The cardiac troponins are integral components of the myofibrillary apparatus and they regulate muscle contraction. The measurement of cardiac troponins has replaced other biomarkers for the specific detection of myocardial necrosis and for the diagnosis of myocardial infarction. The tissue specificity plus sensitivity of the measurement technology has meant that cardiac damage can be detected in circumstances other than conventional acute coronary syndromes. The ability to specifically detect cardiac damage as part of multiple organ failure in intensive care patients has been shown to provide prognostic information, but it is unclear whether this is a dependent or an independent marker of outcome.