OBJECTIVETo investigate the effects of oral administration of low-dose propranolol on heart rate variability (HRV), acceleration capacity (AC), deceleration capacity (DC), and cardiac conduction in the treatment of infantile hemangioma.

METHODSA total of 118 infants with hemangioma (≤1 year) were enrolled, and 24-hour ambulatory electrocardiography was performed before oral administration of low-dose propranolol and after one month of administration. The changes in time-domain indices [standard deviation of all normal sinus RR intervals (SDNN), standard deviation of all mean 5-minute RR intervals (SDANN), root mean squared successive difference (RMSSD), and percentage of successive normal sinus RR intervals >50 ms (PNN50)] and frequency-domain indices [low frequency (LF) and high frequency (HF)] for HRV, AC, and DC were observed, as well as abnormalities in cardiac conduction and other aspects after administration of propranolol.

RESULTSAfter administration of propranolol, the infants had significantly increased SDNN, RMSSD, LF, HF, and PNN50 (P<0.01), and significantly reduced AC, mean heart rate (HR) and minimum HR (P<0.01). The 24-hour ambulatory electrocardiographic findings showed a nonsignificantly higher abnormal rate after administration of propranolol.

CONCLUSIONSIn the treatment of infantile hemangioma, propranolol can inhibit the activity of sympathetic nerve and block cardiac conduction, but without any serious adverse effect.