Predictive value of normal left atrial volume in stress echocardiography.

OBJECTIVES: Our objective was to evaluate whether normal left atrial volume index (LAVI) is a predictor of a normal stress echocardiogram and thus a predictor of low ischemic risk. BACKGROUND: Left atrial enlargement is closely related to the chronicity and intensity of the burden of increased ventricular filling pressure. Typically ischemic heart disease (IHD) has a long period of subclinical dysfunction. Increased filling pressure, reflected by enlarged LAVI, is hypothesized to mirror the burden of subclinical and overt IHD. We hypothesized that a normal LAVI might also be useful in predicting low IHD risk. METHODS: One hundred eighty randomly selected patients (mean age, 63 +/- 15 years; 53% men) underwent outpatient exercise or dobutamine stress echocardiography for known or suspected coronary artery disease. Left atrial volume index was measured retrospectively with the biplane area-length method. The stress echocardiogram was interpreted as abnormal if wall motion abnormalities (WMAs) were noted at rest and/or with stress. RESULTS: Left atrial volume index was categorized as < or =28 ml/m2 (normal), 28.1 to 32 ml/m2, 32.1 to 36 ml/m2, and >36 ml/m2. Abnormal stress echocardiography was identified in 57 patients (31.7%). The percentage of abnormal stress echocardiograms in each LAVI category was 5.7%, 21.9%, 38.7%, and 54.7%, respectively. The negative predictive value for LAVI < or =28 ml/m2 was 94.3%. CONCLUSIONS: Normal resting LAVI (< or =28 ml/m2) was strongly predictive of a normal stress echocardiogram. Left atrial volume index might be a simple means of identifying patients with low ischemic risk and should be further evaluated as a complement to the assessment of ischemic risk.