Aortic Stenosis: Symptoms, Diagnosis & What Your Echocardiogram Reveals

Aortic stenosis is one of the most common and most serious valve diseases — and one of the most underdiagnosed. Millions of adults over 65 have some degree of narrowing and don't know it. The heart compensates silently for years. By the time symptoms arrive, the valve is often already severely obstructed. An echocardiogram is the test that catches it at the mild stage, when monitoring is all that's needed — not surgery.

What Is Aortic Stenosis?

The aortic valve sits at the outlet of the left ventricle, acting as the gateway between the heart and the body's largest artery — the aorta. Normally, the valve opens to an area of approximately 3–4 cm² during systole, allowing blood to pass freely with each heartbeat. When the valve leaflets become calcified, stiffened, or malformed, that opening narrows. The heart must generate significantly higher pressure to force blood through the restricted opening. Over years, this places an enormous burden on the left ventricle — and eventually, the ventricle can no longer keep up.

Aortic stenosis is the most common valvular heart disease in the developed world. Prevalence increases sharply with age: approximately 2–3% of adults over 65 have moderate to severe stenosis, rising to roughly 1 in 8 adults over the age of 75. Three causes account for nearly all cases:

• Calcific (degenerative) disease — the most common form in older adults. Calcium gradually deposits on the valve leaflets over decades, reducing their mobility. This is not simply "wear and tear" — it is an active inflammatory process with similarities to atherosclerosis.
• Bicuspid aortic valve — a congenital abnormality present in approximately 1–2% of the population where the valve has two leaflets instead of three. Bicuspid valves calcify earlier, often causing significant stenosis by the fifth or sixth decade of life.
• Rheumatic heart disease — scarring from rheumatic fever that fuses the valve leaflets. More prevalent in developing countries; still seen in older patients in the U.S. who had childhood streptococcal infections.

Symptoms — The Warning Signs You Shouldn't Ignore

Aortic stenosis has a long silent phase. The left ventricle adapts — thickening its walls to overcome the resistance — and maintains adequate output for years. When that compensation fails, symptoms emerge rapidly. The classic triad is:

• Chest pain (angina) — the hypertrophied ventricle outgrows its blood supply. Exertional chest discomfort or pressure is an ominous sign in the setting of known aortic stenosis.
• Syncope (fainting) — the narrowed valve limits cardiac output during exertion; blood pressure drops suddenly, reducing cerebral perfusion. Exertional syncope or near-syncope demands immediate evaluation.
• Dyspnea on exertion (breathlessness) — the most common presenting symptom. As ventricular function deteriorates, back-pressure builds in the lungs. Initially noticed with activity, it progresses to rest dyspnea and orthopnea.

The prognostic significance of symptom onset cannot be overstated. Once symptoms develop in severe aortic stenosis, survival without valve replacement is measured in months to years. Average survival after the onset of angina is approximately 5 years; after syncope, 3 years; after heart failure symptoms, 1–2 years.

The problem is that many patients attribute their symptoms to age, deconditioning, or other chronic conditions. Gradual symptom onset is easy to normalize. Breathlessness climbing stairs that you once climbed without thinking — that is not simply getting older.

How an Echocardiogram Diagnoses Aortic Stenosis

An echocardiogram is the definitive diagnostic tool for aortic stenosis. It provides four distinct measurements that together classify severity and guide management decisions:

Peak velocity across the valve (Doppler). Using continuous-wave Doppler, we measure the maximum velocity of blood passing through the aortic valve. A normal valve produces velocities below 2.0 m/s. As stenosis develops, the jet velocity rises: mild disease registers 2.0–2.9 m/s, moderate 3.0–3.9 m/s, and severe stenosis produces peak velocities of 4.0 m/s or higher. These velocities directly reflect the obstruction severity — the narrower the valve, the faster the blood must move to pass through.

Mean pressure gradient. Derived from the Doppler velocity, the mean gradient describes the average pressure difference across the valve throughout systole. Mild stenosis produces gradients below 20 mmHg, moderate stenosis 20–39 mmHg, and severe stenosis gradients of 40 mmHg or higher. This number is central to timing intervention: a gradient of 40+ mmHg in a symptomatic patient is a clear signal for referral.

Aortic valve area (continuity equation). The continuity equation uses stroke volume and Doppler measurements to calculate the effective orifice area of the valve. Normal area is 3–4 cm². Mild stenosis: greater than 1.5 cm². Moderate: 1.0–1.5 cm². Severe: less than 1.0 cm². The valve area calculation is particularly valuable when velocity and gradient appear discordant — for example, in low-flow states where gradients may be underestimated.

