ST segment elevation: Difference between revisions
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**80% of inferior STEMI have ST depression in anterior leads | **80% of inferior STEMI have ST depression in anterior leads | ||
***However, may represent reciprocal changes OR posterior STEMI | ***However, may represent reciprocal changes OR posterior STEMI | ||
*Stage 1 | |||
**Timing: 30min - hours | |||
**Finding: hyperacute T waves | |||
***>6mm limb leads | |||
***>10mm precordial leads | |||
**Duration: normalizes in days, weeks, or months | |||
*Stage 2 | |||
**Timing: minutes - hours | |||
**Finding: ST segment elevation | |||
***≥0.1mV in two or more contiguous leads | |||
**Duration: ST segment resolution occurs over 72hrs; completely resolves w/in 2-3wks | |||
*Stage 3 | |||
**Timing: within 1hr; completed within 8-12hr | |||
**Finding: Q waves | |||
**Duration: persist indefinitely in 70% of cases | |||
[[Image:STEMI Progression.jpg]] | |||
*a: 30min after chest pain onset | |||
*b: 45min after chest pain onset (hyperacute T waves) | |||
*c: 70min after chest pain onset (ST elevation) | |||
*d: 3hr after PCI (ST segment has decreased, TWI incdicates reperfusion) | |||
*e: 5 days after PCI (ST segment back to baseline, TWI is near baseline) | |||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
Revision as of 04:49, 25 February 2015
Background
- Its presence must be explained (there is no "nonspecific ST elevation")
- Not a specific marker for STEMI
Diagnosis
Measure ST elevation at the j-point[1]
Early Repolarization versus STEMI
- Early Repolarization suggested by:
- ST elevation <4mm
- Notched J point
- Concave or saddle-back ST morphology
- No reciprocal changes
LVH versus STEMI
- Difficult to exclude MI in pt with LVH (pt already at risk for MI)
- Best aid is prior ECG or serial ECGs
LBBB versus STEMI
STEMI
- ST elevation in those leads that reflect the distribution of a single coronary artery
- RCA: II, III, aVF (inferior)
- LAD: V1-V4 (antero-septal)
- Circumflex: V5-V6, I, aVL (lateral)
- Dominant left circulation: infero-lateral
- ST morphology
- Concave up versus convex
- Convex has Sp 97%, Sn 77%
- Concave up versus convex
- Look for reciprocal ST depression
- 35% of anterior STEMI have ST depression in inferior leads
- 80% of inferior STEMI have ST depression in anterior leads
- However, may represent reciprocal changes OR posterior STEMI
- Stage 1
- Timing: 30min - hours
- Finding: hyperacute T waves
- >6mm limb leads
- >10mm precordial leads
- Duration: normalizes in days, weeks, or months
- Stage 2
- Timing: minutes - hours
- Finding: ST segment elevation
- ≥0.1mV in two or more contiguous leads
- Duration: ST segment resolution occurs over 72hrs; completely resolves w/in 2-3wks
- Stage 3
- Timing: within 1hr; completed within 8-12hr
- Finding: Q waves
- Duration: persist indefinitely in 70% of cases
- a: 30min after chest pain onset
- b: 45min after chest pain onset (hyperacute T waves)
- c: 70min after chest pain onset (ST elevation)
- d: 3hr after PCI (ST segment has decreased, TWI incdicates reperfusion)
- e: 5 days after PCI (ST segment back to baseline, TWI is near baseline)
Differential Diagnosis
ST Elevation
- Cardiac
- ST-segment elevation myocardial infarction (STEMI)
- Post-MI (ventricular aneurysm pattern)
- Previous MI with recurrent ischemia in same area
- Wellens' syndrome
- Coronary artery vasospasm (eg, Prinzmetal's angina)
- Coronary artery dissection
- Pericarditis
- Myocarditis
- Aortic dissection in to coronary
- Left ventricular aneurysm
- Left ventricular pseudoaneurysm
- Early repolarization
- Left bundle branch block
- Left ventricular hypertrophy (LVH)
- Myocardial tumor
- Myocardial trauma
- RV pacing (appears as Left bundle branch block)
- Brugada syndrome
- Takotsubo cardiomyopathy
- AVR ST elevation
- Other thoracic
- Metabolic
- Drugs of abuse (eg, cocaine, crack, meth)
- Hyperkalemia (only leads V1 and V2)
- Hypothermia ("Osborn J waves")
- Medications
See Also
Source
- ↑ Gibbons RJ, Balady GJ, Bricker JT, Chaitman BR, Fletcher GF, Froelicher VF, Mark DB, McCallister BD, Mooss AN, O'Reilly MG, Winters WL Jr, Gibbons RJ, Antman EM, Alpert JS, Faxon DP, Fuster V, Gregoratos G, Hiratzka LF, Jacobs AK, Russell RO, and Smith SC Jr. ACC/AHA 2002 guideline update for exercise testing: summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1997 Exercise Testing Guidelines). Circulation 2002 Oct 1; 106(14) 1883-92. pmid:12356646.