Strain Rate echocardiographic assessment of right ventricular performance in pulmonary arterial hypertension

Purpose: Pulmonary arterial hypertension (PAH) related to different aetiologies (chronic obstructive pulmonary disease -COPD-, congenital heart disease -CHD-; scleroderma -SCL-) is associated with high morbidity and mortality, with the most common cause of death being decompensated right heart failure. Our purpose was to compare tissue Doppler imaging (TDI) and strain rate imaging (SRI) parameters with conventional echocardiographic indexes evaluating right ventricular (RV) function, to assess their correlation with pulmonary artery pressure, and to investigate whether different PAH aetiologies could result in a different impact on RV performance. Methods: Forty-nine adult patients (pts) with PAH (SCL, 16 pts; COPD, 17 pts; CHD, 16 pts) were studied. All had systolic pulmonary artery pressure .35mmHg. Twenty-nine healthy subjects served as controls. RV ejection fraction (RVEF), fractional shortening (RVFS), and tricuspid flow filling parameters (E/A ratio, DT) were determined. Systodiastolic TDI values (Sw, Ew, Aw), peak systolic strain and systo-diastolic strain rate values were determined from RV free wall (RVFW) at 3 levels (basal, mid cavity, and apical) in the apical 4-chamber view. Results: Ew/Aw ratio and strain indexes were lower in pts than in controls (p,0.05 and p,0.001, respectively). There was a trend towards a higher incidence of lower RVEF, RVFS, E/A ratio, and DT in pts compared to controls. No correlation was found between RVEF, RVFS, E/A ratio, DT, and pulmonary artery pressure. A significant correlation was shown between mean peak systolic strain rate at RVFW site and pulmonary artery systolic pressure (r¼0.72, p,0.005). Significant decrease in systolic strain rate was obtained at apical FW site in COPD pts (p,0.005), at apical and mid level in CHD pts (p,0.001), and at basal, mid cavity, and apical levels in SCL pts (p,0.001). Conclusions: In PAH TDI/SRI parameters can determine RV dysfunction that may not be shown by conventional echo indexes and is correlated with severity of pulmonary artery pressure. Different forms of PAH can differently affect ventricular deformation parameters.