Table 4—

QRS duration, PR interval and QTc interval at baseline and following treatment with formoterol (n=23) and terbutaline (n=24)

	Parameter	Formoterol	Terbutaline	Formoterol–terbutaline
	Parameter	Formoterol	Terbutaline	Δ mean	95% CI
QRS duration ms	E₀	86.1	85.4
	E_max	96.0	94.4	1.0	−4.1–6.1
	E_ave	89.0	88.2	0.1	−3.3–3.6
PR interval ms	E₀	128.7	124.1
	E_max	139.8	137.4	0.0	−11.7–11.8
	E_ave	126.7	122.4	1.0	−6.4–8.5
QTc interval ms	E₀	419.2	417.8
	E_max	464.9	474.3	−9.4	−34.0–15.1
	E_ave	437.4	437.3	0.0	−11.9–12.0

Data are presented as mean unless otherwise stated
^#: results from analysis of variance
E₀: value recorded at time zero
E_max: maximum value
E_ave: 12-h average value
CI: confidence interval