Background: Strain and strain rate has been shown to identify subtle contraction abnormalities of left ventricle.
Objectives: We hypothesized that S and SR derived from velocity vector imaging (VVI) will allow early identification of global and regional RV systolic function in patients with pulmonary hypertension (PHT) compared to conventional echo parameters.
Methods: 96 patients, 35 normal RV Systolic Pressure (RVSP < 30 mmHg) and 61 with PHT, {24 mild-moderate (RVSP > 60 mmHg) and 37 severe (RVSP < 60 mmHg)} underwent echo-Doppler assessment of RV. Apical 4 chamber images at end expiration were used for RV lateral wall (LW) and ventricular septal (VS) segment analysis for systolic tangential velocity (Ta V), S and SR. In addition RV end systolic and diastolic area, RV fractional area change (RV FAC), RV performance index (RIMP) and tricuspid annulus systolic excursion were measured.
Results: Peak S, systolic SR and Ta V at the basal, mid and apical segments of the RV LW and VS were depressed in patients with PHT compared with controls, Table 1
, P 0.001. Similarly, significant decrease in RIMP was seen in patients with PHT compared to controls, p <0.001. Significant correlation (p<0.001, r >0.6) was noted between the 2D FAC and S, SR. The time to peak systolic S indexed to end diastolic area (EDA) is significantly prolonged, p<0.01 in all segments in patients with PHT indicating dyssynchrony.
Conclusion: S and SR allows assesment of Regional RV systolic function otherwise difficult to assess from conventional echo-Doppler technique. PHTN is associated with not only regional RV systolic dysfunction but also with dyssynchrony. Thus, this new tool can offer new insights in the functioning of right ventricular global and regional function.
mean±SD of strain