Aortic Valve Regurgitation

• • Aortic valve (AV): Usually tricuspid, composed of fibrous skeleton, 3 cusps, and sinuses of Valsalva

  • Free edge of each cusp is concave and thicker, with fibrous node at midpoint

  • During systole: Eddy currents in sinuses of Valsalva prevent occlusion of coronary ostia

  • During diastole: Cusps fall closed and coapt, supports ejected column of blood

  • Coronary arteries arise from 2 of 3 sinuses of Valsalva

  • Aortic regurgitation (AR) is caused by abnormal coaptation of valve leaflets, allowing blood to return from aorta to ventricle during diastole

  • Etiology of chronic AR:

  • -Rheumatic dilation

    -Annuloaortic ectasia

    -Cystic medial necrosis

    -Atherosclerosis

    -Syphilis

    -Arthritic inflammatory disease

    -Congenital bicuspid valve

  • Etiology of acute AR:

  • -Endocarditis

    -Acute aortic dissection

    -Trauma

  • LV becomes eccentrically hypertrophied and dilated

Epidemiology

• • Causes of valve disease: rheumatic carditis (most common), valve collagen degeneration, infection

  • Less common causes: Collagen-vascular disease, tumors, carcinoid, and Marfan syndrome

Symptoms and Signs

• • Acute AR:

  • -Poorly tolerated

    -Severe pulmonary edema, congestive heart failure (CHF)

    -If diastolic murmur absent, indicates complete valve incompetence

  • Chronic AR:

  • -Patients with early disease are asymptomatic

    -Orthopnea, paroxysmal dyspnea, and CHF develops later

  • Wide pulse pressure, diastolic pressure low (Corrigan pulse)

  • Apical impulse: Sustained and lateral and inferiorly displaced

  • Blowing high-pitched diastolic murmur heard at left lower sternal border at full expiration

  • Third heart sound may be present

  • Austin-Flint murmur: Diastolic rumbling—secondary mitral valve obstruction

Laboratory Findings

• • ECG: LV hypertrophy with left axis deviation

Imaging Findings

• • Chest film

  • -Usually normal cardiac size

    -If chronic AR, LV enlargement, pulmonary congestion

  • Echocardiography: Demonstrates LV function, chamber size, degree of regurgitation

  • Catheterization: Define degree of AR and coronary artery, aortic root anatomy

• • Evaluate for other valvular disease and secondary LV dysfunction

• • Echocardiographic measurement of LV dimensions: Significant ventricular dilation = LV end-diastolic dimension > 70 mm, or end-systolic > 50 mm

• • Vasodilator therapy

  • -Useful in asymptomatic patients

    -Will not prevent need for future surgery

  • AV replacement is standard

  • Select patients can have valve repair with subcommissural annuloplasty if the lesion is simple annular dilation

Surgery

Indications

• • Replace valve before onset of irreversible LV dilation (see Work-up)

Prognosis

• • Medical therapy: 5- and 10-year mortality in severe AR is 25% and 50%, respectively

  • 5-year survival postoperatively with normal ventricular function is 85%

  • Abnormal LV function affects long-term survival

References