Non-ST and ST Segment Elevations

Question 1

what clinical symptoms and clinical exam findings are diagnostic for ACS (acute coronary syndrome)

Answer 1

• substernal chest pain that is
  
  • not reproducible
  • radiating - typically to the left arm, back & jaw
• diaphoresis
• sense of impending doom
• nausea vomitting
• cardiac arrest
• physical exam:
  
  • signs of acute heart failure
    
    • lung rales
    • JVD
  • evidence of acute mitral regurgitation
    
    • ​would be confirmed with a papillary rupture

Question 2

what labs should be ordered during dx of acute coronary syndrome (ACS)

Answer 2

• electrocardiograph (order within 10 minutes)
• troponin levels
  
  • definitively Troponin I and Troponin T
  • if possible, high sensitivity cardiac troponin (hs-cTN)
• sometimes CK-MB (creatinine-kinase-MB), through its falling out of favor

Question 3

what electrocardiogram changes are diagnostic of acute coronary syndrome?

Answer 3

• the changes seen in ischemia, which are
  
  • ST elevation or ST elevation equivalent
    
    • this would mean ST elevation myocardial infarction (STEMI)
  • ST depression
  • T wave inversions (seen in lateral ischemia)
  • Q waves

Question 4

what predisposes 50% of STEMIs?

Answer 4

• a precipitating event
  
  • exercise
  • emotional stress
  • medical/surgical illness

Question 5

• if a patient comes into the ER with symptoms suggestive of ischemia/infarcation
  
  • EMS will do what emergency assessment (s) and do what to prepare patient for the hospital?
  • at the ED (emergency department), what general treatment should be given immediately?
    
    • what assessments should be made while this is happening?

Answer 5

• EMS assessment/hospital prep:
  
  • monitor & support ABCs
  • be prepared to provide CRP & debrillation
  • administer aspirin
    
    • consider oxygen/nitroglycerin/morphine
  • obtain 12 lead ECG
    
    • if there is ST elevation
      
      • notify hospital and determine the time difference between onset of symptoms and beginning of pt’s care
• when at ED:
  
  • immediate treatment:
    
    • give oxygen if O2 saturation < 90%
    • give:
      
      • aspirin - if not given by EMS*
      • nitroglycerin ( sublingual/spray)
      • morphine (IV) - if symptoms not relieved by nitroglycerine
  • concurrent ED assessment:
    
    • check vitals
    • check oxygen saturation*
    • establish IV access
    • order: chest X-ray, troponins, electrolytes

Question 6

after a pt with infarct/ischemia symptoms has been stabilized in the ED, how should their ECG be used to determine treatment?

Answer 6

• ST elevation OR new LBBB:
  
  • = STEMI
    
    • being repurfusion & start adjunctive therapies
    • then, assess how long its been from symptom onset:
      
      • been < 12 hours -
        
        • PCI (percutaneous coronary intervention)
        • fibrinolysis
      • been > 12 hrs
        
        • if they have elevated troponin & are high risk, consider invasive strategy
• ST depression or T-wave inversion
  
  • = high risk non-ST elevation ACS (NSTE-ACS)
• ST segment & T- wave are either normal or have nondiagnostic changes (i.e, they’re not normal but don’t look like ischemia)
  
  • monitor

Question 7

what histories (highly, moderately, or slightly suspiscious), ECG findings, age ranges, # of risk factors and troponin levels warrant the following “scores” on this heart score chart?

what can we do with the total score we calculate from this chart?

Answer 7

• total score dictates treatment of patient:
  
  • 0-3: discharge patient
  • 4-6: observation & risk management
  • 7-10: observation, treatment & CAG
• an example of highly suscpicious would be pain radiating to the jaw.
• atherosclerotic risk factors: hypercholesteremia, HTN, diabetes, smoking history, hx of atherosclerosis, obesity

Question 8

what are the atherosclerotic risk factors?

Answer 8

• hypercholesterolemia
• HTN
• diabetes
• cigarette smoking
• positive family history
• obesity

Question 9

what is the critera for type 1 MI? what about type 2 MI?

Answer 9

• Type 1 MI includes
  
  • detection of a _rise and/or fal_l of cTn (high sensitivity of cardiac troponin) with at least one of those values being in the the 99th percentile
  • • at least one of the following:
      
      • symptoms of acute MI
      • ischemic ECG changes
      • pathological Q wave
      • evidence of loss of viable myocardium OR new regional wall motion abnormality
      • identification of a coronary thrombus by angiography
• Type 2 MI
  
  • if there is evidence of myocardial O₂ supply/demand unrelated to a coronary thrombus*

Question 10

type I vs type II STEMIs

Answer 10

• type I includes
  
  • rise or fall of troponin cTn where one of those values fit into the 99th percentile
  • • one of the following
      
      • symptoms of acute MI
      • new ischemic ECF changes
      • pathological Q waves
      • imaging showing loss of viable myocardium OR new wall motion abnormality
      • identification of coronary thrombus by angiography
• type II:
  
  • evidence of myocardial oxygen supply/demand mismatch unrelated to coronary thrombosis
    
    • ​mismatch indicated by elevated lactate, which signifies hypoperfusion

Question 11

• what does it mean if a an ischemic patient has EKG changes other not indicative of a STEMI and
  
  • their troponin positive?
  • what if their troponin is negative?
• when should troponin be measured?

