Discordant Grading of Aortic Stenosis Severity: New Insights from an In Vitro Study
ADDA ; STANOVA ; ZENSES ; CLAVEL ; BARRAGAN ; PENARANDA ; HABIB ; PIBAROT ; RIEU
Type de document
ARTICLE A COMITE DE LECTURE NON REPERTORIE DANS BDI (ACLN)
Langue
anglais
Auteur
ADDA ; STANOVA ; ZENSES ; CLAVEL ; BARRAGAN ; PENARANDA ; HABIB ; PIBAROT ; RIEU
Résumé / Abstract
Background: Low gradient (mean gradient, < 40 mmHg) aortic stenosis (AS) may occur in conjunction with a small valve effective orifice area (EOA) < 1 cm2. This discordant grading in AS severity raises challenges from both a diagnostic and therapeutic standpoint. We sought to identify echocardiographic markers of severe AS in normal and low flow conditions in vitro.
Methods: In an in vitro mock circulatory system, we tested 6 degrees of AS severity (3 severe and 3 nonsevere), and 3 levels of stroke volume (30, 50, 70 ml), heart rate (60, 80, 100 bpm), and mean arterial pressure (100, 120, 140 mmHg). MG and EOA were measured by Doppler-echocardiography.Results: In normal flow conditions, a MG of 40 mmHg corresponded to an EOA of 0.85 cm2, and an EOA of 1.0 cm2 to a MG of 28 mmHg. The presence of EOA < 0.85 cm2 and MG between 24 and 40 mmHg in the low-flow condition yielded a 100% specificity for severe AS. In normal flow conditions, these thresholds were respectively < 0.9 cm2 and > 36 mmHg. Conclusion: Low gradient AS may occur in severe AS in both low and normal flow conditions. The presence of a valve EOA < 0.85 cm2 with an MG ? 25 mmHg may be used as a criteria to confirm severe AS in presence of low flow. In patients with normal-flow, a MG ? 37 mmHg is generally suggestive of severe AS.
Source
Structural Heart, num. 5, pp.415-422 p.
Editeur
Routledge Taylor & Francis Group
