Objective: To evaluate changes in left ventricular mass and diastolic function during normal pregnancy.
Methods: This was a cross-sectional study of 125 pregnant women at 9-42 weeks of gestation and 19 non-pregnant female controls. Two-dimensional and M-mode echocardiography of the maternal left ventricle and left atrium was performed.
Results: During pregnancy left ventricular mass increased by 52%. There was an increase in left ventricular end-diastolic and end-systolic diameters (12% and 20%, respectively), left ventricular posterior wall diameter during diastole and systole (22% and 13%, respectively) and left intraventricular septum during diastole and systole (15% and 19%, respectively). Mitral valve A-wave maximum velocity increased during pregnancy by 19%, while mitral valve E-wave maximum velocity and the ratio of E-wave/A-wave velocities increased early in pregnancy by about 14% and 6%, respectively, with a subsequent decline to 4% and 10%, respectively, below non-pregnant levels.
Conclusion: Left ventricular mass increases during pregnancy, while left ventricular diastolic function, as demonstrated by the changes in mitral valve flow velocities, increases in the first two trimesters but declines in the third trimester.