Myocardial infarction, commonly known as a heart attack, is the irreversible necrosis of heart muscle secondary to prolonged ischemia. This usually results from an imbalance in oxygen supply and demand, which is most often caused by plaque rupture with thrombus formation in a coronary vessel, resulting in an acute reduction of blood supply to a portion of the myocardium or muscles death. The risk factors for atherosclerosis and heart attack include elevated cholesterol levels, increased blood pressure, tobacco use, diabetes, male gender, and a family history of heart attacks at an early age.
Types of Myocardial Infarction (MI) : - MI is of five types follows as : -
Type 1 - Type 1 is a spontaneous MI related to ischemia from a primary coronary event (e.g., plaque rupture, thrombotic occlusion)
Type 2 - Myocardial infarction secondary to ischaemia due to either increased oxygen demand or decreased supply, e.g. coronary artery spasm, coronary embolism, anaemia, arrhythmias, hypertension, or hypotension.
Type 3 - Sudden unexpected cardiac death, including cardiac arrest
Type 4 - Associated with coronary angioplasty or stents.
Type 4a - Myocardial infarction associated with PCI
Type 4b - Myocardial infarction associated with stent thrombosis as documented by angiography or at autopsy.
Type 5 - Myocardial infarction associated with CABG .