The Study Of The Effects Of Exercise On Cardiac Function In Children After Transcatheter Closure Of Ventricular Septal Defect

Objective:The 6-minute walking test（6MWT）was performed in children after transcatheter closure of ventricular septal defect（VSD）.And the exercise tolerance and cardiac function were evaluated based on the changes of parameters of electrocardiogram and echocardiography before and after 6MWT,and the 6-minute walking distance.Methods:From January 2014 to December 2019,children who were diagnosed with ventricular septal defect and underwent transcatheter closure in our Hospital were selected as VSD group（n=41）.From January 2020 to December 2020,healthy children who underwent physical examination in our hospital were as the control group（n=45）.The subjects in two groups were divided into three segments according to age,namely:5～6 years old,7～8 years old and 9～10 years old.The height and weight of all subjects were recorded.Both VSD group and control group underwent the test.The 6-minut walking distance and parameters of respiratory rate,heart rate,systolic blood pressure and percutaneous oxygen saturation（SP0₂）before and after the test were then collected.Electrocardiogram was examined before and after the test to record,the changes of PR interval,QRS duration and QTc interval.Echocardiography was checked before and after the test to record the changes of left ventricular end-diastolic diameter（LVIDd）,left ventricular end-systolic diameter（LVIDs）,left ventricular ejection fraction（LVEF）and left ventricular fraction shortening（LVFS）.Results:1.All subjects in two groups completed 6MWT.2.In the same age segment,there was no significant difference in 6-minute walking distance between the VSD group and the contral group（5～6 years old segment:525.78±28.40m vs527.39±19.04m,P=0.843;7～8 years old segment:562.47±31.07m vs559.07m±23.74m,P=0.733;9～10 years old segment:592.92±38.33m vs587.50±26.07m,P=0.727）.3.In the same age segment,the respiratory rate,heart rate and systolic blood pressure,but not SPO₂,of the VSD group and the control group after the test were significantly higher than those before the test（P<0.05）.4.There were no significant differences in PR interval,QRS duration and QTc interval of the control group before and after the test（P>0.05）（132.09±18.05ms vs 128.29±13.13ms,90.33±10.06ms vs 86.36±7.93ms and 403.78±17.45ms vs 397.82±16.48ms）.In VSD group,the PR interval and QTc interval was decreased after the test（respectively139.10±19.71ms vs 136.51±18.78ms and 401.85±13.54ms vs 400.71±15.15ms）,while QRS duration was increased（91.76±15.21ms vs 92.71±15.43ms）,however,the differences are not significant（P>0.05）.In addition,there was no significant difference in electrocardiogram parameters between the VSD group and the control group after the test（P>0.05）.5.In the control group,the parameters of LVIDd and LVIDs after 6MWT were decreased compared with those before the test（respectively36.03±3.43mm vs 36.00±3.93mm and 23.08±2.45mm vs 22.50±2.58mm）,but not significant（P>0.05）.While the parameters of LVEF and LVFS after 6MWT were increased compared with those before 6MWT（respectively 67.37±4.40mm vs68.58±3.77mm and 36.56±3.54mm vs 37.94±2.88mm）,but has significant（P<0.05）.The similar results of LVIDd,LVIDs,LVEF and LVFS in VSD group were recorded（36.81±3.19mm vs 35.63±3.17mm,22.52±2.63mm vs 22.03±1.85mm,P>0.05;66.18±3.32mm vs 68.49±5.59mm,35.59±2.83mm vs 37.62±4.47mm,P<0.05）.In addition,there was no significant difference in echocardiography parameters between the VSD group and the control group after the test（P>0.05）.Conclusion:1.There was no significant difference in 6-minute walking distance between control group and VSD group at the same age segment,which suggested that the exercise tolerance of after transcatheter closure of ventricular septal defect children could reach the level of healthy children.2.There was no significant changes in PR interval,QRS duration and QTc interval before and after 6MWT in children after transcatheter closure of ventricular septal defect,which indicated the electrocardiogram parameters were stable and the low risk of arrhythmia in children’s daily life.3.The Changes of echocardiography parameters after the 6MWT in VSD group were similar to control group,which demonstrated that the changes of cardiac function under the exercise in children after transcatheter closure are consistent with those in healthy children.