ABSTRACT
ObjectiveTo explore the relation of heart rate variability (HRV) in neonatal asphyxia with myocardial injury.MethodsContinuous electrocardiographic monitoring by 24-hour Holter recordings was performed in 53 neonates with asphyxia and 40 healthy newborn.The difference of HRV with sinus rhythm was analyzed.Time-domain indexs included standard deviation of R-R intervals (SDNN) ; standard deviation of all mean 5-minute R-R intervals (SDANN) ;standard deviation of all R-R intervals for all 5-minute segments of 24 hours (SDNNindex ) ;root mean squared successive difference (rMSSD) ;percent of NN50 in the total number R-R intervals ( PNN50 ).Results( 1 ) Maximum heart rate,minimum heart rate and average heart rate of 24-hour Holter in healthy newborn were faster than those in newborn with neonatal asphyxia ( P ＜ 0.05 ).And the heart rate was faster in newborn with mild neonatal asphyxia than that in newborn with serious neonatal asphyxia ( P ＜ 0.05 ).(2) SDNN,SDANN of HRV index analysis showed significantly difference between healthy newborn and asphyxia newhom ( P ＜ 0.05 ).There were no difference of SDNN,SDANN,SDNNindex,rMSSD and PNN50 between mild and serious neonatal asphyxia (P ＞ 0.05 ).No significant differences of SDNNindex,rMSSD and PNN50 were found among three groups.ConclusionMyocardial injury caused by neonatal asphyxia can lead to damage of cardiac autonomic nevous and affect heart rate changes.The degree of myocardial injury is related to the degree of neonatal asphyxia.