Impact of left ventricular outflow tract ellipticity on the grading of aortic stenosis in patients with normal ejection fraction

Journal of Cardiovascular Magnetic Resonance

Research

Jamila Boulif¹  Jean-Louis Vanoverschelde¹  Sophie Pierard¹  Christophe de Meester¹  Mihaela Amzulescu¹  Bernhard Gerber¹  Frédéric Maes¹  Agnès Pasquet¹  David Vancraeynest¹  Anne-Catherine Pouleur¹ 

[1] Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium;Division of Cardiology, Cliniques Universitaires Saint-Luc, Brussels, Belgium;

关键词: Aortic stenosis;    Gradient;    Left ventricular outflow tract;   

DOI  :  10.1186/s12968-017-0344-8

 received in 2016-12-09, accepted in 2017-02-16,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundThe pathophysiology of paradoxical low-gradient (LG) severe aortic stenosis (SAS) remains controversial. As low transvalvular flow has been implicated, we sought to investigate the impact of left ventricular outflow tract (LVOT) ellipticity on the estimation of the LV stroke volume, the calculation of the aortic valve area (AVA) by use of the continuity equation and on AS severity grading.MethodsWe studied 190 consecutive patients (mean age: 72 ± 13 years; male: 57%) with SAS (indexed AVA < 0.6 cm2/m2) and preserved LV ejection fraction, including 120 patients with severe high gradient (HG) AS and 70 with severe paradoxical LG-AS. AS severity, LV volumes and LVOT ellipticity were assessed by 2D-Doppler echocardiography and cardiac magnetic resonance (CMR).ResultsThe LVOT exhibited an elliptical shape on CMR images, with a shorter anterior-posterior than median-lateral diameter (2.2 ± 0.2 vs 2.8 ± 0.3 cm, p < 0.01). Accordingly, the LVOT area measured by planimetry was larger than by 2D-echocardiography, assuming a circular orifice (4.9 ± 0.9 cm2 vs 3.7 ± 0.8 cm2, p < 0.01). Inputting the elliptical LVOT area into the continuity equation resulted in a 29% increase in the indexed AVA (from 0.41 ± 0.09 cm2 to 0.54 ± 0.10 cm2). Accordingly, 30 (43%) patients with severe paradoxical LG-SAS were reclassified as having moderate AS. Similar results were obtained when considering 3D-echo for direct planimetry of the LVOT in a subset of 75 patients.ConclusionsOur results confirm that the LVOT is elliptical in shape and that taking this parameter into account in the calculation of the AVA results in reclassification of 43% of patients with severe paradoxical LG-AS into moderate AS.

【 授权许可】

CC BY   
© The Author(s). 2017

【 图 表 】

Fig. 4