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 might be used during or after a heart attack to treat 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 your large coronary (heart) arteries, especially if your heart's pumping action has already grown weak.
CABG also might be a treatment option if you have blockages in your coronary arteries that can't be treated with percutaneous coronary intervention (PCI), also known as coronary angioplasty.
Your doctor will decide whether you're a candidate for CABG based on factors such as:
- The presence and severity of CHD symptoms
- The severity and location of blockages in your coronary arteries
- Your response to other treatments
- Your quality of life
- Any other medical problems you have
Physical Exam and Diagnostic Tests
To find out whether you're a candidate for CABG, your doctor will give you a physical exam. He or she will check your heart, lungs, and pulse.
Your doctor also may 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, as well as how severe they are.
Your doctor will recommend tests to find out which arteries are clogged, how much they're clogged, and whether you have any heart damage.
An EKG is a simple test that detects and records your heart's electrical activity. The test shows how fast the heart is beating and its rhythm (steady or irregular). An EKG also records the strength and timing of electrical signals as they pass through each part of the heart.
An EKG can show signs of heart damage due to CHD and signs of a previous or current heart attack.
Echocardiography (echo) uses sound waves to create a moving picture of your heart. The test shows the size and shape of your heart and how well your heart chambers and valves are working.
Echo also can show 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.
Some heart problems are easier to diagnose when your heart is working hard and beating fast.
During stress testing, you exercise to make your heart work hard and beat fast while heart tests are done. If you can't exercise, you may be given medicine to raise your heart rate.
The heart tests done during stress testing may include nuclear heart scanning, echo, and positron emission tomography (PET) scanning of the heart.
Coronary Angiography and Cardiac Catheterization
Coronary angiography (an-jee-OG-rah-fee) is a test that uses dye and special x rays to show the insides of your coronary arteries.
To get the dye into your coronary arteries, your doctor will use a procedure called cardiac catheterization (KATH-eh-ter-ih-ZA-shun).
A thin, flexible tube called a catheter is put into a blood vessel in your arm, groin (upper thigh), or neck. The tube is threaded into your coronary arteries, and the dye is released into your bloodstream.
Special x rays are taken while the dye is flowing through the coronary arteries. The dye lets your doctor study blood flow through the 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:
- History and past treatment of heart disease, including surgeries, procedures, and medicines
- History of other diseases and conditions
- Age and general health
- Family history of CHD, heart attack, or other heart diseases
Your doctor may recommend medicines and other medical procedures before CABG. For example, he or she may prescribe medicines to lower your cholesterol and blood pressure and improve blood flow through your coronary arteries.
PCI also might be tried. During this procedure, a thin, flexible tube with a balloon at its tip is threaded through a blood vessel to the narrow or blocked coronary artery.
Once in place, the balloon is inflated, pushing the plaque against the artery wall. This creates a wider path for blood to flow to the heart.
Sometimes a stent is placed in the artery during PCI. A stent is a small mesh tube that supports the inner artery wall.