ECG of the Week – 20th February 2017 – Interpretation

The following ECG is from a 20 yr old male who was brought to the Emergency Department following a motorbike accident in which he sustained a head injury. 
He has a GCS of 3, BP 160 systolic and divergent pupils.

Click to enlarge

  • 96 bpm
  • Regular
  • Sinus rhythm
  • Right axis deviation
  • PR - Normal
  • QRS - Normal
  • ST Depression leads II, III, aVL, V3-6
  • ST Elevation aVR & aVL
  • Biphasic T wave in leads V3-4

Remember the ECG is a test that must be taken to the bedside

In a young trauma patient with significant ST segment and T wave changes there are three main considerations:

  • Traumatic Brain Injury causing ECG changes
  • Blunt chest injury causing ECG changes
  • Cardiac event precipitating accident
    • ? Drug ingestion / vasospasm
    • ? Coronary dissection

In this patient there was no suspicion of a proceeding medical event precipitating the event and no evidence of blunt chest injury including clinical features, plain imaging and bedside USS assessment. The patient had sustained an isolated catastrophic head injury which was unfortunately unsurvivable.

Blunt Cardiac Injury

The American Association for the Surgery of Trauma has a very nice overview of blunt cardiac injury here:

ECG Changes Associated with Neurological Pathology

ECG changes are well described in the setting of neurological pathology, especially subarachnoid haemorrhage. but can occur in traumatic brain injury. There following is a nice overview of pathophysiology and outcome effects of cardiovascular abnormalities associated with brain injury:

References / Further Reading

Life in the Fast Lane

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

ECG of the Week – 13th February 2017 – Interpretation

This ECG is from a 91 yr old female who presented to a rural medical center, 260 km (160 miles) from the nearest tertiary hospital, complaining of weakness and difficulty standing. 

ECG on presentation
Click to enlarge
Key features:
  • Bradycardia rate 30 bpm
  • Nil atrial activity visible
  • Normal axis
    • Close to -30 deg with near isoelectric lead II
  • Narrow QRS
    • Similar morphology to old ECG below
  • Late R wave transition
  • T wave inversion leads V2-3
    • New compared with old ECG

ECG from 1 year prior
Click to enlarge

Key features:
  • Sinus rhythm, rate 60 bpm
  • Left axis deviation
  • PR prolongation
  • QRS narrow
  • Voltage criteria for LVH in lead aVL
  • Junctional bradycardia
    • New T wave changes
    • Nil evidence atrial activity
There are broad causes for the clinical picture and new ECG changes that need to be considered in these cases:

  • ACS
    • New anterior T wave change but nil history of chest pain
    • No significant ST segment changes
  • Structural disease
    • Cardiomyopathy
    • Valvular disease
  • Electrolyte abnormality
    • Hypokalaemia - can cause ECG changes and clinical weakness
    • Hyperkalaemia - can cause almost any ECG abnormality
  • Drug toxicity
    • Consider digoxin, calcium channel blockers, beta blockers
    • Usually chronic toxicity in the elderly but can be acute
    • May be seen with worsening of other co-morbidities especially renal failure / chronic kidney disease
  • Environmental / Endocrine
    • Hypothermia
    • Thyroid Dysfunction - hypo or hyper
  • Inflammatory / Auto-immune
    • Pericarditis
    • Myocarditis
    • Sarcoidosis
    • SLE 
    • Lyme disease
  • Idiopathic / Age Related
  • High vagal tone states
    • Usually transient
    • Vomiting
    • Pain
    • Under anaesthetic

References / Further Reading

Life in the Fast Lane

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