Evaluation
Continuous-wave Doppler echocardiography can reliably estimate the severity of AS, especially in the presence of normal cardiac output, which is the case in the great majority of those engaging in competitive sports (13).
Symptoms of dyspnea, syncope, or angina pectoris occur late in the course of AS (14), and the likelihood of sudden death increases significantly with the onset of symptoms. Because even transient symptoms are so important in marking the onset of increased risk of sudden death, the physician must be aware that dyspnea, near-syncope, and even syncope are likely to be unreported in competitive athletes. Although sudden death is more frequent in symptomatic patients with severe AS, it may also occur in completely asymptomatic patients (15). When doubt persists with regard to the severity of AS after Doppler study, or if a patient with mild-to-moderate AS has symptoms, cardiac catheterization should be performed. Sudden death is rare with mild AS.
Athletes with a history of syncope, even with mild AS, should be carefully evaluated by a cardiologist. This should include assessment of arrhythmias with exercise. Syncope should be regarded as a possible surrogate for spontaneously aborted sudden death and should be thoroughly investigated (see Task Force 7: Arrhythmias).
Severity of AS measured by continuous-wave Doppler echocardiography (or in those instances previously noted by cardiac catheterization) is categorized as follows with respect to the calculated aortic valve area: mild = greater than 1.5 cm2; moderate = 1.0 to 1.5 cm2; and severe = less than or equal to 1.0 cm2 (5). This translates roughly (assuming that athletes have normal cardiac output) to the estimated mean aortic valve pressure gradient as follows: mild = less than 25 mm Hg; moderate = 25 to 40 mm Hg; and severe = greater than 40 mm Hg (5).
Because AS is often progressive, periodic re-evaluation at least yearly is necessary and should be performed by a physician with expertise in cardiology. This reassessment includes physical examination and Doppler echocardiography, but may require cardiac catheterization in selected patients as previously noted. In addition, Holter monitoring with intense exercise resembling competition is recommended to detect ventricular arrhythmias in patients with AS who wish to participate in competitive athletics.
In patients with AS, a markedly elevated cardiac output or peripheral vascular resistance for sustained periods of time could result in an exaggerated valvular gradient and a marked increase in LV systolic pressure. Given these precautions, the following recommendations can be made.
Recommendations:
1 Athletes with mild AS can participate in all competitive sports, but should undergo serial evaluations of AS severity on at least an annual basis.
2 Athletes with moderate AS can engage in low-intensity competitive sports (class IA). Selected athletes may participate in low and moderate static or low and moderate dynamic competitive sports (classes IA, IB, and IIA) if exercise tolerance testing to at least the level of activity achieved in competition demonstrates satisfactory exercise capacity without symptoms, ST-segment depression or ventricular tachyarrhythmias, and with a normal blood pressure response. Those athletes with supraventricular tachycardia or multiple or complex ventricular tachyarrhythmias at rest or with exercise can participate only in low-intensity competitive sports (class IA).
3 Patients with severe AS or symptomatic patients with moderate AS should not engage in any competitive sports.
