Journal of Pediatric Cardiology and Cardiac Surgery

Background: In pediatric medicine, beta-blockers are primarily used for treating cardiovascular disease. However, side effects such as hypotension, bradycardia, and hypoglycemia can pose a problem. In particular, while hypoglycemia can cause severe sequelae, its incidence and risk factors in children are unclear.

Purpose: To clarify the relationship between the use of beta-blockers and the onset of hypoglycemic attacks, as well as related risk factors, in infants with tetralogy of Fallot.

Methods: Totally, 422 patients with tetralogy of Fallot who were examined between April 1983 and January 2011 were divided into three groups (group with pulmonary atresia: 116 patients, group using beta-blockers: 214 patients, and group not using beta-blockers: 92 patients), and the relationship between the use of beta-blockers and the onset of hypoglycemic attacks was examined.

Results: Hypoglycemia was observed in 16 patients, all of whom were in the group using beta-blockers (16/214 patients: 7.5%). The mean blood glucose level at onset was 26.4 mg/dL, and the mean age at onset was 2.3 years. There were no gender-related differences, and all patients were using carteolol. The mean Kaup index was 15.2, and no premature deliveries and babies with low birth weight, severe hypoxemia, or heart failure were observed. The causes of onset were poor oral ingestion due to common cold and fasting in 14 of 16 patients (87.5%). Neurological sequelae were observed in 3 patients.

Conclusions: Beta-blockers were used to prevent anoxia in 214 of 306 patients (69.9%) with tetralogy of Fallot, and hypoglycemia was observed in 16 of these patients (7.5%). In many patients using beta-blockers, hypoglycemia was caused by poor oral ingestion as a result of infection. When using beta-blockers, due care should be exercised with regard to the appearance of hypoglycemia.