Assessing the risk of hypoglycemia secondary to propranolol therapy for the treatment of supraventricular tachycardia in infants

Objective: Supraventricular tachycardia (SVT) is the most common arrythmia among infants. Prevention of SVT is frequently managed through propranolol therapy. Hypoglycemia is a known adverse effect of propranolol therapy, but little research has been done on the incidence and risk of hypoglycemia in treatment of SVT in infants with propranolol. This study attempts to offer insight into the risk of hypoglycemia associated with propranolol therapy when treating infantile SVT to help inform future glucose screening guidelines. Methods We conducted a retrospective chart review of infants treated with propranolol in our hospital system. Inclusion criteria were infants < 1 year of age who received propranolol for the treatment of SVT. A total of 63 patients were identified. Data was collected on sex, age, race, diagnosis, gestational age, nutrition source (Total Parenteral Nutrition (TPN) vs oral), weight (kg), weight for length (kg/cm), propranolol dose (mg/kg/day), comorbidities, and whether or not a hypoglycemic event was identified (< 60 mg/dL). Results Hypoglycemic events were identified in 9/63 (14.3%) patients. Of the patients with hypoglycemic events, 8/9 (88.9%) had comorbid conditions. Patients with hypoglycemic events had significantly lower weight and propranolol dose than those without hypoglycemic events. Weight for length also tended to increase risk for hypoglycemic events. Conclusions The high incidence of comorbid conditions in the patients who had hypoglycemic events suggests that hypoglycemic monitoring may only be necessary in patients with conditions predisposing to hypoglycemia.