NSTEMI and Unstable Angina Flashcards
1
Q
Define acute coronary syndrome
A
Term applied to patients in whom there is a suspicion of myocardial ischemia
2
Q
What conditions are included in acute coronary syndrome?
A
- Unstable angina (UA)
- ST elevation MI (STEMI)
- Non-ST elevation MI (NSTEMI)
3
Q
What is the pt care of someone with suspected ACS?
A
- Confirm Dx by ECG and biomarker measurement
- Relieve ischemic pain
- Assess hemodynamic state and correct abnormalities that may be present
- Initiate antithrombotic and re-perfusion therapy if indicated
4
Q
Define MI
A
Clinical event caused by myocardial ischemia in which there is evidence of myocardial injury or necrosis
5
Q
What are the criteria to diagnose an MI
A
- ↑ cardiac biomarkers + at least 1 of the following:
- Sx’s of ischemia
- New ST segment -T wave changes or new LBBB
- New pathologic Q waves
- Imaging evidence of new loss of viable myocardium or new regional wall motion abnormality
- Intracoronary thrombus by angiography or autopsy
6
Q
What are the causes of MI?
A
- Usually result of thrombus formation on ruptured plaque
- Other causes include
A. Coronary artery vasospasm
B. Reduced myocardial blood flow
C. Excessive metabolic demand
D. Embolic occlusion
E. Vasculitis
F. Coronary artery dissection
G. Cocaine use
7
Q
What are the sxs, prognosis, and complications of an MI dependent on?
A
Size and location of infarct
8
Q
What do 20% of pts with an MI die from in the pre-hospital setting?
A
Usually from ventricular fibrillation
9
Q
What percentage of MI’s are silent?
A
33%
10
Q
What demographics have abnormal MI presentation?
A
Elderly
Women
Diabetics: due to nerve damage
11
Q
What are the classic sxs of MI?
A
- Substernal CP or discomfort
- Radicular pain: pain between shoulder blades or that goes along a dermatome
- Dyspnea
- Nausea
- Diaphoresis
- +/-Syncope
12
Q
Approximately 10% of pts have signs of heart failure w/ an MI. What are these signs?
A
- Pleural effusion
- Pulmonary edema
- S3 gallop
- Hepatic congestion: Hepato-jugular reflux
- Pedal edema
13
Q
What are the diagnostic studies for a suspected MI?
A
- CK-MB
- Trop I and T
- Serum Myoglobin
- Serial EKGs
14
Q
What is the timeline for CK-MB?
A
- Rises w/in 6 hrs, peaks @ 12-24 hrs, back to baseline 24-48 hrs post MI
- CK-MB is measured when a troponin assay is not available
15
Q
What is the timeline for troponins?
A
- Trop T remains elevated longer than Trop I
- Troponin can rise 3 hrs post MI
- Trop I remains elevated for 7-10 days post MI
- Trop T remains elevated for 10-14 days post MI
16
Q
What is the usefulness of serum myoglobin?
A
- Early indication of damage to myocardium
- More sensitive than CK-MB, but not as specific
- Trauma, inflammation and ischemic changes to noncardiac muscle will cause ↑ myoglobin levels
17
Q
What do you look for on serial EKGs?
A
- ST depression
- Flattened or inverted T waves
- ST elevation
- Significant Q waves
- Arrhythmias & BBB
18
Q
How is unstable angina differentiated from NSTEMI?
A
1. Unstable Angina (UA) A. Biomarkers not elevated 2. Non STEMI A. Partial thickness damage of heart muscle B. Biomarkers elevated
19
Q
How is unstable angina differentiated from NSTEMI on an EKG?
A
- Both: ST depression and/or T wave inversion w/out ST segment elevation or pathologic Q waves
- NSTEMI - ST segment depressions usually evolve over the subsequent few days to result in residual ST segment depression and T wave inversions, but not to the formation of pathologic Q waves.
- UA - ST segment and T wave changes usually resolve completely
- ST-T wave abnormalities may be present diffusely in many leads; usually localized to the leads associated with the region of ischemia
20
Q
What is the timeline for NSTEMI biomarkers?
A
- With troponin assays, most pts can be diagnosed w/in 2-3 hrs of presentation
- A (-) test at presentation does not exclude myocardial injury
- Acute MI can be excluded in most patients by 6 hrs
A. 12-hour sample should be obtained if high degree of suspicion of ACS - If MI is ruled out, nuclear stress test or stress echo warranted to further evaluate
- If NSTEMI confirmed and sx’s continues, angiogram warranted in 12-24 hr
21
Q
What EKG leads exhibit changes for an inferior MI?
