Strain-Based Echocardiographic Evaluation of Myocardial Adaptation in Normal Pregnancy: Insights into Physiological Remodeling

Objective: To investigate longitudinal changes in biventricular diastolic function and myocardial deformation during pregnancy and early postpartum using tissue Doppler imaging (TDI), speckle-tracking echocardiography (STE), and rotational mechanics.

Method: In this prospective observational study, 65 healthy, normotensive women with singleton pregnancies underwent echocardiography at four standardized time points: first trimester (10–12 weeks), second trimester (20–24 weeks), third trimester (36–38 weeks), and early postpartum (6–12 weeks post-delivery). Comprehensive evaluation included conventional Doppler, TDI-derived parameters, longitudinal strain rates, atrial strain, and left ventricular (LV) twist mechanics.

Results: Pregnancy was characterized by a progressive rise in cardiac output and ventricular volumes, with parallel declines in diastolic indices and atrial function. Although LV ejection fraction remained preserved, early diastolic strain rate decreased by 19% (1.59→1.29 s⁻¹, p<.001), lateral Em velocity declined by 20%, and global LV twist was reduced by 20% (17.8°→14.2°, p=.002). The mitral E/A ratio progressively decreased, while deceleration time remained prolonged postpartum (203→243 ms, p<.001). Atrial strain analysis revealed chamber-specific remodeling: left atrial conduit strain showed near recovery, whereas right atrial parameters showed only partial normalization. Collectively, these findings indicate that diastolic and torsional mechanics did not fully normalize within 6–12 weeks, suggesting heterogeneous recovery trajectories even among healthy pregnancies.

Conclusion: In healthy women, pregnancy-induced myocardial adaptation appears to involve progressive diastolic and deformation changes that may persist into the early postpartum phase. The observation of residual subclinical alterations—despite otherwise physiological remodeling—suggests that longitudinal surveillance could be valuable, even in low-risk populations. Advanced echocardiographic modalities may improve early detection and contribute to refined risk stratification in pregnancy-related cardiac adaptation.

Keywords: Diastolic function, left ventricular twist, myocardial adaptation, postpartum recovery, pregnancy, speckle-tracking echocardiography, strain rate