Evaluation of cardiac autonomic functions in Children with Thalassemia Trait, Iron Deficiency Anemia and Iron Deficiency

INTRODUCTION: Distruption of cardiac autonomic functions during diseases associated with anemia were reported in multiple studies previously. Objective in this study to investigate heart rate variability (HRV) for evaluation of cardiac autonomic functions in children patients with Thalassemia trait (TT), iron deficiency anemia (IDA) and iron deficiency(ID) without anemia.
METHODS: Twenty-five patients with TT, 25 patients with IDA, 25 patients with ID, and 25 healthy controls were assessed with 24-hour ambulatory electrocardiography recordings. The following time-domain indices were calculated; standard deviation values of all normal sinus R-R intervals over 24 hours(SDNN), standard deviation levels of all mean normal sinus R-R interspaces for each 5-minute strip in the 24-hour enrollments(SDANN), the square root of the mean of the sum of squares of differences between adjacent RR intervals(RMSSD), percentage of difference between adjacent normal R-R intervals that are greater than 50 ms computed over the entire 24-hour ECG recording(pNN50). Re-evaluation regarding HRV were done in children with IDA after 4 months of treatment.
RESULTS: Although reduction in HRV parameters was detected in IDA group compared to ID, TT, and control groups, it was statistically not significant(p>0.05). The pNN50 was significantly low only in the IDA group(p=0.042). In the ID and TT groups, HRV parameters were not affected(p> 0.05). In IDA group, SDNN, SDANN, RMSSD and pNN50 index were significantly higher after treatment(p=0.002, p=0.005, p=0.005, p=0.010, respectively).
DISCUSSION AND CONCLUSION: Our results indicate that cardiac autonomic activity are affected in IDA and improvement occurs after treatment. HRV parameters were found to be especially associated with hemoglobin and hematocrit values.