Cardiac Adaptation of the Maternal Heart During Pregnancy: A Color-Coded Tissue Doppler Imaging Study--Feasibility, Reproducibility and Course during Pregnancy.

PURPOSE: Tissue Doppler imaging (TDI) allows the noninvasive quantification of global and regional myocardial function. Since there are changing loading conditions during pregnancy, this study aimed to determine maternal myocardial adaptation in normal pregnancy with TDI and tracking of the heart cycle. PATIENTS AND METHODS: 106 pregnant women, mean age of 33.4 years at baseline, prospectively underwent a total of 161 color-coded tissue Doppler echocardiography samples throughout pregnancy. In further offline analysis of the global and regional myocardial function of the basal segments, maximum tissue velocities at systole (Sm), in the early filling phase of diastole (Em) and during atrial contraction (Am) were assessed.
RESULTS: From those stored samples, S-wave, E-wave and A-wave velocities could be obtained with a feasibility of 94.8 % and with good inter- and intra-observer variability. S-wave velocity first showed an increase during early pregnancy followed by a decline to baseline characteristics at the 3 rd trimester. The E-wave velocity declined throughout pregnancy. The A-wave velocity increased continuously. These alterations result in a continuous decline of Em/Am ratio as pregnancy advances.
CONCLUSION: Alterations in tissue velocities during pregnancy reflect maturational changes that mimic "diastolic dysfunction". Based on an understanding of those normal physiological changes, TDI may therefore assist in the monitoring and/or detecting of subclinical myocardial dysfunction during pregnancy. © Georg Thieme Verlag KG Stuttgart · New York.