Background: Prolongation of the peak and the end of T wave (Tp-e) has been reported to be associated with ventricular arrhythmias. Tp-e/QT ratio and Tp-e/QTc ratio are used as an index of ventricular arrhythmogenesis. An increased incidence of ventricular arrhythmias has been reported in patients with obstructive sleep apnea (OSA). The aim of this study was to assess ventricular repolarization in patients with OSA by using Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio.Methods: We have studied 72 patients who underwent overnight polysomnography (PSG) between the years 2010-2011 at our institution. Patients with moderate and severe OSA (23 patients; mean age: 45 ± 10), according to the apnea-hypopnea index, constituted the study group. Patients with normal PSG (23 patients; mean age: 42 ± 11) were used as the control group. In all patients, Tp-e interval, Tp-e/QT ratio, Tp-e/QTc ratio, as well as some other electrocardiogram intervals were measured. Independent samples t-tests were used for comparison of continuous and categorical variables and correlations were calculated by Spearman rank correlation.Results: Although QT and QTc intervals were not different between the groups, mean Tp-e interval (81.6 ± 11.1 msn; 63.9 ± 7.3 msn; respectively; P < 0.001), Tp-e/QT ratio (0.21 ± 0.03; 0.17 ± 0.02; respectively; P < 0.001), and Tp-e/QTc ratio (0.20 ± 0.03; 0.16 ± 0.02; respectively; P < 0.001) were prolonged in the study group compared to the control group. Correlation analysis showed a significant positive correlation between the presence of moderate and severe OSA and Tp-e interval (r = 0.72; P < 0.001), Tpe/QT ratio (r = 0.70; P < 0.001), and Tp-e/QTc ratio (r = 0.70; P < 0.001). Conclusions:Address for reprints: Alptug Tokatli, M.D., GATA Haydarpasa Egitim Hastanesi, Kardiyoloji servisi, Uskudar-34668; Istanbul, Turkey. Fax: 90 0 212 296 75 12;

BackgroundType 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.MethodsForty-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.ResultsMean 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.ConclusionTp-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.

The results show that chronic cigarette smoking is associated with a prolonged Tp-e interval, increased Tp-e/QT ratio and Tp-e/QTc ratio. These observations may indicate that there may be a relationship between smoking and altered ventricular repolarization. Abnormal ventricular repolarization values on an ECG may explain the increased cardiovascular event risk in long-term heavy cigarette smokers.

The LV diameters and volumes of patients with classic bileaflet MVP were found to be increased even in the absence of significant MR. These results need to be supported by large-scale clinical studies.

Cutaneous analgesia before TRA for coronary interventions is associated with a substantial reduction in the RAS and the procedure-related level of patient discomfort.