Cardiac Biochemistry Flashcards
What is the first stage of atherosclerosis?
initial lesion
histologically normal
macrophage infiltration
isolated foam cells
from first decade
What follows an initial lesion in the artery in the process of atherosclerosis?
fatty streak
mainly intracellular lipid accumulation
What causes troponin release?
plaque rupture
Why is creatinine kinase not the ‘test of choice’ when it comes to cardiac biomarkers?
it is elevated after muscle damage
eg a fall, intense exercise….
What is troponin?
complex of three regulatory proteins (TnC, TnT and TnI) that is integral to skeletal and cardiac muscle contraction
What sub-type(s) of troponin are sensitive biomarkers?
TnI and TnT
What does a ‘positive’ troponin result indicate?
myocardial injury
cardiac cells have died - infarction
What can you infer from an absence of detectable cardiac troponin?
- excludes a currently active unstable plaque
- does not exclude underlying iscaemic heart disease
- does not exclude a flow limiting stenosis
How are troponin levels measured?
by an immunoassay
the marker is detected by electrochemiluminescence
