Evaluation of right ventricular function in pulmonary arterial hypertension by myocardial imaging echocardiography

Background: Pulmonary arterial hypertension (PAH) related to different aetiologies (scleroderma -SCL-, chronic obstructive pulmonary disease -COPD-, congenital heart disease -CHD-) 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 speckle tracking imaging (STI) 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, 19 pts; COPD, 16 pts; CHD, 14 pts) were studied. All had systolic pulmonary artery pressure >35mmHg. Twenty-seven healthy subjects served as controls. RV ejection fraction (RVEF), fractional shortening (RVFS), and tricuspid flow filling parameters (E/A ratio, DT) were determined. RV internal diameters, outflow tract diameter, fractional area change and tricuspid annular systolic excursion were determined by transthoracic echocardiography. RV and LV annular peak systolic velocities (Sa) and peak early (Ea) and late (Aa) diastolic velocities were measured by TDI. RV and LV peak systolic strain, peak systolic strain rate, and early and late diastolic strain rate were obtained in the basal, mid and apical segments in apical 4-chamber view both by TDI and STI. All measurements were taken from an acceptable tracing and determined using offline analysis programs (EchoPAC, version 9.0, GE Ultrasound). Results: RV Ea/Aa ratio and global 2D strain 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 TDI mean peak systolic strain and STI mean peak systolic strain at RVFW site and pulmonary artery systolic pressure (r=0.71 and r=0.74, respectively, p<0.005). Significant decrease in peak systolic 2D strain was obtained at basal 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/STI 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 regional RV function.