What is aortic valve stenosis?
Aortic valve stenosis is a condition characterized by constriction of the aortic valve thus making the lumen narrow. This reduces the quantity of blood that is pumped out to the body from the heart. The aorta is the largest artery in the body and it is a major artery responsible for blood circulation around the body.
Symptoms of aortic valve stenosis
At the early stage of the disease, it is usually asymptomatic. Symptoms begin to show as the disease advances. When the disease has advanced to a point of producing symptoms, the notable symptoms then include:
- Chest pain which is due to the strain encountered by the heart as it tries to pump a sufficient amount of blood through the diseased valve.
- Fatigue experienced on exertion such as in exercise or movement.
- Shortness of breath especially on exertion
- Palpitations or unusual heartbeats
- Heart murmur which is a sound produced due to the turbulence of blood flow.
Symptoms in infants and children
The symptoms seen in children may be distinct from that seen in adults or they may not even be able to manifest any symptom. If they are symptomatic, then the likely symptoms manifested include:
- Eating difficulties
- Failure to gain weight
- Easy fatigability
When it is severe, the infant may have breathing problems that manifest a few weeks after birth. Mild cases could likely get severe as the child grows older.
Causes of aortic valve stenosis
The aortic valve functions by rhythmic opening and closing each time the heart beats. The notable conditions that may impede with this aortic functioning include genetic factors and other health conditions.
Aortic valve stenosis may be diagnosed at birth. This is seen when the leaflets or flaps are improperly formed. These leaflets constitute the openings of the aortic valve. When it is in a good state, the leaflets fit together solidly when closed. Children who are born with aortic stenosis may have any of the following unusual findings in their aortic valve leaflets:
- Absence of the three leaflets
- Improper separation of the leaflets
- Increased thickness of the leaflets thus restricting complete closure or opening.
This is one of the most predominant cause of heart valve abnormality. Rheumatic fever affects many parts of the body such as the brain, joints, heart, and skin.
Rheumatic fever can also affect adults and children who may have a recent or past history of strep throat. Strep throat is just a communicable throat problem caused by Streptococcus specie of bacteria.
Calcification of the valves
When aortic valve stenosis occurs in adults, the most common form is age-related aortic valve stenosis and it occurs often as published by the American Heart Association. It results when the aortic valve hardens or undergoes scarring. The onset is usually in the sixth decade and above though symptoms may not be present until the seventh or eighth decade.
The mineral calcium is essential for the formation of strong bones and teeth but when this calcium finds its way to the aortic valve and lodges there, it may become problematic to the aortic valve leaflets and even stop the aortic valve from opening and closing properly. Calcium keeps accumulating in the aortic valve as one grows older and caused further scarring and damage. Aortic valve leaflets that are dysfunctional may permit backflow of blood to the left ventricle after entering the aorta, a case known as Valvular regurgitation or insufficiency.
Aortic valve stenosis has a predilection for the male gender. It commonly occurs around the ages of 30 and 60 in men.
Children with congenital conditions affecting the aorta such as valve leaflet malformation or decreased number of leaflets will have abnormality of blood flow through the aorta.
Rheumatic fever can cause major problems in the valve. The disease can leave scar tissues which end up hardening the leaflets or even fusing them together. Rheumatic fever results in damage to the valves, tissues of the heart and coronary arteries.
Diagnosis of aortic valve stenosis
A referral is usually made to the cardiologist (specialist in heart medicine) after an initial complaint. The cardiologist then takes a detailed history and conducts a thorough physical and systemic examination listens to the heart for any unusual sound such as murmurs, and requests for imaging studies that will give an idea of what happens in the heart.
The imaging tests usually needed include:
- Magnetic resonance imaging: this produces concise images of internal body structures
- CT scan: this captures cross-sectional pictures of the internal body structures
- Chest x-ray: it produces images of the heart, lung, smaller airways, blood vessels, bones in the spine and chest.
- Echocardiogram: it makes images of the heart in video form
- Cardiac catheterization: it makes use of dye and this enhances the visualization of any obstruction in the heart.
Treatment for aortic valve stenosis
There is no exact treatment for aortic valve stenosis as the condition is permanent once it occurs. Palliative management is done and by this, the symptoms caused by the condition or the precipitating factor to the condition are being treated. Surgery can possibly repair the valve or replace the valve.
They are prescribed to help handle any discomforting symptom experienced due to the disease. They are not curative. The medications given include:
- Antibiotics: a disease such as rheumatic fever requires a prophylactic antibiotic treatment to prevent infection from progressing to cause heart damage.
- Blood pressure medications: beta blockers or calcium channel blockers can be used to lower an elevated blood pressure in people with aortic stenosis.
- Blood thinners: may be necessary. Example is Coumadin.
- Anti-arrhythmic: these are needed to regulate the heart’s rhythm.
The doctor will recommend a surgery that will either repair or replace the aortic valve based on the severity of the condition. Valvuloplasty is a procedure done for valve repair and it is not very invasive. It can be carried out using a catheter which is a soft thin tube and it is not as invasive as the conventional surgery.
The surgeon passes a long thin catheter which has a balloon at its tip into an artery usually the femoral artery in the groin, directs the tube into the heart and inflates the balloon. This opens up the valve and the catheter with the balloon is thereafter removed.
It is a minimally invasive procedure thus the recovery duration is much less than that of open-heart surgery. Other times, the surgeon may insist on replacing the damaged valve, this needs an open-heart procedure using a mechanical valve gotten from cow or pig. Other times, human cadaveric valves may be used but the recovery duration for this open-heart surgery is much longer.
Once treatment has been done, there will be a noticeable improvement in health. Most surgical treatments of aortic valve stenosis are usually successful. Prognosis depends on certain factors such as:
- Duration of illness
- Extent of damage to the heart
- Complications resulting from the illness
MANAGING THE SYMPTOMS OF AORTIC VALVE STENOSIS
Aortic valve stenosis may not be congenital at times, it may be acquired and so some life style modifications may help improve the condition. These include:
- Eating healthy, avoid foods that have high saturated fat content
- Maintain a normal weight and body mass index
- Quit smoking
- Any health problems should be reported to a doctor such as a sore throat so that rheumatic fever can be avoided
- Have a good dental hygiene: this is because dental infections can circulate through the blood stream and damage the heart valves or even muscles.
Note that aortic valve stenosis can also cause difficulty in breathing. This is because the increased pressure seen in the left ventricle and left atrium results in an increased pressure in the blood vessels and this eventually results in shortness of breath or difficulty in breathing as the disease advances. This is noticed first on exertion and later, even at rest.