Evolution of strain and strain rate values throughout gestation in healthy fetuses.

Myocardial deformation by speckle tracking echocardiography is a novel method for evaluating cardiac function. To test the hypothesis that right ventricular and left ventricular function have age-specific patterns of development, we tracked the evolution of ventricular strain mechanics by speckle tracking echocardiography in the fetus. We conducted a retrospective cross sectional echocardiography study in 154 healthy fetuses, and characterized cardiac function by measuring right and left ventricles global longitudinal strain and strain rate. Comparison of the data of both ventricles according to gestational age was carried out. The magnitudes of right and left ventricle global longitudinal strain show wide range values and decreased throughout gestation. Strain values are higher in left ventricle compared to the right one throughout pregnancy. Strain rate values were similar over gestation in each ventricle, but the magnitudes declined overtime in the right and left ventricle. The maturational patterns of left and right strain are gestational specific. With accepted physiological maturation patterns in healthy subjects, these myocardial deformation parameters can provide a valid basis that allows comparison between health and disease.