the overall health state of the patient, situational (elective vs emergent), medications (e.g., anticoagulation), and more. procedure "cardiac catheterization" is a general term for a group of procedures. access to the heart is obtained through a peripheral artery or vein. commonly, this includes the radial artery, internal jugular vein, and femoral artery/vein. each blood vessel has its advantages and disadvantages. once access is obtained, plastic catheters (tiny hollow tubes) and flexible wires are used to navigate to and around the heart. catheters come in numerous shapes, lengths, diameters, number of lumens, and other special features such as electrodes and balloons. once in place, they are used to measure or intervene. imaging is an important aspect to catheterization and commonly includes fluoroscopy but can also include forms of echocardiography (tte, tee, ice) and ultrasound (ivus). obtaining access uses the seldinger technique by puncturing the vessel with a needle, placing a wire through the needle into the lumen of the vessel, and then exchanging the needle for a larger plastic sheath. finding the vessel with a needle can be challenging and both ultrasound and fluoroscopy can be used to aid in finding and confirming access. sheaths typically have a side port that can be used to withdraw blood or injection fluids/medications, and they also have an end hole that permits introducing the catheters, wires, etc. coaxially into the blood vessel. once access is obtained, what is introduced into the vessel depends on the procedure being performed. some catheters are formed to a particular shape and can really only be manipulated by inserting/withdrawing the catheter in the sheath and rotating the catheter. others may include internal structures that permit internal manipulation (e.g., intracardiac echocardiography). finally, when the procedure is completed, the catheters are removed and the sheath is removed. with time, the hole made in the blood vessel will heal. vascular closure devices can be used to speed along hemostasis. equipment much equipment is required for a facility to perform the numerous possible procedures for cardiac catheterization. general: catheters film or digital camera electrocardiography monitors external defibrillator fluoroscopy pressure transducers sheaths percutaneous coronary intervention: coronary stents: bare-metal stent (bms) and drug-eluting stent (des) angioplasty balloons atherectomy lasers and rotational devices left atrial appendage occlusion devices electrophysiology: ablation catheters: radiofrequency (rf) and cryo pacemakers defibrillators history further information: history of invasive and interventional cardiology the history of cardiac catheterization dates back to stephen hales (1677-1761) and claude bernard (1813-1878), who both used it on animal models. clinical application of cardiac catheterization begins with dr. werner forssmann in 1929, who inserted a catheter into the vein of his own forearm, guided it fluoroscopically into his right atrium, and took an x-ray picture of it. however, even after this achievement, hospital administrators removed forssmann from his position owing to his unorthodox methods. during world war ii, andré frédéric cournand, a physician at newyork-presbyterian/columbia, then columbia-bellevue, opened the first catheterization lab. in 1956, forssmann and cournand were co-recipients of the nobel prize in physiology or medicine for the development of cardiac catheterization. dr. eugene a. stead performed research in the 1940s, which paved the way for cardiac catheterization in the usa.