Acute effects of synthetic cannabinoids on ventricular repolarization parameters

OBJECTIVE
An association between ventricular repolarization parameters (VRPs) and ventricular arrhythmias has been demonstrated in previous studies. However, there are limited data related to a relationship between synthetic cannabinoids (SCs) and VRPs. The aim of this study was to analyze the acute effects of SCs on VRPs using electrocardiogram (ECG) measurements of the T-peak to T-end interval (Tp-e), Tp-e/QT ratio, and Tp-e/corrected QT (QTc) ratio.

METHODS
The present study included 58 patients who were admitted to the emergency department who used SCs (SC +) between 2014 and 2016, and 50 healthy control subjects (SC -). The QT and QTc intervals, Tp-e interval, Tp-e/QT, and Tp-e/QTc ratios were measured from a 12-lead ECG. These parameters were compared between groups and correlation analysis was performed.

RESULTS
The Tp-e and QTc intervals were significantly higher in SC + patients when compared with the SC- group (92.2±10.0, 77.4 ±9.3, p<0.001; 434.5±30.8, 410.9±27.3, p<0.001, respectively). Tp-e/QT and Tp-e/QTc ratios were greater in SC + patients in comparison with SC – participants (0.26±0.02, 0.22±0.02, p<0.001; 0.21±0.02, 0.18±0.02, p<0.001, respectively). Significant correlations were found between the use of SCs and the Tp-e interval (r=0.610; p<0.001), Tp-e/QT (r=0.655; p<0.001) and Tp-e/ QTc ratios (r=0.437; p<0.001).

CONCLUSION
The Tp-e interval, Tp-e/QT and Tp-e/QTc ratios were greater in subjects who used SCs. Therefore, SC users might have an increased risk of ventricular arrhythmia.