Lab Testing- Cardiac Disease Flashcards
1
Q
Patients with ACS often present in which 3 ways?
A
- Sudden Cardiac Death
- Myocardial infarction- with new ST segment elevation (STEMI) in 2 or more contiguous ECG leads + troponin OR Without ST elevation (NSTEMI)- may (or may not) have other ECG, but don’t have ST elevation + tropinin
- unstable angina (a history compatible with ACS but no enzyme abnormalities (normal troponin and CK-MB)
2
Q
- Non-Occlusive thrombus
- signs of ischemia on EKG (ST depression or T wave inversions)
- normal cardiac markers
A
Unstable Angina
3
Q
- Occlusion causing mild tissue death and necrosis
- signs of ischemia on EKG (ST depression or T wave inversions)
- Elevated cardiac markers
A
NSTEMI
4
Q
- Complete occlusion of large vessel
- ST elevation on EKG or a new LBBB
- elevated cardiac markers
A
STEMI
5
Q
what is a Type 1 myocardial infarction?
A
plaque rupture with acute coronary artery thrombus/occlusion
6
Q
What is a type 2 myocardial infarction?
A
Oxygen supply/demand mismatch
7
Q
what is a type 3 myocardial infarction?
A
SCD
8
Q
what is type 4 myocardial infarction?
A
Post PCI
9
Q
What is a type 5 myocardial infarction ?
A
Post CABG
10
Q
- Preferred to diagnose MI (increased specificity and better sensitivity)
- regulatory proteins that control the interaction of actin and myosin (Ca mediated)
- unique to the heart
- Values >99% upper reference limit (URL) are considered abnormal
A
Cardiac Troponin I & T (Tn)
11
Q
- Use if troponin is not availabe
- if CK-MB is elevated, but Tn normal likely this is due to noncardiac tissue
- may be useful for re-infarction
A
CK-MB (MB isoenzyme of creatine kinase)
12
Q
How do you use biomarkers?
A
If you suspect ACS, draw SERIAL troponins
* Measure serum troponin at first presentation
* not elevated? repeat serially 2 hours
* not elevated again? AMI can be excluded after 12 hour sample (Tn peak)
