QRS complex

Cite this article as:
Davis, T. QRS complex, Don't Forget the Bubbles, 2014. Available at:

QRS duration

Prolonged QRS is characteristic of ventricular conduction disturbances:

  • Bundle branch blocks
  • Pre‐excitation conditions (e.g. WPW)
  • Intraventricular block
  • Ventricular arrythmias


High QRS amplitudes are found in:

  • Ventricular hypertrophy
  • Ventricular conduction disturbances e.g. BBB’s, WPW

Low QRS amplitudes are seen in:

  • Pericarditis
  • Myocarditis
  • Hypothyroidism
  • Normal newborns