial coupling (Ea/Ees) were compared in fetuses with the calculated values in newborns. An estimation of the normal value for ventricular and arterial elastances and ventricular-arterial coupling in healthy fetuses and newborns were obtained.

The mean arterial elastance of fetuses and newborns was determined as 84.4±20.04 mmHg/ml and 12.6±2.88 mmHg/ml, respectively (P<0.05). The mean ventricular elastance of fetuses and newborns was 88.5±20.49 mmHg/ml and 15.07±2.89 mmHg/ml, respectively (P<0.05). Fetal and newborn ventricular-arterial coupling were calculated as 0.96±0.14 mmHg/ml and 0.84±0.13 mmHg/ml, respectively (P<0.05).

The amounts of arterial and ventricular elastance and ventricular-arterial coupling in fetuses were significantly higher than infants and decreased with increasing age.