Why Does a Heart Murmur in an Older Adult Sometimes Mean Aortic Stenosis?

A heart murmur in an older adult is often a harmless sound, but it can also be the first clue to aortic stenosis, a narrowing of the aortic valve that restricts blood flow out of the heart. The murmur alone does not diagnose anything; clinicians combine its character with your symptoms and an echocardiogram. Chest pain, fainting, or breathlessness with exertion make the question more urgent. This article covers why murmurs happen, how aortic stenosis is found, and when to get care.

What a heart murmur in an older adult actually is

A murmur is a sound, not a disease. Healthy blood flow through the heart is usually quiet to a stethoscope. A murmur is an extra "whooshing" or "swishing" noise that can come from faster-than-usual flow, from blood passing through a narrowed opening, or from blood leaking backward through a valve that does not close fully.

Many murmurs are found at a routine visit in people who feel completely well. Some are called innocent or functional, meaning the heart valves and structure look normal on further testing. Others are linked to a valve problem. Researchers in the Tromsø Study, a population-based project, looked at how common murmurs are in the general population and how useful they are for finding valve disease, which shows that a murmur is a reason to look further and not a verdict by itself (Heart murmurs in the general population).

In older adults, murmurs are worth a closer look because age-related changes in the valves are common. Fever, anemia, an overactive thyroid, and other conditions can also make blood flow faster and produce a murmur that fades once the cause is treated.

How the aortic valve works, and how it narrows

The aortic valve sits between the left ventricle, the heart's main pumping chamber, and the aorta, the large artery that carries blood to the body. It has leaflets that open wide with each beat and close tightly between beats. According to MedlinePlus, heart valve diseases occur when a valve does not open enough, which is called stenosis, or does not close properly, which can allow leaking (Heart Valve Diseases).

In aortic stenosis, the leaflets become stiff and thickened, and the opening gets smaller. The left ventricle then has to push harder to move blood through. Over time, the muscle of the ventricle can thicken, and the heart may struggle to keep up, especially during activity.

Why it becomes more common with age

Several factors contribute, and the mechanism is not fully understood. In older adults, calcium deposits and scarring can build up on the leaflets over many years. Some people are born with an aortic valve that has two leaflets instead of three (a bicuspid valve), which may wear out sooner. Past rheumatic fever can also damage valves, though it is a less common cause in the United States. Conditions that affect the arteries, such as atherosclerosis, share some risk factors with valve calcification, but they are separate problems and can occur independently.

Why this particular murmur gets attention

Clinicians listen for the pitch, timing, location, and loudness of a murmur. The murmur often linked to aortic stenosis is heard between the first and second heart sounds, tends to be loudest near the upper right side of the breastbone, and may carry up toward the neck. A louder or later-peaking murmur may suggest a tighter narrowing, but loudness is not a reliable measure of severity on its own. In a very weak heart, a severe narrowing can produce a softer sound.

Listening also has limits. A mild murmur can be missed in a noisy room, and different examiners may describe the same sound differently. Reviews of auscultation in the era of electronic stethoscopes and artificial intelligence discuss how technology is being studied to support listening skills, but the stethoscope is a starting point, not a final answer (The discerning ear: cardiac auscultation in the era of artificial intelligence and telemedicine). That is why a murmur that sounds new or concerning is usually followed by imaging.

Some murmurs in older adults come from aortic valve sclerosis, in which the valve is thickened but still opens fairly well. This can sound similar to stenosis. Clinicians distinguish them with imaging and by watching how the valve behaves over time.

Symptoms that can accompany aortic stenosis

Many people have no symptoms for a long time, even with a murmur. When symptoms appear, they can develop gradually, and many older adults attribute them to getting older or being out of shape. Possible symptoms include:

• Shortness of breath with activity. Stairs, hills, or carrying groceries may feel harder than before, and you may need to slow down or rest.
• Chest pain or pressure with exertion. The thickened heart muscle can need more oxygen than the narrowed valve allows it to receive.
• Lightheadedness or fainting, especially during or after exertion. The narrowed valve may limit how much blood reaches the brain when the body demands more.
• Fatigue and reduced stamina. You may find yourself cutting back on activities without quite deciding to.
• Heart flutter or a sense that the heartbeat is irregular. This can have many causes, including atrial fibrillation, which can occur alongside valve disease.
• Ankle swelling and trouble breathing when lying flat. These can be signs that the heart is struggling to keep up, as described by MedlinePlus under Heart Failure.

