Cardiac catheterization
Encyclopedia
Cardiac catheterization (heart cath) is the insertion of a catheter
Catheter
In medicine, a catheter is a tube that can be inserted into a body cavity, duct, or vessel. Catheters thereby allow drainage, administration of fluids or gases, or access by surgical instruments. The process of inserting a catheter is catheterization...

 into a chamber
Heart chamber
aHeart chamber is a general term used to refer to any chambers of the mammalian heart. The heart consists of four chambers: the right and left atrium and the right and left ventricle. The top chambers are connected to the bottom chambers by valves and are separated by the coronary sulcus...

 or vessel
Blood vessel
The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and...

 of the heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...

. This is done for both investigational and interventional purposes. Subsets of this technique are mainly coronary catheterization
Coronary catheterization
A coronary catheterization is a minimally invasive procedure to access the coronary circulation and blood filled chambers of the heart using a catheter. It is performed for both diagnostic and interventional purposes....

, involving the catheterization of the coronary arteries, and catheterization of cardiac chambers and valves.

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
Groin
In human anatomy, the groin areas are the two creases at the junction of the torso with the legs, on either side of the pubic area. This is also known as the medial compartment of the thigh. A pulled groin muscle usually refers to a painful injury sustained by straining the hip adductor muscles...

 or the radial artery in the wrist,(Seldinger technique
Seldinger technique
The Seldinger technique is a medical procedure to obtain safe access to blood vessels and other hollow organs. It is named after Dr. Sven-Ivar Seldinger , a Swedish radiologist from Mora, Dalarna County, who introduced the procedure in 1953....

), 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
Femoral artery
The femoral artery is a general term comprising a few large arteries in the thigh. They begin at the inguinal ligament and end just above the knee at adductor canal or Hunter's canal traversing the extent of the femur bone....

 was used, the patient will probably be asked to lie flat for several hours to prevent bleeding or the development of a hematoma
Hematoma
A hematoma, or haematoma, is a localized collection of blood outside the blood vessels, usually in liquid form within the tissue. This distinguishes it from an ecchymosis, which is the spread of blood under the skin in a thin layer, commonly called a bruise...

. If the arm is used, the patient can ambulate sooner. Cardiac interventions such as the insertion of a stent
Stent
In the technical vocabulary of medicine, a stent is an artificial 'tube' inserted into a natural passage/conduit in the body to prevent, or counteract, a disease-induced, localized flow constriction. The term may also refer to a tube used to temporarily hold such a natural conduit open to allow...

 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
Angioplasty
Angioplasty is the technique of mechanically widening a narrowed or obstructed blood vessel, the latter typically being a result of atherosclerosis. An empty and collapsed balloon on a guide wire, known as a balloon catheter, is passed into the narrowed locations and then inflated to a fixed size...

, PCI (percutaneous coronary intervention) angiography, balloon septostomy
Balloon septostomy
Balloon septostomy is the widening of a foramen ovale, patent foramen ovale , or atrial septal defect via cardiac catheterization using a balloon catheter...

, and an Electrophysiology study
Electrophysiology study
An electrophysiology study is a minimally invasive procedure which tests the electrical conduction system of the heart to assess the electrical activity and conduction pathways of the heart. The study is indicated to investigate the cause, location of origin, and best treatment for various...

.

Indications for investigational use

This technique has several goals:
  • confirm the presence of a suspected heart ailment
    Heart disease
    Heart disease, cardiac disease or cardiopathy is an umbrella term for a variety of diseases affecting the heart. , it is the leading cause of death in the United States, England, Canada and Wales, accounting for 25.4% of the total deaths in the United States.-Types:-Coronary heart disease:Coronary...

  • quantify the severity of the disease and its effect on the heart
  • seek out the cause of a symptom such as shortness of breath
    Dyspnea
    Dyspnea , shortness of breath , or air hunger, is the subjective symptom of breathlessness.It is a normal symptom of heavy exertion but becomes pathological if it occurs in unexpected situations...

     or signs of cardiac insufficiency
    Congestive heart failure
    Heart failure often called congestive heart failure is generally defined as the inability of the heart to supply sufficient blood flow to meet the needs of the body. Heart failure can cause a number of symptoms including shortness of breath, leg swelling, and exercise intolerance. The condition...

  • make a patient assessment prior to heart surgery
    Cardiac surgery
    Cardiovascular surgery is surgery on the heart or great vessels performed by cardiac surgeons. Frequently, it is done to treat complications of ischemic heart disease , correct congenital heart disease, or treat valvular heart disease from various causes including endocarditis, rheumatic heart...


Investigative techniques used with coronary catheterization

  • to measure intracardiac and intravascular
    Circulatory system
    The circulatory system is an organ system that passes nutrients , gases, hormones, blood cells, etc...

     blood pressure
    Blood pressure
    Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...

    s
  • to take tissue samples for biopsy
    Biopsy
    A biopsy is a medical test involving sampling of cells or tissues for examination. It is the medical removal of tissue from a living subject to determine the presence or extent of a disease. The tissue is generally examined under a microscope by a pathologist, and can also be analyzed chemically...

