Clinical challenges in accurate assessment of severe aortic stenosis with a special focus on low-gradient aortic stenosis and normal ejection fraction

Aortic stenosis (AS) is one of the most common valvular disorders affecting the aging US population. Although guidelines published by leading cardiac societies outline diagnostic and management strategies for this condition, in daily practice clinicians face dilemmas when trying to confirm the diagnosis of severe AS because of discrepancies in quantitative parameters obtained by echocardiography and cardiac catheterization. More recently, a low-gradient variant of severe AS has been increasingly recognized in the setting of normal ejection fraction. This review focuses on the current clinical challenges of AS diagnosis with a special focus on paradoxical low-flow low-gradient AS in the setting of preserved ejection fraction. We evaluate all aspects of AS quantitation in reference to paradoxical low flow aortic stenosis and discuss newer parameters which may help the clinician reconcile some of the discrepancies of this less understood condition.