None of these symptoms is specific to aortic stenosis. Lung disease, anemia, deconditioning, and other heart conditions can cause similar changes. For fainting in particular, see our separate article on fainting in an older adult.

Symptoms are important because, in aortic stenosis, they are a signal that the valve may be affecting the heart's work. Clinicians often change their approach to follow-up and treatment once symptoms appear, so it is worth telling them about any new limit on your activity even if it seems minor.

How clinicians sort out a murmur

Clinicians combine history, examination and testing; no single step settles it. Expect questions about when you notice symptoms, how far you can walk, any past rheumatic fever or heart problems, family history, and medicines you take. They will check your blood pressure, listen at several positions on the chest, and look for swelling or other signs of fluid.

The tests most often used

• Echocardiogram. This ultrasound of the heart shows how the valve moves, how narrow the opening is, and how the ventricle is working. It is the central test for valve disease, according to MedlinePlus's overview of Heart Health Tests.
• Electrocardiogram (ECG). This records the heart's electrical activity and can show rhythm problems or signs of a thickened ventricle.
• Chest X-ray. It can show the heart's size and whether fluid has built up in the lungs.
• Stress testing, CT, or cardiac catheterization. These may be used in selected cases, for example to clarify how severe the narrowing is or to look at the heart's own arteries before a procedure. Stress testing in someone with severe narrowing and symptoms needs careful supervision, so it is a decision for the cardiology team.

Some murmurs turn out to be harmless. If your echocardiogram shows a normal valve, your clinician may tell you nothing more is needed. If it shows mild narrowing, you may be asked to return periodically so the team can see whether it changes.

What treatment can look like

Treatment depends on how narrow the valve is, whether you have symptoms, your other health conditions, and your preferences. A few general points apply.

Watching and managing related conditions

For mild disease or no symptoms, clinicians often recommend regular follow-up with periodic echocardiograms. They also pay attention to related conditions such as atherosclerosis, high blood pressure, and atrial fibrillation, since each can add strain on the heart. Tell your clinician about every medicine you take, including over-the-counter products, and ask them before changing the dose or timing of anything prescribed, including blood pressure medicines. Some medicines that lower blood pressure or relax blood vessels need extra caution when the valve is narrowed, and the right choice depends on your situation.

Valve replacement

No medicine is known to reverse a narrowed aortic valve. When narrowing is significant, or symptoms appear, the main option is replacing the valve. This can be done with open-heart surgery or with a transcatheter approach, in which a new valve is delivered through a blood vessel with a catheter. Which approach fits depends on your age, anatomy, other illnesses, and what matters most to you, and is usually discussed by a team that includes cardiologists and surgeons. MedlinePlus describes the general landscape of procedures on its Heart Surgery page. Outcomes vary from person to person, and your team can explain the benefits and risks that apply to you.

Everyday points when you have a known valve condition

• Keep a symptom note. Write down when breathlessness, chest discomfort, or lightheadedness happens, what you were doing, and how long it lasted. This helps your clinician judge whether things are changing.
• Ask about activity. Tell your clinician what exercise you do so they can advise what is reasonable for you. Heavy straining or sudden hard exertion may need special advice if the narrowing is significant.
• Ask about dental care and infection. Valve disease can raise the chance of an infection of the heart lining and valves called endocarditis. Tell your dentist and clinician about your valve condition so they can decide whether any preventive step applies to you.
• Do not skip scheduled follow-up. Mild disease can change slowly, and the follow-up echocardiogram is how the team keeps track.
• Keep monitoring that your clinician has recommended, such as home blood pressure checks, and bring the numbers to your visits.

Other murmurs you may hear about

Aortic stenosis is only one cause of a murmur in older adults. A valve that leaks, such as a mitral valve that does not close fully, can also produce one. Murmurs can come from an overactive thyroid or anemia that speeds blood flow, and some are described in older medical papers as accidental or innocent findings in people with a healthy heart (Accidental Heart Murmurs). Congenital conditions present from birth can also cause murmurs, as described by MedlinePlus under Congenital Heart Defects, although these are usually identified earlier in life. A newly discovered murmur in an older adult deserves a conversation with a clinician, and in many cases an echocardiogram, to sort out which type it is.

When to Seek Medical Care