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Specific clinical findings include the typical systolic ejection murmur over the aortic valve, radiating into the carotid arteries. An ejection click can be heard and a thrill may be palpable. The ECG may show LV hypertrophy (LVH) with or without strain. In patients diagnosed with a BAV, CoA should be excluded (see section 4.6). • Echocardiography is the gold standard for the diagnosis of AS and for assessing the degree of calcification, LV function, LVH, and associated lesions including ascending aortic dilatation. With Doppler echocardiography, the degree of AS severity is determined from transvalvular peak velocity (Vmax), mean gradient, and continuity equation-calculated aortic valve area (AVA). For more details, see recent recommendations for the echocardiographic assessment of AS.173 • TOE may occasionally provide more anatomical details about valve dysfunction or AVA planimetry in non-calcified valves. • Exercise testing is recommended in asymptomatic patients, particularly in moderate-to-severe AS, to confirm asymptomatic status and evaluate exercise tolerance, blood pressure response, and arrhythmias for risk stratification and timing of surgery. • Low-dose dobutamine or exercise stress echocardiography is helpful in AS with reduced stroke volume and impaired LV function (classical low-flow, low-gradient AS).173 • CMR/CCT, despite having potential for assessing AS, is mainly required to assess dilation of the ascending aorta, in cases where measurement is unreliable with echocardiography. • CCT has become particularly important for the quantification of valve calcification when assessing AS severity in lowgradient AS, although it should be noted that aortic valve

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Figure 4 Management of patent ductus arteriosus. LV = left ventricle/ventricular; Qp:Qs = pulmonary to systemic flow ratio; PAH = pulmonary artery hypertension; PDA = patent ductus arteriosus; PVR = pulmonary vascular resistance; WU = Wood units. aLV enlargement with increased stroke volume. bIncludes all patients with lower limb desaturation at rest (Eisenmenger physiology) or on exercise. cCareful individual decision in expert centres is required.

Table 12 Diagnostic criteria for degree of aortic stenosis severity173

Mild AS Moderate AS Severe AS

Vmax (m/s)a 2.62.9 3.03.9 >_4.0 Mean gradient (mmHg)a <20 2039 >_40 AVA (cm2) >1.5 1.01.5 <1.0 AVAi (cm2/m2 BSA) >0.85 0.600.85 <0.60 LVOT velocity/aortic valve velocity >0.50 0.250.50 <0.25 AS = aortic stenosis; AVA = aortic valve area; AVAi = indexed aortic valve area; BSA = body surface area; LVOT = left ventricular outflow tract; Vmax = maximum Doppler velocity. aAt normal transvalvular flow. Downloaded from academic.oup.com/eurheartj/article/42/6/563/5898606 by guest on 07 October 2026