CMC ECG MASTERS
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  • P Waves
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    • Short PR
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    • R Wave Progression
    • Pathological Q waves
  • ST Segments
    • ST Elevation
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  • T Waves
    • Flat, Bifid, or Notched
    • Inverted
  • QT intervals
    • Prolonged QT
    • Short QT
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    • STEMI
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    • Pulmonary Disease
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    • Electrolyte Abnormalities
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  • Interpreter

Electrolyte Abnormalities

  • The “hypers” (­K, ­Ca) shorten the QT interval
  • The “hypos” (K, Ca) prolong the QT interval
  • K abnormalities affect the T waves (­increased K: narrow Ts; decreased K: wide Ts)
  • Ca abnormalities affect the ST segments (­increased Ca: shorter STs; decreased Ca: longer STs)
​Hyperkalemia
  • Common findings, in order of severity:
  • Narrow based, peaked T waves (base of Ts “pinched down”)
  • Widened QRS complexes (nonspecific IVCD)
  • Axis shift, new fascicular block
  • Flattened P waves
  • QRS-T “sine wave” morphology
  • Double counting of HR by ECG interpretation software: highly specific for hyperkalemia
  • Arrhythmias: junctional rhythm; asystole; AV block; VT; VF
  • Less common findings:
    • Anterior ST segment elevation
    • “Brugada pattern”
    • Pathologic Q waves
Picture

Hypercalcemia
  • ST segment shortened
  • T waves are inscribed right after the QRS complex
  • May mimic coved ST segment elevation in anterior chest leads
  • May rarely cause a normothermic Osborn wave
  • ECG findings of hypercalcemia usually signify severity of hypercalcemia
Picture

Hypokalemia
  • Nonspecific ST depression (usually upsloping)
  • Wide, bifid T waves or T-U complexes
  • Prolonged QT/QU intervals
  • “Wavy ST-Ts” (3 waves between QRS complexes: T – U – P)
  • Severe hypokalemia may mimic ischemic ST segment depression
Picture

Hypocalcemia
  • Nice, smooth, normal looking T waves
  • Prolonged ST segments – T waves are pushed to the right
  • Prolonged QT intervals
  • A similar pattern is frequently seen in pts with advanced liver failure, even with normal Ca
Picture

Chronic renal failure, uremia
  • Combination of hyperkalemia and hypocalcemia
  • Flat, long ST segment followed by narrow-based, peaked T wave (“tent on a desert”)
  • Slowly upsloping ST segment followed by peaked T wave; QT prolonged
ST-T Patterns
  • Home
    • About Us
    • EM GuideWire
    • CMC Ed Masters
    • Ped EM Morsels
  • Basics
  • P Waves
    • Sinus
    • Not sinus
    • Absent
  • PR interval
    • Short PR
    • Prolonged PR
    • Variable PR
  • QRS
    • Wide
    • Axis >
      • LAD
      • RAD
    • Amplitude >
      • High Voltage
      • Low Voltage
      • Alternans
    • R Wave Progression
    • Pathological Q waves
  • ST Segments
    • ST Elevation
    • ST Depression
  • T Waves
    • Flat, Bifid, or Notched
    • Inverted
  • QT intervals
    • Prolonged QT
    • Short QT
  • Patterns
    • STEMI
    • Pulmonary Embolism
    • Ventricular Hypertrophy
    • Pulmonary Disease
    • ST-T Patterns
    • Electrolyte Abnormalities
    • Cases >
      • Case 1
      • Case 2
      • Case 3
      • Case 4
      • Case 5
      • Case 6
      • Case 7
      • Case 8
      • Case 9
      • Case 10
      • Case 11
      • Case 12
      • Case 13
      • Case 14
      • Case 15
      • Case 16
      • Case 17
      • Case 18
      • Case 19
  • Interpreter