Prolonged QT and Tp-e intervals in male substance abusers: insights from a cross-sectional study

Substance abuse poses a significant global health challenge, particularly due to its adverse effects on the cardiovascular system. This study investigates the association between substance abuse and electrocardiogram (ECG) parameters, specifically the QT interval, corrected QT (QTc) interval, and the novel Tp-e interval, to assess potential arrhythmogenic risks.

In this cross-sectional study, we included 126 male substance abusers and 126 age-matched substance-free male controls. Standard 12-lead ECGs were used to measure QT, QTc (corrected by Bazett and Friedrich methods), and Tp-e intervals. Statistical analyses compared these ECG parameters between the two groups and identified risk factors for QT prolongation.

Substance abusers predominantly used methamphetamine, heroin, and synthetic cannabinoids. Compared to controls, substance abusers exhibited significantly longer QT, QTcB (Bazett), and QTcF (Friedrich) intervals. Methamphetamine users had the longest QTcB, followed by heroin and synthetic cannabinoid users. Multivariate logistic regression identified age, methamphetamine use, multiple substance use, duration of synthetic cannabinoid use, and frequency of heroin use as significant predictors of QTcB > 450 ms.While Tp-e intervals did not differ significantly between groups, the corrected Tp-ec interval was longer in substance abusers.

Substance abuse is linked to prolonged QT and QTc intervals, highlighting an elevated risk of arrhythmias. The corrected Tp-e interval may provide a more sensitive measure of repolarisation heterogeneity in substance abusers, necessitating further research and clinical monitoring.