PREDICTION OF CORONARY ARTERY DISEASE BY DETECTION OF POSITIVE ISOVOLUMIC RELAXATION VELOCITY IN PATIENTS WITH NORMAL RESTING WALL MOTIONS "A Tissue Doppler Echocardiographic Study"

Abstract

Background: Diagnosis of coronary artery disease (CAD) is of importance in the contemporary society of ever-increasing CAD (1,2). Isovolumic relaxation velocity (VIR), Postsystolic motion or postsystolic shortening (PSS) is a delayed ejection motion of the myocardium occurring after the aortic valve closure during a generally prolonged isovolumic relaxation time, which is related with myocardial ischemia in human(3,4) and in experimental studies(5). Spectral tissue Doppler imaging (TDI) is a simple echocardiographic technique that can provide velocity measurement of the myocardial segments(6). A positive myocardial velocity during isovolumic relaxation phase (VIR) detected by TDI, which corresponds to postsystolic motion or PSS, has been shown to indicate severely ischemic myocardium(8). So, detection of positive VIR by spectral TDI may be used as a noninvasive, nonprovocative method to predict possible CAD; specially for those with coexisting morbidities, such as peripheral artery disease in the lower limb, orthopedic diseases. Aim of the work: Diagnostic value of positive myocardial velocity during isovolumic relaxation phase (VIR) by spectral TDI in prediction of CAD in patients with typical ischemic chest pain and normal resting wall motions. Patients and methods: This study was done in Cardiology department, Zagazig University on 80 patients; 41 females (51%) & 39 males (49%)) with typical ischemic chest pain and no regional wall motion abnormalities detected by resting echocardiography. Patients were divided into 2 groups according to presence of significant coronary artery lesion by coronary angiography; group A (patients with CAD) and group B (patients without CAD). All the following parameters were measured by TDI; 5 peak velocities during; Isovolumic contraction phase (VIC), Systolic ejection phase (S'), Early diastolic relaxation phase (Em), Atrial contraction phase (Am) and Isovolumic relaxation phase (VIR) if present and VIR time. Then coronary angiography was done for all patients. Results: As regard to presence of VIR velocity, there was significant difference (<0.05) between group A and group B at mid septal and anterior walls, highly significant difference (<0.001) at basal septal and anterior walls. There was highly significant difference between group A and B at mid and basal lateral and inferior walls. There was highly significant correlation between coronary angiography and VIR velocity regarding detection of positive and negative cases and also there was highly significant correlation between previous 2 tests by Kappa test p value (<0.001). Conclusion: Positive VIR detected by spectral tissue Doppler imaging is a useful indicator of CAD in patients with apparently normal left ventricular contraction and chest pain.
Key words: TDI, VIR velocity, coronary angiofraphy, coronary artery disease.