| Objective Viral myocarditis (VMC) is one of the most common cardiovascular diseases in children. It is danger to children. Clinical doctors have thought highly of the therapy and prognosi of ventricular premature beat in children with VMC. In this years, the research of heart rate variability (HRV) is very popular in cardiovascular diseases. Analysis of HRV provides a quantitive index of autonomic nervous system activity. Practic research had cerificated that HRV analysis is more superiority than ventricle late potential, electric alteration, ejection fraction, heart electric physiology. It is a noninvasive, reliable and susceptible method. HRV has shown to be reduced in many cardiovascular diseases and noncardiovascular diseases. The analysis of HRV is wildly used in clinical work. The initial research of HRV in pediatric was later than that in adult. At present, there are not research regarding to HRV of big exponent children with VMC. The aim of this study was to evaluate autonomic nervous activity, the relation between ventricular premature beat and antonomic nerve and its circadian rhythm over a 24-hour period in children with VMC by analysis of HRV. Then to discuss the value of HRV analysis regarding to diagnisis, therapy and prognosi in children with VMC. Methods We collected 80 (35 males and 45 females, aged 6-14 years, mean age 9.5 years old) children with VMC who were acute period patients as reseaching objects in our hospital, and we devided them into two groups according to whether the children had had ventricular premature beats or not. Ventricular premature beats were classified by LOWN.L1-L2 was a group and L3-L5 was a group.60 (27 males and 33 females, aged 6-14 years, mean age 9.8 years old) healthy children served as control group. They hadn't catched diseases which can affect autonimic nerve activity,such as cardiac diseases,diabetes mellitus,hyperthyreosis,and infectious diseases.All the children's body weight was in the range of X±2SD.We monitored all the children by 12 leads dynamic ectrocardiogram device which was produced by Kang Tai medical company limited in American. We demanded everyone not take medecine which can affect heart activity. Time domain indexes of HRV were measured, including SDNN: the standard deviation (SD) of the R-R interval (RR), SDANN: SD of the mean of RR intervals in all 5-minute segments of the 24-hour ECG, SDNNIndex: the average of SD of RR intervals in all 5-minute segments of the 24-hour ECG, RMSSD: the root mean square of successive differences in RR intervals, PNN50: the percentage between the pieces of RR intervals' phase differencd were above 50ms and all the RR inervals' pieces in the 24-hour ECG. The recording time included 24 hour-period, waking hours (8:00-21:00), sleeping hours (21:-6:00). The HRV numeric value per hour is made into diagram of curve. We also calculated the abnormal result of SDNN, creatine kinase-MB, action-X, Doppler and dynamic ectrocardiogram. Results (1)The HRV indexes during 24-hour period is significantly diffenrence between control group and VMC group, children with ventricular premature beat and children with non ventricular premature beat, L1-L2 group and L3-L5 group. (2)The HRV indexes during waking hours in children with VMC was significantly smaller compared with that in control group.(3)The HRV indexes during sleeping hours in children with VMC was significantly smaller compared with that in control group. (4)The changeable breadth of circadian ryuthm in patients with VMC is significantly smaller compared with that in control group, and the PNN50 and RMMSD were the most sensitive indexes. (5)The most hightest percentage of abnormal index was SDNN (83.8%). Conclusion (1)The automomic nerous system activity in children with VMC is changed, especially the vagus nerve was damaged mostly, so the indexes of HRV was reduced. HRV indexes can become sensitive marker. (2)The severice degree of ventricular premature beat and the damage of autonomic nervous system submitted positive correlation in ch... |
PDF Full Text Request