Overview of Coronary Aneurysm
A localized or diffuse dilatation of a coronary artery that exceeds more than twice the original diameter of the localized area, resulting in a single or multiple aneurysmal change, is called a coronary aneurysm. The clinical manifestations are varied and nonspecific. It depends mainly on the pathologic changes of the aneurysm itself and the presence of comorbidities. The clinical manifestations can be signs and symptoms of angina pectoris or acute myocardial infarction. Heart failure can also occur with a large fistula. Patients with Kawasaki disease may be accompanied by persistent high fever, usually lasting more than 5 days, pharyngitis, desquamation of the hands and feet, erythema multiforme and enlarged lymph nodes in the neck, and bilateral conjunctivitis.
Etiology
Coronary aneurysm is divided into congenital and acquired.
1. Congenital coronary aneurysm
The middle layer of the arterial wall shows segmental defects, muscle fiber dysplasia, and abnormal tissue arrangement. The diseased blood vessels are constantly expanding, thinning and forming aneurysms, or because the cause of the disease is still unclear, so that the arterial wall is cystic necrosis and degeneration, the middle layer of the invasion of the particularly obvious, the elastic fibers are severely damaged so that the arterial wall becomes weak and forms aneurysms, or aneurysms formed by coronary fistulas.
2. Acquired coronary artery aneurysm
(1) Coronary atherosclerosis is the most common cause of coronary artery aneurysm, accounting for 52% of the aneurysms, mostly occurring at the age of 50 years old and above. It is mainly due to the disorder of lipid metabolism, hyperlipidemia, especially the abnormal increase of low-density lipoprotein, so that lipids are firstly deposited in the endothelial layer of the blood vessel wall causing endothelial cell destruction and fibrosis, and then involved in the middle layer of elastic fibers as well as the whole layer of the blood vessel, so that the vascular nutrient is impeded, which results in the endothelial tearing, wall degeneration, and the localized atrophic and fragile formation of the aneurysm.
(2) Kawasaki disease This disease mainly affects children under 6 years of age, but can also involve young people, in which 60% of patients develop cardiac malformations. Such as coronary aneurysm, coronary artery stenosis, myocarditis or myocardial infarction, can also cause papillary muscle dysfunction and mitral regurgitation.
(3) Secondary to severe cyanotic precordial heart disease Patients with severe cyanotic precordial heart disease who live to adulthood experience diffuse dilatation of the coronary arteries as a result of chronically low levels of oxygen saturation.
(4) Supra-aortic stenosis In the presence of supra-aortic stenosis, coronary artery perfusion occurs not during diastole but mainly during systole of the ventricles, resulting in abnormal dilatation of the coronary arteries.
(5) Other etiologies In addition to the common etiologies mentioned above, coronary artery aneurysms can also be seen in advanced syphilis, septic embolism after endocardial infection, neoplastic trauma, scleroderma, etc. They can also occur secondary to coronary artery aneurysms. It can also be secondary to post-coronary angioplasty or post-cardiac surgery, e.g., after endomyocardial biopsy, coronary artery bypass grafting and heart transplantation.
Symptoms
1. Clinical manifestations are varied and nonspecific.
2. It depends largely on the pathologic changes of the aneurysm itself and on the presence or absence of comorbidities. Coronary aneurysms do not cause symptoms per se, and are sometimes very large and asymptomatic, occurring only incidentally at autopsy or coronary angiography. Its clinical manifestations can be angina pectoris or acute myocardial infarction signs and symptoms, fistula large can also occur heart failure.
3. If the fistula breaks into the pericardial cavity, acute pericardial tamponade occurs and death occurs. Giant coronary aneurysms may also present with signs and symptoms of right ventricular outflow tract obstruction.
Examination
1. Electrocardiogram
Usually normal, but may show ST-T changes or corresponding changes of acute myocardial infarction.
2. Cardiac X-ray
Occasionally, abnormal changes in the heart contour, especially at the right cardiac border, or calcification of the aneurysm wall may be detected, which may lead to the suspicion of the disease.
3. Echocardiography, CT, magnetic resonance imaging (MRI)
Echocardiography, CT, MRI are very helpful in the correct diagnosis of coronary artery aneurysm.
4. Angiography or coronary angiography
Provides the most correct diagnosis. It provides accurate information about the involvement of coronary vessels, the size and location of the aneurysm, the distal vascular bed and whether it is combined with coronary fistula.
Diagnosis
Patients with coronary artery aneurysms are often asymptomatic and the electrocardiogram may be normal. Physical examination may be without any positive signs. It is not until complications occur (such as coronary artery thrombosis, myocardial infarction, etc.) that the corresponding clinical symptoms and signs appear, so early diagnosis is more difficult, and the possibility of this disease should be thought of when acute myocardial infarction occurs in young patients (especially around 20 years of age).
Further examinations such as cardiac X-ray and echocardiography, especially ascending aortography and selective coronary angiography, can provide direct imaging signs and provide a basis for diagnosis and later surgical treatment.
Treatment
Coronary artery aneurysms, whether pure or secondary to coronary artery fistulae, require surgical treatment once diagnosed. Coronary artery aneurysms caused by Kawasaki disease generally do not require surgical treatment and can be treated with aspirin and gamma-globulin with significant results.
Surgery for coronary artery aneurysms should be performed under hypothermic extracorporeal circulation, with resection of the aneurysm or ligation of both ends of the aneurysm, and bypass grafting with the saphenous vein or internal mammary artery.
For the complication of acute coronary thrombosis or myocardial infarction, thrombolytic therapy can be adopted, and streptokinase or urokinase can be injected intravenously or intracoronary to dissolve the thrombus. If the effect of thrombolytic therapy is not satisfactory, surgical treatment is still needed.
Questions you may be concerned about
How to treat coronary artery aneurysm
Treatment of coronary artery aneurysm includes surgical treatment, which may be accompanied by medication. Coronary artery aneurysms, whether primary or secondary, need to be treated surgically when they are diagnosed. The specific treatment plan needs to be decided by the clinician after a thorough evaluation. A diagnosed coronary aneurysm should be treated promptly to avoid delay.
Surgery is performed under hypothermic extracorporeal circulation to remove the aneurysm and bypass the saphenous vein. Coronary artery aneurysm surgery is risky and requires good preoperative preparation to avoid complications during surgery. In addition, most patients have atherosclerosis, so it is necessary to check the patient’s medical history before treatment.
Pharmacologic treatment is mainly symptomatic supportive therapy. Antithrombotic drugs are given because of hemodynamic abnormalities, such as aspirin and clopidogrel, etc.; for patients with slower blood flow and vasospasm, calcium channel blockers can be used, such as nifedipine and amlodipine, etc.; and then with the lipid-lowering drugs statin, fluvastatin and simvastatin, etc..