Valproic acid: Does it have an antiarrhythmic action?

Objective: The antiepileptic sodium valproate (valproic acid; VPA) is thought to possess an antiarrhythmic action. We aimed to explore whether this medication influences cardiac atrial ectopics or not. Methods: From December 1, 2009 to June 1, 2011, 80 consecutive patients who were newly diagnosed with cryptogenic generalized tonic-clonic seizures were enrolled in this prospective short-term longitudinal observational study, which was conducted at the Sulaimaniya General Teaching Hospital, Iraq. Forty patients were allocated to receive VPA and the rest (n=40) were given placebo. All patients underwent cardiac 24-hour Holter monitoring before and after one week of VPA or placebo administration. The minimum heart rate (MiHR) and maximum heart rate (MxHR) as well as the total number of atrial ectopics (TNAE) were evaluated. Results: VPA significantly reduced the MiHR, MxHR, and the TNAE. In the placebo group, the reduction in the MiHR was statistically significant while the reduction in the MxHR and the TNAE were not. However, the reduction in the target parameters in the VPA-treated group did not demonstrate a dose-dependent effect. When both groups were evaluated head-to-head for the reduction in the MiHR before and after week of therapy, there was no statistically significant difference between them. Conclusion: Sodium valproate therapy appears to be effective against atrial ectopic beats and may be used as an antiarrhythmic medication in patients who co-experience seizures and troublesome atrial ectopics. [Cukurova Med J 2013; 38(4.000): 592-600]