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Objectives To evaluate the clinical value of heart rate variability (HRV) analysis in school-age healthy chil-dren with functional ST-T changes in electrocardiogram (ECG). Methods In 143 school-age children (50 cases of functional ST-T changes, 43 cases of myocarditis children with ST-T change, 50 cases of healthy controls without ST-T changes), HRV time domain value was measured in three groups with 24 dynamic electrocardiogram. Results Compared with healthy controls, PNN50, rMSSD and SDSD were decreased while the heart rate, SDNN and SDANN were increased in children with functional ST-T changes (P all<0.05). Meanwhile, compared with children with functional ST-T changes and healthy controls, the heart rate was increased while PNN50, rMSSD, SDSD, SDNN and SDANN were decreased in the myocarditis children with ST-T change (P<0.05). Conclusions The autonomic nervous system of school-age children is not stable. The functional ST-T changes are related with the imbalance between sympathetic and vagus nerve activities. HRV analysis has important diagnostic signifi-cance in the functional ST-T changes.
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Objectives To evaluate the values of notched on R wave in inferior leads of electrocardiogram in infant with secundum atrial septal defect. Methods To observe and compare the prevalence of notch on R wave in inferior leads combined with incomplete right bundle branch block (IRBBB) in 162 cases with secundum atrial septal defect (group I) and 162 cases without heart disease (group II). Results The prevalence of notch on R wave in all the three inferior leads, in at least one inferior lead with IRBBB and in all the three inferior leads with IRBBB were 27.16%, 14.20%and 10.49%respec-tively in group I, and were 3.09%, 1.85%and 0.62%in group II respectively, and the differences between two groups were statistically significant (P<0.005). The specificities of notch on R wave in diagnosis of atrial septal defect were 96.91%, 98.15% and 99.38% respectively. Conclusions Notch on R wave in inferior leads is an independent electrocardiographic sign of secundum atrial septal defect in infants, and thus can be used as a diagnostic parameter.
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Objective To explore the relationship between 5-minute Apgar score and heart rate variability (HRV) in severely asphyxiated neonates. Methods A total of 103 severely asphyxiated neonates with 1-minute Apgar score of 0 to 3 points were selected. They were divided into Group A (>7 points, n=50) and Group B (≤7 points, n=53) based on 5-minute Apgar score. Meanwhile, 40 full-term neonates with 1-and 5-minute Apgar score greater than 7 points were selected as control group. 24-hour dynamic electrocardiogram was performed and HRV was analyzed on the third day after birth in three groups. Results PNN50, rMSSD, SDSD were decreased and SDNN, SDANN were increased in group B as compared with group A and control group (P0.05). Conclusions Neonatal asphyxia can cause damage to autonomic nervous system. 5-minute Apgar score and HRV can be joint-ly used as a non-invasive index in autonomic nervous damage and its prognosis in asphyxiated newborns.
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Objective To evaluated T-wave characteristics in newborn infants with different gestational age. Methods One hundred and forty-two newborn infants were divided into four groups based on the gestation age consisting of the 28～30 weeks group,31～33 weeks group,34～36 weeks group and 37～40weeks group, respectively. The T-wave characteristics of electrocardiogram were compared among the newborn infants of four groups. Results TV1 amplitudes ( mV, median ( interquartile range) ) of 4 groups were -0. 10( -0. 30～0. 10), -0. 10( -0. 30～0. 15), -0. 10( -0. 45～0. 25 ) and 0. 10( -0. 30～0. 70) ,respectively. There was a statistical elevation of TV1 amplitude with the increase of the gestational age. TV5 amplitudes( mV, median ( interquartile range ) ) of 4 groups were 0. 10 ( - 0. 10～0. 30), 0. 10 ( - 0. 20～0. 30) ,0. 15( -0. 05～0. 25) and 0. 10( -0. 10～0. 50) ,respectively. No significant differences of TV5 amplitudes were found among 4 groups. The incidences of low or inverted T-waves in leads I and aVL, or low and flat T-waves in all leads reduced significantly with the increase of the gestational age. Conclusion The TV1 amplitude and the incidence of abnormal T-wave in newborn infants are correlated to the gestational age,and TV5 amplitude is not correlated to the gestational age.