Ventricular Dyssynchrony Markers in Healthy Black African Subjects: A Tissue Doppler Imaging Study

Tissue Doppler is a promising method that allows the measurement of time of systolic and diastolic tissue velocities. Ventricular dyssynchrony was assessed in patients with heart failure. In sub-Saharan Africa, very few studies have focused on ventricular dyssynchrony in healthy subjects. The purpose of this study was to measure time-to-peak of systolic and diastolic velocities of different segments of left ventricle and apply ventricular dyssynchrony markers to healthy black African subjects. Fifty healthy black African were enrolled consecutively over a period of 3 months. Time-to-peak systolic velocities (TS) and Time-to-peak early diastolic velocities (TE) were measured at the four basal segments of left ventricle. Five dyssynchrony markers were assessed: difference between maximal time-to-peak systolic velocity and minimal time-to-peak systolic velocity, time between septal time-to-peak systolic velocity and lateral time-to peak systolic velocity, standard deviation of time-to-peak systolic velocity of the four basal segments, difference between maximal time-to-peak early diastolic velocity and minimal time-to-peak early diastolic velocity, and standard deviation of time-to-peak early diastolic velocity of the four basal segments. The frequency of some dyssynchrony markers was similar to that of other studies. The difference between maximal time-to-peak systolic velocity and minimal time-to-peak systolic velocity was correlated with age and was higher among women. The prevalence of diastolic dyssynchrony was higher in black African subjects. Large-scale studies on the healthy black African population could assess the relationship between diastolic dyssynchrony and changes in myocardial performance related to racial differences.