Cardiac Enzymes and Myocardial Infarction Pathology

Flashcards covering cardiac enzyme markers, their diagnostic timelines, and early autopsy findings associated with Myocardial Infarction.

My Time To CALL the ambulance

A pneumonic used to remember the cardiac enzymes of Myocardial Infarction: Myoglobin, Troponin, CKMB, AST, LDH I.

Myoglobin

A cardiac marker that is non-specific for Myocardial Infarction ($MI$), starting at $2$ hrs and falling by $24$ hrs.

Troponin I

A more important cardiac marker compared to Troponin T, starting within $2-4$ hrs, peaking at $48$ hrs, and falling after $7-10$ days.

Flipping of LDH ratio

A phenomenon seen in Myocardial Infarction patients where the normal ratio ($LDH-2 > LDH-1$) is reversed to $LDH-1 > LDH-2$.

CK-MB Timing

Starts within $2-4$ hrs, reaches its peak at $24$ hrs, and falls between $48-72$ hrs.

AST/SGOT Timing

Starts within $<12$ hrs, reaches its peak at $48$ hrs, and falls between $4-5$ days.

LDH I Timing

Starts at $24$ hrs, reaches its peak in $4-5$ days, and stays elevated until after $10$ days.

Marker of Reinfarction

According to the lecture update, Troponin T and Troponin I are markers for this condition.

Ischemia Modified Albumin (IMA)

A marker that rises before myoglobin in the presence of ischemia.

Heart fatty acid binding protein (HFABP)

A marker that rises before myoglobin during a Myocardial Infarction.

First Electron Microscopy Change

Seen in $30$ minutes; includes relaxation of myofibrils and mitochondrial swelling.

First Light Microscopy Change

Seen between $30$ minutes and $4$ hours; includes waviness and vacuolization of the cardiac muscle fibers.

First Gross Change

Occasional mottling noted after $4$ hours.

Necrosis in MI

Coagulative necrosis is the type of necrosis observed under the microscope.