The assessment of adolescent obesity's effects on ventricular repolarization.

BACKGROUND: Currently, there is a lack of research on the Tp-Te interval and Tp-e/QT ratio in obese adolescents who have metabolic syndrome. AIM: Our study aims to compare established ventricular repolarization parameters with these intervals and ratios in obese adolescents with or without metabolic syndrome, alongside a healthy control group, while exploring the association of these repolarization parameters with cardiovascular risk factors and echocardiographic variables. METHODS: The study included 100 obese adolescents and 50 lean subjects, with the obese participants categorized into two subgroups. The Tp-Te interval was identified as the duration from the peak to the end of the T wave. RESULTS: The metabolic and non-metabolic syndrome obese groups exhibited significantly elevated QTc and TpTe values compared to the control group, with no statistically significant differences observed in minimum QT, maximum QT, QT dispersion, QTc dispersion, TpTe dispersion, and TpTe/QT ratio values among obese subjects with metabolic or non-metabolic syndrome and controls. Specifically, TpTe values were significantly elevated in the non-metabolic syndrome obese groups compared to controls, while minimum TpTe values were significantly elevated in the metabolic syndrome obese groups compared to controls, and the prolongation of the QTc interval was notably elevated in the obese groups than in controls. CONCLUSIONS: Obese adolescents demonstrated an elevated TpTe interval compared to healthy controls, without any significant differences observed in TpTe dispersion, and TpTe/QT ratio values between the two groups. Results of our study showed that a negative correlation between TpTe and HDL-cholesterol and a positive correlation between the TpTe/QT ratio and insulin sensitivity indices in adolescents with metabolic syndrome.

The Tp-e/QT ratio as a predictor of nocturnal premature ventricular contraction events in patients with obstructive sleep apnea.

BACKGROUND: Obstructive sleep apnea (OSA) is significantly associated with a higher risk of ventricular arrhythmia (VA). QT, the Tp-e/QT ratio, and QT dispersion (QTd) are used to evaluate myocardial repolarization and are highly correlated with VA. The aim was to evaluate the predictive value of the Tp-e/QT ratio and other electrocardiogram (ECG) parameters for nocturnal premature ventricular contractions (PVCs) in patients with OSA. METHODS: We retrospectively analyzed data from patients with OSA and conducted a 1:1 matched cohort study. Patients diagnosed with OSA who met our criteria for the PVC group, and sex- and age-matched patients with OSA who met our criteria for the control group were enrolled in the study. The Tp-e, Tp-e/QT ratio, corrected QT interval (QTc), corrected Tp-e interval (Tp-ec), and QTd were measured, calculated and analyzed. RESULTS: Patients in the PVC group (n = 31) showed a greater Tp-e, Tp-ec, QTc, Tp-e/QT ratio, and QTd than patients in the control group (n = 31). In the univariate binary logistic regression analysis, higher Tp-ec (OR: 1.025; P = 0.042), QTc (OR: 1.014; P = 0.036), Tp-e/QT ratio (OR: 1.675; P < 0.001), and QTd (OR: 1.052; P = 0.012) values were all significantly associated with nocturnal PVCs. In multivariate analysis and receiver operating characteristic analysis, a higher Tp-e/QT ratio (OR: 2.168; 95% CI: 0.762-0.952; P < 0.001) was an independent predictor of nocturnal PVCs. CONCLUSIONS: The QTc, Tp-e/QT ratio, and QTd in patients with OSA with nocturnal PVCs were significantly increased compared with those in patients without nocturnal PVCs. A prolonged Tp-e/QT ratio was an independent predictor of nocturnal PVCs in patients with OSA.

The predictive value of electrocardiographic polarization parameters on appropriate ICD shock in primary prevention heart failure patients.

