OBJECTIVES
•Definition of ACS
•UA, NSTEMI, and STEMI
•Risk stratification in NSTEMI
•Management
Acute Coronary Syndrome
Definition: a constellation of symptoms related to
obstruction of coronary arteries with chest pain being the
most common symptom in addition to nausea, vomiting,
diaphoresis etc.
Chest pain concerned for ACS is often radiating to the left
arm or angle of the jaw, pressure-like in character, and
associated with nausea and sweating. Chest pain is often
categorized into typical and atypical angina.
Acute coronary syndrome
•Based on ECG and cardiac enzymes, ACS is classified into:
•STEMI: ST elevation, elevated cardiac enzymes
•NSTEMI: ST depression, T-wave inversion, elevated cardiac
enzymes
•Unstable Angina: Non specific EKG changes, normal cardiac
enzymes
Unstable Angina
•Occurs at rest and prolonged, usually lasting >20 minutes
•New onset angina that limits activity
•Increasing angina: Pain that occurs more frequently, lasts
longer periods or is increasingly limiting the patients activity
EKG
STEMI:
Q waves , ST elevations, hyper acute T waves; followed by T wave
inversions.
Clinically significant ST segment elevations:
> than 1 mm (0.1 mV) in at least two anatomical contiguous leads
or 2 mm (0.2 mV) in two contiguous precordial leads (V2 and V3)
Note: LBBB and pacemakers can interfere with diagnosis of MI on EKG
EKG
•NSTEMI:
•ST depressions (0.5 mm at least) or T wave inversions ( 1.0 mm at
least) without Q waves in 2 contiguous leads with prominent
R wave or R/S ratio >1.
• Isolated T wave inversions:
• can correlate with increased risk for MI
•may represent Wellen’s syndrome:
•critical LAD stenosis
•>2mm inversions in anterior precordial leads
•Unstable Angina:
•May present with nonspecific or transient ST segment
depressions or elevations
Cardiac Enzymes
•Troponin is primarily used for diagnosing MI because it has
good sensitivity and specificity.
•CK-MB is more useful in certain situations such as post
reperfusion MI or if troponin test is not available
•Other conditions can cause elevation in troponin such as
renal failure or heart failure
•The increasing troponin trend is the important thing to look
for in diagnosing MI. Order Troponin together with ECG when
doing serial testing to rule out ACS.
Risk Stratification: TIMI score
•NSTEMI or unstable angina are risk stratified:
•Age>=65
•>= 3 CAD risk factors:
•HTN, hyperlipidemia, diabetes, smoker, family hx of early MI
•Documented CAD with >=50% stenosis
•ST segment deviation
•≥ 2 aginal episodes in past 24 hours
•Aspirin use in the past week (marker for more severe case)
•Elevation of cardiac enzymes
•Stratify risk based on number of variables
•Risk:
•0-2: Low 3-4: Intermediate 5-7: High risk
NSTEMI & Unstable Angina
Management
NSTEMI or EKG changes suggest ischemia with high risk:
Telemetry
Aspirin
Beta blocker
Nitrates
Heparin (UFH or LMWH)
ACE-I/ARB
Statin
Consider GP IIb/IIIa inhibitor and clopidogrel
EKG normal or non-specific changes with intermediate or low
risk:
Telemetry
Rule out ACS with 3 sets of troponin, EKG
Consider pre-discharge stress test
STEMI Management
STEMI patients usually go straight to the cath lab from the ED.
Goal: door to balloon 90 minutes.
Initial management for STEMI:
Cardiac monitor
Supplemental O2
Nitrates*
Beta blocker
Morphine
Clopidogrel
Aspirin
Good IV access
Call cardiology fellow!
Case
•60 year old male with history of DM2 for 20 years, HTN, HLD
who presented to the ED with 4 hour onset of chest pain
which was described as in the anterior chest without
radiation. The pain seemed to improve when he sits down and
worsening when he walked upstairs.
•VS: T 36.9, HR: 95, BP: 84/56, RR 22, O2 sat. 99% RA.
•ECGs are shown as followed
•What will you do?
•What’s your diagnosis?
•What should be done now?