Cardiac catheterization is the procedure of inserting a thin, hollow tube into a blood vessel in the legor, less often the arm, then passing it into or around the heart in order to obtain information about cardiovascular anatomy and function. The procedure is most often performed to evaluate the blood flow in the heart arteries and to identify any significant narrowing or blockages. If a significant blockage is identified, the heart artery may be reopened nonsurgically by an another procedure called angioplasty and/or stenting. Alternatively, the artery may require coronary artery bypass graft surgery. The test can also measure pressures within the heart and lungs, measure the amount of oxygen in the blood and heart chambers, identify abnormal heart chamber connections called shunts, assess heart valve function, provide access through which samples of heart muscle tissue can be taken for analysis, and provide an accurate assessment of the pumping ability of the heart.
First attempted experimentally on humans in 1929, cardiac catheterization evolved into widespread clinical use in the 1940’s. More than one million cardiac catheterization procedures are performed in hospitals each year, making it one of the most widely used advanced diagnostic tests. Catheterization of the coronary arteries, called coronary angiography, is considered “the gold standard” against which all other methods of diagnosing coronary artery disease are compared.
The procedure is commonly performed electively with patients not requiring overnight hospitalization. After not eating for approximately 8 hours, patients are prepared for the procedure in a holding area. An IV is placed in the arm and oral and/or intravenous medications are given for sedation. Once in the procedure room, the patient is laid flat on a cushioned moveable table. Blood pressure, heart rate and rhythm, and oxygen level are continuously monitored. The right groin, the most common site used, is shaved and cleaned. Local numbing medicine is then given prior to the insertion of another IV in a leg artery. Catheters are then placed into the various areas of the heart through the IV in the leg. Pressure and blood samples can then be obtained if indicated, and the measurements can be used to calculated valve function and blood mixing within the heart. Contrast is injected to light up heart structures such as the heart arteries so that x-ray movies can be made of the blood flow, heart function, and heart anatomy. An x-ray movie made of the heart arteries is called cineangiography. Patients sometimes may feel a warm sensation when the contrast is injected and the table is often moved during filming. Rotating x-ray cameras are positioned to obtain different angles for filming. After the procedure is completed, the leg IV is removed and hand pressure for approximately 10 minutes is used to prevent bleeding. Often times a plug my be used to close the IV hole in the leg artery allowing the leg to be moved sooner. Patients are recovered in a holding area and the leg immobilized for approximately 6 hours. Patients may be discharged home in 6-8 hours if there are no significant findings from the procedure. If a heart artery is opened with angioplasty and/or stenting, the patient is then admitted for additional medicines and monitoring.
The procedure is very safe but is not completely without risk. Complications may include a heart attack, abnormal heart rhythm, bleeding at the IV site, stroke, kidney damage, and an adverse reaction to the sedating medicines or the contrast agent.
Follow-up care involves avoiding strenuous activity or heavy lifting for 3-5 days. The IV site will be mildly tender for a couple of days and may form some bruising. Often times a small bump or knot can be felt underneath the skin. This may represent the normal blood clot formed over the IV access site or the plug used to close the artery. A follow-up doctor visit is usually made in the following week.
What is the indication for the procedure?
What are the alternatives to the procedure?
How many procedures have you performed?
What are the risks of this procedure and how can they be prevented?
Is heart surgery available if something were to go wrong?
What can be expected after the procedure? What restrictions will there be after the procedure?
Will hospitalization be required?
What medications should I hold before the procedure?
If a significant heart blockage is found during the procedure, can the heart artery be reopened at that time?