A physician is likely to take a medical history and to perform a physical examination when diagnosing heart conditions. If a heart condition is suspected, one or more of the following tests may be performed:

• Blood tests. A sample of blood taken from an artery or a vein to detect and measure various factors in the blood. These tests can be used to diagnose heart disease, establish if a heart attack has occurred, evaluate the extent of damage to the heart and monitor the patient's progress during treatment.
  
  
• Electrocardiogram (ECG or EKG). A recording of the heart's electrical activity as a graph or series of wavy lines on a moving strip of paper or video monitor.
  
  
• Chest x-ray. A painless test in which an image is created of the chest by using low doses of electromagnetic radiation that are reflected on film or fluorescent screens.
  
  
• Echocardiogram. A painless test that uses high-frequency sound waves (ultrasound) to get a picture of the heart chambers and valves.
  
  
• Exercise stress test. Used to find heart problems that are evident only during exercise. Also known as the "treadmill test," the test involves an electrocardiogram that measures how the heart performs during exertion.
  
  
• Holter monitor. A small, portable device worn by a patient that records the heart's electrical activity over a period of time.
  
  
• Coronary angiogram. An x-ray of the coronary arteries to see if any of those arteries are blocked, usually by fatty plaque. A catheter is used to inject dye into blood vessels. X-rays are then taken to look for blockages highlighted by the dye.
  

• CAT scan (computed axial tomography). A noninvasive or minimally invasive test that uses multiple x-ray images, taken from different angles, to create three-dimensional images of body structures.
  
  
• MRI (magnetic resonance imaging). Uses a powerful magnetic field to create images of structures and organs within the body. This noninvasive or minimally invasive test can help physicians diagnose a wide range of diseases and conditions without subjecting the patient to radiation or radioactive isotopes and often without needles or dyes.
  
  
• MUGA scan (multi-gated acquisition). Also known as a nuclear ventriculogram, the MUGA scan is a form of radionuclide imaging that provides the physician with a comprehensive look at blood flow and the function of the lower chambers of the heart.