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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Irreversible injury in myocardium occurs at
assistant
The correct answer is  Only severe ischemia lasting at least 20 to 40 minutes causes irreversible damage and myocyte death leading to coagulation necrosis. Withlonger periods of ischemia, vessel injury ensues, leading to microvascular thrombosis.( Robbins Basic Pathology, 9th edition, page 377 )