Assessment Of Left Ventricular Regional Systolic Function Of CHD By 4D-Strain Technique

Objective:Investigate the feasibility of the four-dimensional strain technique for the assessment of left ventricular regional function of patients with different levels of coronary artery stenosis and primary diagnostic value for coronary heart disease.Materials and methods:60 patients who were suspected of CHD in the First Affiliated Hospital of Kunming Medical University were selected from March,2014 to January,2015. Male 38, female 22, average age (53.00+11.23)) years. Exclude criteria:arrhythmia; history of old myocardial infarction with underwent PCI, heart failure, the heart disease of cardiomyopathy, severe valvular heart disease, congenital heart disease, or the quality of the 4D imaging is too poor that can’t be analyzed. All patients were accepted the examination of regular two dimensional and four dimensional echocardiography before the CAQ gathered and stored the four dimensional full volume dynamic cardiac graphs. Analyzed the 4D dynamic cardiac graph using the 4D-strain technique, then could get the diverse peak strain value (include LS, CS, AS, RS) of the 17 myocardial segments of the left ventricle (consist of 6 segments on the level of mitral orifice,6 segments on the level of papillary muscles,4 segments on apex section, and the apical cap). According to the consequence of the CAG, divided all the subjects into 4 groups:normal group (stenosis extent=0%), mild narrowed group (0%<stenosis extent<50%), moderate narrowed group (50%≤stenosis extent≤75%), severe narrowed group (stenosis extent>75%). Using statistical software of SPSS 17.0 to compare the peak strain in different levels of coronary artery stenosis, investigate the feasibility of 4D-strain for assessment of left ventricular regional function of patients with different levels of coronary artery stenosis. Analyze the sensitivity and specificity of the whole strain variables for the CHD, as well as discuss the value of identification for CHD with 4D-strain.Results:In different levels of coronary artery stenosis groups, the peak strain value of section of the myocardial segments corresponded to the narrowed vessel were descending along with the increasing of the level of setenosis, especially on the severe narrowed group. The CS has the best identified value for the CHD, Az=0.921> the sensitivity of 66.1%, the specificity is 94.2%, and the best positive differential point is-12.50. Then in sequence the identified value were RS>AS> LS. Taking the circumferential strain (CS) peak as a sensitive index, and making use of the best positive differential point-12.50 to infer that those 60 subjects whether they were suffering from CHD or not. The result is:the true positive rate is 61.1%, the false negative rate is 87.5%.Conclusion:4D-srain has the feasibility for assessment of left ventricular regional function of patients with different levels of coronary artery stenosis and has primary diagnostic value for CHD. These provide some available supports for the diagnosis of CHD by noninvasive technique.