Clinical approach to severe aortic stenosis with low flow and low gradient

Treatment of aortic stenosis is based on the aortic valve area and mean gradient. Five to 10% of the patients with severe aortic stenosis have low gradient and low ejection fraction, while 30% patients have low gradient and preserved ejection fraction. Low ejection fraction may result from afterload mismatch or left ventricular systolic dysfunction. Low gradient in patients with preserved ejection fraction may be caused by significant concentric remodeling, small left ventricle cavity, and intrinsic myocardial dysfunction. The existence of low gradient leads to overlooked symptoms and delayed decision of operation. However, these two patient groups may benefit more from surgery compared to medical therapy.