ACS/MI/Angina Flashcards
Ischemia def
lack of O2 or blood flow
Infarction def
death of tissue, results from prolonged ischemia
Myocardial infarction
Heart attack
- cardiac myocyte death secondary to ischemia
Angina
- chest pain due to ischemia
- usually result of atherosclerosis / coronary artery disease
Coronary Artery Disease (CAD)
-predominant cause
atherosclerotic plaque formation and subsequent rupture
Two types of thrombi
- white: platelets and plaques
- red: platelets, fibrin, RBC
Occlusion type
- unstable angina
- NSTEMI
- STEMI
- Unstable angina: partial, white thrombus
- NSTEMI: partial of large artery or total occlusion of small vessel
- STEMI: total occlusion, red thrombus
Two general types of risk factor for CAD
modifiable
non-modifiable
Modifiable risk factors for CAD
- diet
- exercise
- smoking
- ETOH
- dyslipidemia
Non-modifiable risk factors for CAD
- age (men> 45 women>55)
- gender
- family hx
- personality type (??? like type A?)
suspected ACS labs
- general term
- 4 examples
cardiac biomarkers
- Troponin
- CK
- CKMB
- Myoglobin
*not actually enzymes but often called cardiac enzymes
What are cardiac biomarkers
cardiac injury = cellular disruption, loss of intracellular components which are called biomarkers
What is the basis for dx of ACS in the ER
cardiac biomarkers
Troponin
- important regulatory component in cardiac muscle
- most specific and sensitive biomarker for cardiac tissue
- if test is negative and within correct timing, very likely pt does not have disease (specific)
- if test is positive, pt very likely to have dz (sensitive)
Two types of troponin tested and what is difference
- Troponin T
- Troponin I
- typically only affect reference ranges
Sensitive troponin tests
higher threshold than ultra-sensitive tests for detection and time to detection
Ultrasensitive troponin tests
lower threshold for detection and early time to detection
Troponin
- time to rise
- time to peak
- time to norm
- 3-6 hours
- 12 hours
- 10 days
What should you monitor if mildly positive troponin
the change over time, 90-120 minutes in ER
if have sx suggestive of ACS for not long but no troponin yet does negative troponin mean no ACS?
NO - just might not be detectable yet
Why is troponin not a great option to monitor for re-infarctions
bc stays elevated for days
CK
Creatinine phosphokinase
- skeletal muscle, heart, brain
- lacks specificity due to multiple locations
- multiple reasons for elevation
- scott calls it a worthless test
CK timing
- time to rise: 3-4 hrs
- time to peak: 12 hours
- time to normalization: 3-4 days
*almost the same as CKMB
CKMB
- isoenzyme of CK
- more specific to myocardium
- multiple reasons for elevation
- scott calls it a worthless test
CKMB timing
Time to rise: 3-4 hrs
Time to peak: 12-24 hrs
Time to normalization: 3-4 days
*almost the same as CK
Myoglobin
- heme protein rapidly released from damaged m tissue
- non-specific to heart
- not used anymore in ER
- might be more useful monitoring post MI patients bc of faster time to normalization
Myoglobin timing
- Time to rise: 2-4 hours
- Time to peak: 12-24 hrs
- Time to normalization: 24-36 hrs
what is the gold standard in evaluation of chest pain
- EKG
* always get EKG and CXR for pt with chest pain in ED
Standard of care timing EKG for pt with chest pain
within 10 minutes of arrival to ER
Definition of ST elevation/depression
> 1 mm above or below isoelectric line
what is T wave inversion a characteristic sign of
myocardial ischemia
Where is isolated T wave inversion a normal variant?
Flipped T in 3 is Free
What is a new onset of LBBB synonymous with?
acute MI until proven otherwise (would want to compare with old EKGs if possible)
Pathological Q waves
- sign of what
- due to what?
- sign of previous myocardial infarction
- result of absent electrical activity bc there is scarring
does absence of pathological Q wave = no infarction?
no
What is the gold standard treatment of STEMI and NSTEMI
PCI - percutaneous coronary intervention
3 PCI examples
- angioplasty
- balloon angioplast
- arteriography
uses for PCI
- evaluate presence of blockages
2. used to re-vascularize ischemic vessels
Gold standard timing for PCI in ED for STEMI
- 90 min door to needle
- from time pt checks in
timing for PCI with NSTEMI
- within 24 hours of presentation
- some critical its will qualify for fast intervention
cardiac stress testing
- when used
- diagnostic and prognostic tool
- evaluate its with known or suspected CAD/IHD (ischemic heart disease)
Indications for cardiac stress testing
- gender
- age
- sx: SOB, DOE, stable angina, etc.
