Normal pregnancy is associated with reversible changes in both systolic and diastolic mechanics, consistent with an increase in preload and decrease in afterload and systemic vascular resistance. The aim is to evaluate left ventricular (LV) twist and untwist mechanics in a population of pregnant women during differing stages of a healthy pregnancy.Design and Method:
We included 22 pregnant patients, 10 with multiple pregnancy (mean age 36.5 ± 3 years) and 20 healthy non pregnant women (mean age 33 ± 4years). Apical and basal short axis for 2D images were acquired (frame rate 65 ± 7 frames/s) and images will be obtained during the first, second, and third trimester, as well as up to two months postpartum.Results:
Peak LV twist and untwisting rate increased significantly in the 3rd trimester of normal pregnancy (13.48 ± 2.90°, 13.12 ± 3.30°, 16.83 ± 3.61°, P < 0.001; and −111.52 ± 23.54°/sec, −107.40 ± 26.58°/sec, −144.30 ± 45.14°/sec, P < 0.001; in the 1st, 2nd, and 3rd trimester, respectively). The pregnants with twins have the higher value for LVT and LVUR compare p < 0.01), but in the last trimester, the time to peak LVUR is prolonged. An independent association was found between the change in LV twist and LV end-systolic volume between the 1st and 3rd trimester. Peak untwisting rate at the 3rd trimester correlated significantly with peak twist and LV end-diastolic volume. Multiple regression analysis indicates that only systolic blood pressure (r = 0.394, P = 0.005) was an independent predictor for increased LV torsion.Conclusions:
LV twist and peak untwisting rate increase in the 3rd trimester and correlate with end-systolic and end-diastolic volume, respectively. Blood pressure and condition of multiple pregnancy are independently associated with increased torsion during pregnancy and may predict the new onset heart failure and perinatal cardiomyopathy.