Aortic stenosis
Aortic stenosis (AS) refers to narrowing of the aortic valve, resulting in increased pressure load on the left ventricle. AS is mostly a disorder of the elderly (>70 years) men, and it’s the most common valvular disease. Some also have some degree of aortic regurgitation.
Etiology
In most cases, aortic stenosis is a result of dystrophic calcification and degeneration of the aortic valve with age. 1 – 2% of the population have a congenital bicuspid aortic valve, which predisposes to aortic stenosis and causes it to occur at younger ages (<70 years).
In developing countries, rheumatic fever remains a significant cause.
Clinical features
Patients usually progress from asymptomatic to symptoms during exertion to symptoms in rest. Symptoms only occur when the stenosis is severe. The most common symptom is dyspnoea and exercise intolerance, but other symptoms include angina and syncope.
A systolic crescendo-decrescendo ejection murmur is typical. It’s best heard at the punctum maximum of the aortic valve, parasternally in the 2nd right intercostal space. It may radiate to the carotids. Soft S2 is also a typical finding.
Diagnosis and evaluation
Echocardiography allows for assessment of the narrowing of the aortic valve opening area and the pressure gradient and velocity across the valve, which is increased in case of stenosis. Coronary angiography can be used to assess the degree of coronary artery disease.
A chest radiograph may show enlarged left border of the heart and dilation of the ascending aorta.
Treatment
In mild cases, regular follow-up alone might be sufficient, but the only definitive treatment is valvular replacement. This can be achieved by open surgery (surgical aortic valve replacement, SAVR) or transcatheter replacement (transcatheter aortic valve replacement, TAVR). If significant CAD is present, coronary bypass can be performed in the same setting as the surgical replacement of the valve.
Complications
- Left ventricular hypertrophy -> heart failure
- Sudden cardiac death