Since Etienne-Jules Marey and Auguste Chauveau developed cardiac catheterization in the period between 1861 and 1863, many risky cardiac surgeries have become unnecessary, which is not only gentler for patients but also offers many advantages from a health economic point of view.
What is cardiac catheterization?
Cardiac catheterization is minimally invasive, meaning the entire procedure makes do with a small opening through which the catheter – a tube-shaped medical instrument – is inserted. The primary goal of cardiac catheterization is to examine the heart and surrounding vessels. The advantage of this method compared to conventional surgery is that it is gentler on the patient, as it no longer requires opening the chest. Instead, cardiac catheterization is minimally invasive, meaning that the entire operation makes do with a small opening through which the catheter – a tube-shaped medical instrument – is inserted. By irradiating the patient with X-rays, the attending physician can follow the operation on the monitor. However, cardiac catheterization is not exclusively used to visualize the heart or coronary arteries, but offers the possibility of further treatment measures. For example, clogged vessels can be reopened by balloon dilatation during cardiac catheterization. It is also possible to stabilize injured vessels from the inside with a stent – a metallic mesh. Furthermore, diseased or non-functioning heart valves can be replaced without the need for major heart surgery. The main tool used in cardiac catheterization is the catheter, a tubular device that has a guidewire wrapped around it for its own stabilization. Depending on which parts of the heart are to be examined, it is decided from where the catheter is inserted. Possible points of insertion for cardiac catheterization include venous and arterial veins that run along the wrist, groin and elbow.
Function, effect, and goals
Cardiac catheterization begins with anesthesia of the site where the catheter will be inserted. Anesthetics are administered only if specifically requested by the patient; otherwise, sedatives are used. Then, if a change of catheters is expected, a sheath is placed as a simplified guide at the insertion site. The catheter is then inserted. The head of the catheter is designed to be particularly soft in order to prevent injury to the vessels. In order to prevent injuries when the catheter is withdrawn, the catheter deforms when the direction is changed. In addition, it is maneuverable. This is important in that it allows the physician to continue the catheter at the “right” branch. Since the guide wire, which is wrapped by the actual catheter, is made of metal, the catheter is visible when the patient is simultaneously irradiated with X-rays. The physician can thus always see on the monitor where the catheter is currently located. However, the vessels and the heart itself are not visible under X-rays. Therefore, a contrast medium is administered to the patient. However, this is not done by injecting the agent venously into the patient, as is the case with computed tomography, for example, but is injected into the vessels through the catheter itself. Once the catheter has reached its destination, further treatments can be performed as part of the cardiac catheterization, if at all necessary, such as the balloon dilatation already mentioned. Once the cardiac catheterization has been successfully completed, the patient cannot be discharged immediately afterwards. Because even with the greatest care on the part of the physician, damage to the vessels cannot be ruled out and this can have unpredictable consequences, the patient must remain in medical care for several hours, if not a whole day, after the cardiac catheterization before he or she can be discharged.
Risks and dangers
Statistically, cardiac catheterization is a relatively safe procedure. The number of patients who died in the hospital as a result of cardiac catheterization was 1 percent (about 4,000 people), according to a 2009 quality study.cardiac catheterizations in which further treatment measures, such as balloon dilatation, were performed, the in-hospital lethality was twice as high, namely 2.4 percent. Patients also need not worry about radiation exposure, as it is within the harmless range of 2,413 cGy*cm². In contrast, possible side effects of the contrast medium could be problematic during a cardiac catheterization. Patients with chronic hyperthyroidism are particularly affected. Here, the iodine contained in the contrast medium can lead to problems with the thyroid gland.
