Association of Tp-Te/QT Ratio With Ventricular Tachycardia in Patients With Idiopathic Outflow Tract Ventricular Premature Contraction

Abstract

BackgroundIdiopathic outflow tract ventricular premature contraction (VPC) can evolve into ventricular tachycardia (VT) via triggered activity mechanism. Transmural dispersion of repolarization (TDR) might play a role in idiopathic outflow tract VT by inducing phase 2 early afterdepolarization (EAD) and serve as the functional substrate for VT. Tp-Te/QT ratio as an arrhythmogenesis index has been reported to be associated with the incidence of ventricular arrhythmia. This study aims to investigate the association between Tp-Te/QT ratio with VT incidence in idiopathic outflow tract VPC.MethodsObservational research with cross sectional design was conducted. VT episodes were retrospectively tracked from electrocardiogram (ECG), treadmill test (TMT), Holter monitor and electrophysiology study data in Sardjito Hospital of patients with idiopathic outflow tract VPC during September to October 2017. Tp-Te/QT was defined as the time from the peak of T wave to the intersection between the tangent and isoeectric line, divided with QT interval. Tp-Te/QT ratio measurement was performed in leads V4, V5 and V6 by single observer. Tp-Te/QT ratio was categorized into increased (> 0.25) and normal (< 0.25). Chi-square and logistic regression test were performed.ResultsOut of 46 patients, there were 28 patients who had VT. Increased Tp-Te/QT ratio of lead V4 was found in 11 patients, the increased ratios in leads V5 and V6 were found in 13 patients. The prevalence ratio (PR) of Tp-Te/QT ratio to VT incidence in lead V4 was 2.059 (95% CI: 1.464 - 2.895; P = 0.007), while in leads V5 and V6 was 2.200 (95% CI: 1.514 - 3.197; P = 0.002). Tp-Te/QT ratios in leads V4, V5 and V6 were not significantly different and equally strong in predicting VT events (P < 0.001; 95% CI). Adjustment of confounding factor hypertension with multivariate test gave insignificant results (PR: 1.290; 95% CI: 0.444 - 3.747).ConclusionsIncreased Tp-Te/QT ratio in idiopathic outflow tract VPC patients was associated with higher prevalence ratio for VT, although this was affected by hypertension. Leads V4, V5 and V6 were equally strong in predicting VT events.

Effect of Smokeless Tobacco (Maras Powder) on the Epicardial Fat Thickness and Ventricular Repolarization Parameters

“…In addition, it is thought that MP may cause malignant arrhythmias and sudden death, similar to some studies conducted with smoking. Changes in the distribution of transmural repolarization may play a role in this process [ 16 ]. This study aimed to show the relationship between MP use and new ventricular repolarization parameters and EFT, which have not been reported before.…”

“…This interval is called the Tp-e interval. Prolongation of the Tp-e interval has been associated with ventricular arrhythmias and increased sudden cardiac death [ 16 ]. In this study, the Tp-e interval was higher in the MP group.…”

Association between ventricular premature contraction burden and ventricular repolarization duration

“…QRS-T angle is defined as the angle between the QRS axis and T-wave axis 13 , 14 . Widened QRS-T angle predicts abnormal depolarization and repolarization, in situations with abnormal electrical activation including ischemia, bundle branch block, and left ventricular hypertrophy 21 . There is a limitation in the use of spatial QRS-T angle in clinical practice as a result of difficulties in the calculation.…”

Evaluation of Tp-e Interval and Tp-e/QTc Ratio among Patients with Steady State Sickle Cell Disease

“…Recently, the interval from the peak to the end of T wave (T peak-Tend interval [Tp-e]) has been proposed for use in the prediction of malignant arrhythmia in SCD [10] [11] [12] [13]. Previous canine and rabbit left ventricular wedge models have indicated that the Tp-e interval in an electrogram was measured across the wedge correlates well with the transmural dispersion of cellular repolarization (TDR) [14].…”