Influence of chest conformation on ventricular-arterial coupling during normal pregnancy

There is still controversy regarding the changes of ventricular-arterial coupling (VAC) during normal pregnancy. The possible influence of chest shape on VAC during normal pregnancy has never been investigated.

Between October 2019 and June 2020, 59 healthy pregnant women (33.7 ± 4.4 years/old) were consecutively included. They underwent obstetric visit, modified Haller index (MHI) assessment, and complete echocardiographic evaluation with blood pressure measurement to assess arterial elastance (Ea), end-systolic elastance (Ees), and Ea/Ees as an index of VAC, at 12-14 weeks and 36-38 weeks gestation, then 6-9 weeks after delivery.

VAC progressively increased from the first to the third trimester of pregnancy, then decreased in the postpartum (P < 0.0001) in the whole study population. Women with concave-shaped chest wall (MHI >2.5, n = 31) but not women with normal chest shape (MHI ≤2.5, n = 28) showed a progressive increase in VAC during normal pregnancy. Women with MHI >2.5 showed a significantly less pronounced increase in stroke volume index (SVi) from the first to the third trimester of pregnancy. There was a strong linear correlation between third trimester MHI and VAC (r = 0.93).

Anatomical and/or extrinsic mechanical factors rather than impaired arterial elastance or reduced left ventricular contractility may contribute to changes in VAC during normal pregnancy in women with concave-shaped chest wall.