Answer 11

• non-STEMI EKG changes and + troponin: N-STEMI
• non-STEMI EKG changes an - troponin: either
  
  • unstable angina, noncardiac chest pain, other cardiac issue
• order troponin
  
  • troponin I and troponin T
    
    • upon patient arrival to ED
    • every 3 hours / every 6 hours thereafter
  • troponin cTn if available - can rule out ischemia in 1-3 hrs

Question 12

• discuss the medications used to treat N-STEMI.
  
  • note any contraindications/alternatives when applicable

Answer 12

• “MONA BASH-C”
  
  • M = morphine (IV)
    
    • given if chest pain not alleviated by other meds
  • O = oxygen
    
    • given only if oxygen saturation is less than < 90%
  • N = nitrates
    
    • give sublingual nitroglycerine every 5 minutes, then you can assess if IV administration is necessary
    • contraindicated in:
      
      • pts on PDE inhibitors
        
        • ex: viagra (sidinafil)
      • RIGHT VENTRICULAR INFARCTION or INFERIOR MI
  • A = aspirin
    
    • give everybody aspirin (but not other NSAIDS - these should be discotinued)
  • B = beta blockers
    
    • give to patients with normal LV function
    • contraindicate in pts with signs of
      
      • heart failure
      • low output state
      • risk of cardiogenic shock
    • alternative for pts who at shock risk - CCBs
  • ACEs/ARBS
  • S = statins
  • H = hepararin (anti-coagulant)
  • C = clopidegrel (anti-platelet)

Question 13

• discuss the anti-coagulants/anti-platelet regimen given for N-STEMI ACS

Answer 13

• aspirin (anti-platelet)
• P2Y inhibitor (anti-platelets)
  
  • clopidogrel OR ticagrelor
• heparin -like agents (anti-coagulants). give any of these
  
  • UFH
  • Enoxaparin
  • Fondaparinux

Question 14

what defines a STEMI?

Answer 14

• a new ST elevation at the J point (point between QRS complex and ST segment) in at least 2 contiguous leads. the degree of ST elevation depends on sex.
  
  • in men, must be = 2 mm (0.2 mV)
  • in women, must be =
    
    • 1.5 mm (0.15 mV) in women in leads V2–V3 and/or
    • 1 mm (0.1 mV) in other contiguous chest leads or the limb leads

Question 15

• what are the different sets of continguous chest leads?
• ST elevation in these continguous leads point to what coronary artery occlusions?

Answer 15

• inferior leads: II, III and aVF
  
  • ST elevation points to RCA or LCx occlusion
• lateral leads: I, aVL
  
  • if ST elevation extends into these leads, that points to LCx or diagonal artery (branch of LAD) occlusion
• precrordial leads: V1, V2, V3, V4:
  
  • ST elevation in these segments indicate LAD occlusion

Question 16

• an ST elevation in lead V1 that dissapears in the rest its the contiguous precordial leads (V2, V3, V4) is likely indicative of what?
  
  • how would you confirm your suspicion?

Answer 16

• indicates a right sided infarct - likely effecting the right ventricle
  
  • you would switch your precordial leads (V1-V6), which are typically placed over the left chest- to the right side of the body to get a right sided EKG

Question 17

when would you order a posterior heart wall EKG?

how are leads placed to obtain a posterior EKG?

Answer 17

• I believe you do this if you are trying to differentiate between a posterior STEMI and a N-STEMI. a posterior STEMI would result from occlusion in either the RCA or the LCx (the posterior wall is supplied by the LAD, which can come off either of these arteries, tho LCA is most common). a posterior EKG will confirm the source of the infarct
  
  • done by adding leads V7-V9

Question 18

discuss what EKG changes occur throughout the progression of a STEMI

Answer 18

• relative order of events
  
  • 1st: hyperactive T-wave (minutes-hours)
  • 2nd: ST elevation (0-12 hours)
  • 3rd: Q wave development (1-12 hrs)
    
    • can occur at the same time/near the time of ST elevation
  • 4th: T-wave inversion (2-5 days)
  • 5th: T wave recovery (weeks-months)
  • (ST elevation can persist –> can lead to LV anureysm

red arrow = J-point, blue arrow = abnormal Q wave

Question 19

• following the onset of a STEMI, when does the ST elevation typically present?
  
