Evaluation of the asynchronization and function of the left ventricle in patients with chronic pulmonary hypertension by velocity vector imaging

Background Pulmonary hypertension (PH) is a set of pathophysiological syndromes characterized by increased pulmonary artery pressure and pulmonary vascular resistance, resulting in increased right ventricular afterload. The left and right ventricles interact through hemodynamics. What impact will PH have on synchronization and function of the left ventricle (LV)? The aim of this study was to evaluate the synchronization of the left ventricular wall motion and left ventricular function in patients with varying degrees of PH using velocity vector imaging (VVI) technology. Methods Sixty patients with chronic PH served as the experimental group, and 20 healthy volunteers served as the control group. According to the different degrees of pulmonary artery systolic pressure, the experimental group was divided into three groups: mild, moderate, and severe PH groups. The time to peak systolic longitudinal velocity (Tvl), the peak systolic longitudinal velocity (Vsl), the peak diastolic longitudinal velocity (Vel), the peak systolic longitudinal strain (SI), and strain rate (SRI) in 18 segments were measured in each group. Results Tvl in the control group and each group with PH was reduced from basal to apical segment, and in control group Tvl in various segments of the same wall and in different walls showed no significant difference (P>0.05). With increase in pulmonary artery pressure, Tvl values measured showed an increasing trend in groups with PH. In groups with PH, Vsl and Vel of each wall were reduced sequentially from basal to apical segments, showing gradient change; Vsl and Vel values measured showed a decreasing trend with increase in pulmonary artery pressure, in which the differences of Vel values measured in the control group and the mild PH group were statistically significant (P<0.01), and the differences between other groups were statistically significant (P<0.01). In groups with PH, SI and SRI in basal segment and the middle segment of each wall were decreased; the difference between groups was statistically significant (P<0.01). Conclusions Asynchronization of the LV and decreased left ventricular function were present in patients with chronic PH; VVI technology can accurately evaluate left ventricular function in patients with PH, and indicators such as Tvl, Vsl, and Vel are valuable.