History
Neonates with critical stenosis are typically symptomatic and present with symptoms of congestive heart failure, including poor feeding, rapid breathing, poor urine output, and fussiness, as the ductus arteriosus closes within the first few days of life and systemic blood flow decreases.
Older children are usually asymptomatic and have a systolic murmur or systolic ejection click detected during sports physical evaluation or a preschool entrance examination.
Symptomatic children may report easy fatigability. A history of syncope or anginal-type chest pain related to exertion should prompt an immediate evaluation and intervention by a pediatric cardiologist. Most often, these patients have pure aortic valve stenosis, although occasionally a patient presents with predominantly aortic valve insufficiency and minimal stenosis.
Patients who underwent intervention as neonates and have stable palliated aortic valve stenosis, insufficiency, or both require monitoring through childhood. Progression of stenosis or insufficiency may not be readily evident by history, because exercise tolerance is often well preserved until valve dysfunction becomes severe. However, careful questioning about exercise tolerance, activity levels, avoidance of strenuous activities, and the presence of dyspnea, chest pain, presyncope, or excessive nap taking may reveal subtle signs of progressive aortic valve stenosis or insufficiency.
Adolescents diagnosed for the first time with aortic valve stenosis often have a bicuspid aortic valve with mild degrees of stenosis or insufficiency. Many of these patients remain free of symptoms or problems for many years unless valve deterioration progresses.
Symptoms
Symptoms will vary based on the age at presentation and the severity of obstruction. Rarely, aortic valve stenosis may lead to sudden death during exercise or can present later in life when the valve becomes calcified.
Neonatal aortic valve stenosis
Critical aortic valve stenosis presents as congestive heart failure in the first week of life. Once the ductus arteriosus begins to close, clinical signs of heart failure occur that mimic sepsis, and a cardiac murmur may not be detectable in the setting of low cardiac output. Significant mitral valve insufficiency may add to the congestive heart failure symptoms.
If the aortic stenosis is not critical, then neonates are usually asymptomatic but present with a systolic murmur, which leads to cardiology referral. Subsequent progression of aortic valve stenosis can widely vary in rapidity and severity.
Childhood aortic valve stenosis
Older children most often present with a systolic murmur as the first sign of aortic valve stenosis. As previously mentioned, these children are usually asymptomatic.
Physical Examination
Physical examination findings differ in neonates, children, and adolescents with aortic stenosis.
Neonatal aortic valve stenosis
Neonates who present with critical aortic stenosis and low cardiac output have reduced or absent pulses and poor peripheral perfusion. This contrasts with the differential pulses that are present in patients with critical coarctation of the aorta. They are tachycardiac and tachypneic, may have significantly increased work of breathing, and appear distressed.
A systolic murmur may be unimpressive because of low cardiac output secondary to left ventricular dysfunction. A precordial thrill is rare in the neonate. A click is often difficult to discern, because the degree of tachycardia and poor excursion of the valve may make the click less noticeable.
Severe aortic valve insufficiency is rare. However, if it is present, consider the diagnosis of an aortic–left ventricular tunnel.
Childhood aortic valve stenosis
A systolic ejection murmur is present at the left middle and the right upper sternal border. A thrill in the suprasternal notch is common even with modest levels of aortic valve stenosis and helps to localize pathology to the aortic valve. An ejection click is noted along the aortic axis and often is audible at the apex when it is not heard elsewhere. A precordial thrill is less common but, when present, is usually indicative of significant aortic valve stenosis.
The apical impulse may be normal or increased, secondary to left ventricular hypertrophy/dilatation. As with other semilunar valve pathologies, the severity of obstruction is proportional to the length and grade of the systolic murmur, assuming normal ventricular function and cardiac output.
A fourth heart sound, when present, usually indicates significant left ventricular hypertrophy.
The peripheral pulses may be normal or reduced, consistent with a narrow pulse pressure, depending on the degree of obstruction. Bounding pulses (water-hammer pulses) indicate significant aortic valve insufficiency.
Adolescent aortic valve stenosis
Aortic valve stenosis in adolescents is similar to that seen in children, although older patients are more likely to have aortic valve insufficiency. A systolic ejection click is common unless associated calcification of the aortic valve results in diminished valve excursion, which is unlikely in this age group.
Maneuvers to improve auscultation include having larger patients lean forward or assume the left lateral decubitus position. Having the patient squat may accentuate the murmur of aortic insufficiency.
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Valvular calcification of aortic stenosis is seen with cardiac fluoroscopy during catheterization.
