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
