부산대학교 도서관

Introduction: Low gradient aortic stenosis (AS) with preserved ejection fraction (LVEF) is a clinical entity which has been recently described, whose assesment is difficult, resulting in frequent misdiagnosis. Transesophageal echocardiography (TEE) allows an accurate assesment of aortic valvular anatomy, and performance of planimetry of the aortic valvular area (AVA), which allows distinguishing between moderate and really severe AS.Material and methods: between January 2010 and April 2011, we retrospectively analised the patients who underwent a TEE because of conflicting results in transthoracic echocardiogram findings (AVA <1 cm2, mean gradient<40 mm Hg and preserved ejection fraction). We excluded those patients with aortic insufficiency grade III-IV or any other severe valvulopathy. We analized the proportion of patients in which TEE confirmed the severity of AS and we compared the results of AVA measured with bidimensional (2D) and tridimensional (3D) planimetry. The analysis was performed with t-student for dependent samples.Results: among the 45 patients who met the inclusion criteria, TEE confirmed the severity of AS in 41 of them (91,1%). The mean age of the patients included in the analysis was 79 years. Their mean LVEF in TTE was 61,6%, AVA, estimated with continuity ecuation, 0,8 cm2 and mean gradient 26,48 mmHg. The mean indexed AVA calculated with 2D planimetry was 0,47 (+/-0,13) cm2/m2 and 0,44 (+/-0,13) cm2/m2 with 3D, with a mean difference between both values of 0,032 cm2/m2, which is on the borderline of stadistical significance (p=0,056).Conclusions: transesophageal echocardiography makes it possible to confirm the severity of AS in the majority of cases where a low gradient aortic stenosis with preserved ejection fraction is suspected. It is a highly effective test in uncertain cases. The 3D technique provides lightly different measurements, which are probably more accurate, due to a better alignment of the image with the valvular plane.