<prompt> Earliest reliable enzyme to increase in AMICPK-MBLDHSGOTCKP-MM  <response>: Ans. a CPK-MB. Ref. Harrisons, Medicine, 18th Chapter 246.Earliest enzyme elevated after AMI:hFABP and MyoglobinMost specific enzyme:Troponin T returns nomal in 5-14 dysEnzyme imp in Reinfarction:CPKMB returns nomal in 2-3 dysMost common cause of death in AMI:VT leading to VFPost-AMI autoimmune pericarditis 7 dys later:Dressier syndromeTime after AMI when cardiac muscle is most subjected to rupture: 3-7 dysMicroscopic changes after AMI: - Neutrophils:1-3 dys of AMI - Lymphocytes:4-7 dys of AMI - Grabulation tissue:7-14 dys of AMIDIAGNOSIS OF AMI In first six hours ECG is gold standard. Changes include ST elevation transmural ischemia and Q waves transmural infarct- CPK-MB is test of choice in first 24 hours of AMI- Cardiac troponin I is used within the first 4 hours upto 7-10 days. More specific:- LDH is elevated from 2 to 7 post Ml day. LDH decrease is specific for cardiac muscles. Radioisotope Thallium-201 scanning is used to distinguish ischemic from non-ischemic myocardium to detect reversible ischemia. Radioactive stannous pyrophosphate is used to distinguish normal from damaged myocardium. 2D-ECHO is best initial modality for assessment of valvular abnormalities, wall motion ventricular ejection fraction i.e. ventricular function. 