Table 1. Patch clamp IC₅₀ values for block of cardiac ion channels by Vx ^a.

Vx Concentration-Response Relationship
Channel		Hz	Test Pulses / Minute	Cell Line	IC50 (μM)
hKv11.1 (IKr)		0.1	6	HEK-293	0.00084 (n=3-8)
ICa,L		0.05	3	ventricular myocyte	0.32 (n=2-4)
hCav3.2		0.1	6	HEK-293	2.0 b
hNav1.5 (INa)		0.1	6	HEK-293	0.83 (n=2-5)
hKv1.5 (IKur)		0.1	6	HEK-293	1.0 (n=2-3)
rKv4.3	(Ito peak)	0.067	4	L	9.8
	(Ito 70 ms)	0.067	4	L	2.0 (n=2-3)
hKv7.1/hKCNE1 (IKs)		0.067	4	CHO	2.9 (n=3-5)

^aData from 2 or more cells were pooled for IC₅₀ measurements; n indicates the range of replicates from all concentrations used to construct the IC₅₀. See Figure 1 for n at each concentration for hK_v11.1, I_Ca,L and hNa_v1.5.

^bEstimated IC₅₀ from 83% block at 10 μM (n=2).