Steroid-induced Bradycardia During Induction Chemotherapy in Children and Young Adults Diagnosed With Acute Lymphoblastic Leukemia and Lymphoblastic Lymphoma.

Systemic corticosteroids are widely used for the treatment of acute lymphoblastic leukemia (ALL) and lymphoblastic lymphoma. Anecdotal case reports demonstrate bradycardia in patients receiving corticosteroids; however, a more in-depth analysis is lacking. This study aimed to describe the incidence, timing, and outcomes of bradycardia in children with ALL receiving corticosteroids during induction chemotherapy at our center from 2010 to 2016. A total of 153 children were included, with 150 (98%) demonstrating decreased heart rate following steroid administration with a median HR decrease of 23 beats per minute. Bradycardia ≤first percentile for age developed in 90 (59%) patients, with nadir occurring, on average, 7 doses into treatment, corresponding to 79 hours after initiation of therapy. No patient experienced adverse events related to bradycardia. Resolution of bradycardia at outpatient follow-up occurred in 62 of 71 (87%). Examination of nadir heart rate during subsequent hospitalizations in which steroids were not being administered did not demonstrate a significant incidence of bradycardia. Corticosteroid-induced bradycardia is common in children with ALL receiving induction chemotherapy. It was not associated with clinical adverse events and self-resolved without intervention. Therefore, further cardiac assessment may not be warranted in the presence of asymptomatic bradycardia suspected to be secondary to steroid administration.