Assessment Of Left Ventricular Function In Children With Viral Myocarditis By Strain Rate Imaging And Real-Time Three-Dimensional Echocardiography

Viral myocarditis(VMC), infected by coxsackievirus, echov- irus, adenovirus, flu, subsidiary flue and other viruses, is a very common cardiac disease, which can be found for both the old and the young, especially for the kids and the young. The basic pathological changes present inflammatory cellular infiltration in myocardium, myocardial degeneration thanatosis and fibrous chan- ge at the late stage of the illness, which distribution can be topical, sporadic or diffuse. The sizes of heart chamber can be normal or slightly enlarged. When pathological changes affect conduction sys- tem, the conduction blocking or various arrhythmia will happen.The research has applied strain rate imaging and three-dimensional echocardiography to detect and evaluate the children with viral myocarditis for the whole and regional systolic and diastolic func- tion of left ventricular myocardial, and to observe the synchronous change of myocardial movement, which will provide credible basis for clinical diagnosis.Philips iE33 and Q-Lab software were used in this study to examine 56 children with acute viral myocarditis (Group VMC) and 63 normal children(Group N). After traditional 2DE examine, the peak strain value(ε)and strain rate(Ssr)of each segment in left ventricular during vertical systolic, the peak strain rate during early diastole(Esr), the peak strain rate during late diastole(Asr) and the myocardial radial strain and strain rate in posterior of left ventr- icular were measured respectively. With 3DE, when the intima of left ventricular were scanned and recorded, then click the sequence analysis, the software will automatically show the left ventricular volume-time curve, 17 segments volume -time curve, 17 segments EDV% -time curve as well as EDV, ESV and LVEF; meanwhile, Tmsv16-SD, Tmsv12-SD, Tmsv6-SD, Tmsv16-Dif, Tmsv12-Dif, Tmsv 6-Dif and Tmsv 16-SD%, Tmsv12-SD%, Tmsv6-SD%,Tmsv16-Dif%,Tmsv12-Dif%,Tmsv 6-Dif% can also be obtained.The research results indicate that:1. the peak values of systolic strain (ε)of Group VMC at inferior,posterior and the basal segment of posterior septum are obvious lower than those of Group N(P<0.01) and theεat the basal and middle segments of lateral and the middle segment of anterior are also less than those of Group N, which difference has the statistical significance(P<0.05); 2.the peak values of systolic strain rates (Ssr) of Group VMC at inferior,posterior, the middle segments of posterior septum and lateral are apparently less than those of Group N(P<0.01) and the Ssr at the basal segment of posterior septum is also less than that of Group N, which difference has been suitable for statistical significance(P<0.05); 3. the peak values of strain rates during early diastole (Esr) of Group VMC at multiple segments of left ventricular walls are lower than those of Group N(P<0.05); 4.the peak values of systolic strain and strain rates along short axis of left ventricular posterior are almost the same for these two groups(P>0.05); 5. EDV, ESV and EF of Group VMC and Group N are nearly same(P>0.05);6.as to Tmsv16-SD,Tmsv16-Dif,Tmsv12-SD,Tmsv12-Dif,Tmsv6- SD, Tmsv6-Dif and revised heart rates, Group VMC is higher than Group N(P<0.05).From the study, it can be shown that the children with acute viral myocarditis can be early examined by strain rate imaging and three-dimensional echocardiography, which can not be found by conventional echocardiography. The SRI and RT-3DE can detect the abnormal segments movement of regional cardiac and can completely evaluate the whole and regional systolic and diastolic function of left ventricular, which makes systolic asynchrony evaluation for left ventricular more exact and more rapid.