From: The department of healthy life

One of the most common reasons why patients come to the Emergency & Urgent Care Medicine Department is chest pain. A blood sample for troponin-I testing will be taken from most of these patients. This blood sample will be sent to the Urgent Testing Laboratory, which provides service 24 hours a day, every day of the year. The results of this test, together with other methods (such as ECG), are used by the treating physician to determine whether the patient has indeed suffered a heart attack.

Troponin-I is one of the subunits of the cardiac troponin complex, which contains another two subunits (troponin-C and troponin-T). Clinical studies have shown that troponin is released into the bloodstream following a heart attack. This test is specific for myocardial infarction, in contrast to the older CK test, for example, which may indicate general muscular damage, and not necessarily damage specific to the myocardium. Pathological blood levels of troponin can be detected between 4 and 6 hours after the onset of chest pain. The blood level of troponin reaches a peak after 8 to 28 hours, and remains high for up to 10 days after the heart attack.

A clinical example of the significance of troponin testing
A 50-year-old patient came to the Emergency Department with chest pain. Tests previously used for diagnosis of myocardial infarction (CK or even CK-MB) did not show any significant alterations, compared with the normal values. However, examination of troponin values indicated a value of 1.2 ng/ml. (The normal range is 0 0.2 ng/ml.) The patient was transferred immediately (time is all-important when treatment of an occluded blood vessel is required) to the Department of Cardiology. He was treated for myocardial infarction, and discharged home after about a week. In the past, prior to the application of troponin testing in routine hospital practice, many patients were only treated at later stages, after significant damage had already been caused to the myocardium.

By: Judith Attias, Deputy Director of the Urgent Testing Laboratory,
the Rambam Health Care Campus