Aortic Stenosis

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• Angina pectoris

• Dyspnea (left ventricular [LV] heart failure)

• Effort syncope

• Midsystolic murmur radiating to the carotid arteries

• Carotid upstroke delayed in reaching its peak and reduced in amplitude (parvus et tardus)

• Echocardiography shows thickened, immobile aortic valve leaflets

• Doppler echocardiography quantifies increased transvalvular mean and peak pressure gradients and reduced valve area

GENERAL CONSIDERATIONS

• Definition/description:

  • – Narrowing of the aortic valve orifice due to failure of the aortic leaflets to open fully

• Etiology/risk factors:

  • – Aortic valve degeneration caused by inflammation, lipid accumulation, and calcification, and has same risk factor profile as atherosclerosis

  • – This pathologic process is undoubtedly related to genetic polymorphisms but can be accelerated in younger individuals with end-stage renal disease, Paget’s disease, and familial hypercholesterolemia.

  • – Rheumatic fever is less frequently a cause in the developed world and almost always occurs with mitral valve disease and has concomitant aortic regurgitation

  • – Connective tissue diseases such as systemic lupus erythematosus can also cause aortic stenosis (AS)

• Demographics:

  • – More common in men

  • – Rheumatic AS usually clinically manifests in middle age

  • – Degenerative AS is a disease of the elderly

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Angina pectoris

• Effort syncope

• Dyspnea

PHYSICAL EXAM FINDINGS

• There is a long latent period in which a basal systolic murmur can be heard that becomes more intense with time

• Harsh, medium-pitched, midsystolic murmur heard best in the aortic area, usually grade II–IV and may be heard at the apex

• Low-amplitude, delayed carotid artery upstroke (pulsus parvus et tardus), occasionally with a palpable shudder

• Soft second heart sound, occasionally with reversed splitting in severe cases

• Fourth heart sound

• Increased amplitude and duration of apical impulse

• Possible signs of congestive heart failure

DIFFERENTIAL DIAGNOSIS

• Discrete subvalvular AS

• Supravalvular AS

• Hypertrophic obstructive cardiomyopathy

• Pulmonic stenosis

• Ventricular septal defect

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• Occasionally hemolytic anemia seen in severe cases

• Patients with a history of bleeding may exhibit reduced factor VIII and von Willebrand factor antigen levels

• Natriuretic peptide levels often elevated in symptomatic patients

ELECTROCARDIOGRAPHY

• LV hypertrophy, left atrial enlargement

EXERCISE TESTING

• Treadmill exercise testing can be cautiously done to ascertain whether the patient is symptomatic or not

IMAGING STUDIES

• Chest x-ray:

  • – Normal heart size with LV prominence

  • – Occasionally a dilated ascending aorta

  • – Occasionally aortic valve calcification in severe cases

• Transthoracic echocardiography:

  • – Thickened and calcified aortic valve leaflets with reduced mobility

  • – Concentric LV hypertrophy

  • – Left atrial enlargement

• Doppler echocardiography:

  • – Peak and mean pressure gradients across the ...