Correlation between Left Atrial Dimensions & Volumes Changes and the Extent of Myocardial Ischemia Detected by Dobutamine Stress Echocardiography

Abstract

Background: Left atrial volume indexed by body surface area (LAVI) has been associated with cardiovascular risk burden and has been shown to provide prognostic information additional to clinical risk factors in different patient populations. Aim of the work: To detect any possible correlation between left atrial dimensions & volume changes under high-dose dobutamine stress echocardiography and the extent of myocardial ischemia in terms of the number of vessels affected by significant stenosis, as seen by coronary angiography. Patients:100 patients with normal resting wall motion abnormality were enrolled. Exclusion criteria were age <18 years, permanent pacemaker implantation, cardiomyopathy, atrial fibrillation, left ventricular hypertrophy, significant mitral or aortic valve disease. Methods: LAV was measured using biplane area-length method in resting state and after dobutamine stress. Coronary angiography was used to assess severity of CAD. Results: All patients with normal coronary angiography showed resting mean LAVI 25.54±1.88 cc/m2, while those with SVD showed mean LAVI 29.39±3.06cc/m2, 2VD 33.09±4.21 cc/m2 and 3VD 35.14±2.66cc/m2. With dobutamine stress, mean LAVI increased to reach 25.62±2.22, 29.98±3.22, 34.61±4.96 and36.41±3.44 cc/m2 respectively. The best cutoff value of DSE LAVI that best discriminates CAD was 30.1cc/m2. Using this cutoff value,CAD was identified with a 85.71%sensitivity, 95.45%specificity, 96% PPV and 84% NPV. On the other hand, the best cutoff value of DSE LAVI that best discriminates more than SVD was 32.71cc/m2. Using this cutoff value,more than SVD was identified with a 88.71%sensitivity, 96.45%specificity, 97% PPV and 89% NPV. Conclusion: LAVI is a great diagnostic tool for ischemic heart disease. It is normal with normal subjects and increases progressively with increasing severity of the disease.