Low-flow, low-gradient, normal ejection fraction aortic stenosis

A substantial proportion of patients with severe aortic stenosis may paradoxically have low transvalvular flow and a low gradient, despite the presence of normal left ventricular (LV) ejection fraction. These patients are characterized by pronounced LV concentric remodeling with small LV cavity size, impaired LV filling, altered myocardial function, and worse prognosis. This frequent clinical entity is often misdiagnosed, which may lead to an underestimation of aortic stenosis severity and thereby to underutilization or inappropriate delay of surgery. It is important to recognize this entity so we do not deny surgery to a symptomatic patient with small aortic valve area and low gradient. Thus, when there is a discordance between the valve area (in the severe range) and the gradient (in the moderate range) in patients with preserved LV ejection fraction, a more comprehensive Doppler echocardiographic evaluation and potentially other diagnostic tests may be required to confirm disease severity and guide therapeutic management.