In 1959, Dr. Sones, a pediatrician at Cleveland Medical Center, performed a cardiogram on a patient with aortic valve lesions by using a specially designed catheter with a curved tip. In 1964, Sones performed the first coronary angiogram through a brachial artery dissection.
Nowadays, coronary angiography is a common and effective method to diagnose atherosclerotic heart disease (coronary artery disease). Selective coronary angiography involves the use of a specially shaped cardiac catheter to percutaneously puncture into the femoral artery of the lower extremity, retrograde along the descending aorta to the root of the ascending aorta, and then probe the left or right coronary artery for insertion and injection of contrast to visualize the coronary artery. In this way, the entire lumen of the trunk of the left or right coronary artery and its branches can be clearly displayed, and it is possible to understand the presence or absence of stenotic lesions, make a clear diagnosis of the location, extent, severity and condition of the vessel wall, decide on the treatment plan (intervention, surgery or medical treatment), and also use it to judge the efficacy of treatment.
This is a safe and reliable invasive diagnostic technique, which is now widely used in clinical practice and is considered the “gold standard” for the diagnosis of coronary artery disease. However, in recent years, since intracoronary ultrasound imaging (IVUS) and optical interferometric tomography (OCT) have been gradually applied in clinical practice, it has been found that intimal thickening or plaque exists in some of the vessel segments that are normal in coronary angiography. However, because IVUS and other examinations are more expensive and more complicated to operate, they are not routine examination means now. Coronary angiography is still the “gold standard” for the diagnosis of coronary artery disease. Coronary angiography is a very safe procedure. Currently, coronary angiography is the number one procedure in the United States, with an average mortality rate of less than 0.1% in the SCAI registry.
I. Indications for coronary angiography
The main role of coronary angiography is to evaluate the alignment, number and malformation of coronary vessels; to evaluate the presence, severity and extent of coronary lesions; to evaluate the functional changes of coronary arteries, including the presence or absence of coronary artery spasm and collateral circulation; and to evaluate the left heart function at the same time. On this basis, interventional treatment can be performed according to the degree and extent of coronary artery lesions; the effect of coronary artery bypass surgery and interventional treatment can be evaluated; and long-term follow-up and prognostic evaluation can be performed.
(I) Diagnosis as the main purpose
1, unexplained chest pain, non-invasive tests cannot confirm the diagnosis, clinical suspicion of coronary heart disease.
2, unexplained arrhythmias, such as intractable ventricular arrhythmias and conduction block; sometimes coronary angiography is required to exclude coronary artery disease.
3, unexplained left heart insufficiency, mainly seen in dilated cardiomyopathy or ischemic cardiomyopathy, the two identification often need to perform coronary arteriography.
4.Recurrence of angina after percutaneous coronary intervention (PCI) or coronary artery bypass grafting.
5, congenital heart disease and valve disease before surgery, age > 50 years, easily combined with malformations of the coronary arteries or atherosclerosis, can be intervened at the same time as surgery.
6.Asymptomatic but suspected coronary heart disease in high-risk occupations, such as pilots, car drivers, police officers, athletes, firefighters, etc. or medical insurance needs.
(B) Treatment as the main purpose
The diagnosis of clinical coronary artery disease is clear, and coronary angiography can further clarify the scope and degree of coronary artery lesions and select the treatment plan.
1.Stable angina pectoris or old myocardial infarction with poor effect of medical treatment, which affects work and life.
2, unstable angina pectoris, first take internal medicine to actively intensify treatment, once the condition is stable, actively perform coronary angiography; internal medicine treatment is ineffective or the symptoms do not relieve, generally need emergency angiography. For high-risk patients with unstable angina pectoris, mainly spontaneous, accompanied by obvious ST-segment changes in ECG and post-infarction angina, coronary angiography can also be performed directly.
3. The main treatment for acute myocardial infarction (AMI) is reperfusion therapy of occluded vessels, and percutaneous coronary intervention (PCI), with its high success rate, has been used as the preferred method of reperfusion therapy for AMI. If PCI technology is not available, patients with contraindications to thrombolysis after AMI should be transferred to a hospital with the condition as much as possible. patients who do not recanalize with intravenous thrombolysis after AMI should seek remedial PCI in due course.
For patients with uncomplicated AMI, elective coronary angiography should be considered about 1 week after infarction, and AMI with complications such as cardiogenic shock and ventricular septal perforation should be treated with early revascularization with the help of assisted circulation. For patients with high suspicion of AMI but cannot confirm the diagnosis, especially with left bundle branch block, pulmonary embolism, aortic coarctation and pericarditis, coronary angiography can be performed directly to clarify the diagnosis.
4.Asymptomatic coronary artery disease, among them, coronary angiography should be performed in patients with positive exercise test and accompanied by obvious risk factors.
5.CT and other imaging examinations reveal or highly suspect moderate or above stenosis of coronary arteries or the presence of unstable plaques.
6.Primary cardiac arrest with successful resuscitation and a high probability of left main stem lesion or lesion in the proximal segment of the anterior descending branch is a high-risk group and should be treated with early vascular lesion intervention, which requires coronary artery evaluation.
7.After coronary artery bypass grafting or PCI, angina recurs, and coronary artery lesion evaluation is often required again.
II. Contraindications to coronary angiography
1.Allergy to iodine.
2. Combination of severe cardiopulmonary insufficiency.
3, Combination of severe arrhythmia and complete atrioventricular block, etc.
4.Electrolyte disturbance.
5.Severe liver and kidney insufficiency.
How to complete high quality coronary angiography
Successful coronary angiography requires not only the ability to show the whole picture of the main branches of the coronary arteries, the location and extent of coronary artery lesions, and to provide basic information for PCI, but also to provide a reliable basis for surgical procedures, and requires no serious complications. However, high-quality angiography also requires.
(i) adequate visualization of the open branches of the main coronary artery, including the openings and bifurcations of the left main and anterior descending branches, as well as some bifurcations of the distal right coronary artery;
It is very basic to be able to show the lesion in tangential position. Only when the lesion is shown in tangential position can the internal structure of the lesion be truly and objectively reflected, otherwise it is very dangerous;
③More accurate reflection of vascular pathological anatomy and physiology;
④Adequate display of the occluded segment to distant vessels;
⑤ Minimum radiation dose: reduce patient and operator radiation;
⑥Minimal contrast agent: reduce toxic reactions;
⑦Shortest operation time;
⑧No complications.
At present, most interventionalists choose to puncture the right radial artery for coronary angiography, which can be done in less than 10 minutes by skilled operators, without bed rest after the procedure, and the puncture site can be wrapped with pressure for 6 hours. It is the “golden indicator” to confirm the diagnosis of coronary artery disease, and is a necessary test before coronary intervention or coronary artery bypass surgery.