Comparison of Left and Right Atrial Volume by Echocardiography Versus Cardiac Magnetic Resonance Imaging Using the Area-Length Method

Increased atrial volumes predict adverse cardiovascular events Accordingly, accurate measurement of atrial size has become increasingly important in clinical practice The area-length method is commonly used to estimate the volume Disagreements between atrial volumes using echocardiography and other imaging modalities have been found It is unclear whether this has resulted from differences in the measurement method or discrepancies among imaging modalities We compared the right atrial (RA) and left atrial (LA) volume estimates using the area-length method for transthoracic echocardiography and cardiovascular magnetic resonance (CMR) imaging Patients undergoing echocardiography and CMR imaging within 1 month were identified retrospectively For both modalities, the RA and LA long-axis dimension and area were measured using standard 2- and 4-chamber views, and the volume was calculated using the area-length method for both atria The echocardiographic and CMR values were compared using the Bland-Altman method A total of 85 patients and 18 controls were included in the present study The atrial volumes estimated using the area-length method were significantly smaller when measured using echocardiography than when measured using CMR imaging (LA volume 35 +/- 20 vs 49 +/- 30 ml/m(2), p <0 001, and RA volume 32 +/- 23 vs 43 +/- 29 ml/m(2), p = 0 012) The mean difference (CMR imaging minus echocardiography) was 14 +/- 14 ml/m(2) for the LA and 10 +/- 16 ml/m(2) for the RA volume Similar results were found in the healthy controls No significant intra- or interobserver variability was found within each modality In conclusion, echocardiography consistently underestimated the atrial volumes compared to CMR imaging using the area-length method (C) 2010 Elsevier Inc All rights reserved (Am J Cardiol 2010,106 1345-1350)