Cardiovascular Lab Tests
Electrocardiogram (EKG or ECG)
An electrocardiogram is a recording of the heart's electrical activity on a strip of moving paper. It is one of the first tests used to diagnose heart disease, although a normal EKG doesn't guarantee that the heart and coronary arteries are normal. Many patients receive EKGs prior to having surgery to make sure the heart is functioning normally.
An echocardiogram is an ultrasound of the heart. It uses sound waves to produce pictures of the heart in motion. It is used to diagnose abnormalities of the heart valves, the heart muscle and the fluid-filled sac surrounding the heart.
A transesophageal echocardiogram is performed by positioning an ultrasound probe in the esophagus, behind and below the heart. It is used to look for blood clots in the heart and to diagnose the extent of heart valve disease and assess the effectiveness of valve repair or replacement surgery.
Stress testing helps your doctor evaluate your heart at rest, while your heart rate is increasing as you exercise on a treadmill or as a result of medication, and after your heart rate reaches its peak. The test can show how well the heart muscle is contracting and if portions of the heart muscle are deprived of blood. Your doctor may also order a stress test to determine the safety of an exercise program.
Nuclear scans of the heart involve injection of a radioactive isotope followed by one or two 30-minute scans under a gamma camera. Cardiac scans are helpful in finding coronary artery disease and can be used to:
- detect heart attacks, by showing if part of the heart muscle has been damaged
- measure the heart's pumping action
- study the heart's ability to expand and contract
Nuclear scans are often done in conjunction with stress testing.