Table 1.

Atrial action potential parameters in response to blebbistatin. C: control; B: blebbistatin; CL: cycle length (msec); MDP: maximum diastolic potential (mV); P_max: maximum upstroke velocity (mV/msec); AP₁₀, AP₅₀ or AP₉₀: action potential duration to 10%, 50% or 90% of repolarization (msec); ERP: effective refractory period (msec). Values are mean ± SEM.

	luM (n=4)			5uM (n=4)			10uM (n=4)
	C	B	P	C	B	P	C	B	P
CL	1254 ± 262	1366 ± 164	0.40	1110 ± 127	1139 ± 106	0.64	1040 ± 125	1163 ± 181	0.18
MDP	−58.9 ± 1.4	−592 ± 2.6	0.81	−52.6 ± 6.3	−53.6 ± 5.0	0.49	−56.2 ± 6.2	−55.7 ± 6.2	0.41
Pmax	5.1 ± 1.4	4.6 ± 1.2	0.28	4.5 ± 0.8	4.3 ± 1.6	0.23	5.6 ± 1.6	4.8 ± 1.0	0.30
AP10	104.3 ± 15.7	115.7 ± 17.9	0.06	90.2 ± 7.2	88.8 ± 6.9	0.78	83.9 ± 7.7	81.8 ± 8.0	0.16
AP50	151.7 ± 20.3	129.0 ± 8.3	0.79	129.0 ± 8.3	126.9 ± 7.9	0.73	121.1 ± 11.8	118.6 ± 12.5	0.14
AP90	195.8 ± 31.4	190.9 ± 27.8	0.76	161.4 ± 15.2	159.8 ± 11.1	0.83	146.2 ± 14.1	146.3 ± 14.6	0.95
ERP							298 ± 13.1	301 ± 11.6	0.22