Hyde syndrome describes an acquired stenosis of the aortic valve in connection with angiodysplasia of the gastrointestinal tract. Prominent are the acendens colon (ascending large intestine) and caecums (appendix). They can show gastrointestinal bleeding and thus lead to anemia (low blood count).

What is Hyde Syndrome?

According to abbreviationfinder, this disorder is named after its discoverer, American internist Edward C. Hyde, who first described the syndrome in 1958. Arteriosclerotic processes in the area of the heart valves cause this acquired stenosis of the aortic valve. The shear forces (flow rate) in the bloodstream 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 (clotting blood). It initiates platelet adhesion (sticking of blood platelets) and platelet activation (primary blood coagulation) and protects factor VIII (antihemophilic globulin A as a component of blood coagulation) from protein breakdown (proteolysis).

In the next step, this disturbed blood clotting causes the Willebrand-Jürgens syndrome, which is a tendency to extensive hematomas, excessive bleeding after injuries and surgical interventions, increased tendency to bleed, prolonged and increased menstrual bleeding ( menorrhagia (long and heavy menstrual bleeding) ) and joint bleeding ( hemarthrosis ). can cause. This disease belongs to the field of vascular medicine, vice medicine, geriatrics and cardiac surgery.


Simply explained, it is an acquired aortic valve stenosis in combination with bleeding from the ascending colon, which is caused by malformed blood vessels (angiodysplasia). The connection between these two clinical pictures, which are caused by calcification or degeneration of the aortic valve and bleeding in the large intestine, has not yet been conclusively clarified medically.

Aortic valve stenosis leads to left ventricular hypertrophy (enlargement of the myocardium in the left ventricle). Paroxysmal dyspnea (shortness of breath ), syncope ( circulatory collapse ) and angina pectoris (chest tightness, thoracic pain, cardinal symptom of coronary heart disease) occur. Bleeding in the gastro-intestinal area (gastrointestinal) can occur occultly (hidden) or as a visible side effect of the bowel movement ( hematochezia ). If there is angiodysplasia of the stomach, melena (abnormally black colored blood) and vomiting of blood can occur.

Symptoms, Ailments & Signs

In addition to Hyde, other physicians have repeatedly pointed out the importance of clinical findings and an exact anamnesis of these complicated pathomechanisms, since the causes of this syndrome have not yet been finally clarified. Both Hyde in 1958 and his colleagues in the decades that followed repeatedly found that they were treating patients with aortic valve stenosis who were simultaneously suffering from massive bleeding from the gastrointestinal tract.

The physicians went a step further when they determined that gastrointestinal angiodysplasia (vascular malformations) were the cause of this bleeding, and that this no longer occurred after an 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 aortic valve stenosis.

The von Willebrand factor is an amino acid protein monomer, which as a subunit leads 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 (stopping bleeding). Many patients with aortic valve stenosis have a reduced number of high molecular weight multimers.

This condition occurs in combination with decreased adhesion (sticking) and aggregation of blood platelets (thrombocytes) and improves with aortic valve replacement. The path to a reliable diagnosis is via an echocardiographic examination (sonography – ultrasound of the heart) and a colonoscopy ( colonoscopy ) to identify vascular malformations.

Diagnosis & disease progression

The large multimers usually appear in coiled molecular form in the blood plasma. When increased shear forces develop in the area of ​​high-grade stenosis of the aortic valve, this condition causes a change in compliance. A specific area becomes accessible for the plasma protease ADAMTS13, which cuts the multimeric molecule.

Hemostasis is an important process in stopping bleeding caused by vascular injury. If this hemostasis is disturbed, bleeding from angiodysplasia (vascular malformations) of the intestinal mucosa occurs. The blood vessels are anatomically changed by this damage and allow greater shear forces (flow conditions).


Due to Hyde syndrome, the patient suffers from internal bleeding in many cases and can therefore also suffer from anemia. The heart disease can often lead to heart problems, which in the worst case can lead to the death of the patient. Sudden cardiac death can also occur here without any prior warning signs or symptoms.

Many patients experience anxiety or panic attacks as a result of Hyde syndrome because this sudden death could occur unexpectedly. As a rule, many sufferers also suffer from depression and other psychological upsets due to the syndrome. It is not uncommon for physical activities to be severely restricted, which further promotes the development of the syndrome.

Hyde syndrome can usually be treated with blood transfusions. However, the patient must also be examined for bleeding in the small intestine. There are no complications. If Hyde’s syndrome is not treated, heart failure develops after about five years, from which the patients eventually die. This reduces life expectancy enormously.

When should you go to the doctor?

A doctor’s visit is necessary as soon as bleeding occurs repeatedly while going to the toilet. Blood in the stool is a warning sign of the organism. Black-colored stools or blood in the stool should be examined more closely by a doctor. Caution should also be exercised in the event of bloody vomiting. If there is no short-term physical overload as the reason, a doctor must be informed of the observations so that the cause can be determined.

