congenital coronary fistula
Introduction
Introduction to congenital coronary artery fistula Congenital coronary artery fistula (congenitalcoronaryarteryfistula) is a non-capillary bed abnormal traffic between the coronary artery and the heart chamber, the coronary sinus or its branches, the superior vena cava, the pulmonary artery, and the pulmonary vein. basic knowledge The proportion of illness: 0.001% Susceptible people: no specific population Mode of infection: non-infectious Complications: Congestive heart failure in children, endocarditis, myocardial infarction, sudden death
Cause
Congenital coronary artery spasm
(1) Causes of the disease
Like other congenital heart diseases, it may be due to viral infections such as rubella in early pregnancy, malnutrition, uterus affected by certain physical and chemical (including radiation, drugs, etc.) and genetic factors, so that local myocardial development during embryonic period Stopping at an early stage, the sinusoid persists, causing direct communication between the coronary artery and the heart chamber, forming a coronary spasm.
(two) pathogenesis
During the embryonic period, the blood flow of the heart is supplied by a large trabecular space composed of many endothelial cells in the myocardium. This sinus-like gap communicates with the heart chamber and the epicardial blood vessels, and as the heart develops, The coronary artery grows from the root of the aorta, and the coronary vein grows from the coronary sinus, gradually distributed on the surface of the heart, and communicates with the sinusoidal space between the epicardial blood vessel and the myocardium, and gradually expands the sinusoidal space due to the development of the myocardium. Compression, evolved into a small tube, gradually forming part of the normal coronary blood circulation. If the local sinusoidal space remains in the heart development disorder, the abnormal communication of the coronary artery system and the cardiac chamber is formed, and the coronary artery passes through the abnormality. The fistula directly communicates with the heart chamber. This is the coronary artery fistula. The fistula becomes larger with age and the blood of the coronary artery is directly shunted into the heart chamber.
The influence of coronary artery spasm on hemodynamics mainly depends on the size of the fistula and the site of intrusion. Because of the low pressure in the atrium, the wall is thin and the expansion is large. Therefore, the blood flow rate ratio due to sputum If the ventricle is large, the flow into the right ventricle is easier than that in the left ventricle. In the coronary artery and the right heart chamber, both systolic and diastolic phases have a left-to-right shunt, which increases the right heart load and makes Increased pulmonary blood flow, but less pulmonary circulation / systemic blood flow greater than 1.8, long-term left-to-right shunt can lead to pulmonary hypertension, with concomitant congestive heart failure, coronary artery spasm and left heart traffic There is no left-to-right shunt, systolic and diastolic blood flow through the fistula into the left atrium or only diastolic into the left ventricle, both increase the left ventricular load.
Because part of the coronary blood flow from the high-resistance myocardial vascular bed to the low-resistance fistula and directly into the connected heart chamber, this coronary "stolen blood" phenomenon can reduce myocardial perfusion, resulting in partial myocardial blood supply in some patients Insufficient; or due to the formation of coronary aneurysm, blood stasis in the diastolic phase in the aneurysm, can inhibit myocardial ischemia caused by the myocardium and the distal coronary artery, thrombosis can also occur in the aneurysm, thrombosis or shedding can cause far Lateral coronary artery embolization and myocardial infarction.
The heart of congenital coronary artery stenosis can be expanded to varying degrees, especially left ventricular enlargement and hypertrophy. The ascending aorta also expands. On the surface of the heart, the proximal part of the coronary artery of abnormal traffic expands and the wall becomes thinner. Sometimes A fusiform aneurysm can be formed.
The types of coronary fistulas that enter the heart chamber or vein are:
1 coronary artery fistula trunk or branch end fistula is generally a single fistula;
2 multiple branches of the iliac artery or vascular plexus-like changes;
3 The fistula is located on the side of the main branch of the coronary artery and forms a side wall communication with the heart chamber, or the coronary artery is obviously dilated to form a coronary aneurysm. The exact location and size of the fistula cannot be determined from the surface of the heart (Fig. 1). The arteries and the inflowed heart chamber are divided into left and right coronary arteries, and the right coronary artery is more than the left coronary artery. The former accounts for about 50% to 60%, and the latter accounts for 30% to 40%. Less, about 2% to 10%, the coronary artery fistula and the heart chamber connected with the right heart chamber or its connected blood vessels, accounting for about 90%, into the left atrium, left ventricle and other left heart system 10%, according to the incidence of sputum into the heart cavity, followed by the right ventricle, right atrium (including vena cava, coronary sinus), pulmonary artery, left atrium (including the pulmonary vein of the proximal heart), into the left ventricle Rare.
Prevention
Congenital coronary artery spasm prevention
1. Preventing various possible pathogenic factors, vigorously promoting prenatal and postnatal care, avoiding viral infection in early pregnancy, reducing the influence of adverse physical and chemical factors on the uterus, and performing prenatal genetics or chromosome examination if necessary to prevent Not yet.
2. Treatment according to the condition, small flow, no clinical symptoms, can not be treated surgically, but need to prevent infective endocarditis; symptomatics generally advocate early surgery, ligation or repair of mouthwash, can also be permanent Sexual embolization drugs can be blocked by catheter injection, and the symptoms can be relieved after surgery. For those who are not suitable for surgery for some reasons, symptomatic treatment can be taken.
Complication
Congenital coronary artery fistula complications Complications, congestive heart failure, endocarditis, myocardial infarction, sudden death
There may be complications such as congestive heart failure, bacterial endocarditis, myocardial infarction or fistula rupture, and sudden death due to unexplained strenuous exercise.
