Evaluation of heart rate variability before and after treatment in children with iron deficiency anemia

Objective: Iron deficiency is the most common nutritional deficiency in the world and it is a major public health problem especially in developing countries. Iron deficiency anemia is a clinical entity which not only affects the hematological system but also leads to multisystemic disorders. Severe anemia may cause cardiomegaly, systolic murmurs, tachycardia, dyspnea and heart failure. It has been shown that cardiac autonomic functions might be harmed by various anemias as sickle cell anemia, thalassemia major and vitamin B12 deficiency. However, studies that evaluate the autonomic functions of pediatric patients with iron deficiency anemia are very limited. Methods: This is a prospective review of 30 patients (21 girls, 9 boys) who were admitted to the out-patient pediatrics clinics of Afyon Health Sciences University Hospital and who were diagnosed with iron deficiency anemia. The patients with neuropsychiatric diseases, chronic diseases, dysrhythmias, congenital and acquired cardiac diseases were excluded. Complete blood counts, ferritin, serum iron, serum iron binding capacity tests were performed. Time-domain heart rate variability parameters (SDNN, SDNNI, SNN50 De, RMSSD, triangular index, percent-analyzed) were calculated by 24-hour Holter electrocardiography monitorization. Ejection fraction and fractional shortening were also measured by echocardiography. The patients with iron deficiency anemia were reevaluated in terms of hematological parameters and heart rate variability after 3 months of iron supplementation. Results: When the heart rate variability parameters of patients before and after treatment were compared, SDNN 24 h, SDNN index, RMSSD, SNN 50De and triangular index values were found to be increased. Moreover, there was a statistically significant increase in SDNN 24 h index and a significant decrease in percent analyzed values after iron supplementation. After treatment, the minimum, mean and maximum heart rates were decreased and the decrease in maximum heart rate was statistically significant. Conclusion: Iron deficiency anemia adversely affects cardiac autonomic activity in children and this impairment is significantly improved by iron supplementation. Key words: Heart rate variability, iron deficiency, anemia, child