QRS wave
Last reviewed 07/2023
The normal QRS complex has four characteristics:
- the duration of the QRS complex is no greater than 0.12 seconds (3 small squares)
- in a right ventricular lead (V1) the S wave is greater than the R wave
- the height of the R wave in the left ventricular leads (V5, V6) is less than 25 mm
- Q waves due to septal depolarisation may occur in the left ventricular leads (V5, V6) but these are less than 1 mm across and less than 2 mm deep