Cardiovascular response in anemia.

ABSTRACT

OBJECTIVE: To study the functional consequences of nutritional anemia by evaluating the exercise performance in these children. METHODS: The study was conducted on 30 each of anemic and normal children of both sexes aged between 7 and 14 years. Relevant history was taken, and detailed examination was done. These children were classified according to severity of anemia based on hemoglobin estimation as mild (10-11.9 g/dl), moderate (7-9.9 g/dl) and normal (>12 g/dl). Children with severe anemia (Hb < 7g/dl), heart disease, non-nutritional anemia, acute febrile or respiratory illness were excluded. The subjects were tested on Mortara X Scribe colour stress treadmill using the modified Bruce protocol. Continuous computerised electrocardiographic analysis was done. The parameters studied included heart rate, systolic blood pressure, double product (DP = HRxSBP), ECG changes, metabolic equivalents (METS) and exercise duration. The end point of the test was a HR of 170/min (non-fatigue group) or inability to perform further (fatigue group). Statistical analysis was done by appropriate tests. RESULTS: Fifteen children each with mild and moderate anemia and 30 age-matched controls were enrolled in the study. There was no significant difference in the resting HR, exercise duration or DP between the cases and controls. Thirty-one children reached the target HR (non-fatigue group). The end-point HR was significantly lesser among the anemic children in the fatigue group (P 0.04). The percent gain of SBP, at peak exercise (P 0.0007) and recovery SBP as percent of resting SBP (p 0.006) were significantly more in the anemic children, more so in the mildly anemic ones. Lesser METS was achieved by anemics as compared to controls (P 0.04). ECG changes occurred significantly more often in anemic children, 53.8% of those with changes being moderately anemic, the main abnormality being ST depression. None developed arrhythmia during exercise testing. CONCLUSION: The cardiovascular response to physical exercise is compromised in children with nutritional anemia and hence these children may never attain their full potential in various school activities. Prevention of anemia should be a priority in school going children.