Effects of Dantrolene on Arrhythmogenicity in Isolated Regional Ischemia-Reperfusion Rabbit Hearts with or without Pacing-Induced Heart Failure

Table 1

Electrophysiological effects of dantrolene in isolated Langendorff-perfused hearts after IR injury in the HF and non-HF groups.

	(cm/s)	(cm/s)	(cm/s)	(cm/s)	(ms)	(ms)	(ms)	ERP; (ms)	(Hz)	APDR; slope	decay; () (ms)
HF ()
Baseline	72 ± 12	68 ± 11	63 ± 11	55 ± 9	157 ± 16	130 ± 11	108 ± 10	161 ± 27	14.2 ± 1.3	1.14 ± 0.17	69 ± 12
Dantrolene	67 ± 10^*	61 ± 11^*	55 ± 10^*	47 ± 6^*	169 ± 20^*	135 ± 12^*	110 ± 8^*	182 ± 12^*	11.3 ± 1.5^*	1.34 ± 0.24^*	72 ± 10
Non-HF ()
Baseline	81 ± 7	76 ± 9	70 ± 9	64 ± 8	148 ± 9	125 ± 9	107 ± 12	142 ± 11	13.0 ± 1.7	0.97 ± 0.19	66 ± 8
Dantrolene	73 ± 11^*	67 ± 11^*	61 ± 12^*	55 ± 11^*	160 ± 14^*	134 ± 11^*	112 ± 12^*	170 ± 10^*	10.4 ± 1.5^*	1.19 ± 0.30^*	67 ± 8

Values are mean ± SD. , , and , action potential duration at pacing cycle lengths of 300, 200, and 150 ms; , , , and , conduction velocity at pacing cycle lengths of 300, 200, 150, and 120 ms; : the maximal dominant frequency of ventricular fibrillation; Ca_i: intracellular ; ERP: effective refractory period; APDR slope: the mean maximum slope of APD restitution curves.
Asterisks denote values significantly different from the baseline.