elevated troponin: what if its not an MI?

QUICK REVIEW:
--Myocardial necrosis indicated by elevated troponin is NOT always due to atherosclerotic CAD

--Troponin has high sensitivity for detecting very small amount of myocardial cell death

--Troponin is released in the blood due to irreversible as well as reversible cell damage AND does ≠ permanent myocyte damage


EXPANDED DIFFERENTIAL:
--Demand ischemia: sepsis/SIRS, hypotension, hypovolemia, SVT/afib, LVH

--Myocardial ischemia: coronary vasospasm, ICH/stroke, ingestion of sympathomimetic agents

--Direct myocardial damage: cardiac contusion, ICD shock, cardiac infiltrative d/o (amyloidosis), chemotherapy, myocarditis/pericarditis, heart transplant

--Myocardial strain: CHF, PE, PHTN, COPD, strenuous exercise

--Chronic renal insufficiency


Submitted by F. DiFranco.


Reference(s): Jeremias A. & Gibson M. Narrative review: alternative causes for elevated cardiac troponin levels when acute coronary syndromes are excluded. Annals of Internal Medicine. 142(9):786-791, May 2005.