A bedside ultrasound sign of cardiac disease: the left atrium-to-aorta diastolic diameter ratio

PurposeThis study evaluated a simple ultrasound method to detect left atrial (LA) enlargement by comparing the diameters of the LA and aortic root.ProceduresThe LA and aortic diameters, the LA volume index (LAVI), and significant echo findings were analyzed in 101 consecutive echocardiograms. Mean LAVI and the prevalence of an abnormal echo were compared between groups in which the ratio of the LA diameter to aortic diameter in diastole was >1 vs ≤1.FindingsLeft atrial-to-aortic diameter ratio increased with LAVI (r = 0.64, P < .001). Left atrial-to-aortic diameter ratio >1 vs ≤1 was noted in 45% vs 55% of patients and had a mean (±SD) LAVI = 39 ± 12 vs 27 ± 7 mL/m2 (P < .001) and a 78% vs 43% prevalence of an abnormal echo (P < .001).ConclusionThe left atrium-to-aorta diastolic diameter ratio can detect LA enlargement and may be useful as a quick bedside technique to screen for cardiac disease.