Left atrial size and left ventricular function in coronary artery disease: an echocardiographic-angiographic correlative study.

M-mode echocardiography was used to determine left atrial size in 100 patients with coronary artery disease undergoing cardiac catheterization. Patients were divided in two groups on the basis of left atrial diameter (greater than or equal to 40 mm in 40 patients and less than 40 mm in 60). Patients with larger left atria had a higher frequency of electrocardiographic evidence of left atrial abnormality (p less than 0.01) and myocardial infarction (p less than 0.001). Pulmonary capillary wedge and left ventricular end-diastolic pressures were higher (p less than 0.005) in patients with larger left atria. An abnormal end-diastolic volume (greater than 100 ml/M2) was observed in 13 patients with enlarged left atria compared to none with normal left atrial size (p less than 0.001). Triple vessel disease was more frequent (63% vs 32%) and single vessel disease less frequent (10% vs 37%) in patients with larger left atria (p less than 0.005). Abnormal left ventricular contractile patterns were noted in 45% of patients with normal left atrial diameters compared to 80% in those with an enlarged left atrium (p less than 0.001). An abnormally low ejection fraction (less than 0.5) was observed in 25% and 80%, respectively, in patients with normal and enlarged left atria (p less than 0.001). Of 58 patients with normal ejection fractions, only 17% had left atrial diameters greater than or equal to 40 mm compared to 71% of 42 patients with abnormally low ejection fractions (p less than 0.001). Of 18 patients with left atrial diameters greater than 42 mm, only two had normal ejection fractions. The mean ejection fraction for patients with left atrial diameters less than 40 mm was 0.63 +/- 0.13 compared to 0.41 +/- 0.18 for those with diameters greater than or equal to 40 mm (p less than 0.001). The sensitivity, specificity, and predictive value for an enlarged left atrium in identifying an abnormal ejection fraction were, respectively, 71, 83, and 75%. These findings indicate that M-mode echocardiographic left atrial enlargement is a useful marker of advanced hemodynamic and angiographic abnormality in patients with coronary artery disease.