Regional atrial myocardial velocity in normal fetuses: evaluation by quantitative tissue velocity imaging

Quantitative tissue velocity imaging (QTVI) is a new noninvasive method that derives measurements of velocities directly from the myocardium. Data on atrial myocardial tissue velocities in normal fetuses have not been established. The objective of this study was to evaluate atrial myocardial velocity and the myocardial velocity gradient of normal fetuses by using QTVI.

We measured motion velocities of the left and right atrial wall along the long axis in 50 normal fetuses aged 21-32 weeks gestation (mean, 25.3 ± 2.8 weeks). In all fetuses, peak myocardial velocity during early diastole (EW), atrial contraction (AW), and ventricular systole (SW) waves was recorded in the basal and mid-atrial segments. Correlation analysis was conducted between segmental velocities of the left atrium (LA) and right atrium (RA) and gestational age.

The mean values for EW, AW, and SW of the long axis in the same right basal segment of the RA were greater than those of the LA (P < 0.01). There was a degressive gradient with velocity from the basal to superior in the atrial wall. There was a linear relationship with gestation for all basal myocardial velocities of the left and right atrial free wall (P < 0.05). However, the myocardial velocity variables of the midatrial wall showed no age-dependence.

We demonstrated that QTVI is reproducible and provides readily obtained parameters that provide unique data regarding segmental atrial myocardial velocity in normal fetuses.