Aortic Regurgitation · What Is It, Causes, Diagnosis, Treatment, and More

Aortic regurgitation, or aortic insufficiency, is a condition in which there is inadequate closure of the aortic valve during cardiac diastole, leading to the leakage of blood from the aorta into the left ventricle. As a result, there is reverse blood flow through the aortic valve.  

The aortic valve is typically made up of three leaflets and opens widely during systole to allow the ejection of blood, which is pumped from the left ventricle through the aorta to the rest of the body. During diastole, the aortic valve closes to allow the heart to fill with blood and prepare for the subsequent systole. If the valve doesn’t close completely, blood leaks back into the left ventricle, and aortic regurgitation occurs.  

Aortic regurgitation is caused by issues with the supporting structures of the aortic root, which is the first part of the aorta leaving from the heart, or inadequate closure of the aortic valve leaflets during diastole. This can be either due to an impairment of the leaflets, or an increased afterload, which is the resistance that the heart needs to overcome to open the aortic valve.  

The most common cause of aortic regurgitation is aortic root dilation, in which the aortic root becomes enlarged. It mainly occurs as a result of aging. Other causes of aortic root dilation include various conditions, such as Behcet disease, reactive arthritis, Marfan syndrome, osteogenesis imperfecta, syphilitic aortitis, and aortic dissection.  

A common cause of leaflet impairment includes aortic valve calcification. Aortic valve calcification can either result from normal aging or can be caused by congenital conditions, such as a bicuspid aortic valve, which can accelerate calcification. Other causes of leaflet impairment include infectious diseases, such as bacterial endocarditis (i.e., infective endocarditis) and rheumatic fever; inflammatory disorders such as systemic lupus erythematosus (SLE) and rheumatoid arthritis; and traumatic injury. High blood pressure, supravalvular aortic stenosis, and coarctation of the aorta (i.e., narrowing in the aorta) can also lead to aortic regurgitation by increasing the afterload. 

In the early stages of the condition, individuals with aortic regurgitation are typically asymptomatic. As aortic regurgitation develops gradually, symptoms may take years or even decades to manifest. When they do occur, symptoms include exertional dyspnea (i.e., shortness of breath upon exercise), orthopnea, (i.e., shortness of breath upon lying), paroxysmal nocturnal dyspnea (i.e., shortness of breath at night when the heart rate slows), angina (i.e., chest pain), peripheral edema (i.e., swollen ankles and feet), fainting, heart murmur, and palpitations. Sometimes, aortic regurgitation can occur acutely, typically as a result of an infection of the aortic valve, resulting in sudden shortness of breath due to pulmonary edema, where excess fluid accumulates in the lungs.  

Usually, the murmur aortic regurgitation produces is a characteristic whooshing sound that can be heard over the individual’s chest with the help of a stethoscope. The murmur can be best heard with the individual sitting up, leaning forward, and holding their breath in full expiration. These maneuvers bring the aortic valve closer to the chest wall and reduce lung sounds. 

Aortic regurgitation is also associated with classic physical examination findings that result from the consequences of the regurgitant blood flow, specifically a wide pulse pressure, which is the difference between systolic and diastolic pressure. As blood regurgitates back into the left ventricle during diastole, the diastolic pressure in the aorta decreases, leading to an increase in pulse pressure. Additionally, systolic blood pressure is often increased to compensate for the reduction in diastolic pressure, in an attempt to drive the forward flow of blood, which further widens the pulse pressure. Some of these classic clinical signs include the Becker sign, which is the visible pulsation of retinal blood vessels via an ophthalmoscope; Corrigan’s pulse, which is a rapid, forceful upstroke of the pulse followed by a sudden collapse; and the Musset sign, which is when the head bobs in sync with each heartbeat. 

Management of individuals with aortic regurgitation depends on the signs and symptoms of the disease, the degree of the left ventricular dysfunction, and whether aortic regurgitation is  acute or chronic. Individuals with mild disease usually don’t need treatment and may be monitored annually to assess the progression of aortic regurgitation. Asymptomatic individuals may be recommended surgical treatment if heart function is impaired or if there is severe left ventricular dilation. Individuals with mild to severe aortic regurgitation who experience significant symptoms or show an abnormal response to exercise testing, usually undergo surgery. Surgical treatment, which involves aortic valve replacement (AVR) is the definitive treatment of aortic regurgitation. Medical treatment, which aims at reducing the afterload and relieving symptoms, can also be used and often includes ACE inhibitors, such as ramipril, and calcium channel blockers, such as amlodipine.   

For individuals with acute aortic regurgitation emergencies, surgical treatment with aortic valve replacement is recommended to prevent life-threatening complications. Medications may also be used to stabilize the individual until surgery is performed.