Aortic Stenosis
What is aortic stenosis?
Aortic stenosis is a cardiovascular condition characterised by the narrowing of the aortic valve which restricts the flow of blood from the heart to the rest of the body. Aortic stenosis occurs when the opening of the aortic valve becomes narrowed or obstructed, making it difficult for the heart to pump blood efficiently to the body’s organs and tissues. This condition can be mild, moderate or severe with symptoms typically worsening as the degree of stenosis increases.
If left untreated aortic stenosis can be life-threatening. Once symptoms appear, survival rates can reduce to 50% at 2 years and 20% at 5 years. Early intervention is crucial for better outcomes.
In some cases, surgery is necessary to repair or replace the valve and until recently this typically involved open-heart surgery. For more information: Calls for more people to gain access to alternative open-heart surgery.
Causes and risk factors
Aortic stenosis can arise from various causes such as congenital heart defects, calcium buildup on the valve and rheumatic fever.
- Congenital Heart Defects: In some cases, people are born with aortic valves that are abnormally narrow or have malformed leaflets (flaps of tissue) leading to restricted blood flow from the left ventricle to the aorta. These defects can hinder proper valve function and contribute to the development of aortic stenosis over time.
- Calcium Buildup on Valve: Over time calcium buildup can cause the valve leaflets to become thickened, stiff and less flexible, impairing their ability to open fully and obstructing the flow of blood through the valve. This calcific aortic stenosis typically occurs with advancing age and is often associated with other risk factors such as hypertension, high cholesterol and smoking.
- Rheumatic Fever: Rheumatic fever can cause inflammation and scarring of the heart valves including the aortic valve leading to narrowing and dysfunction over time. Although rheumatic fever is less common in developed countries it remains a significant cause of valvular heart disease in certain regions of the world.
- Ageing: With age the aortic valve may undergo degenerative changes, including thickening and calcification of the valve leaflets. These age-related changes can impair the function of the valve and contribute to the development of aortic stenosis particularly in people over the age of 65.
Symptoms
- Chest pain
- Light headedness
- Dizziness
- Fainting
- Rapid or fluttering heartbeat
- Shortness of breath or trouble breathing
- Difficulty with short walks
- Swollen ankles or feet
- Difficulty sleeping
- Reduced activity levels
Diagnosis
Diagnosing aortic stenosis typically involves a combination of clinical evaluation, imaging tests and specialised cardiac assessments to assess the severity of valve narrowing and its impact on heart function.
The diagnostic process often begins with a thorough review of your medical history, including any symptoms suggestive of heart valve disease. A comprehensive physical examination may reveal characteristic findings such as heart murmur or abnormal heart sounds (e.g., a harsh systolic ejection murmur heard best at the upper right sternal border).
TTE allows for visualisation of the aortic valve structure, assessment of valve opening and closure, measurement of the valve orifice area, evaluation of blood flow across the valve (velocity and pressure gradients) and detection of any associated cardiac abnormalities (e.g., left ventricular hypertrophy).
Doppler echocardiography is used to assess the velocity and pressure gradients across the aortic valve which provides valuable information about the severity of stenosis and the degree of obstruction to blood flow.
In some cases, TEE may be performed to obtain more detailed images of the aortic valve and adjacent structures particularly in patients with suboptimal transthoracic imaging or when additional information is needed to guide treatment decisions.
Invasive procedures such as cardiac catheterisation may be indicated in certain cases particularly when there is uncertainty about the severity of aortic stenosis or when additional coronary artery assessment is needed (e.g., before valve replacement surgery).
Depending on the clinical presentation and suspected aetiology of aortic stenosis additional tests such as electrocardiography (ECG), chest x-ray, cardiac magnetic resonance imaging (MRI) or computed tomography (CT) may be performed to evaluate the extent of cardiac involvement and assess for associated complications.
Treatments
Treatment for aortic stenosis varies depending on the severity of symptoms and the overall health of the patient.
In cases where aortic stenosis is mild and symptoms are absent or minimal you may be recommended regular monitoring without immediate intervention. This typically involves periodic check-ups to assess the progression of the condition and monitor the development of symptoms.
Blood pressure medications, diuretics and antiplatelet or anticoagulant medications may be prescribed to manage symptoms and reduce the risk of complications associated with aortic stenosis.
In some cases, particularly in patients with congenital valve abnormalities or isolated valve leaflet prolapse, surgical repair of the aortic valve may be feasible. Valve repair techniques aim to restore proper valve function while preserving the patient’s own valve tissue.
TAVI is a less invasive alternative to traditional open-heart surgery for patients with severe symptomatic aortic stenosis who are at high or intermediate surgical risk. During the procedure a collapsible prosthetic valve is inserted and guided to the heart through a catheter, typically via the femoral artery (transfemoral approach) or alternative access routes such as subclavian artery or the apex of the heart.
Balloon valvuloplasty may be performed in select cases to temporality relieve symptoms by dilating the narrowed aortic valve using a balloon catheter. This procedure is typically reserved for patients who are not suitable candidates for valve replacement surgery or as a bridge to definitive treatment.
Consult a cardiologist
If you’re experiencing symptoms of aortic valve stenosis or are concerned about your heart health, call Cardiology Specialists Melbourne for compassionate heart care.