Pathophysiological alterations of left ventricular myocardial systolic function during normal pregnancy assessed by...

By using conventional echocardiographic indices, cardiac pumping function remains unaltered during pregnancy. However, two-dimensional speckle tracking echocardiography (2D-STE) can detect subclinical changes of myocardial function even in patients with normal and stable left ventricular ejection fraction (LVEF).The aim of this study was to evaluate LV systolic performance during normal low risk pregnancy by using both conventional 2D and 3D echo indices and 2D-STE.

One hundred and twelve pregnant women without any history of heart disease were prospectively recruited. They underwent serial echocardiographic evaluation in each pregnancy trimester and 6 months after delivery (time indicated as 1,2,3 and 4). 2D LVEF, 3D LVEF, LV global longitudinal strain (LVGLS), LV global circumferential strain (LVGCS) and LV-twist were measured and compared to the control group (c).

2D-LVEF and 3D-LVEF were not significantly different among the three trimesters, postpartum and controls. LVGLS progressively decreased during pregnancy (1st :21.71 ± 2.13%, 2nd : 21.20 ± 2.30%, 3rd : 19.82 ± 2.10%, 4th : 21.81 ± 2.05%, c: 21.71 ± 2.2%, overall p < 0,001) which receded during puerperium. No significant difference was noted in LVGCS (1st : 18.08 ± 5.54%, 2nd : 18.57 ± 3.41%, 3rd :18.20 ± 3.33%, 4th : 17.95 ± 3.39%, c: 18.8 ± 2.2%, p > 0.3). LV-Twist was significantly higher in the 1st trimester compared to controls (p = 0.04) and remained constantly high during the rest of the pregnancy and puerperium (1st :13.80 ± 5.09°, 2nd :13.46 ± 5.35°, 3rd :13.58 ± 4.32°, 4th :13.37 ± 4.26°, c: 11.5 ± 4.3°).

In low risk individuals with normal pregnancy, a redistribution of force occurs especially in the 3rd trimester. Longitudinal strain decreases, while torsional movement of the heart increases and counterbalances the temporal change of longitudinal systolic function. These changes would probably reflect the pathophysiological alterations related to pregnancy.