Impaired Left Ventricular Longitudinal Function in Idiopathic Pulmonary Arterial Hypertension Children

Pulmonary arterial hypertension is associated with right ventricular dilation and failure. As a result, left ventricular geometry is affected by shifting of the interventricular septum towards the left ventricle. The aim of the study was to assess the effect of chronic right ventricular pressure overload on left ventricular longitudinal function and synchronicity in idiopathic pulmonary arterial hypertension children, using speckle-tracking echocardiography. We prospectively evaluated 13 children (5 with idiopathic pulmonary arterial hypertension and 8 sex- and age-matched controls) using conventional and speckle-tracking echocardiography and clinical status (WHO functional class). Left ventricular longitudinal strain curve was generated for 17 segments and global left ventricular longitudinal peak systolic strain was calculated. Dyssynchrony index of the left ventricle was determined calculating the standard deviation of time to peak-systolic strain for 12 left ventricular, 6 basal and 6 midventricular segments, from short axis views. Strain imaging showed significantly decreased global left ventricular longitudinal strain and increased dyssynchrony index in idiopathic pulmonary arterial hypertension patients as compared with controls (−16.80 ± 2.94 vs. −21.50 ± 1.60, p = 0.003, and 53.80 ± 16.72 vs. 22.25 ± 6.18, p=0.0001, respectively). There was a significant correlation between left ventricular longitudinal strain, dyssynchrony index and right ventricular fractional area changes (r = −0.66, p = 0.013, and r = −0.72, p = 0.005, respectively), right ventricular myocardial performance index (r = 0.86, p = 0.0001, and r = 0.93, p = 0.000, respectively), and LV eccentricity index (r = 0.82, p=0.001, and r = 0.93, p = 0.000, respectively) in the study population as a whole. Left ventricular longitudinal systolic strain and synchronicity are impaired in idiopathic pulmonary arterial hypertension children with normal left ventricular ejection fraction.