Overview
Coronary artery fistulas include the main branches or branches of the left and right coronary arteries leading directly into the heart chambers, coronary sinuses, pulmonary arteries, pulmonary veins, superior vena cava, or bronchial vessels. The most common is the right coronary artery-right ventricular fistula, accounting for about 25% of cases, while the coronary artery into the left side of the heart cavity is the most rare. With the widespread use of coronary angiography, an increasing number of cases of coronary artery fistulae have been reported in the literature, and in a few cases coronary artery fistulae may involve several coronary arteries. Most cases of coronary artery fistula exist alone, but about 25% of cases can be combined with congenital or acquired heart disease, such as septal defects and valvular disease.
Etiology
The etiology of this disease is mainly caused by abnormal embryonic development. In the early embryonic stage, the myocardial sinusoidal space is connected to the heart chambers and epicardial vessels. As the heart develops, blood vessels are distributed on the surface of the heart from the root of the aorta. The growth and development of the myocardium gradually compresses the sinusoidal space into tiny channels that become intramyocardial coronary arteries and capillaries. If the development is impaired, the local wide sinusoidal gap continues to exist, so that the coronary arteries and the heart chambers produce abnormal traffic between the coronary arteries and the formation of coronary artery termination anomalies.
Symptoms
The vast majority of patients do not present clinical symptoms, often due to physical examination found continuous heart murmur, mild enlargement of the heart or lung field congestion caused by attention. The majority of patients are clinically asymptomatic and are often noticed by a continuous heart murmur, mild cardiac enlargement, or pulmonary field congestion on physical examination, or by incidental detection during selective coronary angiography. Small fistulas can remain asymptomatic for life. Adult cases with large fistulas and high left-to-right shunts may present with weakness, palpitations, and shortness of breath. Angina pectoris and myocardial infarction are rare, with the former occurring in only 7% of cases and the latter in only 3%. congestive heart failure occurs in 12-15% of cases, most often in adult patients, with nearly 20% over the age of 20 years and only 6% under 20 years of age. The main cause of congestive heart failure is a prolonged left-to-right shunt, and in a few patients, congestive heart failure may develop in infancy due to a very high shunt volume. When the complication of bacterial endocarditis, clinical symptoms such as chills and fever.
The main sign of coronary artery fistula is a continuous murmur in the precordial region. In cases where the fistula passes into the right atrium, the murmur is located between the 2nd and 3rd ribs at the right edge of the sternum. In cases where the fistula is in the right ventricle, the murmur is located in the left lower part of the sternum. In cases where the fistula is in the pulmonary artery, the murmur is similar to that of a patent ductus arteriosus. If the fistula enters the left ventricle, only the diastolic murmur can be heard at the left lower border of the sternum. If the fistula is close to the anterior chest wall, a systolic tremor may be heard in the area of the murmur.
Examination
1. Chest X-ray
In most cases, there are no abnormal signs or mild enlargement of the heart, bulging of the pulmonary arteries and congestion of the pulmonary vessels. In cases of congestive heart failure, the heart is markedly enlarged, with an enlarged right or left atrium. Sometimes the edge of the heart is covered by the enlarged and twisted coronary arteries, resulting in irregular deformation of the cardiac silhouette on X-ray.
2. Electrocardiogram
The electrocardiogram is normal in about half of the cases, while the rest may show signs of right or left ventricular overload.
3. Cardiac catheterization
Coronary artery fistula into the right side of the heart, in the right atrium, right ventricle or pulmonary artery level can be found in the blood oxygen content increased, so as to clarify the left to right shunt site. If the shunt flow is large, the pulmonary artery pressure can be mildly increased.
4. Echocardiography
A cross-sectional echocardiogram may show clearly enlarged coronary arteries and enlarged chambers. Ultrasound pulsed Doppler may show the site of coronary artery fistula.
5. Cardiac angiography
Retrograde ascending aortography or selective coronary angiography can show that the contrast agent passes into the heart cavity through the enlarged and sometimes aneurysm-like expansion of the diseased coronary arteries, which can make a clear diagnosis and identify the site of coronary artery fistula.
Diagnosis
Cardiac catheterization, echocardiography, aortography and selective coronary angiography can clarify the diagnosis.
Differential Diagnosis
The continuous murmur produced by coronary artery fistula is similar to that of arterial duct failure, main and pulmonary septal defects, aortic valve sinus aneurysm rupture, high-grade interventricular septal defect with aortic valve closure insufficiency, and thoracic wall or pulmonary arteriovenous fistula, etc., and it is easy to be confused. For the time, location, loudness, nature, conduction direction of the murmur, as well as clinical symptoms of atypical cases, the possibility of coronary artery fistula should be considered in the differential diagnosis.
