Definition and Overview

Also referred to as heart cath or cardiac angiogram, cardiac catheterization is an invasive diagnostic procedure that involves inserting a catheter, a thin hollow tube, to the heart to assess the real condition of the organ.

The heart plays a huge role in the sustainability of life. It helps distribute blood to different parts of the body, allowing cells to obtain the nutrients carried by the blood.

The organ, which is part of the circulatory system, also has its own mechanism to do its work. Aside from pumping blood, it also uses electrical signals to allow blood to flow across different chambers.

Like any other organ, however, the heart can also develop problems. High bad cholesterol and triglycerides, for example, can result in the buildup of plaque on the artery walls and valves. As they narrow, the heart is forced to work even harder, putting a lot of strain in one of the body’s biggest and important muscles. This condition is called stenosis. As it progresses, a person may encounter difficulty in breathing. It can also lead to cardiac arrest, hypertension, or stroke.

A faulty system in the heart can also cause problems. Arrhythmia, for instance, refers to an abnormal or irregular heartbeat usually caused by problems in the heart’s electrical activity.

As a preventive procedure or part of a management plan, doctors including cardiologists, who specialize in any problems of the heart, will recommend tests such as cardiac catheterization.

Along with it, a percutaneous coronary intervention like an angioplasty with stenting, as well as coronary angiography, may also be performed.

Who Needs It and Expected Results

A cardiac catheterization is carried out when:

  • Regular imaging and standard tests provide inconclusive or insufficient data – Doctors recommend the procedure if they need more information to accurately assess the condition of heart, which may not be possible through physical exam or x-ray imaging tests alone.

  • The patient has to undergo PCI – PCI (percutaneous coronary intervention) is a type of procedure performed to prevent the worsening of stenosis, or the blockage of the arteries, valves, and veins. Normally, a catheter is inserted first before a tip with a balloon is delivered towards the heart. Once it’s in position, the balloon is inflated and deflated multiple times, pushing plaque deposits into the walls and expanding the blood’s pathway. To ensure that the path remains open, a stent is also implanted.

  • The patient has to go through coronary angiography – In a coronary angiography, a contrast dye is delivered through the inserted catheter. Once the patient goes through a scan, the dye makes the contents of the arteries more visible.

  • The person has a history of heart failure – The procedure aids doctors in monitoring the pressure and electrical activity of the heart’s chambers, as well as the amount of oxygen present.

A cardiac cath may also be necessary to assess if the existing treatment, preventive, or management plan is working.

The procedure, although invasive, rarely has serious complications or risks. However, depending on where the catheter is inserted, the patient may feel like urinating more frequently after the procedure.

Depending on the suggestion of the doctor, the patient may have to stay overnight in the hospital or have someone else drive him or her home after the procedure.

How Does the Procedure Work?

Prior to the procedure, the doctor takes note of the medications, results of previous tests, and overall health of the patient.

The procedure is carried out in a hospital under conscious sedation; this means that the patient is awake but will not remember most of the procedure. The catheter can then be inserted in any of the large blood vessels in the body found in the neck, groin, or wrist. The chosen area is then numbed with an anesthetic to minimize pain.

A very small incision is then made into the site, after which a sheath is placed before a long thin wire is introduced. This wire will go all the way to the heart, serving as a guide for the catheter. An imaging system or a thin flexible probe may also be inserted to allow the doctors to see the correct placement of both the sheath and the guide wire.

If both are already in their correct places, the doctor then inserts the catheter into the small incision. It goes inside the sheath, follows the path of the guide wire, but stays on top of the wire. The doctor carefully guides the catheter until it reaches the heart.

The doctor can then perform any of the necessary procedures such as angioplasty, stenting, collection of oxygen samples, or coronary angiography.

After all the needed procedures have been completed, the catheter, guide wire, and sheath are all removed. The wound is closed and bandaged. A slight pressure may have to be applied to minimize bleeding. It takes at least 30 minutes to complete the entire procedure.

Possible Complications and Risks

In general, cardiac catheterization rarely has any serious complications or risks. After the procedure, it’s normal to see bruising and minor bleeding.

The incision site is a wound, which means it can serve as an opening for bacteria and viruses. It is therefore necessary for the patient to follow the doctor’s instructions for cleaning and dressing the site. This way, the risk of infection is significantly minimized.

The site may also feel sore (or swollen), red, and tender during the first few days following the procedure. If this worsens or does not subside, the patient should immediately contact his physician.

In some cases, the blood vessels, including the healthy ones, may be damaged. This can happen if the catheter accidentally scrapes the sensitive vessels as it goes through the heart.

For those who are undergoing angiography, they should have functional kidneys since they have to get rid of the contrast dye. Blood clots and allergic reaction are also possible complications of the procedure.


  • Davidson CJ, Bonow RO. Cardiac catheterization. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 20.

  • Fraker TD Jr, Fihn SD, Gibbons RJ, Abrams J, Chatterjee K, Daley J et al. 2007 chronic angina focused update of the ACC/AHA 2002 Guidelines for the management of patients with chronic stable angina: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines Writing Group to develop the focused update of the 2002 Guidelines for the management of patients with chronic stable angina. Circulation. 2007;116:2762-2772.

  • Kern M. Catheterization and angiography. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 57.

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