According to the American Heart Association (AHA), aortic valve stenosis is a common and serious valve problem. Its risk groups are not limited to the elderly and patients with cardiovascular disease. People with congenital heart disease Defects and valve calcification may also be factors. This article helps you understand what aortic stenosis is? What are the 9 major risk factors? as well as its symptoms and treatments.
What is aortic stenosis?
The aortic valve is one of the four major heart valves in the human body. It is located between the left ventricle and the aorta. It bears the greatest pressure and intensity of blood flow among all valves because it must deliver oxygenated blood to all parts of the body. Delivered through the aorta.
The so-called aortic stenosis refers to the narrowing or obstruction of the aortic valve (Aortic valve) of the heart. Narrowed valves block the flow of blood, limiting the amount of blood the heart can pump each time, causing the heart to have to work harder to make up for the loss. Over time, or if the stenosis becomes more severe, patients may develop heart failure or other heart problems.
Aortic valve stenosis causes
1.Congenital heart defect
A normal aortic valve should be composed of 3 leaflets. If the aortic valve has only 2 leaflets (Bicuspid), or even a few people have only 1 leaflet (Unicuspid) or 4 leaflets (Quadricuspid), it is a congenital heart defect; when the patient At a young age, adverse reactions may not occur, but as age increases into adulthood, the risk of aortic valve insufficiency and stenosis increases.
2.Aortic valve calcification
In advanced countries, aortic valve calcification, which increases with age, is the main cause of aortic stenosis; among people aged 65-70, it accounts for more than 50%.
The so-called “calcification” refers to the accumulation of calcium. The bones and blood of the human body contain calcium. Therefore, when the blood flows in the body, it also carries calcium to various organs and blood vessels. Generally speaking, the older you get, the more calcium will accumulate in the blood vessels, and the more calcium will accumulate on the valves. This is why most patients with aortic valve calcification are elderly; the more calcium will accumulate on the aortic valve. , causing the valve to stiffen and eventually become narrow.
In addition to aging, people with valve defects (fewer leaflets) or atherosclerosis are also more likely to develop aortic valve stenosis than the average person.
In developed countries, aortic stenosis caused by rheumatic fever has dropped to less than 10% year by year; rheumatic fever caused by strep throat may damage the aortic valve and leave scars; these scar tissue may not only When the aortic valve becomes narrowed, its rough surface is more likely to accumulate calcium, increasing the risk of valve calcification.
Aortic stenosis symptoms
Aortic stenosis may be asymptomatic in the early stages, and the incubation period can even last for several years; even mild to moderate aortic stenosis may generally be asymptomatic, so patients with aortic stenosis must not think that it does not matter if they have no symptoms; especially When symptoms appear, the disease is often severe enough to not only affect the patient’s daily life, but may even be life-threatening.
The three main symptoms of aortic stenosis are loss of consciousness, angina pectoris, and chest tightness, which include chest tightness during activity, chest tightness when lying flat when heart failure occurs, or chest tightness and swollen feet in the middle of the night.
The main symptoms include the following:
- Chest pain (angina pectoris): Once aortic stenosis is combined with angina pectoris symptoms, the mortality rate within 5 years will be as high as 50% if no replacement surgery is performed. Aortic stenosis causes the left ventricle to work harder. Over time, left ventricular hypertrophy (Hypertrophy) results in left ventricular strain (Ventricular strain). The electrocardiogram shows ST segment depression (ST segment depression) and inverted T waves, which indicates intracardiac disease. Subendocardial ischemia.
- When moving, I feel a heavy pressure on my chest.
- Difficulty and shortness of breath (especially during exercise)
- Fatigue (more obvious after exercise)
- Loss of appetite and underweight in pediatric patients.
- Swelling of the lower limbs (caused by heart failure due to aortic valve)
- Heart murmur
- Syncope or Fainting: Once aortic stenosis is accompanied by fainting symptoms, the mortality rate within 3 years will be as high as 50% if no replacement surgery is performed. In order to avoid the risk of syncope caused by aortic stenosis, if you are using drugs that cause peripheral vasodilation, such as nitroglycerin, nitrates, ACE inhibitors, Terazosin (Hytrin) and Hydralazine, etc., you must pay special attention to the risk of hypotension and syncope.
When should you seek medical attention?
When the above symptoms are discovered, it is recommended to seek medical treatment immediately for relevant examinations, especially for groups at high risk of heart disease. Early diagnosis can reduce the risk of other complications caused by aortic valve stenosis.
