ECGs by diagnosis: Difference between revisions

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==Background==
==Cardiac Ischemia==
#Poor R wave progression: no r's by V4
===T Wave===
*Distribution
**T wave is normally inverted in aVR; sometimes inverted in III, aVF, aVL, V1
*T-wave inversions in V2-V6 are pathologic
*Morphology
**Inverted, symmetric,
**Transient changes suggests ischemia without infarction
**Persistent changes suggests infarction (troponin elevation usually seen)
*Pseudonormalization
**In presence of baseline TWI (within 1 month), reocclusion causes normalization of TWI
**Should be interpreted as evidence of ischemia


==STEMI==
===Q Wave===
*Q waves do not always indicate infarction (see DDX below)
*Must distinguish normal septal q waves from pathologic Q waves:
**Normal septal q wave: <0.04s, low amplitude
**Abnormal septal q wave: >0.04s in I OR in II, III, AND aVF OR V3, V4, V5, AND V6
*Q-wave equivalents in the precordial leads:
**R-wave diminution or poor R-wave progression
**Reverse R-wave progression (R waves increase then decrease in amplitude)
***Must distinguish from lead misplacement
**Tall R waves in V1, V2 (representing "Q waves" from posterior infarction)
 
====Q Wave (Pathologic) DDX====
*Ischemic Q waves
*LBBB
*LVH
*Chronic lung disease
*Hypertrophic cardiomyopathy
*Dilated cardiomyopathy
 
===ST Segment Depression===
*Assume posterior STEMI or reciprocal changes to STEMI until proven otherwise
*Indicators of ischemia:
**>0.5mm depression from baseline (especially >1mm) in two or more contiguous leads
**Transient depression
**Morphology that is flat or downsloping
 
===ST Segment Elevation===
*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
 
===Reciprocal Changes===
#Anterior STEMI
##Reciprocal ST-segment depression in at least one of leads II, III, aVF
##Occurs in 40-70% of cases
#Inferior STEMI
##Reciprocal ST-segment depression usually present in I, aVL; often in V1-V3
##Occurs in 56% of cases
#Posterior STEMI
##Reciprocal ST-segment depression in V1-V4
###Differentiate from inf STEMI reciprocal depression based on upright T waves, posterior leads showing STEMI
##Often associated w/ ST-segment elevation in II, III, aVF (inferior involvement)
 
==Anatomical Correlation==
#Posterior
#Posterior
##ST depression in V1-V2
##ST depression in V1-V2
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==Electrolyte Disorders==
==Electrolyte Disorders==
===Hyperkalemia===
===Hyperkalemia===
#5.5-6.6 -> tall peaked T, deep S in I and V6, QRS nml
*See [[Hyperkalemia#ECG|Hyperkalemia]]
#7.0-8.0 -> QRS widens, slurred initial and term QRS, ST elevation, low wide P's, AV blocks, SA arrest, bradycardia.
#>8.0 -> widened QRS, Vfib, asystole.


===Hypokalemia===
===Hypokalemia===
#3.0-3.5 no change or flat T' sand U's in V2-3, QT interval and QRS nml.
*See [[Hypokalemia#Diagnosis|Hypokalemia]]
#2.7-3.0 U taller, T smaller, esp. V2-3
#<2.6 ECG change includes tall U's, QT and QRS wnl.


===Hypercalcemia===
===Hypercalcemia===
#Increased QRS duration (slight)
*See [[Hypercalcemia#Diagnosis|Hypercalcemia]]
#ST short or absent
#Short corrected QT.
#PR long


===Hypocalcemia===
===Hypocalcemia===
#slight decrease in QRS.
*See [[Hypocalcemia#Diagnosis|Hypocalcemia]]
#ST and corrected QT long
#PR short.
#T's flat to inverted.