Left ventricular response. Beyond the valve itself, the echo evaluates how the ventricle has adapted. Wall thickness (concentric hypertrophy) indicates chronic pressure overload. Ejection fraction reflects systolic function — preserved EF in the setting of severe stenosis is reassuring; reduced EF indicates decompensation. Diastolic function parameters (E/A ratio, tissue Doppler velocities) reveal filling pressures and elevated LVEDP, important for risk stratification before any procedure.

Severity Classification — What Your Numbers Mean

The ACC/AHA guidelines classify aortic stenosis into three hemodynamic stages. Here is what each means for monitoring and management:

Surveillance frequency is determined by severity. Mild aortic stenosis typically warrants repeat echocardiography every 3–5 years. Moderate stenosis is monitored every 1–2 years, with closer follow-up if the patient is older, has a bicuspid valve, or shows rapid progression. Severe stenosis without symptoms requires imaging every 6–12 months — and urgent evaluation at the onset of any symptom. Severe stenosis with symptoms (the classic triad of angina, syncope, or dyspnea) is a class I indication for valve replacement regardless of the patient's age, provided surgical or procedural risk is acceptable. Transcatheter aortic valve replacement (TAVR) has expanded options for high-risk and older patients significantly.

Who Should Be Screened

Aortic stenosis does not announce itself. The following groups warrant echocardiographic evaluation even in the absence of symptoms:

• Adults over 65 with no prior cardiac imaging. Given the prevalence of subclinical stenosis in this age group, a baseline echocardiogram establishes your starting point and catches early disease before it progresses unmonitored.
• Anyone with a known bicuspid aortic valve. Bicuspid valves calcify earlier and progress faster. Established guidelines recommend surveillance echocardiography at regular intervals from the time of diagnosis.
• History of rheumatic fever. Rheumatic disease affects the mitral valve most commonly, but the aortic valve is frequently involved as well. Imaging clarifies the extent of involvement.
• Unexplained exercise intolerance, chest tightness, or lightheadedness. These are the early, non-specific symptoms that precede the classic triad. An echocardiogram is the appropriate first step to rule out a structural cause.
• Heart murmur detected on physical exam. A systolic ejection murmur at the right upper sternal border radiating to the neck is the characteristic murmur of aortic stenosis — but the stethoscope alone cannot grade severity. An echo is required.
• Family history of valve disease or aortic root abnormalities. Bicuspid aortic valve has a heritable component; first-degree relatives of affected individuals warrant screening.

Getting Diagnosed in Maine — No Referral Required

Getting an echocardiogram in Maine shouldn't require a months-long wait for a cardiology appointment. BlackPoint Diagnostics provides hospital-grade cardiac imaging on a mobile platform — we come to your home, workplace, or a partner location throughout Southern and Midcoast Maine. The complete study takes approximately 45 minutes. Results are reviewed by a board-certified cardiologist and delivered to you within 24–48 hours.

Our echocardiogram includes full Doppler assessment of all four cardiac valves — including peak velocity, mean pressure gradient, and valve area via continuity equation for aortic stenosis evaluation. If your results show aortic stenosis at any stage, you receive clear documentation to share with your primary care provider or cardiologist, along with a follow-up timeline based on ACC/AHA surveillance guidelines.

The study is $397. No referral is required to schedule. If you are over 65, have a known murmur, or have any of the risk factors listed above, that is enough reason to get baseline imaging today.

Frequently Asked Questions

How common is aortic stenosis?

Aortic stenosis is the most common valvular heart disease in the developed world. It affects approximately 2–7% of adults over 65 and roughly 1 in 8 adults over the age of 75. The prevalence increases sharply with age, making echocardiographic screening particularly important for older adults who have never had a cardiac imaging study.

Can aortic stenosis be detected on an EKG?

An EKG may show signs of left ventricular hypertrophy (LVH) — a pattern consistent with the heart working harder against an obstructed valve — but it cannot measure valve area, pressure gradient, or flow velocity. An EKG cannot diagnose aortic stenosis, quantify its severity, or determine whether intervention is needed. Only an echocardiogram provides the Doppler measurements required to classify mild, moderate, or severe stenosis.

How often should I get an echo if I have mild aortic stenosis?

ACC/AHA guidelines recommend echocardiographic surveillance every 3–5 years for mild aortic stenosis, every 1–2 years for moderate stenosis, and every 6–12 months once stenosis is severe. Surveillance frequency is individualized based on rate of progression, left ventricular response, and symptom development. Your cardiologist determines the schedule based on your specific measurements.

Does BlackPoint Diagnostics diagnose aortic stenosis?

Yes. Our echocardiograms include full Doppler assessment of all four cardiac valves, including peak velocity, mean pressure gradient, and valve area calculation via the continuity equation for aortic stenosis evaluation. Results are reviewed by a board-certified cardiologist and delivered within 24–48 hours. No referral is required to schedule. We serve patients throughout Southern and Midcoast Maine at your home, workplace, or partner location.