Lecture 10: STEMI and NSTEMI Flashcards
What is the underlying condition/ECG changes called if coronary flow is fully occluded vs. partial occlusion?
- Fully occluded = STEMI
- Partial = Unstable Angina or NSTEMI
Which type of MI is sympathetic hyperactivity (↑ HR, ↑ BP) vs. parasympathetic hyperactivity (↓ HR, ↓ BP) seen in?
- Sympathetic = anterior MI
- Parasympathetic = inferior MI
What are 4 PE findings associated with HF?
- S3
- Crackles
- ↑ JVD
- New murmur
Everything as far as presentation and ECG will be the same for NSTEMI and NSTE ACS, except for what?
NSTEMI will have elevated cardiac enzymes
Which cardiac conduction abnormality can obscure ST elevation analysis and may hide the manifestations of a STEMI?
New LBBB
Which ECG changes will be seen in the early acute phase of a STEMI?
- T wave increase in amplitude (like seen in hyperkalemia)
- Hyper-acute pattern
- Convex upward ST pattern
Besides STEMI, what are 3 other causes of ST segment elevation?
- Pericarditis
- LVH w/ J point elevation
- Normal variant (early repolarization) common in young males and african americans
If a patient with no chest pain and who seems normal has this ECG, what is one characteristic that tells you it’s likely not a STEMI?
- ST elevations are concave (if convex that would be early/acute MI)
- This is early repolarization a normal variant in young males
In the chronic phase following STEMI, if there is persistent ST elevation (after 2 weeks) what complication should you suspect?
LV aneurysm
Q waves shouldn’t be more than how many seconds in width?
No more than .03 sec in width
Which lead is the T wave normally inverted and may be variable in which?
- Inverted in aVR
- Variable in lead III
Which waves/segments of the ECG represent ischemic pattern, injury pattern, and pattern of necrosis/infarction?
- Ischemia –> impaired repolarization –> T waves changes (inverted/tall/peaked)
- Injury –> inability to fully polarize –> ST elevations
- Infarction/necrosis –> lacks depolarization –> Q wave or QS complex
Since there are no posterior leads, how do we view a posterior wall infarction and look for what?
- Look at V1-V3 (anterior leads) and will be a mirror image
- So looking for ST depression and a prominent R
After several weeks or months following an MI what Q, R, T and ST changes will exist?
- Significant Q wave usually persists
- Some R wave may return
- T wave often less inverted
- ST elevation may persist IF aneurysm develops
What does this ECG signify and how can you tell?
- Recent MI of LAD (leads V1-V6)
- Massive Q waves + T wave inversion + ST elevation
What is your interpretation of this ECG?
STEMI - Anterior Wall (LAD)
What is the ECG indicative of?
- Anterior wall STEMI w/ left anterior hemiblock
- The L.A.D and small R waves in II, III, and aVF meet criteria for left anterior hemiblock
Patient presents with what appears to be an MI and this is his ECG, where is the infarction and why?
- TRUE Posterior infarct
- Based on the reciprocal changes in anterior leads;
- V1 shows large R (reciprocal of posterior Q) and upright T wave (reciprocal of posterior T inversion)
What type of MI is this indicative of?
Posterior wall infarction
Pt presents w/ chest pain and what looks do be an MI, this is his ECG, what do you suspect?
NSTEMI or NSTE ACS
*Need enzymes*
Failure of which organ can give false positive elevations of Troponin T (CTnT)?
Renal failure, since is excreted by kidneys
For patient with acute STEMI what are the reperfusion strategies if hospital has cath lab and how soon?
- Primary percuteanous coronoary intervention (PCI) w/ angioplasty and stenting
- Cath lab within 90 minutes (goal)
If hospital does not have cath lab or there isn’t time to get to one what is done for acute STEMI and how quickly?
- Give fibrinolytic or thrombolytic
- Begun in ED within 30 mins. (goal)
After beginning fibrinolysis therapy in pt with acute STEMI if there is failure of ST elevation to resolve by >50-70% within 1-2 hours this suggests what?
Failure of fibrinolysis
If your hospital does not have a cath lab (non PCI capable) how soon must patient with acute STEMI be transferred?
Within 120 minutes
What is the primary reperfusion therapy for STEMI with sx’s <12 hours?
Primary PCI
What is a benefit of primary PCI vs. fibrinolytics for STEMI?
Lower mortality rate and less chance of intracerebral hemorrhage
Fibrinolytic therapy for reperfusion is useful in what instances, but carries what risk?
- For STEMI or new LBBB within 12 hours of onset of sx’s
- Major risk = ICH
What are the major contraindications for administering fibrinolytic therapy?
- Active bleeding (menses is excluded!)
- Prior hemorrhagic stroke
- Severe uncontrolled HTN
- Recent major trauma/surgery
- Acute peptic ulcer
- Pregnancy
Which drug should be given on presentation/immediately for STEMI, unless contraindicated?
