Infarction definition
Pro Research Analysisby 
Searched over 200M research papers for "infarction definition"
Consensus Meter
Understanding Infarction: Definitions and Implications
Cerebral Infarction Definition
Cerebral Infarction is defined as brain or retinal cell death due to prolonged ischemia. This definition encompasses both complete and incomplete infarcts, which are characterized by pannecrosis and neuronal dropout, respectively. The presence of any neuronal or glial cell death is essential for this definition, making it highly relevant for clinical practice and patient care. This approach aligns with the classification of myocardial ischemia and emphasizes the importance of identifying the cause of brain ischemia and the occurrence of end organ injury.
Myocardial Infarction Definition
Myocardial Infarction (MI) is defined by the presence of myocardial injury detected through abnormal cardiac biomarkers in the context of acute clinical myocardial ischemia. The diagnosis requires a rise and/or fall of cardiac biomarkers, particularly cardiac troponins, with at least one value above the 99th percentile of the upper reference limit. Additionally, there must be evidence of myocardial ischemia, which can be identified through symptoms of ischemia, electrocardiographic changes, development of pathological Q waves, imaging evidence of new loss of viable myocardium, or the identification of an intracoronary thrombus .
Pathophysiology of Myocardial Infarction
The pathophysiology of myocardial infarction involves the sudden ischemic death of myocardial tissue, typically due to thrombotic occlusion of a coronary vessel following the rupture of a vulnerable plaque. This ischemia induces significant metabolic and ionic disturbances in the myocardium, leading to rapid depression of systolic function. Prolonged ischemia triggers a wavefront of cardiomyocyte death, extending from the subendocardium to the subepicardium. The heart's limited regenerative capacity results in the formation of a scar, with infarct healing dependent on an inflammatory cascade and subsequent tissue remodeling.
Clinical Implications of Infarction Definitions
The definitions of infarction have significant clinical, psychological, social, and legal implications. For myocardial infarction, the use of highly sensitive cardiac biomarkers, such as troponins, has refined the diagnosis, allowing for the detection of even small areas of myocardial necrosis. This has led to a reclassification of some cases previously diagnosed as unstable angina to myocardial infarction, impacting clinical practice and patient management .
Conclusion
Infarction, whether cerebral or myocardial, is fundamentally defined by tissue death due to prolonged ischemia. The definitions emphasize the importance of sensitive biomarkers and imaging techniques in diagnosing and managing these conditions. Understanding these definitions is crucial for improving patient outcomes and standardizing clinical practices across the globe.
Sources and full results
Most relevant research papers on this topic