Table 4.3 Measurements of the normal complex and interval duration

---

Guideline normal values for ECG wave and

complex durations and intervals IY lead)

	Duration	No. small boxes
	(sec)	(25 mm/sec)
P wave	< or = 0.16	4.0
PR interval	< or = 0.5	12.5
QRS complex	< or = 0.14	3.5
QT interval	< or = 0.6	15.0