Comparison of Diastolic Function of Homozygous Sickle Cell Anaemia with Haemoglobin AA Children Using Basic Mitral Inflow Doppler Echocardiography

Aims: Sickle cell anaemia (SCA) remains the most prevalent and arduous inherited disease in Nigeria. Various adverse cardiovascular consequences have been documented including cardiac chamber enlargement and left ventricular (LV) hypertrophy. Diastolic dysfunction, a recognized risk factor for death, has been reported in adults however the time of onset remains unknown. A dearth of literature persists about the impact of SCA on diastolic function among children. This study aimed to determine LV diastolic function in children with SCA in steady state and compare with apparently healthy haemoglobin type AA controls.

Study Design: Observational, case-controlled, cross-sectional study.

Place and Duration of Study: Department of Paediatrics, Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife and the Bethesda Heart Centre, Ibadan, Nigeria, six months.

Methodology: Fifty subjects aged ≤ 15 years and 50 age- and sex-matched controls to determine and compare basic mitral inflow indices of diastolic function using 2-D guided Doppler echocardiography.

Results: Subjects had significantly higher left atrial and LV dimensions, mean E-wave velocity (1.08 versus 0.94 m/ s, p = .001) and A-wave velocity (0.58 versus 0.52 m/ s, p < .001) than controls. Slightly higher E/ A ratio and longer deceleration time were observed in subjects but without statistical significance [p = .48 and p = .33 respectively]. E- and the A-wave velocities in subjects did not correlate with age or BSA unlike in controls which showed negative correlations. There was however significant negative correlation between haematocrit and the A-wave velocity and the E/ A ratio of subjects.

Conclusion: Even in steady state, children with SCA have relatively abnormal early and also late LV diastolic filling. These did not correlate with age or BSA. Haematocrit showed significant correlation with late diastolic LV filling. Evaluation of left ventricular diastolic function should be routinely used in cardiac assessment of children with SCA.