Cardiac catheterization (heart cath) is the insertion of a catheter into a chamber or vessel of the heart. This is done for both investigational and interventional purposes. Subsets of this technique are mainly coronary catheterization, involving the catheterization of the coronary arteries, and catheterization of cardiac chambers and valves.
Coronary catheterization
Procedure
Local anaesthetic is injected into the skin, usually in the right groin, to numb the area. In some centers access to the coronary arteries is made via the right radial or brachial artery (hand or arm), but the majority of cases are still done from the groin region. A puncture is then made with a needle in either the femoral artery in the groin or the radial artery in the wrist, (Seldinger technique), before a guidewire is inserted into the arterial puncture. A plastic sheath (with a stiffer plastic introducer inside it) is then threaded over the wire and pushed into the artery. The wire is then removed and the side-port of the sheath is aspirated to ensure arterial blood flows back. It is then flushed with saline. This arterial sheath, with a bleedback prevention valve, acts as a conduit into the artery for the duration of the procedure.
Catheters are inserted using a guidewire and moved towards the heart. Once in position above the aortic valve the guidewire is then removed. The catheter is then engaged with the origin of the coronary artery (either left main stem or right coronary artery) and x-ray opaque iodine-based contrast is injected to make the coronary vessels show up on the x-ray fluoroscopy image.
When the necessary procedures are complete, the catheter is removed. Firm pressure is applied to the site to prevent bleeding. This may be done by hand or with a mechanical device. Other closure techniques include an internal suture and plug. If the femoral artery was used, the patient will probably be asked to lie flat for several hours to prevent bleeding or the development of a hematoma. If the arm is used, the patient can ambulate sooner. Cardiac interventions such as the insertion of a stent prolong both the procedure itself as well as the post-catheterization time spent in allowing the wound to clot.
A cardiac catheterization is a general term for a group of procedures that are performed using this method, such as coronary angiography, as well as left ventrical angiography. Once the catheter is in place, it can be used to perform a number of procedures including angioplasty, PCI (percutaneous coronary intervention) angiography, balloon septostomy, and an Electrophysiology study.
Indications for investigational use
This technique has several goals:
- confirm the presence of a suspected heart ailment
- quantify the severity of the disease and its effect on the heart
- seek out the cause of a symptom such as shortness of breath or signs of cardiac insufficiency
- make a patient assessment prior to heart surgery....
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