9 major risk factors for developing aortic stenosis
Your risk of developing aortic stenosis is increased if:
- Elder people
- Congenital heart disease
- Rheumatic heart disease
- Have had radiation therapy to the chest
- High cholesterol
- Chronic kidney disease
Complications of aortic stenosis
- Heart failure: Heart failure caused by aortic stenosis is combined with left ventricular hypertrophy and fibrosis, so it has both systolic dysfunction (ie, reduced ejection fraction EF) and diastolic dysfunction (Diastolic dysfunction (ie, left ventricular filling pressure) pressure rises). Once aortic stenosis is combined with heart failure, the prognosis is very poor. Without replacement surgery, the mortality rate within 2 years is as high as 50%.
- Heart infection (e.g. endocarditis)
Diagnostic methods for aortic stenosis
Some patients with aortic stenosis may only experience a decrease in physical strength but no other obvious symptoms, so it is very important to conduct a thorough diagnosis and examination.
According to research from the Mayo Medical School in the United States, doctors or cardiologists will first detect the patient’s heart murmur, and then further detect the status of the valve and the degree of calcification with transthoracic echocardiography (TTE). As well as the functioning of the left ventricle, it is also one of the best non-invasive examination methods to evaluate aortic stenosis.
Depending on the patient’s symptoms, the physician may also consider other diagnostic methods as follows:
- Electrocardiography (ECG, EKG): left ventricular hypertrophy and left ventricular strain strain may be seen, and may also affect the electrical conduction system in the heart, especially left branch block (LBBB).
- Cardiac CT scan
- Cardiac MRI
- Transesophageal Echocardiography (TEE)
- Chest X-ray
- Exercise electrocardiogram
- Cardiac Catheterization: Cardiac catheterization provides a precise diagnosis of aortic stenosis and provides the severity, which can be used as a basis for surgery. The aortic area is less than 1.0 square centimeters (normal 3.0 square centimeters), and the pressure difference between the left ventricle and the aorta is greater than 40mmHg, both are considered severe aortic stenosis.
Treatment methods for aortic stenosis
If you are asymptomatic or have mild symptoms, your doctor may recommend regular check-ups. Other patients with more severe symptoms may require treatment with medications or surgery.
Medications cannot actually improve aortic stenosis, but they can treat other heart conditions and complications. For example, if aortic stenosis is caused by rheumatic fever, it can be treated with antibiotics.
If aortic stenosis causes heart failure, diuretics and digitalis may be used, and Angiotensin Converting Enzyme Inhibitors (ACEI) must be used with caution. Beta-blockers and/or calcium blockers are generally used for angina pectoris. Nitrate is contraindicated due to fear of causing severe hypotension.
If the patient’s aortic valve stenosis is severe, the doctor may consider surgical repair or replacement of the artificial valve. The surgical methods may be as follows:
- Traditional surgery (open heart surgery):
The surgery will directly repair or replace the heart valve by sawing the patient’s sternum open while the patient’s heart has stopped and is connected to the extracorporeal circulation machine. This type of surgery carries higher risks and the patient’s recovery time after surgery is also longer.
- Transcatheter aortic valve implantation (TAVI or TAVR):
a type of catheter surgery. It is completed by inserting a catheter through the groin or arm, reaching the heart through the blood vessels, and then directly inserting the artificial heart valve fixed on the stent over the catheter. In addition, if there is a problem of valve insufficiency, it can also be improved by placing a valve clip through this surgery. This surgery is suitable for patients who are not suitable for traditional open heart surgery, especially for those over 75 years old. It is a good choice.
- Balloon valvuloplasty:
In fact, it is performed similarly to TAVI, both using a catheter. Balloon dilatation is used to expand the narrowed valve by inflating a balloon carried on the catheter to improve symptoms. This method is more effective for children or infants, but usually only has temporary effects on adults.
No matter which method is used, if it is decided to replace the artificial valve, based on the patient’s physical condition and requirements, the doctor will choose a biological valve or a mechanical valve to replace the patient’s stenotic aortic valve.
How to prevent aortic stenosis
For people who are not born with a heart defect, there are three ways you can prevent aortic stenosis:
- Good hygiene habits:
washing your hands frequently, covering your mouth and nose when coughing or sneezing, staying away from people with cold symptoms, and changing your toothbrush regularly can reduce your chance of developing rheumatic fever.
- Take good care of your oral health:
Tooth decay, periodontal disease, and bleeding gums increase the risk of bacteria entering your bloodstream, causing heart infection, which may lead to damage to the aortic valve.
- Healthy lifestyle:
Regular exercise, no smoking, less alcohol consumption, and a healthy diet can reduce the risk of atherosclerosis. After arteriosclerosis, the chance of calcification will increase, which will also increase the chance of aortic valve calcification.