How is heart disease diagnosed?
The diagnosis of heart disease begins with obtaining a history that the potential for coronary artery disease exists. Risk factors need to be assessed and risk stratification occurs. The type of testing that is recommended, if any, depends upon the potential that the patient's symptoms actually represent angina and are coming from the heart.
Heart disease tests
Not every patient with chest pain needs heart catheterization (the most invasive test). Instead, the healthcare provider will try to choose the testing modality that will best provide the diagnosis, and if coronary artery disease is present, decide what impairment, if any, is present.
Electrocardiogram (ECG or EKG)
The heart is an electrical pump, and the electrical impulses it generates can be detected on the surface of the skin. Normal muscle conducts electricity in a reproducible fashion. Muscle that has decreased blood supply conducts electricity poorly. Muscle that has lost its blood supply and has been replaced with scar tissue cannot conduct electricity. The electrocardiogram (EKG) is a noninvasive test used to reflect underlying heart conditions by measuring the electrical activity of the heart.
Some people have "abnormal" EKGs at baseline but this may be normal for them. It is important that an electrocardiogram be compared to previous tracings if one is available. If a patient has a baseline abnormal EKG, they should consider carrying a copy with them for reference should they ever need another EKG.
If the baseline EKG is relatively normal, then monitoring the EKG tracing while the patient exercises may uncover electrical changes that may indicate the presence of coronary artery disease. There are a variety of testing protocols used to determine whether the exercise intensity is high enough to prove that the heart is normal.
Some patients are unable to exercise on a treadmill, but they can still undergo cardiac stress testing by using intravenous medication that causes the heart to work harder.