Identifying right ventricular dysfunction with tissue Doppler imaging in pulmonary hypertension

Abstract

Background: Standard echocardiographic assessment of right ventricular (RV) function is problematic due to the complex RV geometry. We used tissue Doppler imaging to identify RV dysfunction in patients with pulmonary hypertension (PH).

Methods: Study population consisted of 44 patients (mean age 52+/-11; 30 females) with PH who underwent color tissue Doppler imaging of the RV and right heart catheterization within 2 days of each other. Peak systolic velocity and strain were measured at the RV free wall and correlated with invasive measures of PH and RV function. Myocardial velocity and strain was also measured in 20 healthy volunteers who served as normal controls (mean age 47+/-13; 13 females).

Results: PH patients had significantly reduced RV free wall velocity (6.4+/-2.1 cm/s vs. 8.2+/-2.1 cm/s; p<0.05) and RV strain (-18+/-7% vs. -28+/-6%; p<0.001) versus controls. RV peak strain demonstrated excellent correlation with transpulmonary gradient (r=0.72; p<0.001), pulmonary vascular resistance (r=0.73; p<0.001), and significant inverse correlation with cardiac index (r=-0.69; p<0.001). RV velocity had a significant, but weaker, correlation with cardiac index (r=0.33; p<0.05) and no association with transpulmonary gradient or pulmonary vascular resistance. In a multivariate model, RV strain but not RV velocity was independently associated with cardiac index.

Conclusions: RV myocardial strain demonstrated excellent correlation with hemodynamic variables indicative of RV performance in PH patients.