Before starting a cardiac rehab program, a thorough risk assessment will be done to determine your heart health and the types of exercises you can safely do. Testing may be done before and during cardiac rehab to help your doctor decide whether you can safely take part in a program and to monitor your progress.

Tests to determine your ability to exercise that may be done before you start cardiac rehab include:

• Resting electrocardiogram (EKG or ECG), a test that measures the electrical signals that control the rhythm of your heartbeat. The graph that shows the results is called an electrocardiogram. A resting ECG will sometimes indicate if more extensive testing is needed before you start an exercise program.
• Exercise electrocardiogram (ECG), a test that records the electrical activity of the heart. An exercise electrocardiogram (sometimes called a stress or treadmill test) is done during exercise to evaluate how the heart responds to exercise. Your doctor can use the test results to prescribe a safe amount of exercise for you.
• Echocardiogram (echo), a type of ultrasound test that uses high-pitched sound waves to produce an image of the heart. The sound waves are sent through a device called a transducer and are reflected off the various structures of the heart. This test shows how well your heart is pumping blood and how well your heart valves are working. Sometimes, it is combined with an exercise stress test.
• Thallium scanning, a test to estimate the amount of blood reaching the heart muscle during rest and exercise. It is typically done to determine the cause of unexplained chest pain or to determine the location and amount of injured heart muscle after a heart attack.
• Ambulatory electrocardiogram (Holter monitoring test), which monitors the electrical activity of your heart while you go about your usual daily activities. Many heart problems occur only during certain activities, such as exercise, eating, sex, emotional stress, bowel movements, or even sleeping. A continuous 24-hour recording is much more likely to detect any abnormal heartbeats that occur during these activities.

Other testing can help monitor your progress during cardiac rehab. Additional monitoring may include blood pressure, cholesterol, weight, blood sugar levels, and exercise ECGs.

You will be monitored closely when you first begin your cardiac rehab program, but after your exercise program is well established, you probably won't need continuous supervision. However, if your doctor determines that you have special needs, he or she may want you to wear a monitoring device at home.