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 (QTc I) at 4 and 6 hr. Maximum post-dose QTc I and changes in PR and QRS intervals were measured. No significant differences in 4- or 6-hr QTc I were seen between hawthorn and placebo. Maximum post-dose QTc 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.