Aortic Stenosis
All information about the causes, symptoms, and treatment of the narrowing of the valve that connects the left ventricle of the heart to the aorta.
Symptoms and causes
Aortic stenosis is the narrowing of the aortic valve. This valve allows blood to flow from the left ventricle of the heart into the aorta and be distributed throughout the body. When it does not fully open, blood flow is blocked or significantly reduced.
To pump blood to the rest of the body, the ventricle must work harder. Over time, the ventricular wall thickens and becomes more rigid, reducing the amount of blood entering the chamber and potentially causing heart failure.
As a result of aortic valve narrowing, the valve area decreases, blood flow velocity increases to maintain a constant output necessary for proper body function, as does the mean pressure gradient.
Depending on the severity, aortic stenosis is classified into three grades:
- Mild aortic stenosis
- Moderate aortic stenosis
- Severe aortic stenosis
Life expectancy for untreated patients with aortic stenosis is approximately two years. In severe cases, it can lead to death from heart failure or sudden cardiac death. However, with specialist intervention and proper medical follow-up, outcomes improve depending on the extent of damage and comorbidities. In most cases, life expectancy exceeds five years.
Symptoms
Symptoms of aortic stenosis usually appear or worsen when heart rate increases, typically during exertion or exercise. The most common are:
- Angina: chest pain caused by reduced blood flow to the heart
- Abnormal heart sound (heart murmur)
- Dyspnea: difficulty breathing
- Syncope (fainting)
- Palpitations: rapid heartbeat
- Fatigue
Causes
The causes of aortic stenosis can be:
Congenital: present from birth. Some babies are born with two cusps in the aortic valve instead of three (tricuspid valve), making it harder to control blood flow and prevent backflow.
Acquired: develop over the course of life.
- Aortic calcification: calcium accumulates in the aortic valve, causing narrowing
- Rheumatic fever: streptococcal throat infection (type B hemolytic) can lead to scarring of the valve tissue
Risk Factors
Risk factors for aortic stenosis include:
- Advanced age, as calcium accumulates over life and symptoms may appear after age 70
- Congenital heart defects
- Rheumatic fever
- Diabetes
- Hypercholesterolemia
- Hypertension
- Chronic kidney disease
Complications
The most frequent complications of aortic stenosis are:
- Heart failure
- Blood clots
- Stroke
- Embolism (a blood clot detaches and blocks blood vessels or reaches a vital organ, especially the lungs)
- Excessive bleeding
- Endocarditis: infection of the endocardium, the membrane lining the heart chambers
Prevention
Congenital aortic stenosis cannot be prevented, but the risk of acquiring it later in life can be reduced by:
- Monitoring any signs of illness and consulting a doctor for proper treatment, especially bacterial throat infections
- Attending regular check-ups
- Maintaining a healthy lifestyle
- Keeping an appropriate weight
- Controlling cholesterol levels and blood pressure
Which doctor treats aortic stenosis?
Aortic stenosis is diagnosed and treated in Cardiology. When surgery is required, Cardiovascular Surgery specialists intervene.
Diagnosis
Diagnosis of aortic stenosis is based on the following tests:
- Cardiac auscultation: heart murmurs, arrhythmias, or diminished carotid artery pulse may be detected
- Chest X-ray: shows images of the heart and blood vessels, allowing detection of aortic or cardiac enlargement and calcium deposits in the valve
- Echocardiography: visualizes blood flow through the heart and how it exits via the aortic valve
- Electrocardiogram (ECG): shows the electrical activity of the heart
- Cardiac catheterization
- Ergometry: exercise testing to evaluate heart activity during physical exertion, when symptoms often appear
Treatment
Treatment depends on the severity and patient characteristics. In asymptomatic or mild cases, a conservative approach is recommended:
- Lifestyle changes: healthy diet, regular moderate exercise, avoiding tobacco
- Medication: used to lower blood pressure, correct arrhythmias, eliminate excess fluid, or prevent clot formation. Includes diuretics, nitrates, beta-blockers, digoxin (for atrial fibrillation), and anticoagulants
Severe symptoms that significantly affect quality of life require surgery, the definitive treatment for aortic stenosis. The damaged valve is replaced with a prosthesis made of synthetic materials or biological tissue.