  • to inject various agents for measuring blood flow in the heart; also to detect and quantify the presence of an intracardiac shunt
    Shunt (medical)
    In medicine, a shunt is a hole or a small passage which moves, or allows movement of fluid from one part of the body to another. The term may describe either congenital or acquired shunts; and acquired shunts may be either biological or mechanical.* Cardiac shunts may be described as...

  • to inject contrast agents
    Radiocontrast
    Radiocontrast agents are a type of medical contrast medium used to improve the visibility of internal bodily structures in an X-ray based imaging techniques such as computed tomography or radiography...

     in order to study the shape of the heart vessels and chambers and how they change as the heart beats

Catheterization of chambers and valves

Catheterization of cardiac chambers and valves may be performed in the same round as a coronary catheterization, and may also involve nearby major vessels, such as the aorta
Aorta
The aorta is the largest artery in the body, originating from the left ventricle of the heart and extending down to the abdomen, where it branches off into two smaller arteries...

. It is the main method of cardiac ventriculography
Cardiac ventriculography
Cardiac Ventriculography is a medical imaging test used to determine a patient's cardiac function in the right, or more typically, left ventricle. Cardiac ventriculography involves injecting contrast media into the heart's ventricle to measure the volume of blood pumped...

 (another being radionuclide ventriculography
Radionuclide ventriculography
Radionuclide ventriculography, a type of cardiac ventriculography, is a form of nuclear imaging, where a gamma camera is used to create an image following injection of radioactive material, usually Technetium-99m . In radionuclide ventriculography, the radionuclide has the property of circulating...

, whose use has largely been replaced by echocardiography
Echocardiography
An echocardiogram, often referred to in the medical community as a cardiac ECHO or simply an ECHO, is a sonogram of the heart . Also known as a cardiac ultrasound, it uses standard ultrasound techniques to image two-dimensional slices of the heart...

).

It has the ability to measure the pressure gradient
Pressure gradient
In atmospheric sciences , the pressure gradient is a physical quantity that describes in which direction and at what rate the pressure changes the most rapidly around a particular location. The pressure gradient is a dimensional quantity expressed in units of pressure per unit length...

 across a valve and derive valve area from it. Thereby, it can assist in diagnosis of, for example, aortic stenosis.

This is also the procedure used in balloon septostomy
Balloon septostomy
Balloon septostomy is the widening of a foramen ovale, patent foramen ovale , or atrial septal defect via cardiac catheterization using a balloon catheter...

, which is the widening of a foramen ovale
Foramen ovale (heart)
In the fetal heart, the foramen ovale , also ostium secundum of Born or falx septi, allows blood to enter the left atrium from the right atrium. It is one of two fetal cardiac shunts, the other being the ductus arteriosus...

, patent foramen ovale (PFO), or atrial septal defect
Atrial septal defect
Atrial septal defect is a form of congenital heart defect that enables blood flow between the left and right atria via the interatrial septum. The interatrial septum is the tissue that divides the right and left atria...

 (ASD) using a balloon catheter
Balloon catheter
A balloon catheter is a type of "soft" catheter with an inflatable "balloon" at its tip which is used during a catheterization procedure to enlarge a narrow opening or passage within the body...

.

History

The history of cardiac catheterization dates back to Claude Bernard
Claude Bernard
Claude Bernard was a French physiologist. He was the first to define the term milieu intérieur . Historian of science I. Bernard Cohen of Harvard University called Bernard "one of the greatest of all men of science"...

 (1813-1878), who used it on animal models. Clinical application of cardiac catheterization begins with Werner Forssmann
Werner Forssmann
Werner Theodor Otto Forßmann, was a physician from Germany who shared the 1956 Nobel Prize in Medicine for developing a procedure that allowed for cardiac catheterization. In 1929, he put himself under local anesthetic and inserted a catheter into his own arm...

 in the 1930s, who inserted a catheter into the vein of his own forearm, guided it fluoroscopically into his right atrium, and took an X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...

 picture of it. Forssmann won the Nobel Prize in Physiology or Medicine
Nobel Prize in Physiology or Medicine
The Nobel Prize in Physiology or Medicine administered by the Nobel Foundation, is awarded once a year for outstanding discoveries in the field of life science and medicine. It is one of five Nobel Prizes established in 1895 by Swedish chemist Alfred Nobel, the inventor of dynamite, in his will...

 for this achievement, though hospital administrators removed him from his position owing to his unorthodox methods. During World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, André Frédéric Cournand
André Frédéric Cournand
André Frédéric Cournand was a French physician and physiologist.He was awarded the Nobel Prize in Physiology or Medicine in 1956 along with Werner Forssmann and Dickinson W. Richards for the development of cardiac catheterization.Born in Paris, Cournand emigrated to the United States in 1930 and,...

, a professor at Columbia University College of Physicians and Surgeons
Columbia University College of Physicians and Surgeons
Columbia University College of Physicians and Surgeons, often known as P&S, is a graduate school of Columbia University that is located on the health sciences campus in the Washington Heights neighborhood of Manhattan...

who also shared the Nobel Prize, and his colleagues developed techniques for left and right heart catheterization.

External links

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