A feeling of pressure in the upper body or tightness in the chest are considered unusual. If the symptoms persist for several days or weeks, a doctor should be consulted. If you experience shortness of breath or stop breathing, you should see a doctor as soon as possible. In the event of disturbances of consciousness or loss of consciousness, an ambulance must be called. Until it arrives, first aid measures must be taken to ensure the survival of the person concerned.

Since the patient with Hyde syndrome is at risk of premature death, it is life-saving to see a doctor quickly. Check-ups are advisable if you have problems with heart activity or if you feel unwell, dizzy or general weakness. If the symptoms lead to further psychological impairments, therapy is recommended. A doctor should therefore be consulted in the event of depressive phases, anxiety disorders or behavioral problems.

Treatment & Therapy

After heart valve replacement, the tendency to bleed decreases. Other therapy options are blood transfusions, application of factor III and desmopressin (antiduiretics – synthetic substance to reduce urine excretion), partial resection of the colon (partial removal of the longest part of the large intestine).

If angiodysplasia in the small intestine is suspected, intraoperative enteroscopy (endoscopic examination) with diaphanoscopy (transillumination of body parts using an attached light source) proves useful in order to visualize and treat the 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 diagnose possible simultaneous bleeding in the colon in the context of Hyde’s syndrome.

This disease therefore requires regular check-ups. 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 case of heart failure. When the aortic valve is replaced, not only do the heart problems disappear, but also the gastrointestinal bleeding in the gastrointestinal area.

Outlook & Forecast

Without adequate medical care, the prognosis of Hyde syndrome is unfavorable. The patient’s resilience decreases, anemia and a significant loss of quality of life occur. Coping with everyday life is more difficult and many activities cannot be carried out. In severe cases, there is also a risk of the victim dying prematurely.

If the congenital disorder is treated by a doctor, the goals of therapy are to regulate blood flow and alleviate any symptoms that arise. A heart valve replacement is performed in a surgical procedure. The surgery comes with the usual risks and side effects. If no complications occur, the patient’s prognosis improves. The required amount of blood is regulated via blood transfusions until normal heart activity is restored.

Although good treatment improves health, there is no complete freedom from symptoms. Physical performance is reduced for life with the disease. In addition, regular check-ups must be carried out in order to document changes and to be able to react immediately in the event of abnormalities.

The practice of high-performance sports or intensive physical activities should always be avoided. For a good prognosis, attention should also be paid to emotional irregularities. Persistent psychological stress can trigger health problems at any time and contribute to a deterioration in well-being.


Prevention in the clinical sense is not possible because there is no event or parameter with a predictive probability. Since aortic valve stenosis falls under the category of heart disease, a healthy lifestyle with sufficient exercise can have a positive effect on the entire organism.

Older people who are no longer physically active should take part in soft sports such as Nordic walking, since walking has a positive effect on blood circulation and thus regular blood flow. Patients found to have an elevated pressure gradient across the aortic valve should limit their physical activity until surgery to avoid sudden cardiac death.


In the case of Hyde syndrome, the person affected has very few measures or direct options for aftercare. Since this is a congenital disease, complete healing or self-healing cannot occur. If the person concerned wishes to have children, genetic counseling can also be carried out to prevent the syndrome from reoccurring.

This disease is usually treated by taking various medications. It is always important to ensure correct intake and the correct dosage. If anything is unclear or if you have any questions, you should always consult a doctor first. Since Hyde syndrome can also have a negative effect on the internal organs, regular examinations of the internal organs should also be carried out, paying particular attention to the heart.

In the worst case, if left untreated, it can lead to heart failure, which can lead to death. A healthy lifestyle with a healthy diet can also alleviate the symptoms of Hyde syndrome and prevent further complications. In many cases, physical activity can also have a positive effect on the course of the disease. However, the life expectancy of those affected may be reduced by Hyde syndrome.

You can do that yourself

Unfortunately, those affected by Hyde syndrome have no special options for self-help. With this syndrome, treatment by a doctor is definitely necessary in order to avoid further complications or the premature death of the person concerned.

If the patient loses consciousness due to Hyde’s syndrome and suffers from heart failure or circulatory disorders, an ambulance must be called immediately or the hospital must be visited directly. If you have blood in your stool, you should see a doctor immediately. Furthermore, due to the heart failure, the person concerned must not perform any strenuous sports or activities in order not to strain the heart unnecessarily. A healthy lifestyle with a healthy diet also has a positive effect on the course of the disease. The person concerned should also stop drinking alcohol and nicotinedispense. However, light sports that do not particularly demand the circulation can be carried out.

In order to avoid sudden cardiac death, patients with Hyde syndrome should see a doctor regularly and have examinations carried out. In the event of any psychological complaints, discussions with other affected persons or with friends and acquaintances are often suitable.

Hyde Syndrome

Hyde Syndrome Guide