Cardiac Catheterization Health Article

Definition

Cardiac catheterization (also called heart catheterization) is a diagnostic and occasionally therapeutic procedure that allows a comprehensive examination of the heart and surrounding blood vessels. It enables the physician to take angiograms, record blood flow, calculate cardiac output and vascular resistance, perform an endomyocardial biopsy, and evaluate the heart's electrical activity. Cardiac catheterization is performed by inserting one or more catheters (thin flexible tubes) through a peripheral blood vessel in the arm (antecubital artery or vein) or leg (femoral artery or vein) under x-ray guidance.

Purpose

Cardiac catheterization is most commonly performed to examine the coronary arteries, because heart attacks, angina, sudden death, and heart failure most often originate from disease in these arteries. Cardiac catheterization may reveal the presence of other conditions, including enlargement of the left ventricle; ventricular aneurysms (abnormal dilation of a blood vessel); narrowing of the aortic valve; insufficiency of the aortic or mitral valve; and septal defects that allow an abnormal flow of blood from one side of the heart to the other.

Symptoms and diagnoses that may be associated with the above conditions and may lead to cardiac catheterization include:

• chest pain characterized by prolonged heavy pressure or a squeezing pain
• abnormal results from a treadmill stress test
• myocardial infarction (heart attack)
• congenital heart defects
• valvular disease

Cardiac catheterization with coronary angiography is recommended in patients with angina (especially unstable angina); suspected coronary artery disease; suspected silent ischemia and a family history of heart attack; congestive heart failure; congenital heart disease; and pericardial (lining outside the heart) disease. Catheterization is also recommended for patients with suspected valvular disease, including aortic stenosis (narrowing) or regurgitation, and mitral stenosis or regurgitation.

Patients with congenital cardiac defects are also evaluated with cardiac catheterization to visualize the abnormal direction of blood flow associated with these diseases. In addition, the procedure may be performed after acute myocardial infarction (heart attack); before major noncardiac surgery in patients at high risk for cardiac problems; before cardiac surgery in patients at risk for coronary artery disease; and before such interventional technologies and procedures as stents and percutaneous transluminal coronary angioplasty (PTCA) or closure of small openings between the atria (upper chambers), called atrial septal defects.

Left- and right-side catheterization

Cardiac catheterization can be performed on either side of the heart to evaluate different functions. Testing the right side of the heart allows the physician to evaluate tricuspid and pulmonary valve function, in addition to measuring blood pressures and collecting blood samples from the right atrium, right ventricle (lower chamber), and pulmonary artery. Catheterization of the left side of the heart is performed to test the blood flow in the coronary arteries, as well as the level of function of the mitral and aortic valves and left ventricle.

Coronary angiography

Coronary angiography, which is also known as coronary arteriography, is an imaging technique that involves injecting a dye into the vascular system to outline the heart and coronary vessels. Angiography allows the visualization of any blockages, narrowing, or abnormalities in the coronary arteries. If these signs are visible, the cardiologist may assess the patient's readiness for coronary bypass surgery, or a less invasive approach such as dilation of a narrowed blood vessel by surgery or the use of a balloon (angioplasty). Because some interventions may be performed during cardiac catheterization, the procedure is considered therapeutic as well as diagnostic.

Outpatient catheterization

Cardiac catheterization is usually performed in a specially designed cardiac catheterization suite in a hospital, so that any procedural complications may be handled rapidly and effectively. Cardiac catheterization may also be performed on patients presenting to the emergency department with chest pain or chest injuries. The procedure may be performed on an outpatient basis, depending on the patient's pre- and post-catheterization condition. As of 2000, however, the American Heart Association (AHA) and the American College of Cardiology (ACC) issued a joint statement denying approval of the use of separate cardiac catheterization laboratories that are not part of a hospital, on the grounds that a small number of patients having the procedure on an outpatient basis will have unexpected reactions or complications.

Demographics

Coronary artery disease is the first-ranked cause of death for both men and women in the United States. More than 1.5 million cardiac catheterizations are performed every year in the United States, primarily to diagnose or monitor heart disease. There is an expected growth to more than three million procedures by 2010.