  • what happens if it is not treated?

Answer 19

• typically present 0-12 hours after onset
  
  • if not treated, an abnormal Q wave can present (usually near the same time).
    
    • this can persist
  • next, we might see a T-wave inversion (2-5 days).

Question 20

• post STEMI EKG findings
  
  • an “old infarct” seen on an EKG of a pt who has recovered from a STEMI is referring to what?
  • when might we be worried?

Answer 20

• “old infarct” = resence of a persistent, slightly abnormal Q wave seen on a few leads
  
  • isnt a huge problem
• if there is a persistent ST elevation__​
  
  • that is consistent with LV aneurysm morphology - and this patient might be having a residual complication from their STEMI.

Question 21

what arythmia is an equivalent ot a STEMI?

Answer 21

LBBB

Question 22

• after confirming a STEMI patient using an EKG- what are the next steps?

Answer 22

• first:
  
  • start any adjunctive therapy (MONA-BASH-C) that is indicated
• next, determine time from onset of ischemic symptoms:
  
  • > 12 hrs from onset
    
    • consider early invasive strategy if the patient meets the following criteria:
      
      • has elevated troponin
      • is high risk
      • and has one/more of the following characteristics:
        
        • has refractory chest pain
        • persistent ST elevation
        • V-tach
        • hemodynamic instability
        • signs of heart failure
  • < 12 hrs from onset
    
    • do surgery
      
      • if PCI (percutaneous intervanetion) - aka left heart catheterization - is available, pick this option. this is better than thrombolytics.
        
        • done by balloon angioplasty
        • ideally start 90 minutes from STEMI onset (door to balloon time)
      • if no PCI available: fibrinolysis
        
        • with these thrombolytics:
          
          • tenecteplase
          • reteplase
          • alteplase
          • streptokinase
        • ​ideally start 30 minutes (door to needle time) from STEMI onset

Question 23

if PCI (catherization) is not available for a STEMI patient, what are the next options?

Answer 23

• depends on wait time for a hospital with a PCI
  
  • if PCI not available within 90 minutes:
    
    • this patient should be put on fibrilnolytics (tenecteplase, reteplase, alteplase, streptokinase)
      
      • this should within 30 minutes of STEMI onset.
        
        • especially if the person needs to eventually have a PCI & anticipated time wait time before available is over 90 minutes (i.e., > 120 minutes from STEMI onset)
          
          • this applies to STEMI patients that also have cardiogenic shock & acute severe HR
  • if patient can be transferred to a PCI hospital within 90 minutes:
    
    • they should be sent to that hospital & catherized as soon as possible, but at the very least, no more than 120 minutes after onset of STEMI

Question 24

how do you treat a STEMI patient with a non-stentable lesion?

Answer 24

coronary artery bypass surgery (CABG)

Question 25

• what is the pharmaceutical intervention for treatment for STEMI?

Answer 25

* = indicates this is really important & dont under almost all circumstances.

• “MONA-BASH-C” (like N-STEMI)
  
  • M = morphine
    
    • given IV if other pain management doesnt work
  • O = oxygen
    
    • given if O2 saturation is less than 90%
  • N = nitrates*
    
    • nitroglycerin given 5 minutes after pt arrival to ED
      
      • effects:
        
        • helps symptoms
        • increases blood flow
      • contraindications:
        
        • RV INFARCT
          
          • aka an inferior MI
            
            • typically due to obstruction in inferior or proximal RCA
              
              • ​if you suspect this, order a right sided EKG
        • recent PDE inhibtor (viagra)
        • patient systolic BP < 90
          
          • ​nitroglycerine will drop BP further, perhaps inducing cardiac arrest
  • A = aspirin*
    
    • given to all patients
    • in the form of 324 mg non-enteric coated, chewable tablet
  • B = beta blockers
    
    • contraindicated in low cardiac output patients: cardiogenic shock risk, HF
    • CCBs given as alternative
  • A - ACEs/ARBS
  • S - Statins
  • H - herparin like agents (UFH, enoparinix, fondparanix)
  • C- clopidogrel (plavix)*
    
    • ​OR:
      
      • prasugrel (effient)
      • ticagrelor (brillinta)

Question 26

“summary” of STEMI treatment

Answer 26

• stabilize patient with
  
  • MONA-BASH-C (do what’s indicated)
    
    • only give O2 is O₂ saturation < 90%
    • dont give nitrates in people on viagra, SPB <90, or with RV infarct (inferior MI)**
    • give aspirin always
• take patient to cath lab if
  
  • < 12 hrs since STEMI onset
  • are hemodynamically unstable/electrically unstable
• once at cath lab, do PCI > thrombolytics if PCI available