Aortic Stenosis

Key Features

Essentials of Diagnosis

• Harsh systolic ejection murmur at the upper right sternal border with radiation to the neck

• Thrill in the carotid arteries

• Systolic click at the apex

• Dilation of the ascending aorta on chest radiograph

General Considerations

• Defined as obstruction to outflow from the left ventricle (LV) at or near the aortic valve producing a systolic pressure gradient > 10 mm Hg between the LV and aorta

• Accounts for approximately 7% of congenital heart disease

Clinical Findings

Symptoms and Signs

• Although isolated valvular aortic stenosis seldom causes symptoms in infancy, severe heart failure occasionally occurs when critical obstruction is present at birth

• Physical findings vary depending on the anatomic type of lesion

  • Valvular

  • Subvalvular

  • Supravalvular

• Valvular aortic stenosis

  • Diminished pulses with a slow upstroke if gradient is > 80 mm Hg

  • LV thrust at the apex

  • A systolic thrill at the right base, the suprasternal notch, and over both carotid arteries

  • A prominent aortic ejection click at the apex

  • A loud, rough, medium- to high-pitched ejection-type systolic murmur

    • Loudest at the first and second intercostal spaces, radiating well into the suprasternal notch and along the carotids

    • Grade of the murmur correlates well with the severity of the stenosis

• Subvalvular aortic stenosis

  • Findings are the same as those of valvular aortic stenosis except for the absence of a click

  • Murmur and thrill are usually more intense at the left sternal border in the third and fourth intercostal spaces

  • In the setting of aortic insufficiency, a diastolic murmur is commonly heard

  • Risk of sudden death highest in this type of stenosis

• Supravalvular aortic stenosis

  • Chest pain with exercise, dizziness, and syncope manifest in the first decade in a small percentage of patients

  • There may be a difference in pulses and blood pressure between the right and left arms if the narrowing is just distal to the takeoff of the innominate artery, with more prominent pulse and pressure in the right arm (the Coanda effect)

  • Mild exercise intolerance and fatigability

  • Thrill and murmur are best heard in the suprasternal notch and along the carotids but are well transmitted over the aortic area and near the mid left sternal border

Diagnosis

Imaging

• LV may be slightly prominent, but heart is not enlarged in most cases

• Dilation of the ascending aorta is frequently seen in valvular aortic stenosis

• Echocardiography

  • Doppler accurately estimates the transvalvular gradient

  • Level of obstruction can be confirmed by both two-dimensional echocardiographic images and by the level of flow disturbance revealed by color Doppler

Diagnostic Procedures

• Electrocardiography

  • Normal in mild cases

  • LV hypertrophy and LV strain may be seen in severe obstruction

  • Progressive LV hypertrophy on serial ECGs indicates significant obstruction

  • LV strain is an indication ...