Coronary angiography is an invasive examination of the heart vessels for diagnostic or therapeutic purposes. It is also referred to as coronary artery examination. Coronary angiography has the highest significance and informative value in all arteriosclerotic changes of the coronary vessels.
What is coronary angiography?
Coronary angiography is an invasive examination of the heart vessels for diagnostic or therapeutic purposes. Illustration shows the coronary arteries. Conventional coronary angiography is an imaging procedure used to visualize the coronary arteries, which are the so-called coronary arteries. These blood vessels permanently supply the heart muscle with nutrients and oxygen. The aim of the examination is to visualize the interior of these finely branched blood vessels, the lumen. For this purpose, X-rays are used in addition to contrast media, so that constrictions can be detected and treated in real time. These narrowings of the coronary vessels are the most common cause of so-called coronary heart disease and heart attacks. The extent of symptoms and functional impairment in the event of an infarction always depends on the degree of narrowing. All intermediate stages are possible, from asymptomatic microinfarction to severe transmural infarction with a lethal outcome. Conventional coronary angiography allows precise visualization of the extent and impact of stenoses of the coronary arteries. The examination is performed with the aid of a left heart catheter. The diagnostic value of a cardiac catheterization is considered to be high to very high. The procedure can be performed on an outpatient basis or under inpatient conditions as a routine procedure or as part of an emergency diagnostic procedure for suspected myocardial infarction.
Function, Effect, and Objectives
Coronary angiography is a frequently performed examination in Germany; therefore, sufficient empirical data are available for a targeted and safe examination procedure. It has proven its worth both in the prevention of severe heart disease and in emergency therapy against coronary artery disease, CAD, and can be repeated several times if medically indicated. Coronary angiography is performed under sedation and analgesia under partial or brief general anesthesia. The actual procedure always depends on the patient’s condition. Medical guidelines provide for standardized procedures when performing cardiac catheterization. Although there may be certain variations depending on the clinical picture, the basic procedure is initially the same for every selective coronary angiography. After palpation of the left inguinal artery, a tiny incision is made with a scalpel; this allows the left heart catheter to be advanced slowly from this site into the descending aorta under x-ray guidance. After the catheter has been brought to the correct position, the contrast medium is immediately applied, also via the catheter. The contrast medium is now distributed very rapidly in the coronary arteries with the blood flow, and precisely this process is documented in several X-ray images. The procedure used for this is known as X-ray fluoroscopy. Several X-ray images are taken at short intervals, which also allow the beating heart to be visualized. The physician can therefore precisely observe the path of the contrast medium through the coronary arteries in real time and assess the shape and size of any constrictions. Documentation on CD, video or DVD has already proven its worth since the procedure was introduced. This is because with this image material, a careful analysis can still take place after the actual examination. Especially in the case of complex findings, the careful subsequent evaluation of the image material has proven to be very helpful with regard to therapy. In order to accurately assess coronary perfusion using coronary angiography, the TIMI classification is used. This system divides the blood flow in the coronary vessels into 4 grades. Grade 3 means unrestricted, complete perfusion. At grade 2, perfusion is already partially restricted, at grade 1, some contrast medium is already backing up in front of a constriction, and at the worst grade 0, perfusion no longer occurs, i.e. in this case the contrast medium does not penetrate beyond the occlusion.Therapeutically, an inflatable balloon or a fine wire mesh, the so-called stent, can also be advanced via the catheter to restore blood flow to the constriction. In balloon dilatation, the balloon is removed after the constriction is inflated, and a stent remains at the constriction to support the usually fragile vessel wall from the inside.
Risks, side effects, and hazards
Despite all the routine involved in coronary angiography, the risks and dangers should never be underestimated. The most common side effects include intolerance reactions to contrast media, vascular injury during the procedure, or cardiac complications such as ventricular fibrillation or asystole, both of which are medical emergencies requiring intensive care and endangering life. Central emboli can lead to strokes due to introduced thrombi in the bloodstream. Postoperative bleeding, hematoma, or infection are among the other nonspecific hazards of coronary angiography. If nerves are injured during the procedure, permanent sensory disturbances may result. Also not to be underestimated is the relatively high exposure to ionizing radiation, which poses a danger not only to the patient but also to medical and non-medical personnel. While lead aprons and lead gloves protect the physician from much of this radiation during the procedure, a certain amount of stray radiation cannot be avoided. However, the medical benefits far outweigh the dangers from potential risks. For high-risk patients, there are now also good alternatives to conventional coronary angiography. Coronary magnetic resonance angiography works entirely without harmful X-ray radiation from nuclear spin, and the results are almost equivalent to those of conventional coronary angiography. Another alternative is noninvasive coronary angiography using computed tomography.
