Aortic regurgitation is a heart valve condition where blood leaks backward through the aortic valve into the heart’s main pumping chamber (the left ventricle) each time the heart relaxes between beats. Normally, the aortic valve acts as a one-way gate: it opens to let blood flow out to the body, then snaps shut. When the valve doesn’t close completely, some blood slips back, forcing the heart to work harder with every beat. Mild cases can go unnoticed for years, while severe cases carry a yearly mortality rate above 9% once symptoms appear.
How the Valve Fails
The aortic valve has three thin flaps (called cusps) that press tightly together when closed. Aortic regurgitation happens when these cusps no longer meet properly, a problem called malcoaptation. This can result from damage to the valve itself, a widening or distortion of the aortic root (the section of the aorta attached to the valve), or both.
When the seal is incomplete, blood flows backward into the left ventricle during the resting phase of each heartbeat. The ventricle now receives blood from two directions: the normal flow coming from the lungs and the leaked blood returning from the aorta. Over time, this extra volume stretches the ventricle, causing it to enlarge. The heart muscle thickens to compensate, and for a while, it manages to keep up. Eventually, though, the muscle can weaken, pumping efficiency drops, and heart failure develops.
This progression matters because the condition can be chronic or acute. In chronic aortic regurgitation, the heart has months or years to gradually adapt. In acute cases, such as from a sudden tear in the aorta or an infection that destroys part of the valve, the left ventricle has no time to adjust. Pressure builds rapidly, fluid backs up into the lungs, and the situation becomes a medical emergency.
Common Causes
Several conditions can damage the aortic valve or distort the aortic root enough to cause leaking:
- Bicuspid aortic valve: About 1 to 2% of people are born with only two valve cusps instead of three. This structural difference makes the valve more prone to leaking or stiffening over time.
- Age-related wear: The valve naturally degenerates with age. Calcium deposits can stiffen the cusps, preventing them from closing fully.
- Aortic root dilation: High blood pressure, connective tissue disorders like Marfan syndrome, or simply aging can widen the aorta where it attaches to the valve, pulling the cusps apart.
- Endocarditis: A bacterial infection of the heart lining can erode or perforate valve tissue, sometimes causing sudden, severe regurgitation.
- Rheumatic fever: Though less common in developed countries, this complication of untreated strep throat can scar valve cusps, leading to chronic leaking.
Symptoms and How They Develop
Chronic, mild aortic regurgitation often produces no symptoms at all, sometimes for decades. Your heart compensates quietly, and you feel fine. As the leak worsens and the heart enlarges, symptoms typically emerge gradually:
- Shortness of breath during physical activity, later progressing to breathlessness while lying down or trying to sleep
- Fatigue and reduced exercise tolerance
- Heart palpitations, often described as a pounding or racing sensation
- Chest pain
- Swelling in the ankles and feet
- Cough
- Fainting
The sneaky part of this condition is that the heart’s ability to compensate can mask the damage being done. By the time symptoms appear, the left ventricle may already be significantly enlarged or weakened. That’s why regular monitoring matters even when you feel perfectly healthy.
What Doctors Look For on Exam
Aortic regurgitation has a distinctive sound: a high-pitched, blowing murmur heard during the resting phase of the heartbeat (diastole), best detected along the left side of the breastbone. The murmur tends to start loud and fade, a pattern called decrescendo.
Severe cases also produce characteristic changes in your pulse. The pulse may feel like a strong, quick thump followed by a rapid collapse, sometimes called a “water-hammer” pulse. This happens because blood rushes forcefully out of the heart during each beat, then quickly falls back through the leaky valve. In pronounced cases, a doctor can actually see the carotid arteries in the neck visibly pulsing with each heartbeat.
How Severity Is Graded
An echocardiogram (heart ultrasound) is the primary tool for measuring how much blood is leaking. Doctors classify the regurgitation into three grades based on several measurements:
- Mild: Less than 30 mL of blood leaks back per beat, representing under 30% of the total output.
- Moderate: Between 30 and 60 mL leaks back, or 30 to 50% of output.
- Severe: More than 60 mL leaks back per beat, exceeding 50% of the total output.
Other ultrasound clues help confirm severity. A narrow jet of leaking blood suggests mild disease, while a wide jet filling more than 65% of the outflow area points to severe disease. In severe cases, blood flow actually reverses direction in the descending aorta throughout the entire resting phase of the heartbeat, a highly specific finding.
Prognosis by Stage
How aortic regurgitation affects your life depends heavily on whether symptoms have developed and how well the heart muscle is functioning. A long-term follow-up study published in Circulation tracked patients across these categories and found striking differences.
Asymptomatic patients with preserved heart function (ejection fraction of 55% or higher) had the best outlook, with a yearly mortality rate of about 2%. Once even mild symptoms appeared, that rate tripled to 6.3% per year. Patients with severe symptoms (significant breathlessness or inability to perform daily activities) faced a 24.6% yearly mortality rate without surgical intervention.
Heart function matters independently of symptoms. Asymptomatic patients whose ejection fraction had already slipped below 55% had a yearly mortality rate of 5.8%, comparable to patients with mild symptoms. This is one reason guidelines recommend intervention before symptoms force the issue.
When Surgery Is Recommended
No medication can fix a leaking aortic valve. Blood pressure drugs and other medicines can manage symptoms and reduce the strain on the heart, but they don’t address the underlying problem. Surgery is the definitive treatment for severe aortic regurgitation.
Current guidelines from both the American College of Cardiology and European Society of Cardiology agree on the core triggers for surgery. If you have severe aortic regurgitation, surgery is recommended when any of the following are present:
- Symptoms have developed (breathlessness, chest pain, fainting)
- The heart’s pumping efficiency (ejection fraction) has dropped to 55% or below by American guidelines, or 50% or below by European guidelines
- The left ventricle has enlarged beyond a critical size, specifically an end-systolic dimension greater than 50 mm
The goal is to operate before the heart muscle sustains irreversible damage. Waiting until symptoms become severe worsens outcomes significantly.
Surgical Options
The standard approach is aortic valve replacement, where the damaged valve is removed and replaced with either a mechanical valve or a biological valve made from cow, pig, or donated human tissue. Mechanical valves are extremely durable but require lifelong blood-thinning medication. Biological valves don’t require blood thinners long-term but typically wear out after 10 to 20 years, potentially requiring a second procedure.
In some cases, particularly when the valve cusps themselves are still in reasonable shape but the aortic root has widened, surgeons can repair the existing valve rather than replace it. Valve repair avoids the drawbacks of both mechanical and biological replacements, but it requires specific anatomy and surgical expertise.
For patients who are too high-risk for open-heart surgery, catheter-based valve replacement (where a new valve is threaded through a blood vessel and positioned inside the old one) is an emerging option, though it has been used far more extensively for aortic stenosis than for regurgitation.
Living With Aortic Regurgitation
If you’ve been diagnosed with mild or moderate aortic regurgitation, the condition is typically managed with regular echocardiograms to track valve function and heart size over time. How often you need imaging depends on severity: mild cases might be checked every few years, while moderate cases warrant annual or biannual monitoring.
Keeping blood pressure well controlled reduces the force driving blood backward through the leaky valve, which can slow progression. Moderate aerobic exercise is generally safe and encouraged, though heavy weightlifting and intense isometric exercises that spike blood pressure are best avoided, particularly in severe cases or when the aorta is dilated. Your cardiologist can help tailor activity recommendations to your specific situation.