Melatonin May Be Associated With Left Ventricular Diastolic Dysfunction in Pediatric Patients With Heart Failure

Background: Melatonin has a protective role in adults with cardiovascular diseases. Diastolic dysfunction has been less well investigated in pediatric heart disease, and the effects of melatonin on cardiac diastolic dysfunction in children are not well understood. This study was designed to explore whether diastolic dysfunction is associated with the serum levels of melatonin or NO in children suffering from heart failure (HF) due to different etiology. Methods: forty-seven pediatric patients with HF were enrolled in this study. Echocardiographic parameters were employed to evaluate the cardiac diastolic dysfunction. Diurnal serum levels of melatonin and NO were measured and analyzed in all pediatric patients. Results: Diurnal serum melatonin levels were positively correlated with mitral valve E:A ratio (E/A) in children with HF (P=0.044), especially in children with HF due to cardiomyopathy (P=0.023). Moreover, serum melatonin levels showed significant positive correlation with E/A ratio in children with deteriorate diastolic dysfunction when employing E/A 2 as an indicator (P=0.012), and especially in children with HF due to cardiomyopathy (P=0.0014). Serum melatonin levels demonstrated significant positive correlation with mitral regurgitation (MR) jet area (P =0.005) and showed significant negative correlation with pulmonary valve regurgitation (PVR) velocity (P =0.009). In addition, serum NO levels were positively correlated with isovolumetric relaxation time (IRT) in children with HF(P=0.0047). Furthermore, the optimal cutoff value of serum melatonin levels for diagnosis for predicting E/A＞2 in pediatric patients with HF was 84 pg/mL. Conclusions: Diurnal serum melatonin and NO levels may be associated with left ventricular diastolic dysfunction in pediatric HF especially due to cardiomyopathy.