Symptom
Congenital coronary artery spasm symptoms Common symptoms Shortness of breath angina pectoris heart failure Arteriolar ductus arteriosus hemoptysis wounds form a stroke... Weak ventricular septal defect
Symptom
Most patients can have no symptoms for life, and a small number of patients have a mouthwash that increases with age, making it appear asymptomatic in childhood and appearing in adulthood. Generally, when the pulmonary blood flow/systemic blood flow is greater than 1.5, Frequent fatigue, palpitations, labor shortness of breath, even edema, hemoptysis and paroxysmal dyspnea, and other degrees of heart failure, "coronary bloodletting phenomenon" leads to ischemic angina, the incidence rate is 6.7% ~ 18.4 %, but myocardial infarction rarely occurs.
2. Signs
In the anterior region, 2 to 3 continuous murmurs can be heard, sometimes accompanied by local tremors. The affected part of the murmur is related to the location of the arterial sac into the heart chamber. Generally, the right ventricle is the 4th and 5th ribs of the left sternal border. Between the right atrium and the second intercostal space on the right side of the sternum, the pulmonary artery or the left atrium is more prominent in the second intercostal space on the left sternal border.
Examine
Examination of congenital coronary artery fistula
X-ray inspection
1 coronary artery - right heart and pulmonary artery spasm, hemodynamics is from the bottom of the heart to the left to the right shunt, X-ray performance according to the size of its sub-flow, lung blood can be increased to varying degrees, generally light to moderate increase, the heart The enlargement is mainly in the left ventricle, often accompanied by enlargement of the left or right ventricle. The aortic ascending arch is often more bulging, and a small number of diverters may be in the normal range;
2 Coronary artery - left ventricular fistula, there is no sign of increased pulmonary blood, coronary artery - left ventricular fistula, hemodynamically equivalent to aortic valve regurgitation, the heart with a larger flow is more "aortic" Type, the left ventricle to the height increases, the aortic ascending arch bulges, the heart beats enhanced, showing a "sinking vein";
3 In some cases, the dilated coronary arteries (especially the right side) may constitute the edge of the heart shadow or form an outward bulge. In a few cases, the coronary artery of the tumor-like dilatation may be calcified.
2. Echocardiography Two-dimensional echocardiography can clearly show the dilated coronary artery and track the direction of the coronary artery. At the same time, the color Doppler observation is used to find the location of the fistula, so the two-dimensional echocardiogram and color Doppler combines to accurately diagnose the disease.
3. ECG examination of the larger flow rate can be seen in the left ventricular high voltage, left ventricular hypertrophy and double ventricular hypertrophy, sputum in the right ventricle, right ventricular hypertrophy, divided into the right atrium, often atrial fibrillation, coronary artery sputum There is potential myocardial ischemia, but in the ECG there are ST, T changes are rare.
4. Cardiac catheterization The dilated blood volume of the heart chamber of the fistula is increased. Especially in the right heart system, the blood oxygen content of the right atrium, right ventricle or pulmonary artery can be increased, indicating that the shunt exists and is at the same level. The size of the sub-flow is measured, and the pulmonary artery pressure can be measured.
5. Cardiovascular angiography should be the first choice for ascending aorta angiography. Coronary angiography in patients with large coronary arteries requires selective coronary angiography.
1 The affected coronary arteries are obviously distorted or expanded to form a saccular sac aneurysm. The fistula that communicates with the heart chamber or the large blood vessels is generally one, where there is a tumor-like dilation, and a few can be seen as two or more Rinse mouth
2 Some coronary artery iliac crests, especially branches, do not expand or slightly distort, and the end of the microvascular network is connected with the heart chamber.
Diagnosis
Diagnosis and diagnosis of congenital coronary artery fistula
Diagnostic criteria
Syndrome, premature murmur, X-ray heart image, electrocardiogram and echocardiography, the diagnosis of this disease is not difficult, but need to be combined with patent ductus arteriosus, aortic sinus tumor, primary-lung septal defect and ventricular septal defect Aortic valve dysfunction is identified, and atypical cases can be identified by ascending aortic angiography or selective coronary angiography.
The disease can be divided into the following categories:
1. According to the origin of the fistula, the coronary artery is divided into right coronary artery spasm, left coronary artery spasm, single coronary artery spasm, multiple coronary artery spasm and coronary artery spasm not explicitly indicated.
2. The location of fistula drainage is divided into coronary artery - right atrium or coronary sinus fistula, coronary artery - right ventricular fistula, coronary artery - pulmonary artery spasm, coronary artery - left atrial fistula, coronary artery - left ventricular fistula.
3. The presence or absence of other malformations in the heart is divided into isolated coronary artery spasm, including the communication between the coronary artery and the heart chamber and the pulmonary artery; secondary coronary artery fistula with aortic or pulmonary root atresia and ventricular septal integrity, secondary Coronary artery spasm accounts for about 20% of congenital coronary artery spasm, congenital coronary artery spasm from right coronary artery accounts for 50% to 60%, left coronary artery accounts for 30% to 40%, and two coronary arteries account for 2%. 10%, the sputum part in the right heart system (right atrium, right ventricle, pulmonary artery, superior vena cava and coronary vein) accounted for 90%, in the left heart system (left atrium, left ventricle) accounted for 10%, of which The right ventricle is the most and the left ventricle is the least.
Differential diagnosis
The main diseases that need to be identified with this disease are patent ductus arteriosus, aortic sinus aneurysm rupture, aortic-pulmonary septal defect, high ventricular septal defect with aortic regurgitation, left coronary artery originating from pulmonary artery, Doppler Echocardiography, cardiovascular angiography, especially coronary angiography, and magnetic resonance imaging are helpful in identifying and confirming the diagnosis.