OBJECT: The effect of frontal QRS-T angle, Tp-e and Tp-e/QT ratio on cardiac events have been shown in many studies. In this study, we aimed to determine the prognostic value of frontal QRS-T angle, TPe and Tp-e/QT ratio on ICD shock in patients who had ICD (Implantable Cardioverter Defibrillator) implanted due to heart failure with reduced ejection fraction (HFrEF). MATERIAL AND METHOD: 158 patients with HFrEF who had previous ICD implantation were retrospectively analyzed. 27 patients were found to have an appropriate shock. Frontal QRS-T angle, Tp-e interval, Tp-e/QT ratio were calculated by evaluating the basal ECG records of the patients. Comparisons of these arrhythmogenic predictors were made in patients with and without ICD shock at follow-up. RESULT: When 158 patients with previous ICD implantation were analyzed in two groups with and without ICD shock, the number of patients with frontal QRS-T angle >120°, Tp-e interval > 105 ms, Tp-e/QT > 0.2 in the shock group (n: 27) was found to be high with a different significance (p:<0.01, p:<0.01, p:<0.01). There was no significant difference between the two groups regarding other ECG parameters such as QRS duration, QT interval, PR interval, fragmented QRS and positive T wave. In addition, more amiodarone use was observed in the shock group, and more hyperlipidemia cases were observed in the non-shocked group (p:0.01; p:<0.01). CONCLUSION: Increased frontal QRS-T angle, Tp-e interval, and Tp-e/QT ratio are arrhythmogenic parameters and predict appropriate ICD shock.

Correlation between frontal QRS-T angle, Tp-e interval, and Tp-e/QT ratio to coronary artery severity assessed with SYNTAX score in stable coronary artery disease patients.

Background: It is known that a wide frontal QRS-T(f[QRS-T]) angle in the electrocardiography (ECG) is associated with poor cardiovascular outcomes. The Tp-e (the interval from the peak to the end of the T wave) interval and Tp-e/QTc ratio show the dispersion of repolarization, and increased levels lead to ventricular arrhythmogenesis in congenital channelopathies and coronary heart disease. In this study, we aimed to investigate the relationship between f(QRS-T), Tp-e interval, and Tp-e/QTc ratio and SYNTAX score in stable coronary artery disease (SCAD) patients. Methods: A total of 403 patients who performed coronary angiography for SCAD were included. The study population was divided into two groups based on the SYNTAX score. Group 1 included 248 patients (high SYNTAX score > 0), and group 2 included 155 patients (low SYNTAX score = 0). SYNTAX score was calculated using an online SYNTAX score calculator from the coronary angiography images of each patient. The f(QRS-T) angle (QRS angle minus T angle) was calculated from the automated reports of the 12-lead ECG device. Tp-e interval and Tp-e/QTc ratio and other electrocardiographic parameters were recorded. Results: The mean SYNTAX score in group 1 was 8. F(QRS-T) angle, Tp-e duration, Tp-e/QT, and Tp-e/QTc were significantly higher in group 1 compared with group 2. In the multivariate regression analysis, F(QRS-T) angle and Tp-e duration were independent predictors for SYNTAX scores in SCAD patients. Conclusions: Our study showed that Tp-e interval, Tp-e/QTc ratio, and f(QRS-T) angle were increased in patients with higher SYNTAX scores in patients with SCAD patients.

Association of Tp-e/QT ratio with SYNTAX score II in patients with coronary artery disease.

Background. The SYNTAX score II (SS) is an angiographic tool, which grades the complexity of coronary artery lesions and predicts short- and long-term events. Tp-e/QT ratio is a novel electrocardiographic marker for the risk of ventricular arrhythmias. We aimed to investigate whether there was a correlation between SS and Tp-e/QT ratio.Methods. A total of 227 consecutive patients who underwent elective coronary angiography were enrolled in this study. Patients who had a lumen diameter >1.5 mm and at least % 50 diameter stenosis on coronary angiogram were determined as coronary artery disease (CAD) group, and others were identified as a control group. The SS was calculated for the CAD group, and SS ≥23 was defined as a high SS group, and SS < 23 was identified as a low SS group. Electrocardiographic indices, such as Tp-e and Tp-e/QT, were measured for all patients. A multivariable logistic regression analysis was performed with variables age, interventricular septum thickness (IVS), hypertension, and Tp-e/QT. Results. Tp-e interval and Tp-e/QT ratio were higher in the CAD group compared with the control group. Tp-e, corrected Tp-e (cTP-e) and Tp-e/QT were higher in the high SS group than in the low SS group. The cTp-e and Tp-e/QT were correlated with SS score. Age, IVS and Tp-e/QT ratio were independent predictors of high SS in the logistic regression analysis. Conclusions. Tp-e/QT ratio was an independent predictor of high SS and might be used for risk stratification in CAD patients.

