ESSENTIALS OF DIAGNOSIS
Usually asymptomatic until middle age; presents with left-sided failure or rarely chest pain.
Wide pulse pressure and high stroke volume leads to many of the peripheral examination findings.
Hyperactive, enlarged LV.
Diastolic murmur along left sternal border.
ECG shows LVH; radiograph shows LV dilation.
Echocardiography/Doppler is diagnostic.
Surgery for symptoms, EF < 50%, LV end-systolic dimension > 50 mm, or LV end-diastolic dimension > 65 mm.
Of all patients with isolated aortic valve disease, about 13% have predominately aortic regurgitation. Rheumatic aortic regurgitation has become much less common than in the preantibiotic era, and nonrheumatic causes now predominate. These include congenitally bicuspid valves, infective endocarditis, and hypertension. Many patients also have aortic regurgitation secondary to aortic root diseases, such as that associated with Marfan syndrome or aortic dissection. Rarely, inflammatory diseases, such as ankylosing spondylitis, may be implicated. Chronic aortic regurgitation presents both an increased preload and an increased afterload to the LV. The response to these effects is to hypertrophy by laying sarcomeres end to end, increasing the LV chamber size greater than the wall thickness (eccentric hypertrophy). The amount of LVH in chronic aortic regurgitation is substantial and greater than that seen in aortic stenosis or mitral regurgitation.
The clinical presentation is determined by the rapidity with which regurgitation develops. In chronic aortic regurgitation, the only sign for many years may be a soft aortic diastolic murmur (AUDIO 10–20). As the severity of the aortic regurgitation increases, diastolic BP falls, and the LV progressively enlarges. Most patients remain asymptomatic for long periods even at this point. LV failure is a late event and may be sudden in onset. Exertional dyspnea and fatigue are the most frequent symptoms, but paroxysmal nocturnal dyspnea and pulmonary edema may also occur. Angina pectoris or atypical chest pain may occasionally be present. Associated CAD and presyncope or syncope are less common than in aortic stenosis.
Audio 10-20. Severe aortic regurgitation due to aortic valve endocarditis.
Note the rough 3/6 mid-systolic murmur, then S2, a musical early diastolic murmur, and a mid-diastolic Austin-Flint murmur. (Reproduced, with permission, from T. Anthony Michael, MD, Mastering Auscultation [CD-ROM], McGraw-Hill, 2000.)
Hemodynamically, because of compensatory LV dilation, patients eject a large stroke volume, which is adequate to maintain forward cardiac output until late in the course of the disease. LV diastolic pressure may rise when heart failure occurs. Abnormal LV systolic function as manifested by reduced EF (less than 50%) and increasing end-systolic LV volume (greater than 5.0 cm) are signs that surgical intervention is warranted.
The major physical findings in chronic aortic regurgitation relate to the high stroke volume being ejected into the systemic vascular system with rapid runoff as the regurgitation takes place ...