. 2017 Mar 23;113(7):817–828. doi: 10.1093/cvr/cvx063

Table 1.

Susceptibility to ventricular fibrillation

	Ibutilide (n=7)			SNS (n=6)			Flecainide (n=6)			Ischaemia (n=5)
	Cont	Treat	P value	Cont	Treat	P value	Cont	Treat	P value	Cont	Treat	P value
APD_ss (ms)^a	115±2	132±3	0.010	114±5	102±3	0.045	120±2	137±3	≥0.001	123±2	86±6	0.003
ERP (ms)^a	106±6	125±4	0.007	110±5	93±2	0.031	114±3	131±3	0.005	^*	^*	^*
Max slope^a	1.44±0.13	1.99±0.30	0.045	1.72±0.25	1.32±0.12	0.048	1.49±0.11	2.08±0.38	0.206	1.67±0.24	0.69±0.10	0.019
Min DI (ms)^a	11±2	9±1	0.341	14±3	11±1	0.130	8±3	22±5	0.015	8±2	21±4	0.078
Baseline TAct (ms)	30±3	28±3	0.186	28±2	29±2	0.867	26±3	34±4	0.025	21±1	22±2	0.486
VF susceptibility
Burst—10×30 ms^b	0/28	0/28	>0.99	0/24	12/24	≤0.001	0/24	0/24	>0.99	3/20	12/20	0.008
Burst—60×30 ms^b	22/28	7/28	≤0.001	18/24	20/24	0.723	17/24	0/24	≤0.001	10/20	20/20	≤0.001
Total^b	22/56	7/56	0.002	18/48	32/48	<0.001	17/48	0/48	≤0.001	13/40	32/40	≤0.001

Summary data on the influence of ibutilide, sympathetic nerve stimulation (SNS), flecainide and low-flow ischaemia on action potential duration (APD), effective refractory period (ERP), dynamic restitution parameters and VF susceptibility. Colour coding: red = decrease, green = increase.

Data represent mean ± SEM, where appropriate.

^aPaired Student’s t-test.

^bFisher’s exact test (incidence of VF/number of trials).

P < 0.05 are underlined.

Accurate assessments of ERP could not be made in ischaemic conditions owing to the induction of VF at short coupling intervals.

APD_ss, action potential duration at steady state; DI, diastolic interval; Tact, time from pacing spike to activation of action potential; VF, ventricular fibrillation.