Novel markers of ventricular repolarization are associated with mortality in patients undergoing surgical aortic valve replacement for severe aortic stenosis.

INTRODUCTION: Aortic stenosis (AS) is the most common degenerative valvular heart disease that can affect left ventricular functions. Tp-e interval and Tp-e/QT ratio is a novel repolarization marker which is associated with adverse cardiovascular events in several cardiovascular diseases. In our study, our aim is to investigate the prognostic effect of Tp-e interval, Tp-e/QT and Tp-e/QTc ratios on mortality in patients who underwent successful surgical aortic valve replacement (AVR). METHODS: A total of three hundred seventy-five patients undergoing successful surgical AVR were included in this study. Then, patients were divided into two groups according to mortality as group 1 without mortality (342 patients) and group 2 with mortality (33 patients). Tp-e interval, Tp-e/QT, and Tp-e/QTc ratios were calculated for both groups. RESULTS: Tp-e interval (71 (63.7-77); 86 (84-88), p < .001), Tp-e/QT ratio (0.19 (0.17-0.20); 0.23 (0.22-0.23), p < .001) and Tp-e/QTc ratio (0.17 ± 0.02; 0.21 ± 0.01, p < .001) were higher in group 2 compared to group 1. In multivariate logistic regression analyses Tp-e interval (odds ratio [OR]: 1.315, 95% confidence interval [CI]: 1.203-1.437, p < .001), Tp-e/QT ratio (OR: 7.334, 95% CI: 3.274-1.643, p < .001) and Tp-e/QTc ratio (OR: 2.567, 95% CI: 4.106-1.605, p < .001) were found to be independent predictors of mortality. Additionally, a Kaplan-Meier survival analysis also revealed that long term survival was found to be significantly decreased in patients with higher Tp-e/QT ratio (Log-Rank p < .001) and Tp-e/QTc ratio (Log-Rank p < .001). CONCLUSION: Tp-e interval, Tp-e dispersion, Tp-e/QT, and Tp-e/QTc ratios are associated with worse prognosis after surgical AVR in patients with severe AS. All of them are also independent predictors of mortality.

Effect of dialysis and transplantation on myocardial repolarization parameters and P-wave dispersion in chronic kidney disease.

BACKGROUND: Chronic kidney disease (CKD) patients are at higher risk for cardiac arrhythmias. The risk of arrhythmia may change with different treatment modalities. We proposed to compare the effects of varied therapy methods on myocardial repolarization parameters (Tp-e, QT, QTc intervals, Tp-e/QT, Tp-e/QTc ratios) and P-wave dispersion (PWD) in patients with CKD. METHODS: Three groups were formed from the patients aged between 18 and 65 years, as Group 1 consisting of CKD patients receiving hemodialysis (HD) three times a week, Group 2 consisting of predialysis CKD patients and Group 3 consisting of CKD patients who underwent successful transplantation. All patients' basic demographic data, risk factors, and echocardiographic parameters were recorded, and electrocardiographic repolarization parameters and PWD were analyzed. RESULTS: The PR, QT, and QTc intervals were significantly shorter in the transplantation group compared to the other groups (P = .020, P < .001, P = .035; respectively). Tp-e interval, Tp-e/QT, and Tp-e/QTc ratios were significantly higher in the predialysis group compared to the other groups (P < .001, P < .001, P = .001; respectively), while there was no significant variation between the HD and transplantation groups (P > .05). PWD was significantly increased in the predialysis group compared to other two groups (P < .001), while no significant variation between the HD and transplantation groups was observed. CONCLUSION: We found that the Tp-e interval, Tp-e/QT, Tp-e/QTc, and PWD were significantly higher in the predialysis CKD group, but the PR, QT, and QTc intervals were significantly shorter in the transplantation group compared to the other groups. The prognostic significance and prediction of these parameters in arrhythmic events in CKD patients requires further evaluation with long-time follow-up.

Comprehensive non-invasive assessment of electrocardiographic abnormalities and cardiac arrhythmias in patients with genetically confirmed mitochondrial diseases.

