Can aortic regurgitation cause fainting (syncope)?

From the Guidelines

Aortic regurgitation can indeed cause fainting (syncope), particularly in severe cases or during advanced stages of the disease, as it may lead to decreased blood pressure and inadequate cerebral perfusion. Syncope occurs when blood flow to the brain is temporarily reduced, leading to a brief loss of consciousness. In aortic regurgitation, the aortic valve doesn't close properly, allowing blood to leak backward into the left ventricle during diastole. This creates a situation where blood volume is inefficiently managed - some blood flows forward normally while some flows backward, reducing the effective forward cardiac output. When severe, this can lead to decreased blood pressure and inadequate cerebral perfusion, resulting in syncope, as noted in guidelines for the diagnosis and management of patients with thoracic aortic disease 1.

Key Points to Consider

• Fainting is more common during physical exertion when the heart rate increases but the compromised valve function cannot maintain adequate forward blood flow.
• Syncope in aortic regurgitation is generally considered a late and serious symptom that often indicates the need for valve replacement surgery.
• Other symptoms that may accompany syncope include shortness of breath, chest pain, palpitations, and fatigue.
• The mechanism of syncope in structural cardiac diseases, including aortic regurgitation, can be multifactorial, involving both hemodynamic impacts and neurally-mediated reflex effects, as discussed in guidelines on management of syncope 1.
• If you experience fainting with known aortic regurgitation, you should seek immediate medical attention as this may indicate disease progression requiring intervention.

From the Research

Aortic Regurgitation and Fainting (Syncope)

• Aortic regurgitation (AR) is a condition where blood flows back from the aorta into the left ventricle during diastole, which can lead to various symptoms and complications.
• While the provided studies do not directly mention fainting (syncope) as a symptom of aortic regurgitation, they do discuss the potential consequences of severe AR, such as pulmonary edema, hypotension, and left ventricular dysfunction 2, 3.
• Severe AR can cause a decrease in cardiac output, which may lead to reduced blood flow to the brain, potentially resulting in fainting (syncope).
• However, the studies suggest that symptoms such as fainting are not typically associated with chronic AR, unless there is significant left ventricular dysfunction or other comorbidities 4.
• In some cases, severe systemic hypertension can cause severe aortic regurgitation, which may lead to symptoms such as fainting, but this is rare and has not been extensively studied 5.
• The primary diagnostic test for AR is echocardiography, which can help determine the severity of the condition and its effect on left ventricular function 2, 3.
• Treatment for AR typically involves surgery, such as aortic valve replacement, or medical therapy with vasodilators to delay the need for surgery or manage symptoms 2, 4.