Aortic stenosis overview
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Aortic Stenosis Microchapters |
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Diagnosis |
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Treatment |
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Percutaneous Aortic Balloon Valvotomy (PABV) or Aortic Valvuloplasty |
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Transcatheter Aortic Valve Replacement (TAVR) |
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Case Studies |
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Aortic stenosis overview On the Web |
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American Roentgen Ray Society Images of Aortic stenosis overview |
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Risk calculators and risk factors for Aortic stenosis overview |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editors-In-Chief: Mohammed A. Sbeih, M.D. [2], Claudia P. Hochberg, M.D. [3]; Abdul-Rahman Arabi, M.D. [4]; Keri Shafer, M.D. [5]; Priyamvada Singh, MBBS [6]; Assistant Editor-In-Chief: Kristin Feeney, B.S. [7]
Overview
The aortic valve controls the direction of blood flow from the left ventricle to the aorta. When functioning appropriately, the aortic valve does not impede the flow of blood between these two spaces. Under some circumstances, the aortic valve becomes narrower than normal, impeding the flow of blood. This is known as aortic valve stenosis, or aortic stenosis, often abbreviated as AS.
Pathophysiology
When the aortic valve becomes stenosed, it can result in the formation of a pressure gradient between the left ventricle (LV) and the aorta [1]. The more constricted the valve, the higher the gradient between the LV and the aorta.
In individuals with AS, the left ventricle (LV) has to generate an increased pressure in order to overcome the increased afterload caused by the stenotic aortic valve and eject blood out of the LV. The more severe the aortic stenosis, the higher the gradient is between the left ventricular systolic pressures and the aortic systolic pressures. Due to the increased pressures generated by the left ventricle, the myocardium (muscle) of the LV undergoes hypertrophy (increase in muscle mass). This is seen as thickening of the walls of the LV. The type of hypertrophy most commonly seen in AS is concentric hypertrophy, meaning that all the walls of the LV are (approximately) equally thickened.
Clinical presentation
When symptomatic, aortic stenosis can cause:
Patients exhibiting multiple symptoms often experience a worsened prognosis and overall decrement in quality of life.
Diagnostic tests
After the history and physical examination, some tests may be done to confirm the diagnosis of aortic stenosis. Tests include:
- Echocardiogram (heart ultrasound) is the best non-invasive test to evaluate the aortic valve anatomy and function and to diagnose aortic stenosis.
- Electrocardiogram (ECG) manifestations of left ventricular hypertrophy (LVH) are common in aortic stenosis.
- Chest x-ray can show enlarged left ventricle if there is severe aortic stenosis for a long time.
- Magnetic resonance imaging can be helpful as a diagnostic tool if the echocardiographic findings are inconclusive.
- Computed tomography also can be helpful as a diagnostic tool if echocardiographic findings are inconclusive.
- Cardiac catheterization: simultaneous left ventricular and aortic pressure tracings may demonstrate a pressure gradient between the left ventricle and aorta, suggesting aortic stenosis.
Treatment
Prior to surgical intervention, clinicians may utilize medical therapy for aortic stenosis treatment. Pharmacological therapies can be used on some aortic stenosis patients. Caution must be taken to avoid complications such as excess vasodilation, as such could lead to functional decline in the patient.
Surgical intervention may be a necessary component of treatment for symptomatic severe aortic stenosis. Intervention methods may include mechanical and device based therapies such as bileaflet mechanical aortic valves. An alternative treatment method includes aortic valvuloplasty or aortic valve repair.
Prognosis
30% reduction in gradient is expected as the immediate result of surgical intervention. Patient survival after treatment is higher than that of untreated patients.
References
- ↑ Lilly LS (editor) (2003). Pathophysiology of Heart Disease (3rd ed. ed.). Lippincott Williams & Wilkins. ISBN 0-7817-4027-4.