ECG of the Week – 9th January 2017 – Interpretation

This ECG is from a 59 yr old male who presented with episodic chest pain for the last 2 weeks which had been constant for the last 1 hour. He has a past medical history of hypertension.

 
 
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Rate:
  • ~125 bpm
Rhythm:
  • Regular
  • Sinus Rhythm
Axis:
  • Normal
Intervals:
  • PR - Normal (~180ms)
  • QRS - Normal (60ms)
Segments:
  • ST Elevation leads: I (0.5-1mm), aVL (1mm), V1 (1mm), V2 (8-9mm), V3 (4mm), V4 (1mm)
  • ST Depression leads: II, III, aVF, V5-6
Interpretation:
  • Anterior STEMI
 What happened ?

The patient was transferred for urgent angio which showed:
  • Left main 40% ostial lesion
  • LAD diffuse disease with severe mid disease and severe distal disease - PCI with DES x 2
  • Cx severe ostial
  • RCA Diffuse mild-mod disease
Post procedure echo:
  • Mod-severe segmental dysfunction with extensive anterior wall akinesis - EF 37%
  • No significant valvular dysfunction
The patient had an uneventful further in-patient stay.
References / Further Reading
 
Life in the Fast Lane
Textbook
  • Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.

ECG of the Week – 2nd January 2016 – Interpretation

The following ECG's are from a 89 yr old male who presented with worsening dizziness and light-headedness. Clinical examination revealed postural hypotension. He is on no medication.




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Key features:

  • Mean ventricular rate ~48 bpm
  • Mean atrial Rate ~84bpm
  • 2:1 AV block
  • LBBB Morphology
    • Sgarbossa negative


Click to enlarge
Key features:

  • Mean ventricular rate 30 bpm
  • Mean atrial rate 102 bpm
  • Complete heart block
    • AV Dissoication
    • Atrial rate > ventricular rate
  • Complexes #1 & #4 
    • LBBB Morphology - same as ECG above 
  • Complexes #2, #3, & #5
    • RBBB Morphology
    • Deep T wave inversion leads V1-3
    • ? Cardiac T wave memory
Pacemaker Insertion Indication

This patient has a clear indication for PPM insertion given the AV block seen on the ECG's. However even in the absence of AV block the second ECG also has another indication for PPM insertion. The second ECG also shows bilateral bundle branch block, evidence of both RBBB and LBBB, this is clear evidence of disease in all 3 fascicles and is a Class I recommendation for PPM insertion (as per 2012 AHA Guidelines).

What happened ?

The patient was admitted under the cardiology team and placed on an isoprenaline infusion. He underwent subsequent single chamber pacemaker insertion and was discharged following a brief in-patient stay.

References / Further Reading

Life in the Fast Lane

Textbook
  • Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.

    ECG of the Week – 26th December 2016 – Interpretation

    The following ECG is from a 36 yr old male who presented with chest pain and dysponea.





    Click to enlarge
    Rate:
    • 54 bpm
    Rhythm:
    • Regular
    • Sinus rhythm
    Axis:
    • Right axis deviation / Inferior
    Intervals:
    • PR - Normal (~160ms)
    • QRS - Normal (80ms)
    • QT - 480ms (QTc Bazette 455 ms)
    Segments:

    • Nil change in interpretable leads

    Additional:

    • Significant high frequency baseline artifact
      • Maximal in precordial leads
      • Obscures P wave, T wave, PR segment, ST segment and baseline
    • P inversion aVL 
      • Pattern not consistent with lead reversal
      • Normal P wave axis in other leads

    Interpretation:

    • High frequency artifact
    • Unable to fully interpret ECG due to artifact but likely normal


    Troubleshooting artifact

    There are multiple factors that can generate artifact during the ECG recording / printing process including:

    • Patient factors
      • Habitus - very thin or obese patients, paediatric patients
      • Poor pad contact due to hair
      • Poor pad contact due to moisture - sweating, immersion etc.
      • Movement artifact - tremor, resp pattern, agitation, shivering, rigor
    • Lead factors
      • Poor pad contact
      • Pad misplacement
      • Damaged lead or lead connection
    • ECG Machine Factors
      • Inappropriate settings of gain or filtering modes
      • Electrical artifact from power supply
    • Printing factors
      • Low ink
      • Print head tracking
      • Paper alignment
    • External factors
      • Electrical interference from other devices - mobile phones, diathermy, computers etc.
    An awareness of these factors and a systemic approach to addressing each point in the recording process, from patient to printer, is important in addressing recording problems such as artifact and lead malpositioning. 


    References / Further Reading

    Textbook

    • Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.