Mid-esophageal bicaval versus short-axis view of interatrial septum in two-dimensional transesophageal echocardiography for diagnosis and measurement of atrial septal pouches.

BACKGROUND: Recent studies suggest that the left-sided septal pouch (SP) may increase the risk of cryptogenic stroke and act as an arrhythmogenic substrate. The aim of this study was to compare two transesophageal echocardiography (TEE) projections of the interventricular septum: mid-esophageal bicaval and short-axis views toward evaluating their ability to detect SPs.

MATERIALS AND METHODS: A total of 146 patients with both bicaval and short-axis TEE views were included in this study. The presence of SPs was determined, and they were evaluated for morphology.

RESULTS: Irrespective of TEE projection view, the left SP was detected in 74 cases (50.7%), right SP in 16 cases (11.0%), and double in one case (0.7%). Agreement between both projections occurred in 119 cases (81.5%) with a weighted kappa coefficient of 0.68 (good agreement). We detected more left SPs from the bicaval view compared to the short-axis view; however, the observed difference was statistically insignificant (72 vs 59, P = .13). The detection of right SPs was higher in the short-axis view, but also statistically insignificant (9 vs 13, P = .38). Bland-Altman analysis revealed a significant difference in the left SP depth with higher values in the bicaval than short-axis view (systematic difference = 1.17 mm, LoA: -4.88-7.22 mm, P = .02, ICC = 0.58).

CONCLUSIONS: The mid-esophageal bicaval view should be preferable over mid-esophageal short-axis view of interatrial septum for the diagnosis and measurement of the left SP.