It’s Topic Tuesday!
- Alvaro Jose Martinez Santacruz
- 3 hours ago
- 3 min read
Understanding Aortic Stenosis
Aortic stenosis is one of the most common and serious valve diseases. It occurs when the aortic valve opening becomes narrowed, making it harder for blood to leave the heart and reach the body.
At first, the heart compensates. Over time, that compensation fails — and symptoms appear.
🔬 How it happens?
Think of the aortic valve like a door that should open wide with every heartbeat.
In aortic stenosis, that door becomes stiff and narrow.
This happens because of:
Progressive calcification of the valve leaflets
Chronic inflammation
Abnormal valve anatomy (such as a bicuspid aortic valve)
As the opening narrows:
Blood flow out of the heart is restricted
The left ventricle must generate higher pressure to push blood through
The heart muscle thickens (left ventricular hypertrophy)
At first, this helps maintain blood flow. But over time, the thickened muscle becomes stiff, oxygen demand increases, and the heart begins to fail.
🧠 A Simple Way to Understand It
Imagine trying to blow air through a straw.
A wide straw? Easy.
A very narrow straw? You have to blow harder.
Blow like that for years? You get exhausted.
That’s exactly what happens to the heart in aortic stenosis.
📈 Disease Progression Matters: ACC/AHA Stages of Aortic Stenosis
Aortic stenosis is a progressive disease, and its management is based on structured stages (A–D) rather than valve area alone. These stages integrate anatomy, hemodynamics (how blood flows), symptoms, and ventricular function.
Stage A – “At Risk”
Patients do not yet have stenosis, but are at risk.
Examples:
Bicuspid aortic valve
Aortic sclerosis
History of rheumatic disease
🔹 Hemodynamics: Normal valve gradients
🔹 Symptoms: None
Management:
Risk factor control (hypertension, lipids, diabetes), Periodic echocardiographic follow-up, No surgery or intervention
Stage B – Progressive Aortic Stenosis
Structural valve disease is present with mild to moderate obstruction.
Typical findings:
Increasing valve calcification
Mild–moderate gradient elevation
🔹 Symptoms: Usually asymptomatic
🔹 LV function: Preserved
Management (Medical):
Optimize blood pressure (careful afterload control), Treat coronary disease if present, Avoid unnecessary vasodilation, No valve intervention yet
Regular echo surveillance
👉 Surgery is not indicated unless another cardiac surgery is planned.
Stage C – Severe AS (Asymptomatic)
The valve is severely narrowed, but the patient has no symptoms.
This stage is divided into:
C1 – Normal LV function
Severe stenosis
Preserved ejection fraction (EF)
C2 – LV dysfunction
Severe stenosis
Reduced EF (<50%), even without symptoms
Management:
C1: Careful monitoring, exercise testing in selected patients
C2: Aortic valve replacement is recommended, even if asymptomatic
👉 LV dysfunction = the heart is already failing to compensate.
Stage D – Severe Symptomatic Aortic Stenosis
This is the most advanced and dangerous stage.
Key features:
Severe valve obstruction
Classic symptoms:
Angina
Dyspnea / heart failure
Syncope
Subtypes:
D1: High-gradient severe AS
D2: Low-flow, low-gradient with reduced EF
D3: Paradoxical low-flow, low-gradient with preserved EF
Management:🚨 Definitive intervention is mandatory
Surgical AVR (SAVR)
Transcatheter AVR (TAVR)
Choice depends on: Surgical risk, Age,Anatomy, Comorbidities
📌 Medical therapy alone is NOT sufficient at this stage.
📌 Key Takeaway
Aortic stenosis is not just a valve problem — it’s a disease of progressive pressure overload on the heart. Understanding the pathophysiology helps explain:
Why symptoms appear late
Why timing of intervention is crucial
Why treatment must be individualized
🔜 Coming in the next weeks:We’ll dive deeper into how we decide between surgery and endovascular treatment, how imaging guides management, and what outcomes look like for each approach.
✍️ Have questions about valve disease or heart surgery?Drop them in the comments and stay tuned for the next Topic Tuesday!
Bibliography
[1] Carabello BA, Paulus WJ. Aortic stenosis. Lancet 2009;373:956–66. https://doi.org/10.1016/s0140-6736(09)60211-7.
[2] Pujari SH, Agasthi P. Aortic stenosis. StatPearls, Treasure Island (FL): StatPearls Publishing; 2025.
[3] Otto CM, Nishimura RA, Bonow RO, Carabello BA, Erwin JP 3rd, Gentile F, et al. 2020 ACC/AHA guideline for the management of patients with valvular heart disease: A report of the American college of cardiology/American heart association joint committee on clinical practice guidelines. Circulation 2021;143:e72–227. https://doi.org/10.1161/CIR.0000000000000923.
[4] Aortic stenosis prognosis: What 6 facts should you know? Heart-valve-surgery.com n.d. https://www.heart-valve-surgery.com/aortic-stenosis-prognosis.php (accessed February 2, 2026).
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