Cardiac Catheterization

Cardiac catheterization — often called a heart cath or coronary angiogram — is the most direct way to see the heart's arteries. A thin, flexible catheter is guided through an artery in the wrist or groin up to the heart, contrast dye is injected into the coronary arteries, and X-ray video records exactly where blood flows and where it is obstructed.

It remains the reference standard against which other tests are measured. It is also frequently both diagnosis and treatment in one visit: if a significant blockage is found, angioplasty and a stent can often be performed immediately.

• An abnormal stress test, or chest pain that testing has not explained
• During a heart attack, as the emergency treatment to reopen the blocked artery quickly
• Before valve or heart surgery, to map the coronary arteries
• To measure pressures inside the heart chambers and lungs, or to assess a valve problem
• To evaluate a weakened heart muscle of unclear cause

Plan on several hours at the facility, though the procedure itself often takes 30 to 60 minutes.

You will have nothing to eat or drink after midnight and specific instructions on medications — particularly blood thinners, and metformin if you take it, since it is usually held around contrast. Tell your team about kidney problems and about any previous reaction to contrast dye, as both change the preparation.

An IV is started and you are given sedation to relax, but you remain awake — your cooperation with breath-holds is useful, and the procedure is not painful. The wrist or groin is numbed thoroughly. You may feel pressure as the catheter is placed, and a brief warm flush through the chest when dye is injected. Tell the team if you feel chest pain, which is useful information rather than something to endure quietly.

Radial access through the wrist is preferred where suitable: bleeding risk is lower and you can sit up and walk sooner. Femoral access through the groin requires lying flat for several hours afterward while the site seals.

The wrist is held with a compression band that is loosened over a few hours; the groin is held with firm pressure or sealed with a closure device. Most diagnostic catheterizations are same-day procedures.

For about a week, avoid heavy lifting and strenuous activity. Keep the site clean and dry and watch it. Drink fluids to help clear the contrast dye.

Return or call promptly for bleeding that does not stop with firm pressure, a rapidly expanding lump, increasing pain, numbness or coldness in the hand or leg, fever, or chest pain.

Serious complications are uncommon in a planned procedure. They include bleeding or vessel injury at the access site, contrast-related kidney injury, allergic reaction to the dye, irregular heart rhythms, and rarely heart attack or stroke. Risk depends heavily on your kidney function, your overall condition and whether the procedure is elective or emergent — your cardiologist will put your specific risk in context.

Your cardiologist can usually tell you what the pictures showed the same day. Findings lead to one of three paths: medication alone, angioplasty and stenting, or referral for bypass surgery when the disease pattern makes surgery the better option.