Background Through ventricular interdependence, pulmonary hypertension (PH) induces left ventricular (LV) dysfunction. We hypothesized that pediatric PH patients have LV diastolic dysfunction, related to adverse pulmonary hemodynamics, leftward septal shift, and prolonged right ventricular (RV) systole. Methods and Results Echocardiography was prospectively performed at two institutions in 54 pediatric PH patients during cardiac catheterization, and in 54 matched controls. Diastolic LV measures including myocardial deformation were assessed by echocardiography. PH patients had evidence of LV diastolic dysfunction, most consistent with impaired LV relaxation, though some features of reduced ventricular compliance were present. PH patients demonstrated the following: reduced mitral E velocity and inflow duration, mitral E’ and E’/A’, septal E’ and A’, pulmonary vein S and D wave velocities, and LV basal global early diastolic circumferential strain rate; and increased mitral E deceleration time, LV isovolumic relaxation time, mitral E/E’, and pulmonary vein A wave duration. PH patients demonstrated leftward septal shift and prolonged RV systole, both known to affect LV diastole. These changes were exacerbated in severe PH. There were no statistically significant differences in diastolic measures between patients with and without a shunt, and minimal differences between patients with and without congenital heart disease. Multiple echocardiographic LV diastolic parameters demonstrated weak to moderate correlations with invasively-determined PH severity, leftward septal shift, and prolonged RV systole. Conclusions Pediatric PH patients exhibit LV diastolic dysfunction most consistent with impaired relaxation and reduced myocardial deformation, related to invasive hemodynamics, leftward septal shift, and prolonged RV systole.

Background Through ventricular interdependence, pulmonary hypertension (PH) induces left ventricular (LV) dysfunction. We hypothesized that LV strain/strain rate, surrogate measures of myocardial contractility, are reduced in pediatric PH and relate to invasive hemodynamics, right ventricular (RV) strain, and functional measures of PH. Methods and Results At two institutions, echocardiography was prospectively performed in 54 pediatric PH patients during cardiac catheterization, and in 54 matched controls. PH patients had reduced LV global longitudinal strain (LS) (-18.8 [-17.3 - -20.4]% vs. -20.2 [-19.0 - -20.9]%, P=0.0046) predominantly due to reduced basal (-12.9 [-10.8 - -16.3]% vs. -17.9 [-14.5 - -20.7]%, P<0.0001) and mid (-17.5 [-15.5 - -19.0]% vs. -21.1 [-19.1 - -23.0]%, P<0.0001) septal strain. Basal global circumferential strain (CS) was reduced (-18.7 [-15.7 - -22.1]% vs. -20.6 [-19.0 - -22.5]%, P=0.0098), as were septal and free-wall segments. Mid CS was reduced within the free-wall. Strain rates were reduced in similar patterns. “Basal septum” LS, the combined average LS of basal and mid interventricular septal segments, correlated strongly with degree of PH (r=0.66, P<0.0001), pulmonary vascular resistance (r=0.60, P<0.0001), and RV free-wall LS (r=0.64, P<0.0001). Brain natriuretic peptide levels correlated moderately with septal LS (r=0.48, P=0.0038). PH functional class correlated moderately with LV free-wall LS (r=-0.48, P=0.0051). The septum, shared between ventricles and affected by septal shift, was the most affected LV region in PH. Conclusions Pediatric PH patients demonstrate reduced LV strain/strain rate, predominantly within the septum, with relationships to invasive hemodynamics, RV strain, and functional PH measures.