BACKGROUND: There is limited data on cardiac arrhythmias and ventricular repolarization and dispersion abnormalities in patients with mitochondrial diseases (MitD). METHODS: Consecutive 40 patients with genetically proven MitD and 35 healthy controls were studied. Among other examinations all subjects underwent 24-h Holter recording and 12­lead electrocardiography (ECG) with corrected QT (QTc), QT dispersion (QTd), Tp-e and Tp-e/QT ratio assessment. RESULTS: Patients with MitD were 55.4 ± 15.7 years old, the disease duration was 18.5 ± 10.3 years, presented 6 clinical syndromes while mitochondrial and nuclear DNA type of mutation was present in 40 and 60% of cases, respectively. In MitD more frequently 1st degree atrioventricular block and intraventricular conduction defects were observed and also QRS complex duration was increased. Mean values of QTc (p = 0.001), QTd (p = 0.02), Tp-e (p < 0.00001) and Tp-e/QT (p < 0.00001) were significantly higher in MitD than in controls. Correlations between disease duration and PR interval duration (p = 0.003) and Creatine Kinase MB isoenzyme activity (p = 0.02) were found. No differences in depolarization and dispersion parameters were observed according to type of mutation or dominant clinical syndromes. In addition to supraventricular extrasystoles, nonsustained supraventricular tachycardias occurred more frequently in MitD (in 45.0 vs 14.3%, p = 0.0004). Ventricular arrhythmias were rare and observed almost exclusively in subjects with mitochondrial DNA mutation. CONCLUSIONS: In contrast to healthy controls, in MitD patients intraventricular, repolarization and dispersion disturbances were more frequently observed. In addition to bradyarrhythmias observed in some defined MitD syndromes, supraventricular rather than ventricular arrhythmias are more common.

Acute effect of outflow tract premature ventricular complex ablation on QT dispersion, Tp-e interval and Tp-e/QT ratio.

BACKGROUND: There is limited data regarding the effect of idiopathic premature ventricular complexes (PVC) on myocardial repolarisation. Most of PVC's originate from right and left ventricular outflow tracts (RVOT and LVOT). AIM: The aim of this study is to evaluate the acute effect of outflow tract PVC ablation on electrocardiographic repolarisation markers. METHODS: A total of 180 patients (49.2 ± 13.6 years, 74 male) without any exclusion criteria who had undergone outflow tract PVC ablation between 1 January 2015 and 1 November 2018 constituted our study population. Electrocardiographic recordings that had been obtained before and after ablation procedure on the same day were retrospectively evaluated for the QTc dispersion, Tp-e interval, Tp-e/QT ratio and Tp-e/QTc ratio. Significance of difference between pre- and postablation values was tested. RESULTS: There was no significant difference regarding QTc dispersion between pre- and post-ablation state (36.5 ± 20.9 vs. 35.3 ± 16.4 ms, p: NS). However, Tp-e and Tp-e/QT values in all lateral precordial derivations were observed to decrease significantly after PVC ablation (in the respective order on derivation V5: 104.0 ± 21.6 ms vs. 91.1 ± 14.8 ms, p<.001 and 0.26 ± 0.05 vs. 0.23 ± 0.04, p<.001). CONCLUSIONS: Based on these observations, it may be suggested that frequent outflow tract PVC's increase transmural dispersion of repolarisation and this effect is attenuated by catheter ablation in the acute phase. Results of further prospective studies are required for evaluation of the long term effects of PVC ablation on myocardial repolarisation.

The impact of fever on myocardial repolarization parameters.

BACKGROUND: It has been reported in the literature that the increase in body temperature shortens QT interval on electrocardiogram through heart rate modulation. However, the effects of fever on ventricular repolarization are not clearly known. This study elaborates on QT interval of isolated fever, corrected QT (cQT), Tp-e interval, the ratio of corrected Tp-e (cTp-e) and Tp-e/QT, and their impacts on arrhythmia potential. METHODS: This prospective study was performed on 74 patients without any active and chronic diseases other than fever and upper respiratory tract infection. The study included patients at the age of 18-50 years suffering from fever above 38.2 °C. QT and Tp-e intervals of the patients were measured from their ECGs taken in febrile and afebrile periods. cQT and cTp-e values were calculated according to Bazett, Fridericia, and Framingham formulations. RESULTS: QT and Tp-e intervals were observed to be shorter in the febrile period (p < 0.001 and p = 0.006 respectively). cTp-e was found to be longer in the febrile period according to Bazett, Fridericia, and Framingham formulations (p < 0.001, p = 0.002, p < 0.001, respectively). Tp-e/QT ratio was found to be higher in the febrile period than in the afebrile period (p < 0.001). CONCLUSION: Although QT, cQT, and Tpe intervals were shorter, cTpe interval and Tpe/QT ratio were longer and higher in the febrile period, respectively. These findings may indicate that fever may create a proarrhythmic effect by causing variability in the transmural distribution of myocardial repolarization.

