Evaluation of Tp-e interval, Tp-e/QT ratio and Tp-e/QTc ratio in patients with acute myocarditis

Acute myocarditis (AM) can be defined as an inflammatory disease of the myocardium and characterized by large heterogeneity of clinical presentation. Myocarditis is becoming increasingly recognized as a contributor to unexplained mortality, and is thought to be a major cause of sudden cardiac death in the first two decades of life. The present study aimed to search the assessment of repolarization dispersion measured from the 12-lead surface electrocardiogram (including Tp-e interval, Tp-e/QT and Tp-e/QTc ratios) in AM patients.

Totally 56 patients (mean age was 22 ± 3.7 years and 67% of the patients were male) with AM and 56 control subjects (23 ± 4.7 years and 64% of the patients were male) were enrolled. Tp-e intervals, Tp-e/QT and Tp-e/corrected QT (QTc) ratios were calculated from 12-lead electrocardiogram.

Heart rate, QT and QTc values were similar between groups. QRS interval was lower in AM group compared to the control group (p <  0.001). Tp-e, Tp-e/QT and Tp-e/ QTc were significantly higher in AM group (p <  0.001, p <  0.001, p = 0.03 respectively) and they were significantly correlated with high troponin and high sensitive C reactive protein levels. In hospital follow-up time was 6 ± 2 days. Four patients have non sustained ventricular tachyarrhythmias and 1 patient dead because of cardiac arrest.

Our study demonstrated that Tp-e intervals, Tp-e/QT and Tp-e/QTc ratios were higher in patients with AM than control subjects. The increased frequency of ventricular arrhythmias can be clarified by increased indexes of ventricular repolarization parameters in patients with AM.