Aortic Regurgitation Clinical Presentation

Acute aortic regurgitation

The typical presentation of acute severe aortic regurgitation (AR) includes sudden, severe shortness of breath, rapidly developing heart failure, and chest pain if myocardial perfusion pressure is decreased or an aortic dissection is present. Because the LV is non-compliant in acute cases, the LV end-diastolic pressure is high resulting in a smaller diastolic gradient across the aortic valve and, in some cases, a short or minimal diastolic murmur on examination. Cases may be fulminant and lead to cardiogenic shock. Early surgical intervention is recommended in cases due to infective endocarditis, and emergent intervention is warranted in cases due to aortic dissection.

Chronic aortic regurgitation

Patients with chronic AR often have a long-standing asymptomatic period that may last for several years. A compensatory tachycardia may develop to maintain a large forward stroke volume, resulting in a decreased diastolic filling period. As a result, patients may be asymptomatic even with exercise. Over time, chronic volume overload eventually leads to LV dysfunction as the LV dilates. Significant deterioration of LV function may begin prior to the development of symptoms in up to one-fourth of patients, highlighting the importance of periodic echocardiographic surveillance.^[5] Among patients with asymptomatic LV dysfunction, more than one-fourth develop symptoms within 1 year. Once symptoms arise, cardiac function usually worsens more rapidly and mortality may exceed 10% per year.

Symptoms of chronic severe AR include the following:

• Palpitations, often described as the sensation of having forceful heart beats, due to widened pulse pressure with hyperdynamic circulation
• Shortness of breath, which may not worsen with exertion in the early stages due to compensatory tachycardia with shortened diastole
• Chest pain, if LV end-diastolic pressure compromises coronary perfusion pressure gradients
• Sudden cardiac death, although this is uncommon (< 0.2%/y) in asymptomatic patients with preserved LV function

Many classical physical examination findings have been described in patients with chronic severe AR. However, these findings may be minimally present (if at all) in patients with acute severe AR.

Manifestations of chronic severe AR are often the result of widened pulse pressure (ie, an exaggerated difference between systolic and diastolic blood pressure) because (1) of elevated stroke volume during systole and (2) the incompetent aortic valve allows the diastolic pressure within the aorta to fall significantly. Diastolic pressures are often lower than 60 mm Hg with pulse pressures (ie, the difference between the systolic and diastolic pressure) often exceeding 100 mm Hg, although younger patients with more compliant vessels may have a less widened pulse pressure. Many physical examination findings have associated eponyms.

• Becker sign - Visible systolic pulsations of the retinal arterioles
• Corrigan pulse ("water-hammer" pulse) - Abrupt distention and quick collapse on palpation of the peripheral arterial pulse
• de Musset sign - Bobbing motion of the patient's head with each heartbeat
• Hill sign - Popliteal cuff systolic blood pressure 40 mm Hg higher than brachial cuff systolic blood pressure
• Duroziez sign - Systolic murmur over the femoral artery with proximal compression of the artery, and diastolic murmur over the femoral artery with distal compression of the artery
• Müller sign - Visible systolic pulsations of the uvula
• Quincke sign - Visible pulsations of the fingernail bed with light compression of the fingernail
• Traube sign ("pistol-shot" pulse) - Booming systolic and diastolic sounds auscultated over the femoral artery

On palpation, the point of maximal impulse may be diffuse or hyperdynamic but is often displaced inferiorly and toward the axilla. Peripheral pulses are prominent or bounding. Auscultation may reveal an S₃ gallop if LV dysfunction is present. The murmur of AR occurs in diastole, usually as a high-pitched sound that is loudest at the left sternal border. The duration of the murmur correlates better with the severity of AR than the loudness of the murmur. A functional systolic flow murmur may also be present because of increased stroke volume, although concurrent aortic stenosis may also be present. An Austin Flint murmur may be present at the cardiac apex in severe AR and is a low-pitched, mid-diastolic rumbling murmur due to blood jets from the AR striking the anterior leaflet of the mitral valve, which results in premature closure of the mitral leaflets.

In many cases, physical examination also reveals findings relating to the underlying cause. For example, there may be various embolic phenomena in patients with AR due to infective endocarditis or skeletal features suggestive of Marfan syndrome or a spondyloarthropathy if AR is due to these conditions.

Acute aortic regurgitation

• Infective endocarditis may lead to destruction or perforation of the aortic valve leaflet. A bulky vegetation can also interfere with proper coaptation of the valve leaflets or cause lead to frank prolapse or disruption of a leaflet (flail leaflet).
• In acute ascending aortic dissection (type A), the retrograde proximal dissection undermines the suspensions of the aortic valve leaflets. Varying levels of aortic valve malcoaptation and prolapse occur.
• Prosthetic valve malfunction can lead to AR.
• Chest trauma may lead to a tear in the ascending aorta and disruption of the aortic valve support apparatus.

Chronic aortic regurgitation

• Bicuspid aortic valve is the most common congenital lesion of the human heart and leads more commonly to progressive aortic stenosis, but is also the most common cause of isolated AR requiring aortic valve surgery. In addition, an associated aortopathy may be present, resulting in aortic dilation and/or dissection that worsens the AR.^[8]
• Connective tissue disorders, including Marfan syndrome, Ehlers-Danlos syndrome, floppy aortic valve, aortic valve prolapse, sinus of Valsalva aneurysm, and aortic annular fistula can all lead to significant AR.
• Certain weight loss medications, such as fenfluramine and dexfenfluramine (commonly referred to as Phen-Fen), may induce degenerative valvular changes that result in chronic AR.
• Rheumatic fever was a common cause of AR in the first half of the 20th century but has become less common in the United States, although it remains prevalent in some immigrant populations. Fibrotic changes cause thickening and retraction of the aortic valve leaflets, resulting in central valvular regurgitation. Leaflet fusion may occur, resulting in concurrent aortic stenosis. Associated rheumatic mitral valve disease is almost always present.
• Ankylosing spondylitis often causes an aortitis that most frequently involves the aortic root with associated AR.^[9] Further extension of the subaortic fibrotic process into the intraventricular septum may result in conduction system disease. Coronary and more distal aortic abnormalities are also seen in this condition.
• Behcet disease rarely causes cardiac complications (< 5% of patients) but potential findings include proximal aortitis with AR as well as coronary artery disease.^[10]
• Giant cell arteritis is a systemic vasculitis that typically affects the extracranial branches of the carotid artery but may also cause aortic inflammation and AR (as well as coronary artery disease and LV dysfunction.^[11]
• Rheumatoid arthritis uncommonly causes granulomatous nodules to form within the aortic valve leaflets and, in rare cases, this may lead to clinical AR, although it is more commonly an incidental finding postmortem.^[12]
• Systemic lupus erythematosus can cause valvular fibrosis and consequent dysfunction, including AR.^[13] Lupus is also associated with Libman-Sacks endocarditis, resulting in sterile verrucous valvular vegetations that can cause AR.^{[14, 15]}
• Takayasu arteritis can produce an aortitis in addition to aortic valve (and coronary) involvement. The aortitis may increase the risk of prosthetic valve detachment, leading some to advocate for concurrent aortic root replacement in patients undergoing valve surgery.^[16]
• Whipple disease has been reported in the literature in association with AR or aortic valve endocarditis.^[17]