Right Ventricular Systolic Strain Is Altered in Children with Sickle Cell Disease

Abstract

Several adult studies have shown that sickle cell disease is associated with cardiac abnormalities and premature death. The aim of this study was to use speckle-tracking strain, a relatively load independent parameter, to evaluate systolic left ventricular (LV) and right ventricular (RV) function in a pediatric sickle cell disease population. Twenty-eight patients with sickle cell disease (mean age, 10.0 ± 3.6 years; mean body surface area, 1.14 ± 0.27 m(2)) and 29 controls matched for age and body surface area were compared. Cardiac output, LV dimension, wall thickness and circumferential strain, LV and RV longitudinal systolic strain, conventional and tissue Doppler parameters, and pulmonary pressure were assessed. LV cardiac output was significantly higher in patients, as were indexed LV systolic diameter, indexed LV mass, and E/E' septal ratio. Indexed LV diastolic diameter, wall thickness, LV shortening fraction, and global LV longitudinal and circumferential strains were similar in patients and controls. However, their global RV longitudinal strain was significantly lower, although tricuspid annular plane systolic excursion and color-coded tricuspid S-wave velocity were similar. Among patients, 21% had tricuspid regurgitation velocities > 2.5 m/sec, but none had tricuspid regurgitation velocities > 3 m/sec. Indexed LV diastolic dimension and systolic pulmonary artery pressure were significantly higher in patients whose hemoglobin was <80 g/L, but parameters of systolic and diastolic LV function were similar. In children with sickle cell disease, LV diastolic function is significantly altered, although LV systolic function, evaluated by global longitudinal strain, is normal. In addition, cardiac output is increased, and elevated tricuspid regurgitation velocity is common, whereas it is never found in controls. Most importantly, global RV longitudinal systolic strain is significantly altered.