Hyde syndrome describes acquired stenosis of the aortic valve associated with angiodysplasias of the gastrointestinal tract. Prominent are colon acendens (ascending colon) and caecums (appendix). They may present with gastrointestinal bleeding, leading to anemia (anemia).
What is Heyde syndrome?
This condition is named after its discoverer, US internist Edward C. Hyde, who first described this syndrome in 1958. Atherosclerotic processes in the heart valves cause this acquired stenosis of the aortic valve. The shear forces (flow velocity) in the blood stream in the area of the narrowed heart valve destroy the Von Willebrand factor. This factor is the medical term for a glycoprotein that is responsible for two important functions in hemostasis. It initiates platelet adhesion and platelet activation (primary blood clotting) and protects factor VIII (anti-hemophilic globulin A as a component of blood clotting) from protein degradation (proteolysis). This impaired blood coagulation causes Willebrand-Jürgens syndrome in the next step, which can cause a tendency to extensive hematomas, excessive bleeding after injuries and surgical procedures, increased bleeding tendency, prolonged and increased menstrual bleeding (menorrhagia), and joint bleeding (hemarthros). This condition belongs to the field of vascular medicine, vizeral medicine, geriatrics, and cardiac surgery.
Causes
Simply explained, it is acquired aortic valve stenosis combined with bleeding from the ascending colon caused by malformed blood vessels (angiodysplasia). The relationship between these two clinical pictures, which are caused by calcification or degeneration of the aortic valve and bleeding from the colon, has not yet been conclusively clarified medically. Aortic valve stenosis results in left ventricular hypertrophy (tissue enlargement of the myocardium of the left ventricle). Seizure-like dyspnea (shortness of breath), syncope (circulatory collapse), and angina pectoris (chest tightness, thoracic pain, cardinal symptom of coronary artery disease) occur. Bleeding in the gastrointestinal tract (gastrointestinal) may be occult (hidden) or may be visible accompanying bowel movements (hematochezia). In the presence of angiodysplasia of the stomach, melena (abnormally black-colored blood) and hematemesis may occur.
Symptoms, complaints, and signs
Repeatedly, other physicians besides Hyde have pointed out the importance of clinical findings and an accurate history of these complicated pathomechanisms, as the causes of this syndrome have not been conclusively determined. Both Hyde in 1958 and his colleagues in subsequent decades repeatedly noted that they were treating patients with aortic valve stenosis who were simultaneously suffering from massive gastrointestinal bleeding. Physicians took a step further when they discovered that gastrointestinal angiodysplasias (vascular malformations) were the cause of these bleedings, and that they no longer occurred after aortic valve replacement. In the late 1980s, two medical research groups were able to demonstrate that multimers of von Willebrand factor are reduced in acquired and congenital stenoses of the aortic valve. The von Willebrand factor is an amino acid-protein monomer that acts as a subunit leading to the concatenation (polymerization, demerization) of two molecules. This subunit multimerizes in blood plasma to form a large molecular complex. This is important for proper hemostasis (hemostasis). Many patients with aortic valve stenosis have a decreased number of high molecular weight multimers. This condition occurs in combination with decreased platelet (thrombocyte) adhesion and aggregation and improves with aortic valve replacement. The path to a definite diagnosis involves an echocardiographic examination (sonography – ultrasound of the heart) and performance of a colonoscopy (colonoscopy) to identify vascular malformations.
Diagnosis and disease progression
The large multimers usually appear in coiled molecular form in the blood plasma.If increased shear forces develop in the area of high-grade stenosis of the aortic valve, this condition causes a conformational change. A specific area becomes accessible to the plasma protease ADAMTS13, which cuts the multimeric molecule. Hemostasis is an important process for stopping bleeding caused by vascular injury. When this hemostasis is disrupted, bleeding occurs from angiodysplasias (vascular malformations) of the intestinal mucosa. The blood vessels are anatomically altered by this damage, allowing greater shear forces (flow conditions).
Complications
In most cases, Heyde’s syndrome causes the patient to bleed internally, which not infrequently leads to so-called anemia. This has a very negative effect on the general condition of the patient and, in severe cases, can become life-threatening. Due to Heyde’s syndrome, most patients experience symptoms such as dizziness or nausea. The resilience of the affected person also decreases enormously and it is not uncommon for the patient to lose consciousness. The quality of life is relatively strongly reduced and the everyday life of the patient is made more difficult by the syndrome. The diagnosis of the syndrome is relatively simple and fast, so that an early treatment can occur. Complications occur mainly when Heyde syndrome is not treated. In this case, the remaining life expectancy decreases to about five years, as this usually leads to heart failure and thus cardiac death in the patient. During treatment, there are usually no particular complications and the symptoms disappear relatively quickly. Transfusions may be necessary for the affected person. If treatment is successful, life expectancy is not reduced.
When should one go to the doctor?
