The art of assessing aortic stenosis

Abstract

This review describes the assessment of the aortic valve by echocardiography and also the roles that multidetector CT (MDCT) and cardiac magnetic resonance have to play as complimentary imaging modalities. It describes how to resolve apparent discrepancies in grading aortic stenosis and discusses the management of apparently moderate stenosis associated with cardiac symptoms or left ventricular dysfunction. The role of cardiac imaging including three-dimensional (3D) echocardiography and MDCT scanning in the preparation for transcatheter aortic valve implantation and during and after the procedure are described. While echocardiography remains the mainstay of imaging, 3D modalities, notably MDCT, are increasingly useful and a multimodality approach is likely to become established as routine clinical practice.

Valve Stress Echocardiography

“…Gradient thresholds (1,2,11,(16)(17)(18)(19) Aortic stenosis. As with MS, a noncompliant aortic valve may be moderately stenotic at rest but severely stenotic during stress (20,21) because the valve fails to open further.…”

“…Consequently, gradient increase and calculated functional valve area failure to increase during VSE suggest severe aortic stenosis (AS) (5,8,11,13,20,21). VSE is indicated (1,2) to regrade AS severity in symptomatic patients.…”

“…Nevertheless, some patients, particularly asymptomatic, physically active patients with incidental low-flow, low-gradient AS, might potentially achieve the target workload (20% increase in LVOT-derived stroke volume), which allows for a correct diagnosis(8,20,23,(38)(39)(40)(41)(42)(43)(44).An exertion-induced increase in stroke volume, demonstrating the existence of flow reserve with an associated rise in calculated functional AV area, suggests target workload and test endpoint achievement.It is the opinion of the current writing group that a dobutamine test can be avoided in this case. Nevertheless, some patients, particularly asymptomatic, physically active patients with incidental low-flow, low-gradient AS, might potentially achieve the target workload (20% increase in LVOT-derived stroke volume), which allows for a correct diagnosis(8,20,23,(38)(39)(40)(41)(42)(43)(44).An exertion-induced increase in stroke volume, demonstrating the existence of flow reserve with an associated rise in calculated functional AV area, suggests target workload and test endpoint achievement.It is the opinion of the current writing group that a dobutamine test can be avoided in this case.…”

Management of aortic stenosis in pregnancy

“…(6) Severe AS is also associated with a higher incidence of preterm labor, intrauterine growth retardation and lower birth weight. (1,8) The onset of symptoms in patients during pregnancy usually manifests around 20 weeks gestation when the haemodynamic load on the heart significantly increases. Onset of symptoms related to AS before this stage is a poor prognostic sign.…”

Transcatheter aortic valve implantation: revolution and evolution 10 years on

“…Next in this series of reviews, Rajani et al 26 explore the assessment of AS, a process that has taken an increasingly multimodality perspective in recent times. The 2012 ESC/EACTS guidelines continue to advocate Doppler echocardiography as the preferred technique for determining AS severity 6 27 28.…”