Cardiovascular Adaptation in Normal Pregnancy With 2D and 3D Echocardiography, Speckle Tracking, and Radial Artery Tonometry

Abstract

Background: Comprehensive cardiovascular assessment in normal pregnancy using advanced techniques has limited data.

Objectives: The aim of the study was to evaluate cardiovascular changes in normal pregnancy using two-dimensional/three-dimensional (3D) echo and applanation tonometry in healthy pregnant women.

Methods: Two-dimensional/Doppler, speckle tracking strain, 3D echocardiography, and vascular compliance by applanation tonometry were performed during the first, second, and third trimesters and postpartum.

Results: There were 45 healthy women (96% Hispanic) included. The heart rate increased in all trimesters vs postpartum (70.538 ± 9.208 beats/min, 74.878 ± 8.094 beats/min, 74.107 ± 9.231 beats/min vs 61.613 ± 9.790 beats/min, P < 0.001). A 3D left ventricular (LV) end systolic volume (34.583 ± 6.946 mL, 39.405 ± 7.345 mL, 45.994 ± 15.180 mL, 36.077 ± 7.116 mL), LV end diastolic volume (83.672 ± 14.022 mL, 91.512 ± 14.602 mL, 97.581 ± 19.864 mL, 85.163 ± 13.960 mL), right ventricular (RV) end systolic volume (30.690 ± 6.194 mL, 35.390 ± 7.345 mL, 40.929 ± 15.178 mL, 30.740 ± 6.911 mL), RV end diastolic volume (77.074 ± 14.875 mL, 86.871 ± 16.783 mL, 92.926 ± 18.083 mL, 78.267 ± 15.07 mL), and cardiac output increased (P < 0.01 for all) in the 2nd and 3rd trimester. LV longitudinal strain rate (SR) (-1.242 ± 0.350, -1.194 ± 0.181, -1.231 ± 0.263 vs -1.068 ± 0.218, P < 0.05) increased in all trimesters, RV longitudinal SR (-1.612 ± 0.314, -1.540 ± 0.284, -1.281 ± 0.748 vs -1.361 ± 0.306) in the 1st and 2nd trimester, P < 0.01), left atrial SR (1.735 ± 0.461, 1.687 ± 0.540, 1.588 ± 0.0.526 vs 1.414 ± 0.325), and right atrial SR (2.389 ± 0.582, 2.264 ± 0.741, 2.241 ± 0.793 vs 1.861 ± 0.600) in all trimesters, (P < 0.05). Left atrial volume increased in 2nd and 3rd trimesters, left atrial contraction velocity in 3rd trimester (P < 0.05), and pulmonary vein systolic filling velocity throughout pregnancy (P < 0.001). E/e' ratio did not change and LV ejection duration increased. Systolic augmentation of central aortic pressure decreased throughout.

Conclusions: Increased contractility of all four cardiac chambers, LV ejection-duration, and reduced LV afterload provide efficient cardiovascular adaptation despite increased chamber volumes and heart rate during normal pregnancy.

Keywords: arterial compliance; pregnancy; strain imaging; three-dimensional echocardiography.

Graphical abstract

Figure 1

Relationship Between LV Longitudinal Deformation With LV 3D Variables Correlation between LV longitudinal strain and strain rate with 3D LV end systolic and end diastolic volumes. EDV = end diastolic volume; ESV = end systolic volume; LV = left ventricle; SR = strain rate; 3D = three-dimensional.

Central Illustration

Physiologic Cardiovascular Changes in Normal Pregnancy Physiologic changes during normal pregnancy compared to postpartum were studied using echocardiography and radial artery tonometry. Two-dimensional and 3D echocardiographic imaging during each trimester and in postpartum state in 45 women with normal pregnancy showed cardiac remodeling with four-chamber enlargement, increased 3D LV and RV cardiac volumes, and improved LV, RV, LA, and RA longitudinal strain rate throughout pregnancy. LV radial strain rate also trended higher. There was a reduction in LV, RV, LA and RA longitudinal strain in the third trimester. Radial artery tonometry demonstrated a reduction in aortic augmentation index with increased vascular compliance and reduced peripheral vascular resistance. These changes, along with increased heart rate and stroke volume throughout, allowed increased cardiac output during pregnancy. This cardiovascular adaptation reversed during the postpartum period. EDV = end diastolic volume; EF = ejection fraction; ESV = end systolic volume; IVS = inter ventricular septum; LA = left atrium; LV = left ventricle; PV = pulmonary vein; RA = right atrium; RV = right ventricle; Vcfc = velocity of circumferential fibre contraction; 3D = 3-dimensional.