A
II, III, avF
22
Q
What EKG leads exhibits changes for an lateral MI?
A
I, avL, V5, V6
23
Q
What EKG leads exhibits changes for an anteroseptal MI?
A
V1, V2
24
Q
What EKG leads exhibits changes for an anterior MI?
A
V1, V2, V3, V4
25
What EKG leads exhibits changes for an anterolateral MI?
V4, V5, V6
26
When is an angiogram warranted in the presence of an NSTEMI?
If NSTEMI confirmed and sx’s continues, angiogram warranted in 12-24 hr
27
When is a nuclear stress test or a stress echo warranted?
If MI is ruled out, nuclear stress test or stress echo warranted to further evaluate
28
What are the general measures of treatment for a pt with a NSTEMI?
1. Hospitalization with bed rest x 24 hours
2. Cardiac monitoring
3. Supplemental oxygen
4. Treat anxiety
29
What are the anticoag and antiplt therapy treatments in the presence of a NSTEMI?
1. ASA 81-325 mg PO qd: chew and swallow
| 2. Clopidogrel (Plavix) 300 mg PO loading dose, then 75 mg PO qd x 9-12 months
30
What are the antiplatelet therapy options for a NSTEMI and what is the preferred options?
1. Clopidogrel (Plavix) 75 mg po qd-preferred
A. 6 months – 1 year
B. Pantoprazole (Protonix) only safe PPI
2. Ticegrelor (Brilinta) 90 mg po bid
3. Prasugrel (Effient) 10 mg po qd
A. More effective at prevention of stent thrombosis, but ↑ hemorrhagic risk by 30
31
What is the first line treatment for pts with ACS presenting with CP?
Nitroglycerin
32
what is the physiologic effect of nitro?
↑ O2 supply by vasodilation & ↓ O2 consumption by ↓ vent .preload
33
what are the cautions an contraindications for nitro?
1. Avoid if hypotensive (SBP < 100)
2. Use w/caution in IWMI due to high risk of hypotension w/preload change
3. Avoid if pt took Viagra or Levitra in past 24 hr; Cialis in 48 hrs
34
What is the route of administration of nitro?
1. SL, spray or transdermal ointment usually sufficient
2. If pain persists or recurs, IV NTG should be started
A. 10 mcg/min titrated up (max 200 mcg/min) until angina disappears
35
When are beta blockers used in tx of ACS? which ones are used?
1. Used early in Tx of ACS unless contraindicated
2. Metoprolol (Lopressor), atenolol (Tenormin)
3. PO delivery usually sufficient
36
What is the effect of beta blockers in the event of an NSTEMI?
1. Decrease Myocardial oxygen demand
| A. ↓ HR, contractility, CO & BP
37
Why are beta blocker ineffective against prinzmetal angina?
Prinzmetal angina
| Occurs in cycles & caused by vasospasm
38
When are CCB used in the event of an NSTEMI? Which agents are used?
1. 3rd line agent in pts unable to tolerate nitrates or beta blockers
2. Diltiazem (Cardizem) or verampamil(Calan) preferred
3. Nifedipine (Procardia) and other dihydropyridines are more likely to cause reflex tachycardia
39
Why are statins used post MI?
Use of high dose statin (atorvastatin/Lipitor 80 mg po daily) following ACS decreased death and major CV events as early as 3 months after starting therapy
40
What is the TIMI risk score for MI?
1. Categorizes a patient's risk of death & ischemic events; provides a basis for therapeutic decision making
2. Thrombolysis In Myocardial Infarction
41
What are the variables in the TIMI risk score?
1. Age > 65 yrs
2. 3 or more cardiac risk factors
3. Prior coronary stenosis ≥ 50%
4. ST segment deviation
5. 2 anginal events in 24 hrs
6. ASA in prior 7 days
7. Elevated cardiac markers
42
What are the indications for cardiac cath and percutaneous cardiac intervention in NSTEMI?
1. Recurrent angina/ischemia @ rest or with low level activity
2. Elevated troponin
3. ST segment depression
4. Recurrent ischemia without evidence of CHF
5. High risk stress test result
6. EF < 40%
7. Hemodynamic instability
8. Sustained V Tach
9. PCI within 6 months
10. Prior CABG
