Table 2.

Comparison of the mean heart rate, QTcB, QT and QRS in single-lead ECGs versus leads I and II of 12-lead ECGs

	Single-lead	12-lead ECG
		Lead I	Lead II
Heart rate (/min)
n	125		125
Mean	73		72
SD	13		13
QRS (ms)
n	125	121	122
Mean	85	83	84
SD	8	10	10
QT (ms)
Mean	360	360	369
SD	29	33	32
QTcB (ms)
Mean	393	392	401
SD	25	27	26

QTcB, corrected QT interval by Bazett’s formula.;