Determinants of an abnormal septal curvature in chronic pulmonary hypertension

Even though systolic eccentricity index has been traditionally categorized based on right ventricular (RV) pressure overload, which hemodynamic component is particularly responsible for modulating leftward ventricular septal bowing (LVSB) in chronic pulmonary arterial hypertension (PAH) is less well-known.

Therefore, currently used echocardiographic variables, as suggested by the American Society of Echocardiography, for evaluation of RV performance were evaluated in 60 patients to determine which of these commonly used parameters best determine an abnormal LVSB in chronic PAH patients.

In a stepwise multiple regression analysis of the echocardiographic variables used in this study, elevated pulmonary artery systolic pressures was the best discriminatory variable to identify an abnormal LVSB at any level along the interventricular septum in chronic PAH patients followed by smaller left ventricular end-diastolic volumes and larger RV end-systolic areas.

Progressive RV failure in chronic PAH not only is associated with a decline in longitudinal base to apical motion of the annulus; but also with reduced inward displacement of the RV free wall. Additional reduction in RV systolic function also occurs as a result of progressive displacement of the interventricular septum toward the left ventricle. Therefore, as measures of LVSB along the interventricular septum not only are easily obtained and related to RV systolic performance in chronic PAH patients, routine use of these parameters might be helpful in monitoring decline of RV function as well as progression of end-stage PAH.