Acute Coronary Syndrome Flashcards
angina
chest discomfort not necessarily in the chest, relieved with rest or nitroglycerin
relief with nitroglycerin
does not always mean cardiac in origin
unstable angina
angina that increases with frequency and intensity, lasting longer than 20 min, not necessarily a heart attack
acute myocardial infarction
presence of positive cardiac enzymes suggestion myocyte death AND presentation of ischemic-type chest pain or changes in EKG
How many types of myocardial infarction (MI) are there?
5 (type 4 has two sub types)
Type 1 MI
spontaneous MI due to plaque erosion, rupture, or dissection
Type 2 MI
secondary to ischemia from increased oxygen demand or decreased supply
Type 3 MI
sudden, unexpected cardiac death (or cardiac arrest) with symptoms suggestive of MI, accompanied by STEMI, new LBBB, or evidence of a fresh thrombus in coronary artery by angiography or autopsy –> vtach, ACLS
Type 4 MI
associated with coronary angioplasty or stents
- 4a: MI associated with PCI
- 4b: MI associated with stent thrombus evident by angiography or autopsy
Type 5 MI
associated with CABG
Can you have a MI without EKG changes?
Yes, 5-10% of pts having an active MI can have a normal EKG
EKG findings in MI
- T wave inversions or tall/symmetric “peaked” T-waves
- presence of Q-waves
- ST segment depression
- ST segment elevations
- new LBBB
atypical MI
active MI without chest pain; 1/3 - 1/2 of pts present this way; mainly in elderly, diabetics with neuropathy, females
risk factors for atypical MI
- women
- non-Caucasian
- diabetes
- uncontrolled or long-standing HTN
- hyperlipidemia
- smokers
- family h/o CAD
Physical exam consistent with decreased cardiac output
- anxious
- diaphoretic
- presence of rales
- hypotension
- presence of an S3
- new or worsening mitral regurgitation
What are the cardiac markers?
- myoglobin
- CK-MB
- troponin
Initial rise of cardiac markers
- myoglobin: 1-2 hrs
- CK-MB: 3-4 hrs
- troponin: 3-6 hrs
Peak levels of cardiac markers
- myoglobin: 4-6 hrs
- CK-MB: 12-24 hrs
- troponin: 12-24 hrs
Duration of cardiac markers
- myoglobin: 24 hrs
- CK-MB: 2 days
- troponin: 7 days
How is troponin cleared in the body?
renally
When to give oxygen? (MONA)
if O2 saturation is < 94%, start O2 at 4L per nasal canula and titrate as needed
What effect does nitroglycerin have on preload and afterload?
decreases which decreases workload
When is reducing the preload bad?
in patients that have R sided MI since they are preload dependent
Which of the P2Y12 inhibitors is reversible?
ticagrelor
In which patients is nitroglycerin recommended?
pts w/ persistent ischemia, heart failure, HTN, or anterior MI
Contraindications to using nitroglycerin
- Hypotension (<90 SBP or >30 decrease from baseline)
- Brady or tachy - cardia
- Recent use of PDE5 inhibitor (can cause profound hypotension and shock)
If medium or high risk and invasive surgery is indicated, what antiplatelet therapy to give upon presentation?
DAPT
With initial conservative strategy and diagnostic angiography not indicated, what antiplatelet therapy to give?
- aspirin
- anticoagulant + clopidogrel or ticagrelor
- low risk: continue ASA forever, cont clopidogrel or ticagrelor up to 12 months
With initial conservative strategy and presence of recurring symptoms, what antiplatelet therapy to give?
- ASA
- anticoag
- Glycoprotein IIb/IIIa Inhibitors (tirofiban or eptifibatide) OR P2Y12 inhibitors (clopidogrel or ticagrelor)
- diagnostic angiography
- PCI: cont ASA, loading dose of P2Y12, stop anticoag
- CABG: cont ASA, stop gp IIb/IIIa 4 hr b4 CABG, cont UFH or stop enoxaparin 12-24 hr or fonda 24 hr B4 CABG and start UFH,
Pros and cons to using beta blockers in ACS
- Pros: mortality benefit, decrease rate of reinfarction and ventricular fibrillation
- Cons: increased risk of cardiogenic shock
Risk factors for increased risk of shock of using beta blockers in ACS
- Age > 70 y/o
- SBP < 120
- Bradycardia or sinus tachycardia
- Increased time since onset of symptoms
When is heparin indicated in ACS?
- High-risk unstable angina (troponin positive)
- NSTEMI
- PCI
- No evidence or concern for aortic dissection (can open up and bleed)
Reperfusion time goal
- Door to balloon (PCI): 90 min
- Door to needle (fibrinolysis): 30 min
Thrombolytic mechanism of action
converts plasminogen to the proteolytic enzyme plasmin, which lyses fibrin as well as fibrinogen
What type of MI are thrombolytics indicated?
STEMI
Thrombolytic fail rate
20% of infarcted arteries –> PCI
Half-life of thrombolytics
- Alteplase: 3-6 min
- Reteplase: 13-16 min
- Tenecteplase: 22 min
Absolute contraindications to thrombolytics
- Prior intracranial bleeding
- Known structural cerebral vascular lesion
- Malignant intracranial neoplasm
- Ischemic stroke previous 3 mos
- Aortic dissection
- Active bleeding or bleeding disorder
- Significant head trauma in last 3 months
Relative contraindications to thrombolytics
- Severe or poorly controlled HTN (SBP > 180 or DBP > 110)
- Ischemia stroke > 3 months ago or dementia
- Traumatic or prolonged CPR (> 10 min)
- Major surgery in last 3 wks
- Recent internal bleed in last 2-4 wks
- Active peptic ulcer
- Chronic anticoag w/ high INR
