Dauricine suppressed CsCl-induced early afterdepolarizations and triggered arrhythmias in rabbit heart in vivo.

AIM: To study the effect of dauricine on CsCl-induced early afterdepolarizations (EAD) and ventricular arrhythmias in rabbits.

METHODS

Monophasic action potentials (MAP) of the left ventricle of the rabbit heart in situ were recorded with MAP recording technique. CsCl 1-2 mmol.kg-1 i.v. was used to induce EAD and ventricular arrhythmias.

RESULTS

CsCl resulted in decrease of MAP amplitude (MAPA, P < 0.05) and prolongation of MAP duration at 90% repolarization (MAPD90, P < 0.01), QRS, and R-R duration (P < 0.05) compared with those before CsCl in the dauricine and control group. CsCl injection induced EAD that appeared within about 30 s and disappeared 5-15 min thereafter. EAD always preceded ventricular arrhythmias including ventricular premature beats and paroxysmal ventricular tachycardia. The EAD amplitude (EADA) in the dauricine group (26% +/- 9% of MAPA) was smaller than that in the control group (52% +/- 5% of MAPA, P < 0.05) and the incidence of arrhythmias in dauricine group (28%) was lower than that in control group (80%, P < 0.05).

CONCLUSION

Dauricine exerted an antagonistic effect on EAD and suppressed triggered ventricular arrhythmias by decreasing EADA.