Discussion on the characteristics of heart rate recovery after primary radical treatment of tetralogy of Fallot / 中华实用儿科临床杂志

ABSTRACT

Objective To explore the characteristics of postoperative heart rate recovery (HRR)in children who underwent primary radical repair of tetralogy of Fallot(TOF).Methods A total of 32 patients who underwent pri-mary radical repair of TOF were chosen as the TOF group(18 male,14 female,aged from 7 to 15 years old,ranged from 5 to 12 years after primary radical repair of TOF),and 86 healthy children were selected as the healthy control group (42 male,44 female,aged from 6 to 14 years).All children had the treadmill test in Shanghai Children's Medical Cen-ter from January 2013 to December 2015.The data of HRR in 2 groups were reviewed,and the data of HRR were also analyzed in TOF group who had ventricular tachycardia during treadmill test and they were treated with β-blocker.The maximal heart rate(HRmax)at the peak exercise level and the heart rate in 1-6 minute(HRR1-HRR6)in the recovery period were measured and the HRR1-HRR6 was defined as difference between the HRmax and the heart rate in 1-6 minutes during the recovery period.Results The heart rate in first 2 minutes after treadmill exercise showed the rapid recovery in both TOF group and the healthy control group.It recovered slowly after the third minute in two groups.The healthy control group reached the steady HRR period after the fifth minute,whereas TOF group entered the steady HRR period after the sixth minute,and later in the TOF group it reached steady HRR period.There was no difference in HRmax in 2 groups(P＞0.05).But there were significant differences in the resting heart rate[(82.3 ± 3. 4)times/min vs.(79.0 ± 2.5)times/min],and the levels of HRR1-HRR4 minutes were (25.9 ± 1.5)%,(39.4 ± 1.6)%, (43.0 ± 1. 6 )%,and (44. 7 ± 1. 8 )% in TOF group,respectively;while in the healthy control group they were (26.3 ± 1.3)%,(40.0 ± 1.1)%,(43.8 ± 0.7)%,and(45.4 ± 1.4)%;the incidence of ventricular premature beat was 18/32 cases(56.3%)and 5/86 cases(5.8%)during treadmill test between 2 groups (t＝5.77,5. 59,10.32, 18.65,10.66,χ2＝37.80,all P＜0.05).β-blocker treatment was given to 7 cases who had ventricular tachycardia during treadmill test in TOF group.After treatment,the resting heart rate was (77.6 ± 2.6)times/min,significantly de-creased(t＝3.93,P＝0.01),the level of HRR1-HRR4 was(26.3 ± 1.9)%,(39.8 ± 0.9)%,(43.8 ± 0.8)%, (46.2 ± 1. 3)%,respectively,which was significantly increased (t＝2.49,4.63,8.30,7.90,all P＜0.05).The inci-dence of ventricular tachycardia(2/7 cases,28.6%)decreased significantly(χ2＝7.78,P＝0.02).Conclusions There exists cardiac autonomic dysfunction in children who had the primary radical repair of TOF,which is related to the occurrence of ventricular arrhythmia and may influence the long-term prognosis of TOF.HRR can be used as an important indicator to assess and reassess the cardiac autonomic function in patients after TOF repair.