Coronary artery bypass grafting (CABG) is used to treat people who have severe coronary heart disease (CHD) that could lead to a heart attack. CABG also may be used to treat people who have heart damage following a heart attack but still have blocked arteries.
Your doctor may recommend CABG if other treatments, such as lifestyle changes or medicines, haven't worked. He or she also may recommend CABG if you have severe blockages in the large coronary (heart) arteries that supply a major part of the heart muscle with blood—especially if your heart's pumping action has already been weakened.
CABG also may be a treatment option if you have blockages in the heart that can't be treated with angioplasty.
Your doctor will decide whether you're a candidate for CABG based on a number of factors, including:
CABG may be done on an emergency basis, such as during a heart attack.
To decide whether you're a candidate for CABG, your doctor will do a physical exam. He or she will check your cardiovascular system, focusing on your heart, lungs, and pulse.
Your doctor also will ask you about any symptoms you have, such as chest pain or shortness of breath. He or she will want to know how often and for how long your symptoms occur and how severe they are.
Tests will be done to find out which arteries are clogged, how much they're clogged, and whether there's any heart damage.
An EKG is a simple test that detects and records your heart's electrical activity. This test is used to help detect and locate the source of heart problems.
An EKG shows how fast your heart is beating and its rhythm (steady or irregular). It also records the strength and timing of electrical signals as they pass through each part of your heart.
Some heart problems are easier to diagnose when your heart is working hard and beating fast. During stress testing, you exercise (or are given medicine if you're unable to exercise) to make your heart work hard and beat fast while heart tests are done.
These tests may include nuclear heart scanning, echocardiography, and magnetic resonance imaging (MRI) and positron emission tomography (PET) scanning of the heart.
Echocardiography (EK-o-kar-de-OG-ra-fee), or echo, uses sound waves to create a moving picture of your heart. The test provides information about the size and shape of your heart and how well your heart's chambers and valves are working.
The test also can identify areas of poor blood flow to the heart, areas of heart muscle that aren't contracting normally, and previous injury to the heart muscle caused by poor blood flow.
There are several types of echo, including stress echo. This test is done both before and after a stress test. A stress echo usually is done to find out whether you have decreased blood flow to your heart, a sign of CHD.
Coronary angiography uses dye and special x rays to show the insides of your coronary (heart) arteries. During the test, a long, thin, flexible tube called a catheter is put into a blood vessel in your arm, groin (upper thigh), or neck.
The tube is then threaded into your coronary arteries, and the dye is injected into your bloodstream. Special x rays are taken while the dye is flowing through your coronary arteries.
The dye lets your doctor study the flow of blood through your heart and blood vessels. This helps your doctor find blockages that can cause a heart attack.
When deciding whether you're a candidate for CABG, your doctor also will consider your:
Medicines and other medical procedures may be tried before CABG. Medicines that lower cholesterol levels and blood pressure and improve blood flow through the coronary arteries often are tried.
Angioplasty also may be tried. During this procedure, a thin tube with a balloon or other device on the end is threaded through a blood vessel to the narrowed or blocked coronary artery.
Once in place, the balloon is inflated to push the plaque against the wall of the artery. This widens the artery and restores the flow of blood. Often, a small mesh tube called a stent is placed in the artery to keep it open after the procedure.