The cardiac catheterization or cardiac catheterization , colloquially also called "cardiac catheter", is a minimally invasive medical examination of the heart via a catheter that is inserted through venous or arterial veins in the groin , the elbow or the wrist . Depending on the aim of the examination, different points in the heart or in the coronary vessels are targeted. The position of the target also determines the choice of access, one speaks of the right heart catheter when the area of the right heart part is to be examined, correspondingly the left heart catheter when examining the left heart part. The right heart catheterization is rarely performed, the left heart catheterization common, especially to aid in the coronary angiography the coronary arteries to make them visible and possibly as part of a balloon dilatation dilate.
Right heart catheterization in humans was first carried out in 1929 by Werner Forßmann in a self- experiment. Forßmann was awarded one of the three Nobel Prizes for Medicine in 1956 for this. Left heart catheterization is associated with the names of the Americans Charles Dotter , Mason Sones , Melvin P. Judkins and the Germans Andreas Roland Grüntzig and Eberhard Zeitler . The electrophysiological examination (EPU) of the heart is also carried out in a similar way to a right heart catheter.
Examination and treatment options
The following types of examination are common within the framework of a cardiac catheter examination:
- Right heart catheter: pressure, oxygen and temperature measurement in the right heart and especially in the pulmonary arteries with and without load
- Left heart catheter
There are also a number of treatments that can be performed with cardiac catheterization:
- If there is an obstruction or narrowing of the coronary arteries , e.g. B. indicated by a myocardial infarction , the vessel in question can be widened by balloon dilatation , also known as percutaneous transluminal coronary angioplasty, PTCA .
- If the expansion is not sufficient, a metal mesh tube, a so-called stent , can be implanted to support the blood vessel. The stent is folded up on a balloon catheter like a cardiac catheter to the narrowed point and then expanded by the balloon.
- In congenital heart defects , such as the Vorkammerscheidewanddefekt , the ventricular or valvular today there is the possibility the disease to be treated, depending on the case design directly during cardiac catheterization and thus an open surgery to avoid.
- Implantation of heart valves (transfemoral or transfemoral catheter-supported valve replacement "TAVI")
- Implantation of coils (wire spirals) with disruptive additional vascular connections ( MAPCAs ).
- Ablation (sclerotherapy of tissue) of additional pathogens or of thickened heart muscle in HOCM (TASH).
Performing the catheterization
The aim of the examination method is to insert specially shaped catheters into certain areas of the heart. The cardiac output can also be determined. Depending on the type of examination, the catheter is used to measure the pressure in certain areas of the heart or an x-ray contrast agent containing iodine is given to show the action of the heart ( ventriculography ) or the vessels in the heart ( coronary angiography ). An X-ray film is recorded over several seconds for documentation and, if necessary, re-evaluation.
To insert the catheter, the puncture site is anesthetized locally. A general anesthetic is not usually applied, if required, one may sedatives are administered. Since the catheter has to be moved during the examination and usually changed during the left heart examination, a lock is first inserted into the blood vessel using the Seldinger technique . This is only removed again at the end of the examination. The sheath serves as a flexible guide rail through the interior of which the catheter can slide into the blood vessel, with the puncture site being sealed at the same time.
A metal guide wire is then inserted and advanced to the target area. Its tip is made of a softer, more flexible material and is curved so that the risk of damaging the interior of the blood vessels is minimized. After checking the position with the aid of fluoroscopy with X-rays , the catheter is brought forward over the wire as a splint. The wire is then removed. The catheter falls back into its original shape and is positioned if necessary with fluoroscopy and the aid of a contrast medium. The eventual administration of the contrast agent is sometimes perceived by the patient as a feeling of warmth that spreads with the flowing blood.
The catheter change for different parts of the examinations is carried out with the help of the reinserted guide wire again using the Seldinger technique through the sheath. After the examination, the guide wire, catheter and sheath are removed and the puncture site is closed with a pressure bandage or with a vascular occlusion system .
Risks and Complications
A cardiac catheterization exam is not free from possible complications. In a quality examination of the German hospitals in 2012, the total ( regular examinations as well as emergency interventions ) in-hospital mortality was 1.1% ( 4,622 deaths of 419,772 patients with coronary angiography, without percutaneous coronary intervention (PCI) ). In patients with additional intervention (dilatation or stent) it was 2.7% ( 7,666 deaths in 286,000 patients ). The overall complication rate MACCE ( Major Adverse Cardiac and Cerebrovascular Events = major cardiac and cerebral vascular complications intra- post-procedural: stroke, myocardial infarction, death ) was 1.3% in the group without intervention and 3.3% in the group with PCI.
Problems in the area of the vascular puncture site are comparatively common . This can lead to secondary bleeding or the development of vascular anomalies ( AV fistula , aneurysm spurium ). Vascular surgery is very rarely required here .
The average radiation exposure for the patient without intervention is approx. 2,413 cGy * cm², for patients with intervention approx. 5,100 cGy * cm² and is thus typically well below the dose reference value (DRW) for coronary angiographies in adults of 6,000 cGy * cm². Due to the daily exposure, the staff must protect themselves with lead coats, among other things.
Allergic reactions to the contrast medium (itching of the skin, swelling, shortness of breath) rarely occur, but can be treated immediately by administering appropriate medication. If such a contrast agent allergy is known in advance, the appropriate medication is given prophylactically .
Since the X-ray contrast medium used is harmful to the kidneys, appropriate preparation should be carried out if the kidney function is impaired . In order to minimize the exposure to the contrast agent, these patients are examined on a biplane system (two X-ray tubes ) with the option of documenting two views per administration of the contrast agent. A levocardiogram may not be required . The need for temporary or permanent dialysis is extremely rare.
In patients with an overactive thyroid ( hyperthyroidism ), the iodine contained in the contrast medium can lead to thyrotoxicosis . Accordingly, the thyroid gland is examined in a laboratory prior to the examination and, if necessary, medication is given before and a few days after the examination.
Cardiac catheter examinations in horses were developed between 1861 and 1863 by Étienne-Jules Marey and Auguste Chauveau , who were able to use them to measure the pressure curve in the beating heart.
- H. Lapp, I. Krakau (Hrsg.): The heart catheter book - Diagnostic and interventional catheter techniques . 3. Edition. Thieme, Stuttgart / New York 2009, ISBN 978-3-13-112413-5 .
- S1 guideline hygiene requirements for invasive examinations and treatments in the cardiac catheter laboratory of the AWMF (working group "Hospital & Practice Hygiene"). In: AWMF online (as of 2013)