Non-cardiac ECGs

• Hypokalaemia:

  • ST depression
  • prominent U waves
  • Prolonged PR interval
  • T wave flattening and inversion
• Hypokalaemia is often associated with hypomagnesaemia
• Hyperkalaemia:

  • First change - narrowing and peaking of the T wave
  • Prolonged PR interval and then P waves disappear
  • Widening of QRS complexes - lead to sine wave pattern
• Hypercalcaemia:

  • Shortens ventricle repolarization = shortens QT interval
  • Widens and rounds T wave
• Hypocalcaemia:

  • Lengthens ventricular repolarization = prolonged QT interval
• Signs and symptoms of hypomagnesaemia:

  • Tremor
  • Tetany
  • Seizures
  • Weakness
  • Delirium
  • Coma
• Hypomagnesaemia causes resistance to PTH and causes hypocalcaemia

  Hypomagnesaemia on an ECG = QT prolongation
• Pericarditis:

  • Widespread saddle shaped ST elevation
  • PR depression
• Pulmonary embolism:

  • Most common - sinus tachycardia
  • New RBBB
  • Right ventricular strain
  • S1Q3T3 pattern