14. Cardiac Disease and Markers Flashcards
ECG checks for what 5 things?
- Rate
- Rhythm
- Axis
- Hypertrophy
- Infarction
Drug that controls arrhythmias?
Digoxin
Main cause of cardiac ischemia?
Coronary atherosclerosis
Caused by hemolytic streptococcus induced immune reaction
Valvular disease
CKMB relative index indicating myocardial damage?
> 3%
CKMB relative index indicating skeletal muscle damage?
< 3%
CKMB relative index formula
(CKMB/Total CK) * 100%
BNP stimulus release
Ventricular stretch and increased volume
3 reasons for increased CK?
- Myocardial diseases (AMI)
- Skeletal muscle disease/injury (alcohol abuse)
- Cerebral injury, meningitis
2 methodologies for CKMB?
- Enzyme immunoassay
- Electrophoresis
Troponin methodology?
Chemiluminescence sandwich antibody assay
Troponin rise, peak, fall window
4-6 hrs
12-24 hrs
By 7 days
Troponin RI
< 0.04 ug/L
Troponin range indicating possible MI, repeat in 6-8 hrs?
0.05 - 0.49 ug/L
Myoglobin rise, peak, fall window
1-4 hrs
8-12 hrs
24 hrs
CK rise, peak, fall window
4-6 hrs
12-24 hrs
48 hrs
Sac around heart that anchors it to diaphragm
Pericardium
6 properties of an ideal cardiac marker
- Specific for myocardial injury
- Sensitive to small injuries
- Rapidly released following injury
- Around long enough in blood to permit diagnosis
- Produce blood levels proportional to infarct size
- Be technically easy to assay
Negative predictor of myocardial damage
Myoglobin
Lactate dehydrogenase rise, peak, fall window
36-48 hrs
72 hrs
7-12 days
Effects of BNP on blood vessels
Vasodilation
Which troponin unit is most specific for cardiac
Troponin I
Which troponin unit peaks soonest in myocardial damage
Troponin I
Which troponin unit remains high the longest
Troponin T
Normal levels of _________ and _________ rules out heart failure
BNP, NT-proBNP
How does homocysteine cause atherosclerosis
It damages inner lining of arteries = promotes clots
Also degrades, inhibits formation of structural components of arteries (collagen, elastin)
