The aortic valve is one of the four heart valves whose job is to ensure that blood flow cannot go in the wrong direction. It consists of three crescent-shaped semilunar valves and sits at the beginning of the aorta. If aortic valve stenosis (narrowing) occurs, the normal function of the aortic valve is impaired.
What is aortic valve stenosis?
Aortic valve stenosis, also known medically as aortic stenosis, is a serious heart condition. It is the most common acquired heart valve disease and affects mostly older people. Aortic valve stenosis is characterized by a narrowing of the aortic valve opening surface. Frequently, the heart valves are deformed in this case. The resulting increased pressure on the left ventricle, which is necessary to maintain systolic-arterial blood pressure, leads to left ventricular hypertrophy and coronary insufficiency. Typical of aortic valve stenosis is low blood pressure amplitude associated with delayed duck rise and low-amplitude pulse, which also has a low slope of rise. Aortic valve stenosis is divided into congenital and acquired forms. Congenital defects include, for example, narrowing of the valve annulus, adhesion or thickening of the valve leaflets, and a valve with only two leaflets instead of three. In the latter case, the valve formed by the pockets has only one slit-shaped opening. In most patients, this bicuspid valve is not noticed until adulthood. Such a malformed valve tends to calcify and offers germs a better opportunity to colonize than healthy valves, which can lead to so-called endocarditis in some affected individuals. Most often, such congenital aortic valve stenoses appear in patients younger than 60 years.
Causes
Acquired aortic valve stenosis is most often caused by inflammation (endocarditis) or by the process of wear with age. Stenosis caused by natural wear or calcification occurs mostly in patients younger than 60 years. This wear and tear process, which is characterized by connective tissue remodeling and calcification of the heart valve and thus roughly corresponds to the calcification of the coronary and other vessels (arteriosclerosis), is favored by various factors. These include diabetes, high blood pressure, smoking, excessive calcium concentration in the blood, and genetic factors. The process of orifice narrowing often lasts for many years, so those affected usually do not feel effects of aortic valve stenosis until they are older.
Symptoms, complaints, and signs
At the onset of aortic valve stenosis, sufferers complain of dizziness and other circulatory symptoms. As a result of the lack of blood flow to the brain, circulatory collapse may occur, manifested by rapid heartbeat, sweating, panic attacks, and eventual unconsciousness. Especially in physically stressful situations, symptoms such as increased blood pressure or a pounding heart occur. A feeling of tightness in the chest and chest pain are also typical accompanying symptoms. Furthermore, cardiac arrhythmias such as atrial fibrillation, shortness of breath and pulmonary edema may occur. In the absence of treatment, aortic valve stenosis causes heart failure. Heart failure is noticeable, among other things, by reduced physical and mental performance. In addition, pain and breathing difficulties may occur. Even if no heart failure develops, patients with aortic valve stenosis are quickly weakened physically and occasionally also suffer from impaired thinking. Congenital aortic valve stenosis may cause other symptoms. Many affected individuals suffer from growth disorders or secondary diseases of the internal organs, which usually exist from birth or develop during the first years of life. The typical symptoms and complaints allow an unambiguous diagnosis. If aortic valve stenosis was acquired, the signs can usually be traced to a specific cause.
Diagnosis and progression
Patients suffering from a mild form of aortic valve stenosis often have no symptoms. If the narrowing is of a higher degree, there are usually clear signs of disease. One of the first complaints is shortness of breath, which is initially felt with heavy exertion and later with light exertion.There is a reduction in general performance. Often the shortness of breath is associated with a feeling of tightness and anxiety in the chest, which can increase to the point of heart pain typical of aortic valve stenosis. The low blood pressure under stress can lead to a brief reduction in blood supply to the brain and, as a result, to dizziness and a brief loss of consciousness. Due to the general damage to the heart, many patients in advanced stages of aortic valve stenosis suffer from swelling (edema) of the ankles and lower legs. Echocardiography is the most informative and fastest examination method when aortic valve stenosis is suspected. This ultrasound examination of the heart can detect and classify diseases of the heart valves and any resulting changes in the heart. An ECG (electrocardiogram) and chest X-ray can complete the cardiological diagnosis. If the need for heart valve surgery to treat aortic valve stenosis becomes apparent, cardiac catheterization is used to more accurately determine the severity as well as possible damage to the heart and to identify any parallel narrowing in the coronary arteries.
Complications
The occurrence of complications that can be caused by aortic valve stenosis depends on the causes of the valve stenosis and the further course of the disease. One of the most common complications occurs when permanent bloodstream turbulence develops at the narrowed site of the aortic valve. The turbulence can promote the formation of a thrombus (blood clot). As a result, it can travel with the arterial blood flow to the brain, where it can lead to occlusion of a thin artery. This can lead to a deficiency in the supply of oxygen and nutrients to brain cells dependent on the corresponding artery. The lack of oxygen triggers irreversible destruction of the affected brain cells within a very short time. This is a classic case of a stroke. Depending on the severity of the aortic valve stenosis, a moderate to severe loss of performance occurs, which, in addition to shortness of breath and feelings of tightness in the chest, can also be the trigger of a typical left heart pain. During exertion, temporary dizziness may occur or even unconsciousness, which, depending on the activity, may lead to dangerous situations for oneself and for others. If aortic valve stenosis is left untreated, serious damage to the left ventricular muscles can occur with an unfavorable prognosis. Usually, aortic valve stenosis is treatable, so the impending complications of untreated stenosis of the aortic valve can be avoided.