Two main types of stress testing
- exercise stress test
2. pharmacologic stress testing
Exercise stress testing
- run/bike with simultaneous EKG
- look for EKG changes indicative of ischemia
- limited if pt can’t move at moderate pace
Pharmocologic stress testing
- meds used to stress the heart
- adenosine, dobutamine, atropine, etc.
Two scoring systems often used to evaluate ACS/MI
- HEART score
- TIMI score
HEART score category names
History EKG Age Risk Factors Troponin
History HEART score
- highly suspicious
- moderate suspicious
- slightly suspicious
EKG HEART score
- significant ST depression
- non specific
- normal
Age HEART score
- > 65
- 45-65
- <45
Risk factors HEART score
- > 3 factors
- 1 to 1 factors
- No risk factors
Troponin HEART score
- > 3X normal limit
- 1-3X normal
- Normal
HEART final score three categories
- 0-3: early discharge and f/u
- 4-6: admit for observation and serial enzymes
7-10: aggressive tx and possible PCI
TIMI scoring categories
one point for:
- Age
- ASA use
- 2 episodes of angina
- ST changes
- elevated biomarkers
- Known CAD
- > RF
UA
unstable angina
- present at rest
- no EKG changes or elevation in troponin
NSTEMI
- angina at rest
- does have ischemic EKG findings and/or elevation of troponin
True/false: treatment of UA and NSTEMI is the same
true
what percent of MIs occur >65 yo
60-65%
Atypical sx of elderly and women
usually non-specific:
- weakness
- nausea
- vomiting
- dizzy
- abd pain
- HA
- neck pain
OPQ for NSTEMI/UA
O: gradual onset, can be sudden
P: pain worse with activity
Q: discomfort/pressure vs. pain. crushing, burning, tightness, squeezing
RST for NSTEMI/UA
R: to epigastrium, shoulders, arms, neck, lower jaw
S: site is diffuse, typically not just one spot
T: brief 5-15 min
Scott’s tx of NSTEMI/UA
- nitroglycerin
- Oxygen IF hypoxic (SpO2 <92%)
- Fentanyl/Dilaudid
- Antithrombotic
When should avoid nitro
inferior right ventricular MI bc can cause hypotension/cardiogenic shock
Why avoid morphine
CRUSADE study indicates 30% higher adjusted mortality (Dr. Letassy says the study’s results aren’t strong - observational retrograde etc.)
Two main types of antithrombotic therapy
Antiplatelets
Anticoagulation
What meds should be started within 24 hours of admission for UA/NSTEMI
beta-blockers
statins
What is NOT indicated to tx NSTEMI/UA
fibronolytics (are indicated in STEMI if PCI is not available per Dr. Letassy)
STEMI def
ST elevation MI
- MI leads to development of full thickness cardiac muscle death = ST elevation on EKG
STEMI sx
same as UA/NSTEMI
Labs for STEMI
Cardiac biomarkers
when is PCI preferred tx of STEMI
- older
- high bleeding risk
- fibrinolytic contraindications
What is timing of fibrinolytics for STEMI
30 minutes from identification of STEMI
What is complication of re-perfusion?
re-perfusion arrhythmia
- looks like v-tach or wide-complex arrhythmias
- unless pt is unstable, don’t shock/tx
Prinzmetal
vasospastic angina
- episodes of angina at rest
- promptly resolve with nitrates
dx criteria for Prinzmetal
- nitrate responsive angina
- transient EKG changes
- angiographic evidence of coronary artery spasm
Prinzmetal S&S
same as ischemic chest pain
- most events at rest/early am
Prinzmetal EKG
- transiet ST seg elevation
Prinzmetal labs
cardiac biomarkers can be elevated, depends on length of episode
Prinzmetal stress test
normal non-invastive stress test
Prinzmetal tx
- lifestyle modification (smoking cessation)
- Calcium channel blockers
- long acting nitrates
- others (mg, statins, rho kinase inhibitors)
Stable angina
- ischemic chest pain occurs predictably and reproducible at certain level of exertion
- resolved with nitroglycerin
Stable angina S&S
same as all the other except resolves with rest
Stable angina lab/radiographic testing
- stress testing and coronary angiography will ID blocked arteries
Stable angina tx
- acute: nitro
- chronic: ASA, beta blocker, Calcium channel blocker, long acting nitrates
