Assessment of right ventricular global and regional longitudinal peak systolic strain, strain rate and velocity in healthy fetuses and impact of gestational age using a novel speckle/feature-tracking based algorithm.

OBJECTIVE To evaluate the correlation between feature tracking-derived measurements of the right ventricular myocardium and gestational age in healthy fetuses. METHODS Global and segmental longitudinal peak systolic strain, strain rate and velocity values of the right ventricular myocardium were assessed by a novel feature-tracking technique in 150 healthy fetuses at between 13 and 39 weeks' gestation. Reference ranges were constructed with respect to gestational age, and inter- and intraobserver variability was analyzed. RESULTS Strain, strain rate and velocity exhibited a segmental base to apex gradient (P < 0.001). Global longitudinal peak systolic velocities increased significantly across the gestational age range considered (P < 0.001), whereas global longitudinal peak systolic strain and strain rate (taken as absolute values) decreased significantly (P < 0.001 and P < 0.001). Inter- and intraobserver variability of global right ventricular peak systolic strain, strain rate and velocity was acceptable. The SDs of measurement error between the two observers were 5.9%, 0.7/s and 0.5 cm/s, respectively. CONCLUSIONS Global myocardial peak systolic velocities of the right ventricle increase with gestational age whereas global myocardial peak absolute systolic strain and strain rate significantly decrease throughout gestation. This novel angle-independent technique offers a new non-invasive approach for quantifying and monitoring fetal myocardial function throughout gestation.