Complications
This disease can be complicated by congestive heart failure and bacterial endocarditis, as well as some postoperative complications: when the fistula of coronary artery fistula has more than one fistula, it can form a spongy vascular plexus.2.5%-10% of the cases of coronary artery fistula can be complicated by bacterial endocarditis.
Treatment of coronary artery fistula
The only treatment for coronary artery fistulae is surgical closure of the abnormal passage between the coronary arteries and the chambers of the heart.
Surgical treatment should be considered once the diagnosis is clear in patients presenting with increased ventricular filling load, congestive heart failure, myocardial hypoperfusion, and bacterial endocarditis. There is no consensus on the indications for surgery in infants or young children with small coronary artery fistulas, low fractional flow, a ratio of pulmonary to circulatory blood flow of less than 1.3, and clinically asymptomatic. Some scholars believe that long-term follow-up observation can be made, and if the coronary artery fistula tends to increase in size or presents clinical symptoms, then consider surgical treatment. Another opinion is that coronary artery fistula is very unlikely to close on its own, surgical treatment is relatively simple and safe, the therapeutic effect is good, in order to prevent various complications that may occur after growing up, the diagnosis is clear that surgery should be carried out in childhood.
Surgical methods can be selected according to the lesion: ① coronary artery ligation; ② coronary artery fistula incision suture closure; ③ coronary artery incision suture closure of fistula; ④ transcardiac incision suture closure of fistula. The first two surgical methods do not need to apply extracorporeal circulation, the latter two procedures must be operated under extracorporeal circulation. Coronary artery fistula surgical treatment is good, and the complication of huge coronary artery aneurysm is higher risk of surgery, surgical mortality is about 2%. The complication rate of postoperative myocardial infarction is 3-6%. 4% of patients have recurrence of coronary artery fistula after surgery. Long-term postoperative follow-up, clinical symptoms disappear and cardiac function returns to normal.
Questions you may be concerned about
Is surgery necessary for coronary artery fistula in the elderly?
Coronary artery fistula in the elderly does not necessarily require surgery, which is related to the physical condition of the elderly, the severity of the symptoms and so on.
If the elderly coronary artery fistula is small, you can not do surgery, can be treated through intervention. If the elderly coronary artery fistula is larger, then the patient’s physical condition also needs to be considered. If the elderly also suffer from diabetes, breast disease, etc., surgery is not recommended. In addition, due to the poor physical function of the elderly, resistance is lower, it is more difficult to fully recover after surgery, so there is a greater risk.
Elderly people suffering from coronary artery fistula are advised to go to the hospital for electrocardiogram, ultrasound, imaging test, etc., and according to the results of the examination, determine whether surgery is needed under the guidance of the doctor. Imaging examination is a kind of invasive examination, people who are allergic to contrast agent, have infectious disease, or have poor liver function can not do imaging examination, it is recommended to consult with the doctor before the examination to see if they meet the conditions of the examination.
What is the interventional treatment of coronary artery fistula?
Interventional treatment of coronary artery fistula refers to the healing of coronary artery fistula by sealing the fistula through interventional treatment.
Coronary artery fistula refers to the existence of abnormal deformity between the coronary artery and the large blood vessels or the heart, most of them are congenital, and a small number of patients are triggered by cardiovascular disease or trauma. The main symptoms include dyspnea, palpitations, angina, fatigue, etc., and are often complicated by heart failure, endocarditis and other diseases.
Interventional therapy refers to the X-ray image guidance, with a fiber tube from the large blood vessels, along the blood vessels to reach the coronary arteries, the blocking material to the fistula, play the role of closing the fistula, such a treatment method on the human body is less traumatic, fast healing after the operation, but also need long-term follow-up observation, such as recurrence of the need to again interventional therapy.
It is recommended that if a coronary artery fistula exists, a specialist physician should be consulted, examined and treated.
Prognosis
The natural course of coronary fistulae is uncertain. Spontaneous closure of coronary fistulas is extremely rare. Self-rupture is rare. Coronary artery fistulas present at birth or in childhood, small fistulas may persist and not increase in size; moderate-sized fistulas may gradually increase in size but progress slowly, often over a period of more than 15 years; and large fistulas may present with shortness of breath, congestive heart failure, and angina pectoris in infancy or in young adulthood. Because the fistula is usually small in most cases, the clinical signs of prolonged left ventricular filling volume increase only begin to appear at age 50 years or older.Bacterial endocarditis can occur in 5% to 10% of patients, and can occur at any age.