Aspirin
After aspirin, what other drugs should be given alongside fibrinolytic agents for STEMI?
- IV Heparin
- Antiplatelet agent (clopidogrel)
If STEMI pt receives PCI w/ stenting which drugs should be given for at least 1 year to prevent stent stenosis?
- Aspirin
AND
- Antiplatelet agent (clopidogrel)
What is the initial standard tx while hospitalized for STEMI?
- Morphine
- O2
- Nitroglycerin
- Aspirin
- Beta-blocker if ↑ BP or ↑ HR
- ACEI = helpful if EF ↓, ↑ BP; prevent remodeling
Tx for NSTEMI will depend first on assessment for high risk pt, which includes what factors?
- Age >65 w/ >3 CAD risk factors
- Prior stenosis
- ST deviation
- >2 anginal events <24 hrs
- Elevated cardiac enzymes
In pt’s at highest risk for complications presenting with NSTEMI what should be done and how soon?
Cardiac cath lab within 48 hrs (consider PCI or CABG if indicated)
For high-risk unstable pt’s with NSTEMI who undergo PCI, which type of drug should be considered?
IV GP IIb/IIIa antagonist
Which anti-ischemic therapies should be given for NSTEMI?
- Nitroglycerin (don’t use if recently taken PDE-5 inhibitor)
- Beta-blocker if HR is ↑
After admitting/monitoring pt with NSTEMI what are some additional drugs to consider giving?
- Morphine for refractory chest pain
- High dose statin initially
- Consider ACE-I
If there is recurrent chest pain that may be atypical for them, 2-4 days post-MI, what complication should be considered?
How about recurrent chest pain 2-10 weeks post-MI?
- 2-4 days = acute pericarditis
- 2-10 weeks = could be Dressler Syndrome (immune mediated)
Treatment for acute pericarditis/Dressler syndrome as a post-MI complication?
Aspirin, NSAIDs
After performing reperfusion on pt with MI you see this on ECG, what is your interpretation and what should be done?
- Accelerated idioventricular rhythm (60-100 BPM)
- Indicates reperfusion following fibrinolytic and is a good sign
- Benign
Which type of heart block is often associated with an inferior wall MI?
2nd degree AV block (Wenckebach)
How does the tx for 3rd degree AV block differ if associated with anterior or inferior wall MI?
- Anterior wall MI will require a pacemaker
- Inferior wall MI will usually be transient and NOT require a pacemaker and if it does it will only be a temporary pacemaker
RV infarction is a potential complication of an MI where and presents how?
- Inferior MI
- ↓ BP, clear lungs, and ↑ JVP
- Kussmaul sign (distention of jugular vein on inspiration)
What is tx for RV infarction as complication of inferior STEMI?
IV fluids
What are complications of the LV/septum which can arise post-anterior wall STEMI?
- Septal rupture –> VSD
- LV free wall rupture (typically 7 days) –> causes tamponade
- LV aneurysm (persistent ST elevation weeks after MI)
Tx for LV free wall rupture post-MI?
Surgery
What are thromboembolic complications which can arise from a LV aneurysm?
Arterial emboli —> stroke or ischemic bowel
Proximal occlusion of RCA before acute marginal branch can cause an MI where?
Use what leads and look for what?
- Acute inferior wall MI —> RV infarction
- Use R precordial leads (V4R- V6R) for RV
- ST elevation of 1mm or > in V4-V6R
List 4 conditions which can present like STEMI and should be differentials?
- Pericarditis
- Myocarditis
- Stress induced (takotsubo) syndrome
- Early repolarization
How should you treat ventricular tachycardia after an MI?
1 mg/kg bolus of lidocaine
use procainamide or amiodarone if that doesn’t work
How do you treat ventricular fibrillation?
electrically
if unresponsive –> amiodarone and repeat cardioversion w/ CPR
What defines first degree AV block?
PR interval >0.2 sec (one little block)
What is wenckebach 2nd degree block?
PR interval keeps increasing in length until finally there is a P wave w/ no QRS response
(PR interval is long, but QRS is normal)
What is Mobitz 2nd degree block?
multiple P waves followed by 1 QRS response in a ratio (2:1)
QRS is widened, but PR interval is normal
In pts w/out ST-segment elevation, what lets you know there is an MI?
elevated CK-MB or troponin
What is the universal definition of myocardial infarction?
rise of cardiac biomarkers with at least one value above the 99th percentile w/ evidence of MI w/ at least one of the following:
sx of ischemia
ECG changes of new ischemia
new Q waves
imaging evidence of loss of myocardium
What did the CURE trial find?
20% reduction in death, MI, and stroke w/ addition of clopidogrel to aspirin in pts w/ non-STE acute coronary syndroms
Who is clopidogrel reserve for?
pts who cannot receive either ticagrelor or prasugrel
ticagrelor and prasugrel are both faster and more potent, work better
What did the EARLY-ACS trial show?
IV abciximab reduces ischemic events by about 25% when undergoing PCI w/ high risk sx
