ECG of the Week – 14th August 2017 – Interpretation

The following ECG is from a 74 yr old male who presented with suspected cardiac chest pain.





Click to enlarge
Rate:
  • 103 bpm
Rhythm:
  • Regular
  • Abnormal P wave preceding each QRS
  • P wave inversion leads II, III, aVF, V3-6
  • Positive P wave in lead aVR and V1
Axis:
  • Normal
Intervals:
  • PR - Short (~100ms)
  • QRS - Normal (80ms)
  • QT - 330ms (QTc Bazette 430 ms)
Additional:

  • Early R wave transistion
  • Very flat T waves through-out

Interpretation:

  • Ectopic Atrial Tachycardia

The ECG machine failed to recognize the abnormal P wave axis instead reading the ECG as showing delta waves in leads V5-6 and II due to relatively short pr with superimposed p inversion trailing into the QRS. 
Remember always look at the ECG yourself, don't trust the machine and take the ECG to the bedside.

What happened ?


The patient was admitted under the cardiology team for further investigation of suspected ACS. Coronary angiogram showed diffuse non-obstructive coronary disease for medical management. Following commencement of beta-blocker therapy the patient's ECG reverted to normal sinus rhythm with unchanged QRS morphology. 

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 – 7th August 2017 – Interpretation

The following ECG is from a 59 yr old female who presented to the Emergency Department complaining of palpitations.





Click to enlarge
Rate:
  • Mean ventricular rate 144 bpm
Rhythm:
  • Irregular
  • Nil regular P waves visible
  • Notching terminal QRS complexes #8 and #9 in aVF 
    • ? fibrillation waves ? Retrograde P ? SA activity
Axis:
  • Normal
Intervals:
  • QRS - Normal
Additional:
  • ST Depression leads II, III, aVF, V3-6
  • ST elevation lead aVR
  • T wave inversion leads II, III, aVF

Interpretation:

  • Atrial fibrillation
    • Rapid ventricular response
    • ST / T wave changes likely rate-related demand ischaemia

Clinical Factors in Atrial Fibrillation

There are several features to establish on assessment of the patient in atrial fibrillation that will influence both the immediate and long-term management strategies, including:

  • Onset and duration of symptoms
  • Likelihood of paroxysmal episodes
  • Evidence of compromise from AF
    • Chest pain, cardiac failure, hypotension etc.
  • Current medications
    • Especially anti-coagulation and anti-arrhythmics
  • Potential precipitant / cause
    • E.g. sepsis, electrolyte abnormality, endocrine disease
  • Suitability and contra-indications to management options
    • E.g. fasting status, anaesthetic risk, drug allergy / intolerance, bleeding risk

Management Options in Atrial Fibrillation

There are several considerations in the management of AF which include:
  • Rate vs. rhythm control
    • Electrical vs Chemical rhythm control
  • Anti-coagulation
    • Risk vs Benefit
    • Drug to use
  • ? Underlying precipitant
    • Infection / ischaemia / structural / endocrine / metabolic etc.
  • Follow-up / disposition
  • Ablation suitability
Despite being one of the commonest arrhythmia encountered in medicine there is considerable variability in the clinical management of atrial fibrillation. There are a number of international guidelines and protocols regarding AF management, including:
AF Related Calculators (links to MDCalc)
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.