The Gatekeeper of the Body: A Guide to the Aortic Valve
Updated: 6 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD | Last reviewed: October 7, 2026
Quick Answer: What is the aortic valve?
The aortic valve is one of your four heart valves, sitting between the left ventricle and the aorta [1], typically with three leaflets that open and close with each heartbeat to keep blood flowing out of the heart. Malfunction can cause stenosis or regurgitation, and treatment ranges from monitoring and lifestyle changes to procedures such as minimally invasive TAVR.
What the research says
For severe aortic stenosis, TAVR and open surgery have not been shown to differ in overall survival, but their side effects differ. A systematic review and meta-analysis of nine randomized trials (8,818 participants) found no overall difference in all-cause mortality (30 days: risk ratio 0.89, 95% CI 0.65–1.22; 5 years: RR 1.09, 95% CI 0.98–1.22) or stroke. TAVR was linked to a shorter hospital stay (mean difference −3.08 days) and less major bleeding, acute kidney injury and new atrial fibrillation, but more major vascular complications and pacemaker implantation. All the trials were rated at high risk of bias (Swift et al., BMJ Open, 2021) [2].
TAVR also appears feasible in older adults with a bicuspid aortic valve, though the evidence is limited. A meta-analysis of seven studies (149 patients with a bicuspid valve and 2,096 without) found similar 30-day mortality (8.3% vs 9.0%, P = 0.68) and no significant differences in vascular complications (8.6% vs 10.1%) or major bleeding (20% vs 16.8%); the authors called for larger studies of long-term durability (Phan et al., Heart, Lung and Circulation, 2015) [3].
Where is the aortic valve, and what is its anatomy?
The aortic valve sits near the middle of the heart [1], at the junction between the left ventricle (the chamber that pumps blood to the entire body) [1] and the aorta. It is called a semilunar valve because its flaps, known as leaflets or cusps, resemble crescent moons [1]. The aortic valve is one of two semilunar valves; the other is the pulmonary valve, which sits in front of it and slightly to its left [1]. In a healthy heart, the aortic valve has three leaflets made of strong, flexible collagen.
Some people are born with a bicuspid aortic valve, which has only two leaflets instead of three [1]. This congenital variation can increase the risk of circulatory problems later in life [1].
Component | Description | Primary role |
Left ventricle | The heart’s main pumping chamber | Pumps oxygen-rich blood through the aortic valve |
Leaflets (cusps) | Three crescent-shaped collagen flaps | Open to allow flow; close to prevent backflow |
Aorta | The body’s largest artery | Receives blood from the valve and distributes it to the body |
Semilunar design | The crescent-moon shape of the flaps | Helps the valve seal tightly and open efficiently |
How does the aortic valve work during the cardiac cycle?
The aortic valve works as a one-way gate within the cardiac cycle. The right side of the heart pumps blood to the lungs, where oxygen levels are restored, and the blood then returns to the left side of the heart [1].
When the left ventricle contracts, the pressure forces the aortic valve open and blood surges into the aorta. Right after the contraction, the leaflets come together and seal, so no blood leaks back into the heart [1]. This one-way flow is essential for maintaining blood pressure and delivering oxygen and nutrients to the organs.
What conditions affect the aortic valve, and how are they treated?
Aortic valve stenosis occurs when the valve narrows [1], forcing the heart to work harder to push blood through a smaller opening. Aortic valve regurgitation happens when the valve does not close properly, so blood leaks backward into the ventricle [1]. Endocarditis, inflammation of the heart’s inner lining [1], can also damage the valve.
Treatment depends on severity. See a provider if you have chest pain or tightness, shortness of breath, or dizziness or fainting with activity, and call 911 for sudden chest pain or fainting. If symptoms are severe, your healthcare provider may recommend surgery to repair or replace the valve [1]. Many people with aortic stenosis also qualify for TAVR (transcatheter aortic valve replacement), also called TAVI, a less invasive way to replace the valve using a catheter, without open-heart surgery [1].
A note from the experts: The aortic valve controls blood flow into the aorta and keeps blood moving in one direction. Some heart conditions can affect it, and if symptoms are severe, your provider may recommend repairing or replacing the valve [1].
How can you keep your heart and aortic valve healthy?
Some valve problems are present from birth, but you can support your heart overall by managing your cardiovascular health. Key strategies include maintaining a healthy weight, eating a diet rich in fruits and vegetables, getting at least 30 minutes of exercise most days of the week, managing stress and avoiding smoking [1].
Frequently Asked Questions
What is the aortic valve?
The aortic valve is a semilunar valve that connects the left ventricle to the aorta.
How many leaflets does a normal aortic valve have?
A typical aortic valve has three leaflets made of collagen.
What is a bicuspid aortic valve?
A congenital condition in which the valve has only two leaflets instead of three.
What is the primary function of the aortic valve?
To make sure blood flows in one direction, from the heart into the aorta.
What happens when the aortic valve opens?
Blood flows from the left ventricle into the aorta to be distributed to the body.
Why does the aortic valve close?
To prevent blood from leaking back into the heart from the aorta.
What is aortic valve stenosis?
A condition in which the valve narrows, restricting blood flow.
What is aortic valve regurgitation?
A condition in which blood leaks backward because the valve does not close tightly.
What is endocarditis?
Inflammation of the heart’s inner lining that can affect the valves.
What is TAVR?
A less invasive procedure that replaces the aortic valve using a catheter instead of open-heart surgery. It may be an option for people with aortic valve stenosis.
Where is the aortic valve located?
Between the left ventricle and the aorta, near the middle of the heart.
What is a semilunar valve?
A valve with crescent-moon-shaped flaps, like the aortic and pulmonary valves.
Can lifestyle changes help valve health?
Yes. A healthy diet, regular exercise and not smoking improve overall heart health.
How long should I exercise for heart health?
Aim for at least 30 minutes on most days of the week.
What should I ask my doctor about my aortic valve?
Ask how your valves are working and what treatment options are available if problems arise.
Related reading on Rinnit
Sources
Cleveland Clinic. Aortic Valve. Cleveland Clinic. Last updated February 23, 2022. https://my.clevelandclinic.org/health/body/22458-aortic-valve
Swift SL, Puehler T, Misso K, et al. Transcatheter aortic valve implantation versus surgical aortic valve replacement in patients with severe aortic stenosis: a systematic review and meta-analysis. BMJ Open. 2021;11(12):e054222. PMID 34873012. https://doi.org/10.1136/bmjopen-2021-054222
Phan K, Wong S, Phan S, et al. Transcatheter Aortic Valve Implantation (TAVI) in Patients With Bicuspid Aortic Valve Stenosis--Systematic Review and Meta-Analysis. Heart Lung Circ. 2015;24(7):649-659. PMID 25818374. https://doi.org/10.1016/j.hlc.2014.12.163
Medical disclaimer
This article is provided for general educational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified healthcare provider with any questions about a medical condition.
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