When should you see a doctor?
Personal behavior when aortic valve stenosis is detected should depend on the severity of the narrowing of the valve in the left ventricle. Likewise, the cause of the valve defect may play a role in the decision if it can provide a better prognosis for the further course of the disease. If the degree of severity is determined to be “mild”, by definition no subjective symptoms are recognizable and therefore no loss of performance occurs. A further visit to the doctor is initially unnecessary, especially since there are also no restrictions with regard to the types of sports practiced. In the case of a medium degree of severity, stress losses are noticeable when peak physical performance is demanded. Nevertheless, sports or other physical activities should not be completely abandoned. Suitable endurance sports are those that do not involve uncontrollable short-term peak loads, as is the case with many types of ball games. It is advisable to have a stress ECG performed beforehand in order to determine the maximum pulse rate, which must not be exceeded during the sporting activities. The stress ECG can be written by a general practitioner with the appropriate equipment or by a cardiologist. Only in cases of high-grade valve stenosis do the symptoms become so severe that any exercise can be counterproductive and immediately life-threatening. The topic of replacing the aortic valve with a biological or artificial valve should be discussed with an experienced cardiologist and possibly considered.
Treatment and therapy
High-grade aortic valve stenosis is treated by surgery to replace the defective valve. There are two types of prosthetic heart valves: biological and artificial. After the use of artificial (mechanical) heart valves, which consist of two metallic wings, a lifelong blood thinning is necessary, which is carried out with drugs such as Falithrom or Marcumar. The advantage of these prostheses is their almost unlimited durability. Biological valves, which are made from tissues derived from the pericardium of pigs or cattle, have approximately the same structure as natural heart valves. Lifetime blood thinning is not necessary with these, but there is some disadvantage from the shorter shelf life, which is approximately between 10 and 15 years. Which type of valve is ultimately used for aortic valve stenosis is decided between the heart surgeon and the patient depending on factors such as the age of the patient, any concomitant diseases, the type of valvular heart disease and the patient’s desire to have children. In rare cases, scaffoldless valves, known as stentless valves, are also used for aortic valve stenosis.
Outlook and prognosis
The prognosis of aortic valve stenosis depends on the progression of the disease, the earliest possible start of treatment, and the patient’s overall health. If medical care is sought, the aortic valve is replaced in a surgical procedure. This restores the full functionality of the aortic valve. The procedure is performed routinely and usually without further complications. Nevertheless, it carries the normal risks of surgery under general anesthesia. An adult who is in good health and has no other pre-existing conditions can usually be discharged as cured within a few weeks or months. No further surgery is needed. A change in lifestyle is necessary so as not to cause overwork or overexertion. Medications are given for strengthening to help improve health. After the surgical wound has healed, the patient can lead a largely normal life without further impairments. However, regular check-ups are still advisable. People with pre-existing conditions have a less favorable prognosis. Depending on the disease, the healing process may be delayed. In addition, a functional disorder of the heart is possible. Without medical care, the risk of a serious illness resulting in death increases. Blood circulation cannot be ensured and disturbances of various systems as well as multiple organ failure occur. A stroke would be the result.
Prevention
Aortic valve stenosis and the associated changes in aortic valves with age can hardly be prevented. Timely recognition and treatment of these conditions are necessary to avoid complications of bacterial endocarditis and rheumatic fever. Relapses should be prevented by consistent administration of antibiotics.
Follow-up
In most cases of aortic valve stenosis, the options for follow-up care are relatively limited. In this case, the patient is primarily dependent on medical treatment by a physician to avoid sudden death of the affected person. It can also prevent further complications. The earlier the aortic valve stenosis is detected, the higher the probability of a complete cure of this disease. In most cases, the disease is treated with the help of surgery. This usually proceeds without complications, so that the valve is replaced by a new valve. As a rule, the new valve does not need to be replaced and lasts until the death of the affected person. After such a procedure, patients should rest and take it easy on their bodies. They should refrain from exertion or other stressful activities. Likewise, a healthy lifestyle with a healthy diet has a positive effect on the course of aortic valve stenosis. Patients should refrain from smoking or taking alcohol. After the procedure, further regular check-ups are necessary to detect further damage to the heart.
You can do it yourself
Recommended behaviors in everyday life and which self-help measures can be considered depend very much on the severity (mild, moderate, severe) of aortic valve stenosis and on the etiology. It is by no means the case that total avoidance of circulatory stress and thus total abstinence from sports activities will have a favorable effect on the course of the disease. Avoidance of any cardiovascular stress is indicated only in the presence of severe aortic valve stenosis. In the presence of mild valve stenosis, usually asymptomatic and detected only by appropriate diagnostic tools such as ultrasound and ECG, there are no restrictions on sports activities. If the valve stenosis is moderate, sports that involve endurance exertion but do not demand punctuated peak exertion are the order of the day. Sports such as hiking in non-mountainous terrain, golfing in flat terrain, moderate Nordic walking and light gymnastics are suitable. Ball sports such as soccer, tennis or squash and many martial arts are less suitable because they are associated with uncontrollable peak loads. The permissible individual load can be controlled by checking the pulse rate using a pulse rate watch. The maximum permissible pulse rate should be determined beforehand in an exercise ECG. Beyond adherence to the maximum pulse rate, attention must also be paid to warning signs such as shortness of breath, chest pain, onset of nausea, and other symptoms that may occur during exercise.
