The Application Of Cardiac Contractility Monitor In Children With Cardiovascular Disease

Part 1 STUDY ON CARDIAC RESERVE IN CHILDREN WITH VIRAL MYOCARDITISObjective: To investigate cardiac reserve in children with viral myocarditis (VMC) by using the cardiac contractility monitor.Methods: The phonocardiograms of children with viral myocarditis (n=60) and healthy control (n=60) were recorded in rest state by using the cardiac contractility monitor and cardiac reserve software produced by Bioengineering College of Chongqing University and BoJing Medical Informatics Institute recently. Then the amplitude of the first (S1) and second heart sound (S2), the duration of diastole (D) and systole (S) were measured,ratio of the amplitude of first and second heart sound (S1/S2) and ratio of the duration of diastolic and systolic (D/S) were calculated in two groups: 1~3year, ~7year.Results: Compared with control group,the ratios of S1/S2 and D/S were all decreased (1.36±0.05,1.22±0.14 vs 1.50±0.11,1.33±0.12 in 1~3 year old group,and 1.44±0.05,1.29±0.11 vs 1.63±0.13,1.45±0.16 in ~7 years old group,respectively) in VMC group (P<0.01).Conclusion: Cardiac reserve is reduced in systolic function and diastolic function in children with VMC. Part 2 ANLYSIS OF CARDIAC RESERVE IN CHILDREN WITH ASD BEFORE AND AFTER INTERVENTION USING TWO METHODSObjective: To study cardiac function and cardiac reserve in children with atrial septal defect (ASD) before and after intervention therapy by echocardiogram and cardiac contractility monitor.Methods: Forty patients with ASD.before intervention and3,6 months following up after intervention, left ventricular end-diastole diameter (LVED),left ventricular end-systole diameter (LVSD),left ventricular end-diastole volume (LVEDD),left ventricular end-systole volume (LVESD),left ventricular stroke volume (LVSV) and left ventricular ejective fraction (LVEF),right ventricular end-diastole diameter(RVED)and right ventricular outflow tract(RVOTD) were detected by transthoracic echocardiogram(TTE) , and the ratio of the amplitude of first and second heart sound (S1/S2) and the ratio of the duration of diastolic and systolic (D/S) measured by cardiac contractility monitor,and comparing the results.Results:①Compared with pre-intervention, LVED,LVSD,LVEDD,LVESD,LVSV were all increased significantly(P<0.01),RVED,RVOTD were decreased significantly(P<0.01) 3 months and 6 months following up after intervention.②Compared with pre-intervention S1/S2 ratio, D/S ratio were increased after intervention, and it is increased more significantly in 6 months after intervention than that of 3 months(P<0.01).Conclusion:Cardiac geometry and systolic function, measured with traditional method of transthoracic echocardiagram, are improved, meanwhile cardiac systolic and diastolic reserve function, examed with the cardiac contractility monitor, are increased after interventional occlusion in children with ASD. So the cardiac contractility monitor could be used as a new method to evaluate the effect of interventional therapy in children with ASD. Part 3 ANALYSIS OF CARDIAC RESERVE IN CHILDREN WITH ASD WITH AND WITH OUT PULMONARY HYPERTENSION BEFORE AND AFTER INTERVENTIONObjective: To investigate cardiac reserve by using a method based on the relation between cardiac contractility and heart sound in children with ASD before and after intervention.Methods: Children with ASD (n=20), and ASD with pulmonary hypertension (n=20), and normal control(n=20) were enrolled in this study. The phonocardiograms were recorded in each control subject, each patient with ASD before intervention, one day and 6 months after intervention by using a cardiac contractility monitor. The first heart sound amplitude (S1), the second heart sound amplitude (S2), diastolic (D) and systolic (S) durations were measured though cardiac reserve software. The ratios of S1/S2 and D/S were analysed in three groups.Results: Compared with the control group, the ratios of S1/S2 and D/S were lower in the group of ASD before intervention, which were the lowest in the group of ASD with pulmonary hypertension. The ratios of S1/S2 and D/S were increased in the group after intervention, and more significantly increased in the group of 6 months after intervention.Conclusion:The cardiac reserve was decreased in children with ASD decreases before intervention, and increased after intervention.