Wednesday, 14 December 2016

ECG of the Week - 12th December 2016 - Interpretation

The following ECG is from a 67 yr old male who was brought to the Emergency Department following an Out-of-Hospital Cardiac Arrest (OOHCA). Return of circulation was achieved pre-hospital following 8 mins of CPR. He has a history of 'heart muscle weakness', T2DM and 'kidney problems'. 



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Rate:
  • 72 bpm
Rhythm:
  • Irregular
  • No organised atrial activity
Axis:
  • Normal
Intervals:
  • QRS - Prolonged (160 ms)
Segments:

  • Minor ST depression leads V5-6

Additional:
  • QRS prolongation without typical BBB pattern
  • Very low voltage
Interpretation:
  • Atrial Fibrillation
  • QRS Prolongation
  • Low voltage

Given the patient's history there are a very broad range of differentials for these ECG findings, including:
  • Chronic cardiomyopathy
  • Chronic atrial fibrillation
  • Pericardial effusion - inflammatory, infective, uraemic
  • ACS - chronic / acute
  • Electrolyte abnormality - never forget K+ especially in patients with known renal impairment
  • Drug toxicity - beta-blocker, calcium channel blocker, digoxin
  • Environmental - hypothermia
  • Multi-factorial

What happened ?

This patient had a combination of issues:

  • Chronic atrial fibrillation
  • Chronic dilated cardiomyopathy - EF 34%
  • Acute on chronic renal - creatinine 235 from baseline 150 umol/L
  • Hyperkalaemia - K 7.6 mmol/L
  • Acidaemia - pH 7.15 HCO3 14 mmol/L
  • Chronic digoxin toxicity

He required inotropic support, volume replacement, digifab/digibind therapy, correction of hyperkalaemia / acidaemia and renal replacement therapy.

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.