Table 5.

Arrhythmias elicited by PAF vehicle or by the final concentration of PAF in hearts perfused with Krebs containing elevated K⁺ and/or supplementation with norepinephrine (NA)

Perfusion solution modification	PAF vehicle	100 nmol PAF
	VPB(%)
None	0	91*
K elevated to 8 mM	0	33
K elevated to 15 mM K	0	17
+0.1 μM NA	25	90*
K elevated to 8 mM +0.1 μM NA	17	18
K elevated to 15 mM +0.1 μM NA	75	100
	Bigeminy(%)
None	0	82*
K elevated to 8 mM	0	0
K elevated to 15 mM K	0	17
+0.1 μM NA	0	60*
K elevated to 8 mM+0.1 μM NA	0	0
K elevated to 15 mM+0.1 μM NA	58	75
	Salvo(%)
None	0	55*
K elevated to 8 mM	0	17
K elevated to 15 mM K	0	0
+0.1 μM NA	0	30
K elevated to 8 mM+0.1 μM NA	0	0
K elevated to 15 mM+0.1 μM NA	58	83
	VT(%)
None	0	45*
K elevated to 8 mM	0	0
K elevated to 15 mM K	0	0
+0.1 μM NA	0	20
K elevated to 8 mM+0.1 μM NA	0	0
K elevated to 15 mM+0.1 μM NA	45	58
	VF(%)
None	0	9
K elevated to 8 mM	0	0
K elevated to 15 mM K	0	0
+0.1 μM NA	0	0
K elevated to 8 mM+0.1 μM NA	0	0
K elevated to 15 mM+0.1 μM NA	0	0

Hearts in all groups shown were initially exposed to PAF. The data represent group incidence (%) of arrhythmias during a second exposure to PAF or PAF vehicle. The results shown refer to administration of 100 nmol PAF or identically timed bolus of PAF vehicle (data from Tables 3 and 4). The hearts were perfused with K⁺ and/or NA added to the perfusion solution during the second exposure to PAF (or vehicle); n=12 per group.

^*P<0.05 versus PAF vehicle.