Arsenic induces cardiac rhythm dysfunction and acylcarnitines metabolism perturbation in rats

Arsenic has been shown to cause various diseases (such as blackfoot disease, cardiovascular diseases, bladder cancer and skin cancer) in many areas of the world. However, the effects of arsenic on cardiac rhythm functions still lack investigation.

In this study, different concentrations of arsenic were orally applied to Sprague Dawley rats in order to examine the relationship between arsenic and cardiovascular rhythm (i.e. long QT) via electrocardiography measurement. In addition, QT correction formulas were used to correct the QT interval. Linear regression analysis was used to examine the correlation between the QT interval and cardiac cycle length, corrected QT and heart rate. A metabolomic approach was applied to study carnitine-derived metabolites under arsenic exposure by using an ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS) system.

The present findings showed that exposure to arsenic causes QT and corrected (QTc) prolongation and heart rate declines. However, the linear correlation analysis showed that there is no significant correlation between cardiac cycle length and the QT interval in both the uncorrected QT and corrected QT. The expression of acylcarnitine metabolites can be used to discriminate the control and arsenic-treated groups.

This study provides information concerning the effect of arsenic at different concentrations on cardiac rhythm (such as QT, QTc, and heart rate) but not on cardiac cycle length. The metabolism of acylcarnitine metabolites can be a potential pathway for arsenic-induced cardiac rhythm dysfunction in rats.