Role of stress testing in diagnostics of aortic stenosis

Abstract

Aortic valve stenosis (AS) is the most common valvular disease in developed countries. It occurs due to progressive degenerative changes and calcification that cause increased leaflet stiffness, narrowed aortic valve orifice and increased transaortic valve pressure gradient. Aortic stenosis is usually diagnosed during routine physical examination that reveals typical systolic murmur. Symptoms such as: dizziness, angina or syncope usually occur in advanced stenosis. Sometimes the first manifestation of AS is heart failure. The onset of severe symptoms is of a bad prognostic value and requires aortic valve replacement. The key diagnostic modality in AS is resting echocardiography, but in some specific situations stress tests provide significant diagnostic and prognostic information. Exercise testing is safe and important in risk stratification in patients with severe asymptomatic AS. It can help identify patients who are at high risk and in whom early surgery can be beneficial. In asymptomatic patients with normal response to exertion, stress exercise echocardiography can unmask hemodynamic abnormalities and facilitate decision concerning operative treatment. Dobutamine stress echocardiography is appropriate in patients with reduced ejection fraction (EF) to differentiate between severe low-flow, low-gradient AS and pseudo-severe AS in patients with reduced EF due to other reasons than progressive left ventricle pressure overload.