Myocardial infarction is one of the leading diseases causing death and disability worldwide. As research in related fields progressed, the European Society of Cardiology, the American College of Cardiology, the American Heart Association, the European Society of Hypertension and the World Heart Federation formed a joint working group to issue a unified definition of myocardial infarction worldwide in 2007.
The criteria for the definition of acute myocardial infarction are.
1. an elevation of biochemical markers of myocardial necrosis (preferably cTn) detected above the upper reference
1. an elevation of a biochemical marker of myocardial necrosis (preferably cTn) above the upper 99th percentile of the reference value (URL) with dynamic changes, accompanied by one of the following evidence of myocardial ischemia: ischemic symptoms, ECG suggestive of new ischemic changes (new ST-segment changes or left bundle branch block [LBBB]), ECG suggestive of pathological Q-wave formation or imaging evidence suggestive of new segmental wall motion abnormalities or loss of surviving myocardium;
2. sudden cardiac death (including cardiac arrest), usually with symptoms of myocardial ischemia, new ECG ischemic changes or LBBB and/or evidence of new thrombus confirmed by coronary artery (coronary) angiography (or autopsy), but death often occurs before blood specimens are obtained or myocardial enzyme markers are found to be
The death often occurs before blood specimens are obtained or elevated myocardial enzyme markers are found;
3. Elevated cardiac marker levels above the URL99 percentile after percutaneous coronary intervention (PCI) in individuals with normal baseline cTn levels suggest peri-procedural myocardial necrosis.
Myocardial necrosis was defined as PCI-related myocardial infarction if cardiac marker levels exceeded three times the URL99 percentile;
4. Coronary artery bypass grafting (CABG) in patients with normal baseline cTn levels
If cardiac marker levels are elevated above the URL99 percentile after coronary artery bypass grafting (CABG), peri-procedural myocardial necrosis is indicated; if cardiac marker levels exceed 5 times the URL99 percentile with any of the following: new pathological Q waves, new LBBB, coronary angiography confirming new bridge vessel or self coronary occlusion, imaging evidence of new surviving myocardial loss In the case of CABG-related myocardial infarction, it is defined as a CABG-related myocardial infarction;
5. Acute myocardial infarction was found at pathological examination.
The criteria for the definition of old myocardial infarction are.
1. new pathological Q waves with or without symptoms;
2. Imaging evidence of myocardial thinning or scarring, loss of contractility or inactivity;
3. myocardial infarction that has healed or is healing on pathological examination.
The most striking point in the new definition is the classification of myocardial infarction into 5 types by etiology for the first time.
Type 1: Spontaneous myocardial infarction due to myocardial ischemia caused by a primary coronary event such as plaque rupture;
Type 2: Myocardial infarction secondary to myocardial ischemia caused by imbalance between oxygen supply and consumption, such as coronary artery spasm, anemia, coronary embolism, arrhythmia or hypotension;
Type 3: sudden cardiac death with symptoms of myocardial ischemia and the new appearance
ST-segment elevation or new LBBB, but death before blood samples are collected;
Type 4: myocardial infarction associated with PCI for an ischemic coronary event;
Type 5: myocardial infarction associated with PCI performed for an ischemic coronary event
CABG-associated myocardial infarction. Of these.
Type 1 is the classic myocardial infarction ;
Type 2 needs to be diagnosed in the context of the patient’s specific situation, and treatment is mainly directed at the primary disease rather than blind interventional treatment;
Type 3 is the most dangerous and has a high mortality rate, and requires enhanced education for all, especially primary and secondary prevention for high-risk patients;
Type 4 is subdivided into two subtypes, 4a and 4b. Type 4a is myocardial infarction associated with PCI operation, and type 4b is myocardial infarction confirmed by autopsy or coronary angiography associated with stent thrombosis;
Both type 4 and type 5 are actually complications related to surgical operations, but cannot be completely avoided in practice.