==CNS==
==CNS==
#SAH, IC bleed, CVA
#SAH, IC bleed, CVA
##Diffuse wide, deep, blunted, inverted T's
##Diffuse wide, deep, blunted, inverted T waves
##QT prolongation
##QT prolongation


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#ECG should mimic LBBB w/ LAD
#ECG should mimic LBBB w/ LAD


==PE==
==Pulmonary Embolism==
#S1Q3T3 (Sp, not Sn)
#S1Q3T3 (Sp, not Sn)


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==Source==
==Source==
DONALDSON 17/09 (Adapted from Niemann/Lampe)
*Electrocardiography in Emergency Medicine. ACEP Textbook.


[[Category:Cards]]
[[Category:Cards]]

Revision as of 21:54, 2 March 2012

Cardiac Ischemia

T Wave

  • Distribution
    • T wave is normally inverted in aVR; sometimes inverted in III, aVF, aVL, V1
  • T-wave inversions in V2-V6 are pathologic
  • Morphology
    • Inverted, symmetric,
    • Transient changes suggests ischemia without infarction
    • Persistent changes suggests infarction (troponin elevation usually seen)
  • Pseudonormalization
    • In presence of baseline TWI (within 1 month), reocclusion causes normalization of TWI
    • Should be interpreted as evidence of ischemia

Q Wave

  • Q waves do not always indicate infarction (see DDX below)
  • Must distinguish normal septal q waves from pathologic Q waves:
    • Normal septal q wave: <0.04s, low amplitude
    • Abnormal septal q wave: >0.04s in I OR in II, III, AND aVF OR V3, V4, V5, AND V6
  • Q-wave equivalents in the precordial leads:
    • R-wave diminution or poor R-wave progression
    • Reverse R-wave progression (R waves increase then decrease in amplitude)
      • Must distinguish from lead misplacement
    • Tall R waves in V1, V2 (representing "Q waves" from posterior infarction)

Q Wave (Pathologic) DDX

  • Ischemic Q waves
  • LBBB
  • LVH
  • Chronic lung disease
  • Hypertrophic cardiomyopathy
  • Dilated cardiomyopathy

ST Segment Depression

  • Assume posterior STEMI or reciprocal changes to STEMI until proven otherwise
  • Indicators of ischemia:
    • >0.5mm depression from baseline (especially >1mm) in two or more contiguous leads
    • Transient depression
    • Morphology that is flat or downsloping

ST Segment Elevation

  • 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

Reciprocal Changes

  1. Anterior STEMI
    1. Reciprocal ST-segment depression in at least one of leads II, III, aVF
    2. Occurs in 40-70% of cases
  2. Inferior STEMI
    1. Reciprocal ST-segment depression usually present in I, aVL; often in V1-V3
    2. Occurs in 56% of cases
  3. Posterior STEMI
    1. Reciprocal ST-segment depression in V1-V4
      1. Differentiate from inf STEMI reciprocal depression based on upright T waves, posterior leads showing STEMI
    2. Often associated w/ ST-segment elevation in II, III, aVF (inferior involvement)

Anatomical Correlation

  1. Posterior
    1. ST depression in V1-V2
    2. R-S ratio of >1 in V1 or V2
    3. ST elevation >1 in V7-9
    4. Often accompanied by inferior ST changes
    5. Often accompanied by RV MI
  2. Anterior
    1. ST depression in II, III, aVF usually due to high lateral ST elevation (I, aVL)
  3. Inferior
    1. Look at I, aVL for reciprocal changes (ST depression or TWI)
      1. If no changes pt probably not having an inf STEMI

Aneurysm

  1. ST elevation > 2wk

Pericarditis

Electrolyte Disorders

Hyperkalemia

Hypokalemia

Hypercalcemia

Hypocalcemia

CNS

  1. SAH, IC bleed, CVA
    1. Diffuse wide, deep, blunted, inverted T waves
    2. QT prolongation

Pacemakers

  1. Should be in the apex of R ventricle
  2. ECG should mimic LBBB w/ LAD

Pulmonary Embolism

  1. S1Q3T3 (Sp, not Sn)

See Also

Source

  • Electrocardiography in Emergency Medicine. ACEP Textbook.
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