A visit to the doctor is necessary as soon as blood is detected in the urine or stool. If bleeding occurs repeatedly, a visit to the doctor should be made as soon as possible. If there are black stools or visible blood clots in the feces, there is cause for concern. If the affected person vomits blood, this should also be examined by a doctor. Digestive problems, pain in the gastrointestinal tract or cramps should be clarified and treated. If there is a loss of appetite or a refusal to eat, the affected person needs medical help. A severe loss of body weight or a feeling of internal dryness may constitute an emergency situation. There is a threat of an undersupply of the organism, which must be treated as quickly as possible. In case of shortness of breath, a feeling of pressure in the chest or complaints of cardiac activity, a doctor should be consulted. If a loss of consciousness occurs, an emergency physician must be called immediately. If the affected person suffers from disturbances in blood circulation, heavy menstrual bleeding or increased wound bleeding, the observations should be discussed with a physician. If there is joint discomfort or discoloration of the skin, a doctor should also be consulted. Dizziness, nausea, a general weakness or a diffuse feeling of illness are signs that must be followed up. If they occur repeatedly or increase in intensity, further investigation should be initiated.
Treatment and therapy
After heart valve replacement, the tendency to bleed is regressed. Other therapeutic options include blood transfusions, application of factor III and desmopressin (antiduiretics – synthetic substance to decrease urinary excretion), partial resection of the colon (partial removal of the longest part of the colon). If angiodysplasia is suspected in the small intestine, intraoperative enteroscopy (endoscopic examination) with diaphanoscopy (fluoroscopy of parts of the body using a light source placed on top) proves useful to visualize and treat corresponding lesions. In many patients, aortic valve stenosis is initially asymptomatic because they have a low peak systolic pressure gradient, which makes it difficult to make a finding regarding any concomitant bleeding in the colon in the setting of Hyde syndrome. This condition therefore requires regular follow-up examinations. The average survival rate of untreated patients with angina pectoris is about five years, four years after development of syncope (circulatory collapse) and three years in the case of heart failure. With replacement of the aortic valve, not only heart symptoms disappear, but also gastrointestinal bleeding in the gastrointestinal tract.
Outlook and prognosis
The course of Heyde syndrome can vary widely. The prognosis depends on the treatment and the course of the disease. In milder forms of the syndrome, there are often no symptoms at all. In most cases, however, the symptoms are so severe that, without treatment, fatal courses are quite possible. Symptoms include bleeding in the gastrointestinal tract, shortness of breath, angina pectoris or seizure-like unconsciousness. A causal treatment of the bleeding complications is not possible. However, valve replacement has been found to reduce the tendency to bleed. Other components of largely symptomatic therapy include blood transfusions, partial removal of the colon, and drug treatment to prevent thrombosis. Without treatment, heart failure occurs in many cases due to damage to the heart valves. So-called shear forces form at the narrowed heart valve, which can lead to the destruction of the Von Willebrandt factor. This results in an acquired Von Willebrandt syndrome, which causes the increased bleeding tendency. At the same time, the risk of developing venous thrombosis increases. This, in turn, increases the risk of emboli (especially pulmonary emboli), which can damage lung tissue and, moreover, are often fatal. When the damaged heart valve is replaced, the shear forces naturally decrease as well. For this reason, it is also understandable why the replacement of the heart valve can push back the symptoms of Heydes syndrome.
Prevention
Prevention in the clinical sense is not possible because there is no event or parameter with predictive probability. Because aortic valve stenosis falls within the realm of heart disease, a healthy lifestyle with adequate exercise can have a positive effect on the whole organism. Elderly people who are no longer physically active should do soft sports such as Nordic walking, as walking has a positive effect on blood circulation and thus on the orderly flow of blood. Patients who have been diagnosed with an increased pressure gradient across the aortic valve should limit their physical activity until surgery to avoid sudden cardiac death.
Follow-up
In Heyde syndrome, measures of follow-up care are severely limited in most cases. In this regard, affected individuals are primarily dependent on a rapid diagnosis with subsequent treatment to prevent complications and also to prevent further worsening of symptoms. The focus is therefore on early detection, so that those affected should see a doctor at the first symptoms and signs of the disease. In most cases, the disease is treated by surgery. Afterwards, those affected should rest and take it easy on their bodies. From efforts or from stressful activities is to be refrained from, in order not to load the body unnecessarily. Furthermore, only light and especially no fatty food may be taken after the procedure. Only after a few days the body may get used to the usual food again. Since Heyde’s syndrome can also cause heart problems, regular examinations of the internal organs should also be performed. Affected persons are not infrequently also dependent on the help and support of their own family, which has a positive effect on the course of Heyde syndrome.
What you can do yourself
Heyde syndrome cannot be directly prevented, nor can it be treated with self-help measures. Affected individuals are dependent on medical treatment in any case. However, a healthy lifestyle with a healthy diet and exercise can have a very positive effect on this condition. Avoiding excess weight can also lead to relief of the symptoms. When it comes to sports, Nordic walking is particularly recommended, as it positively promotes blood flow. However, sufferers with high blood pressure should avoid strenuous sports or activities, otherwise sudden cardiac death may occur. In the event of acute heart failure or loss of consciousness, an emergency physician must be called immediately or the hospital must be visited directly. Until the emergency physician arrives, the affected person must be given emergency artificial respiration and placed in a stable lateral position. Due to the severe restrictions in everyday life, many patients also suffer from psychological complaints.These can be limited by conversations with friends and relatives. Of course, conversations and therapies with other Heyde syndrome sufferers are also suitable in this regard.
