The tests you get to diagnose heart disease are based on who you are and your risk factors.  When getting tests, it's important to know that sometimes technology has outpaced our ability to know what to do with the results, and you need to ask if the tests will make a difference in your outcome.

If you discuss possible coronary problems with your doctor, the first thing to do is to give as open, honest, accurate, and complete a report of your symptoms and your lifestyle as possible.  Make sure you tell your doctor about your eating habits, sleeping habits, lifestyle choices (such as whether and how much you smoke). Never be afraid to discuss the "little details;" they actually may be very important to helping your doctor arrive at an accurate diagnosis. 

Certainly the first tests to have are the old standbys: blood pressure, cholesterol level, weight, and blood sugar.  Then you might move on to the other diagnostic tests currently available, such as:

• Blood tests
  
• Electrocardiogram (EKG, ECG, or cardiogram): a measurement of the heart's electrical activity (which controls the heartbeat) made by an EKG machine, which is attached to the chest with wires called electrodes.  If an EKG doesn't give conclusive results, a portable EKG machine, called a "Holter monitor," may be used.  It monitors the heart rate and notes any arrhythmias (irregularities).
  
• Stress EKG (stress test): an electrocardiogram made while the person is exercising (usually by jogging on a treadmill or riding a stationary bike).  If a patient is unable to exercise, a drug can be injected that makes the heart react as it would during exercise.
  
• Echocardiogram: sound waves are bounced off the heart to produce still and moving images of it (similar to ultrasound imaging used with pregnant women to produce images of fetuses).  A stress echocardiogram is a stress test and echocardiogram done at the same time.
  
• Myocardial perfusion imaging: an imaging test in which a small dose of a harmless radioactive tracer is injected into the patient, who then exercises (as in a stress echo test) while a specialized camera detects the tracer passing through the heart, creating images of the heart at work and at rest.
  
• MRI (magnetic resonance imaging): an imaging technique that "sees through" bones and other obstructions (like an x-ray) to produce detailed cross-sectional pictures of internal organs and body parts; a coronary MRI can help discover a wide range of cardiovascular problems.
  
• Cardiac catheterization: in this more invasive test, a small tube (catheter) is inserted through a blood vessel and threaded up into the heart, to measure blood flow and pressure; a tiny sample of the blood vessel can be removed for examination in the medical laboratory.
  
• Coronary angiogram (also called arteriogram): an x-ray of the inside of the coronary arteries to look for blockages.  During cardiac catheterization, a contrast dye is injected into the catheter that enables blockages to be seen on the x-ray.  The process of making an angiogram is called angiography.

Recently, a new type of imaging test, often called a "heart scan" but actually known as EBCT (electron beam computerized tomography or "Ultrafast CT"), has received a lot of publicity.  It's a type of computerized tomography (popularly known as CT scan or CAT scan).  Computerized tomography is a sophisticated imaging system that creates a series of very detailed, cross-sectional images of organs and tissues. EBCT is a variation that works much more quickly.  It provides an accurate measurement of calcium deposits in the coronary arteries.  These calcium deposits are reported as a calcium score; the higher the score, the greater the amount of calcium deposits.  Scores range from 0 (no evidence of calcium deposits) to over 400 (very high amounts of calcium are present).

There does appear to be a correlation between large calcium deposits in the coronary arteries and the development of coronary artery disease.  However, the correlation seems age-dependent; that is, it is stronger for younger people (up to about 50) than older (above 50).  People over 50 seem to develop calcium deposits naturally, so they're not as accurate a predictor of future CAD. 

Moreover, the medical profession believes certain standards must be met before a screening test (a diagnostic tool, such as EBCT) can be called cost-effective. One of these is that it must provide information that will affect treatment and prognosis.  So far, there are no studies showing that EBCT heart scanning has any significant effect on reducing deaths from CAD or improving the lives of people with it. 

For example, EBCT will identify small build-ups of calcium (such as 10-20%), but these results generally don't lead to changes in treatment, other than re-emphasizing the importance of reducing risk factors, such as smoking and cholesterol.  Further, the test finds only calcium deposits that have become hard, called hard plaque; it does not find soft plaque which can also cause heart attacks.

Besides being of limited value in the early detection of CAD, EBCT is unavailable in many areas, expensive, and generally not covered by insurance.  In early 2007, a committee of the American College of Cardiology Foundation (ACCF) updated the report on EBCT issued by it and the American Heart Association in 2000.  It found that there is still not enough solid data about the cost-effectiveness of EBCT on which to base medical decisions or set policy.

The committee did report that it may be reasonable to consider use of EBCT for people with intermediate risk ratings, but no symptoms.  It does not recommend using it for people at low risk, for the general population, nor for people at high risk (because they would already be candidates for intensive risk reducing therapies).

Three-Dimensional Helical Computed Tomography (or DHCT) is another advanced variation on traditional CT scanning.  Like EBCT, there are many places where it isn't available, it's expensive and generally not covered by insurance, and at present may be of limited value in the early detection of CAD.