Electrocardiographic effects of hawthorn (Crataegus oxyacantha) in healthy volunteers: A randomized controlled trial

The objective of this study was to evaluate the electrocardiographic effects of hawthorn in healthy adult volunteers. It was double-blind cross-over trial randomized 20 healthy adult volunteers to receive either a single oral 160-mg dose of hawthorn or matching placebo. Triplicate 12-lead electrocardiograms were taken before treatment and at 1-, 2-, 4-, and 6-hr post-dose. Following at least a 7-day washout period, participants were crossed over to the opposing treatment arm and had the measurements repeated. The primary endpoint was the change in corrected (Fridericia) QT intervals (QT_c I) at 4 and 6 hr. Maximum post-dose QT_c I and changes in PR and QRS intervals were measured. No significant differences in 4- or 6-hr QT_c I were seen between hawthorn and placebo. Maximum post-dose QT_c I in the hawthorn and placebo groups were similar (346 ± 35 vs 346 ± 40 ms; p = .979). No significant adverse events were seen. In conclusion, a single dose of oral hawthorn had no effect on electrocardiographic parameters in healthy volunteers.