Aortic Regurgitation, Chronic

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• After a long asymptomatic period, presentation with heart failure, arrhythmias, or angina

• Wide pulse pressure with associated peripheral signs

• Diastolic decrescendo murmur at left sternal border

• Left ventricular (LV) dilation and hypertrophy with preserved function

• Diagnosis confirmed and severity estimated by Doppler echocardiography or aortography

GENERAL CONSIDERATIONS

• Caused by diseases of the valve leaflets or aortic root (dilatation), or high blood pressure

• Root diseases: Marfan’s syndrome, cystic medial necrosis, aortic dissection, syphilis, and connective tissue diseases such as ankylosing spondylitis

• Leaflet diseases: rheumatic, infectious endocarditis, congenital and connective tissue diseases such as rheumatoid arthritis

• Causes a volume load on the LV, which, if progressive, eventually leads to LV dysfunction

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Most remain asymptomatic for years

• Palpitation: arrhythmias or awareness of forceful heartbeat

• Angina pectoris, mechanism: low diastolic pressure plus LV hypertrophy

• Dyspnea and fatigue when LV dysfunction supervenes

• Congestive heart failure symptoms: orthopnea and edema

PHYSICAL EXAM FINDINGS

• Bounding peripheral pulses with wide pulse pressure

• Enlarged apical impulse

• Auscultation: LV gallops, high-pitched decrescendo murmur at the right second (aortic area) or left third intercostal space, systolic ejection murmur, occasional apical diastolic rumble (Austin Flint murmur)

DIFFERENTIAL DIAGNOSIS

• Pulmonic regurgitation associated with high pulmonary pressures (Graham Steell murmur)

• Patent ductus arteriosus; at fast heart rates, the systolic and diastolic murmurs of aortic regurgitation may resemble a continuous murmur

• Mitral stenosis mimicking an Austin Flint murmur

• Arteriovenous malformation with wide pulse pressure

• Arteriovenous fistula near heart with continuous murmur

• Left anterior descending coronary artery stenosis

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• Tests pertinent to potential causes or prognosis:

  • – Antinuclear antibody test for connective tissue disease

  • – B-type natriuretic peptide levels to assess the degree of volume loading.

ELECTROCARDIOGRAPHY

• LV hypertrophy

• Left atrial enlargement

• Ventricular arrhythmias (ectopic beats)

STRESS TESTING

• Treadmill exercise is useful to evaluate patients with equivocal symptoms or guide those interested in participating in athletic activities

• Semi-supine bicycle exercise echocardiography is useful for determining the effect of exercise on estimated pulmonary artery systolic pressure (PASP); rises in PASP to > 50 mm Hg suggest hemodynamically significant aortic regurgitation

IMAGING STUDIES

• Chest x-ray: cardiomegaly, aortic dilatation, pulmonary vascular congestion

• Echocardiography: LV and left atrial enlargement, eccentric ventricular hypertrophy

• Doppler echocardiography; severity can be assessed by:

  • – Width of color flow jet at its origin relative to LV outflow tract diameter

  • – Calculated regurgitant volume and fraction of forward flow from pulsed-wave Doppler comparison of LV outflow to mitral valve inflow

  • – Regurgitant pressure half-time by continuous-wave Doppler

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