3, 4 These universal definitions of MI were published in 2000 and 2007, and they included more standardized and reproducible definitions and a new classification of MI.3 The first global MI task

force classified any degree of myocardial necrosis in the setting of myocardial ischemia as MI and provided qualifications to characterize the MI (size, trigger, timing, etc).3 The second global MI task force updated the first MI definition and included a new five-category Inhibitors,research,lifescience,medical classification.4 Significant developments in the diagnosis of cardiac necrosis (i.e., high-sensitivity assays) and revised definitions of myocardial necrosis, particularly in the settings of critical illnesses and post-revascularization, resulted in the publication of the Third Universal Definition of Myocardial Infarction.2 Last December, the American College of Cardiology Foundation5 published the 2012 expert consensus document on the practical clinical considerations Inhibitors,research,lifescience,medical in the interpretation of troponin elevations.5 The Third Universal Definition of Myocardial Infarction The detection of

a rise and/or fall of cardiac biomarkers, with at least one of the values being elevated (>99th percentile upper reference limit, or URL), is central to the third universal definition of MI.2 The highly sensitive and specific Inhibitors,research,lifescience,medical cardiac troponin (cTn) is the preferred biomarker of myocardial necrosis. In addition, one of the five following predefined criteria should be satisfied before a diagnosis of MI is made: (1) symptoms of myocardial ischemia; (2) new (or presumably Inhibitors,research,lifescience,medical new) significant ST-segment/T-wave changes or left bundle branch block; (3) development of pathological Q waves on ECG; (4) new loss of viable myocardium or regional wall motion abnormality by imaging; (5) identification of intracoronary thrombus by angiography or autopsy.

The third global MI task force maintains that the electrocardiogram (ECG) is an integral part of the diagnostic work-up in patients with suspected MI and should be obtained and interpreted in a timely manner.2 It also advocates the use of serial recordings Inhibitors,research,lifescience,medical to detect dynamic ECG changes, and it adopts ECG criteria similar to the 2007 expert consensus document for the diagnosis of acute myocardial injury/ischemia and prior MI (criteria pertaining to the ST-segment shift and Q waves/QS I-BET151 in vivo complexes, respectively).2 Additionally, the third global MI task force summarizes unless the ECG abnormalities that mimic myocardial ischemia or MI (e.g., left bundle branch block, pre-excitation). It also includes brief discussions on the utility of various imaging modalities and highlights their improved capabilities in assessing myocardial thickness, wall motion, perfusion, and fibrosis.2 This task force updated the universal classification of MI with a few notable modifications (Table 1).2 Type 1 MI is spontaneous MI induced by plaque disruption (e.g., rupture, erosion, fissuring) with overlying coronary thrombosis.