RT3DE,SRI Comparing With 2DE In Ventricular Wall Motion Analysis

Ventricular Wall motion is one of the most important contents of echocardiography. Ventricular wall motion analysis is not only an important content of myocardial disease diagnosis, but also an important guidance in observing therapeutic effect and prognotic assessment of myocardial disease. More than 90 percent of ventricular wall motion abnormalities are caused by myocardial ischemia. In China, the incidence of coronary heart disease tends to rise every year. As a kind of noninvasive, cheap examination with high repeatability, Echocardiography plays an important role in CHD diagnosis. Wall motion analysis is regarded as a sensitive index in diagnosing myocardial ischemia, it detects ischemia earlier than electrocardiogram. Ventricular septum is between left and right ventricles; its myocardium is composed of left and right ventricular myocardium fabric tissue; the resultant force of left and right ventricular myocardium fabric tissue and ventricular chamber's pressure affects the movement of ventricular septum. The blood supply of ventricular septum principally comes from anterior and posterior branches of interventricular septum and atrioventricular nodal artery. interventricular septum is the borderline of the left and right coronary artery and one of the ventricular walls supplied by ramus anastomoticus of right and left coronary artery. The amplitudeof ventricular septum motion is normally lower than free left ventricular wall. The diagnosis rate of Abnormal interventricular septal motion is rather high in clinical work. Real-time three dimensional echocardiography is a new technique. It has a good consistency with magnetic resonance and electromagnetic flowmeter in the measurement of chamber volume and heart function. Collins M et al have found that 2DE and 3DE had good dependability (r=0.89, P<0.001) when analyzing wall motion abnormalities of myocardial infarct. Doppler tissue imaging was invented by McDicken in 1992, and applied in clinical work by Steward, Miyatake in 1993. Applying Doppler principle, DTI obtains low frequency transduction and high amplitude of vibration signals of myocardium motion by cutting down overall gain and using low pass filter, and transports information of tissue motion to autocorrelation and speed calculating mode for color coding, using Digital Analog Converter, and displays myocardium motion information in multiple ways. Strain rate imaging is a new technique derived from DTI. Strain is a physical word; it is the mobile quantity of solid object from fundament state to certain direction. Strain rate is strain in unit time. Strain and strain rate investigate object essence and reflect myocardium proper characteristics. Strain rate reflects spatial distribution of shear rate between two points; it is not influenced by the drag from peripheral myocardium. We apply real time 3-dimensional echocardiography and strain rate imaging to detectleft ventricular wall motion, comparing with 2 dimensional echocardiography. The consequence displays as follows: the 17 segment volume-time curves of T2 group have ill-defined appearances, comparing with that of normal control group; the end systolic time reaching minimal systolic volume is irregular; the wall motion has bad synchronism. there are differences among Tmsv 6-SD,Tmsv 12-SD,Tmsv 16-SD,Tmsv 6-Dif and heart rate correction value of T2 group and normal control group (p<0.05), while T1 group and normal group showed no significant difference. End systolic EDV% of 17 segment in T2 group showed significant differences in basal inferoseptal, mid inferoseptal, mid anteroseptal compared with that of normal control, while T1 group had no significance with that of normal control. The analysis on strain rate showed that the strain rate curve of ventricular septum in T2 group was chaotic,with peak value of basal, mid, apical inferoseptal of T2 group during systolic phase and early diastolic phase reduced obviously compared with that of N group, indicating that the inferoseptal myocardium of T2 group had decreased systolic, diastolic mobility and deformative ability. The decrease of peak value of basal inferoseptum in diastolic phase demonstrate that the deformative ability of the initiative diastolic activity in this myocardial area depressed, and that the myocardium injured. Meanwhile, hypoxia and ischemia attacks heart, macroaxis directed motion happens earlier than minor axis direction.We get conclusion that the detection of abnormal inter- ventricular septal motion by 2DE is believable. RT3DE not only observes the degradation of wall motion amplitude, but also estimates accurately wall motion phase. SRI has great superiority in wall motion assessment. The application of new ultrasound technique provides accurate and reliable diagnostic evidence to myocardial infarction, coronary heart disease patients in early stage and evaluate curative effect and prognostic heart function.