ABSTRACT
BACKGROUND: Type 2 diabetes mellitus (T2DM) is associated with increased risk of malignant ventricular arrhythmias. Cardiac electrical inhomogeneity may be the leading cause of the increased arrhythmic risk in patients with T2DM. The peak and the end of the T wave (Tp-e) interval and associated Tp-e/QT ratio are promising measures of ventricular repolarization indicating transmural dispersion of repolarization. The aim of this study was to assess ventricular repolarization in patients with T2DM by using Tp-e interval, Tp-e/QT ratio and Tp-e/corrected QT interval (QTc) ratio. METHODS: Forty-three patients with T2DM and 43 healthy control subjects, matched by gender and age, were studied. All participants underwent electrocardiography (ECG) recording. PR, RR and QT intervals represents the ECG intervals. These are not abbreviations. In all literature these ECG intervals are written like in this text. Tp-e intervals were measured from 12-lead ECG. Rate QTc was calculated by using the Bazett's formula. Tp-e/QT ratio and Tp-e/QTc ratio were also calculated. RESULTS: Mean Tp-e interval was significantly prolonged in patients with T2DM compared to controls (79.4±10.3, 66.4±8.1 ms, respectively; P<0.001). We also found significantly higher values of Tp-e/QT ratio and Tp-e/QTc ratio in patients with diabetes than controls (0.21±0.03, 0.17±0.02 and 0.19±0.02, 0.16±0.02, respectively; P<0.001). There was no difference in terms of the other ECG parameters between the groups. CONCLUSION: Tp-e interval, Tp-e/QT ratio and Tp-e/QTc ratio were prolonged in patients with T2DM. We concluded that T2DM leads to augmentation of transmural dispersion of repolarization suggesting increased risk for ventricular arrhythmogenesis.
Subject(s)
Humans , Abbreviations , Arrhythmias, Cardiac , Diabetes Mellitus , Diabetes Mellitus, Type 2 , ElectrocardiographyABSTRACT
Background: Risk stratification of patients with acute pulmonary embolism (PE) allows assessment of individual prognosis and guides therapeutic decision making. Several electrocardiographic (ECG) markers measuring the arrhythmogenic substrate(s) in ventricular myocardium are used to identify the high-risk patients with acute PE. However studies on Tp-e/QT ratio in patients with acute PE are lacking therefore the present study is aimed to evaluate the in hospital prognostic significance (death and in hospital adverse clinical events [ACE]) of Tp-e/QT ratio at admission in acute PE patients. Materials and methods: This was a retrospective study that included adult patients who had been diagnosed with acute PE and were treated at our hospital between January 2012 and March 2016. After considering inclusion and exclusion criteria, data was collected from eligible patients. All ECG recordings were digitalized and evaluated by a computer based program. Tp-e and QT intervals were measured from all precordial leads and mean value is calculated. Statistical analysis was performed using SPSS 17.0. Receiver operator characteristic (ROC) curves were computed for the Tp-e/QT ratio to assess the optimal cutoff values for predicting mortality and ACE. Univariate logistic regression analysis for the predictors of in hospital events (death and in hospital ACE) in the study population was done. The statistical significance was considered for a p-value <0.05. Results: A total of 48 patients were included in the study with mean age of 37.95 years (±13.86) and male: female ratio of 1.18:1. Patients with pulmonary embolism have mean Tp-e/QT ratio of 0.25 and the range of Tp-e/QT ratio was 0.18 to 0.29. In regression analysis, a Tp-e/QT ratio ≥0.26 increased the risk of death (P = 0.03) and a Tp-e/QT ratio ≥0.25 increased the risk of ACE (P = 0.01) significantly.
ABSTRACT
Objective To detect Tp-e/QT ratio in patients with acute ST-segment elevation myocardial infarction (STEMI) and explore its clinical significance. Methods Healthy individuals and patients with acute STEMI were recruited in this study. Their first QTc,QTd and Tp-e were measured within 24 h after admission to hospital,and Tp-e/QT ratio was calculated so as to analyze the relation between Tp-Te/QT ratio and malignant ventricular arrhythmia. Results Compared with those of the healthy individuals,the intervals of QTd,Tp-e and QTc were significantly lengthened \[(33.66?16.76)ms vs. (55.29?31.12)ms,(89.55?12.61)ms vs. (142.65?39.33)ms,and (426.57?65.03)ms vs. (482.26?48.03)ms,P