What Are the Risks of Angiograms?

Cardioangiography is a method of rapidly injecting a contrast agent into a heart cavity or blood vessel through a cardiac catheter, so that the heart and blood vessel cavity are developed under X-ray irradiation. The imaging process is photographed, and the sequence of blood flow containing the contrast agent and the filling of the blood vessels in the heart can be seen from the results of the development, so as to understand the physiological and anatomical changes of the heart and blood vessels. Is a valuable method for the diagnosis of cardiovascular disease.

Basic Information

English name

angiocardiography

Visiting department

Cardiology

Cardiovascular classification

Commonly used are selective right heart angiography, left heart angiography, pulmonary angiography, aortic angiography, coronary angiography, and hepatic, renal, cerebral, peritoneal, and mesenteric angiography.

Cardiovascular contrast drugs and equipment

For selective cardiovascular angiography, appropriate contrast agents and X-ray rapid continuous radiography equipment are needed, as well as appropriate cardiogram catheters and pressurized syringes for imaging.

Contrast agents are currently mainly used in clinical ionic contrast agents such as 60% to 76% diatrizoate, non-ionic contrast agents such as Youweixian, iohexol, Onipak, etc., and hypotonic ionic contrast agents. Children mainly use non-ion contrast agents. The dosage is: 1 to 1.5 ml / kg for children, the total dose should not exceed 8 to 10 ml / kg; for adults, 50 to 60 ml, the total dose should not exceed 200 ml. If you need an iodine allergy test before using an ionic contrast agent, you can use 30% diatrizoate 1ml for intravenous injection, observe for 20 minutes, and use it without reaction. If you are allergic to ubiquitamine glucosamine, you can use a non-ionic contrast agent. It may also have some minor reactions such as nausea, vomiting, itching and rash in a few patients. Therefore, patients with a history of iodine allergy should also consider emergency Remedy or use corticosteroids and antihistamines before imaging. In addition to the low risk of reaction, non-ionic contrast agents produce better images, but they are more expensive than ionic ones.

The X-ray machine for cardiovascular angiography needs to output a large number of X-rays in a short time, thereby shortening the exposure time, facilitating rapid continuous photography and improving image clarity, so a large capacity of more than 50mA is required. X-ray tube power is above 50kW. For simultaneous bi-directional photography, X-ray machines above 1000kW or two X-ray machines above 500kW are required for simultaneous photography.

Quick photography requires the rapid changer to continuously change the film during continuous exposure. Generally, the fast changer can take a maximum of 6 films per second, and the two changers on the front and side can be synchronized and synchronized. The fluorescence image enhancement device is equipped with X-ray film photography, which can take 24 to 80 frames per second. The entire imaging process can be monitored by the television system. During the film projection, the flow of the contrast agent in the heart and blood vessels and the major blood vessels of the heart can be monitored. Dynamic observation of the structure. At the same time, the imaging process can also be recorded on tape.

When photographing, it is necessary to select positive, side or left and right oblique positions, and in recent years, use the axial angle projection. Make the radiographic site display better.

Digital subtraction angiography is a comprehensive image enhancement-TV system data collection and computer processing generate images, which can significantly reduce the concentration and dose of contrast agents, receive excellent diagnostic results, thereby reducing or avoiding high-concentration, high-dose contrast agent injections Side effects, especially for cases with reduced renal function. Mainly used in large blood vessels and peripheral angiography.

Cardiac catheters for imaging are mainly pig tail catheters, lateral hole radiography catheters, end-to-side radiography catheters, floating balloon radiography catheters, and coronary angiography catheters. F5 and F6 catheters are commonly used in children.

When the contrast agent is injected into the large vessel lumen of the heart through the cardiac catheter, it is required to form a ball in a projectile style, and quickly enter the blood from the front end of the cardiac catheter, in order to reach the highest concentration and clear development in the department, so the injection must be rapid. Because the contrast agent has a certain viscosity and the catheter lumen has a certain resistance, a high-pressure syringe must be used to achieve the purpose of rapid injection. Generally, a single dose is injected in about 1.5 seconds. After a certain amount of contrast agent is injected, the rapid on the syringe is triggered. Exposure triggering device for film or movie photography to start shooting. If an injection is required at a certain time during the cardiac cycle, a certain waveform of the patient's electrocardiogram must be used as a signal to trigger the start of the syringe.

Cardiovascular angiography operation method

Before surgery

Skin should be prepared for iodine allergy tests. To avoid nausea and vomiting caused by contrast agents, aspiration is fasted for 6 hours before surgery. Some sedatives such as barbiturates or sedatives can be given before surgery. For older children and adults 1 % Lidocaine is locally numb. Infants and young children need intravenous or intensive anesthesia combined with 1% lidocaine local anesthesia.

Intraoperative

Generally, the femoral artery and vein are percutaneously inserted into the cardiac catheter during the operation. The coronary artery can be selected for the coronary artery. The catheter is delivered to the site where the radiography is selected. When the catheter is in the blood vessel and the heart cavity, heparin saline (40mg in 500ml) is flushed and dripped into the cardiac catheter to prevent the catheter from clotting. For left heart system imaging, the catheter should be pushed into the artery system when it is placed in the arterial system. 0.5mg / kg heparin is anticoagulated to prevent thrombosis and embolism. After the angiography is completed, the cardiac catheter is withdrawn to press the hemostasis at the site to be punctured, and the pressure is bandaged after the bleeding no longer occurs, especially the arterial puncture should pay attention to complete hemostasis to prevent the formation of hematoma.

3. postoperative

After returning to the ward, patients with cardiovascular angiography should observe changes in heart rate, respiration, blood pressure, and body temperature within the first 4 to 6 hours, and timely detect changes in cardiac function, arrhythmias, and adverse effects of contrast agents for timely treatment. Patients who are awake should be encouraged to drink more water. Patients who are not anesthetized should be given appropriate intravenous fluids to promote the discharge of contrast medium to reduce the impact on the kidneys. The patient's wound must be observed for bleeding. Patients with femoral artery puncture need to stay in bed for 24 hours to avoid premature hematoma at the puncture site or dissection aneurysm formation.

Cardiovascular Angiopathy Diagnosis

Right heart angiography

A clear diagnosis before congenital heart disease, especially the development of the surrounding pulmonary arteries;

Guide interventional treatment of congenital heart disease, such as right ventricular angiography of pulmonary stenosis;

Evaluation of the effect after cardiac surgery determines the next surgical plan.

Left heart angiography

Mitral stenosis or insufficiency;

Aortic stenosis or insufficiency;

A clear diagnosis of congenital heart disease

Guide interventional treatment of congenital heart disease

Left ventricular ventricular aneurysm.

3. coronary angiography

Recurrent severe angina, or angina after myocardial infarction;

Determine the degree of coronary artery stenosis and decide whether to perform balloon dilation or stent placement;

Review after coronary artery bypass surgery;

Coronary congenital malformation;

Coronary heart disease is clinically suspected but the symptoms are atypical.