When a patient comes to the hospital with chest pain, the following diagnostic steps are usually taken to determine any heart problems, and, if present, their severity:
- The patient will report all symptoms so that a health care provider can rule out either a non-heart problem or possible other serious accompanying conditions.
- An electrocardiogram (ECG) reading is taken, recording the electrical activity of the heart. It is the key tool for determining if heart problems are causing chest pain and, if so, how severe they are.
- Blood tests showing elevated levels of certain factors (troponins and CK-MB) indicate heart damage. (The doctor will not wait for results, however, before administering treatment if a heart attack is strongly suspected.)
- Imaging tests, including echocardiogram and perfusion scintigraphy, help rule out a heart attack if there is any question.
An electrocardiogram (ECG or EKG) measures and records the electrical activity of the heart. The waves measured by the ECG correspond to the contraction and relaxation pattern of the different parts of the heart. Specific waves seen on an ECG are named with letters:
- P. The P wave is associated with the contractions of the atria (the two chambers in the heart that receive blood from outside).
- QRS. The QRS is a series of waves associated with ventricular contractions. (The ventricles are the two major pumping chambers in the heart.)
- T and U. These waves follow the ventricular contractions.
|Click the icon to see an image of a normal sinus rhythm.|
Doctors use a term called the P-Q or P-R interval, which is the time taken for an electrical impulse to travel from the atria to the ventricle.
Review Date: 05/05/2011
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.