cardiovascular disorders
Aortic Stenosis
Diagnosis of Aortic Stenosis
Echocardiography Diagnosis of aortic stenosis is suspected clinically and confirmed by Echocardiography . Two-dimensional transthoracic echocardiography is used to identify a stenotic aortic valve and possible causes, to quantify LV hypertrophy and degree of systolic dysfunction, and to detect coexisting valvular heart disorders (aortic regurgitation, mitral valve disorders) and complications (eg, endocarditis). Doppler echocardiography is used to quantify degree of stenosis by measuring jet velocity, transvalvular systolic pressure gradient, and aortic valve area. Severityof aortic stenosis is characterized echocardiographically as Mild: Peak aortic jet velocity 2.5 to 2.9 m/second, mean gradient 10 to 20 mm Hg, or valve area 1.5 to 2.0 cm2 Moderate: Peak aortic jet velocity 3 to 4 m/second, mean gradient 20 to 40 mm Hg, or valve area 1.0 to 1.5 cm2 Severe: Peak aortic jet velocity > 4 m/second, mean gradient > 40 mm Hg, or valve area<1.0 cm2 Very severe: Peak aortic jet velocity > 5 m/second or mean gradient > 60 mm Hg Clinical judgment and critical review of the data are used to resolve any discordance among these parameters (eg, moderate valve area but severe mean gradient). Quantification of aortic valve stenosis is least accurate when LV volume or systolic function is reduced, or when systemic hypertension is present. The gradient may be overestimated when Aortic Regurgitation is present. The gradient may under-represent severity when the stroke volume is low, eg, in patients with systemic hypertension or LV systolic dysfunction (low-gradient AS with reduced EF) or a small, hypertrophied LV (low-gradient AS with normal EF—see table Sometimes LV systolic dysfunction results in low ventricular pressure that is inadequate to open nonstenotic valve leaflets, causing echocardiographic appearance of low valve area in the absence of stenosis (pseudostenosis). Differentiation of pseudostenosis from low-gradient AS can be aided by calculation of the ratio of outflow tract to aortic velocity (Doppler velocity index [DVI]). A DVI value < 0.25 suggests true severe stenosis. Assessment of the degree of valve calcification by CT can help determine the severity of AS. Severe AS is likely when the valvular calcium score is > 2000 (men) and > 1300 (women). It is very likely when the calcium score is > 3000 (men) and > 1600 (women). Low-dosedobutaminestress echocardiography distinguishes low-gradient AS from pseudostenosis. Cardiac Catheterization None An ECG and chest x-ray are obtained. Electrocardiography None Chest x-rayfindings may include calcification of the aortic cusps (seen on the lateral projection or on fluoroscopy) and evidence of heart failure. Heart size may be normal or only mildly enlarged. Stress Testing None 1.Otto CM, Nishimura RA, Bonow RO, et al: 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines.Circulation143(5):e35–e71, 2021. doi: 10.1161/CIR.0000000000000932 