Evaluation of inflammatory and cardiac-electrophysiological markers in patients undergoing peritoneal dialysis.

Background: The Tp-e/QT (peak to end of T-wave duration/QT interval) ratio is a promising marker of myocardial repolarization and ventricular arrhythmogenesis. Its elevation is associated with sudden cardiac death in different clinical conditions. This study was designed to assess the possible association between increased Tp-e/QT ratio and clinical factors in peritoneal dialysis patients. Materials & methods: We devised a prospective cross-sectional study, which included 107 patients who were divided into groups according to their Tp-e/QT ratio. The association of an increased Tp-e/QT ratio with related factors was analyzed with multivariate logistic regression. Results: Thirty-one patients, who had an elevated Tp-e/QT ratio, showed higher values of IL-6, left ventricular end-systolic diameter, Tp-e, percentage of diabetes mellitus, coronary artery calcification, and left ventricular ejection fraction. Multivariate analysis revealed that IL-6 was an independent risk factor for a higher Tp-e/QT ratio after adjustments. Conclusion: Our study revealed that a high serum IL-6 level in peritoneal dialysis patients increased the risk of a higher Tp-e/QT ratio, which indicated a potentially hazardous interplay between inflammation and arrhythmogenesis.

Evaluation of electrocardiographic ventricular repolarization variables in patients with newly diagnosed COVID-19.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) is a newly recognized infectious disease that has spread rapidly. COVID-19 has been associated with a number of cardiovascular complications, including arrhythmias. The mechanism of ventricular arrhythmias in patients with COVID-19 is uncertain. The aim of the present study was to evaluate the ventricular repolarization by using the Tp-e interval, QT dispersion, Tp-e/QT ratio, and Tp-e/QTc ratio as candidate markers of ventricular arrhythmias in patients with newly diagnosed COVID-19. In addition, the relationship between the repolarization parameters and the CRP (C-reactive protein) was investigated. METHODS: 75 newly diagnosed COVID-19 patients, 75 age and sex matched healthy subjects were included in the study between 20th March 2020 and 10th April 2020. The risk of ventricular arrhythmias was evaluated by calculating the electrocardiographic Tp-e and QT interval, Tp-e dispersion, corrected QT(QTc), QT dispersion (QTd), corrected QTd, Tp-e/QT and Tp-e/QTc ratios. CRP values were also measured in patients with newly diagnosed COVID-19. RESULTS: Tp-e interval (80.7 ±â€¯4.6 vs. 70.9 ±â€¯4.8; p < .001), Tp-e / QT ratio (0.21 ±â€¯0.01 vs. 0.19 ±â€¯0.01; p < .001) and Tp-e/QTc ratio (0.19 ±â€¯0.01 vs.0.17 ±â€¯0.01; p < .001) were significantly higher in patients with newly diagnosed COVID-19 than the control group. There was a significant positive correlation between Tp-e interval, Tp-e/QTc ratio and CRP in patients with newly diagnosed COVID-19 (rs = 0.332, p = .005, rs = 0.397, p < .001 consecutively). During their treatment with hydroxychloroquine (HCQ), azithromycin and favipiravir, ventricular tachycardia episodes were observed in in two COVID-19 patients during their hospitalization in the intensive care unit. CONCLUSION: Our study showed for the first time in literature that the Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio, which are evaluated electrocardiographically in patients with newly diagnosed COVID-19, were prolonged compared with normal healthy individuals. A positive correlation was determined between repolarization parameters and CRP. We believe that pre-treatment evaluation of repolarization parameters in newly diagnosed COVID-19 would be beneficial for predicting ventricular arrhythmia risk.

Variation of Tpeak-end, corrected Tpeak-end, QT, and corrected QT intervals, Tpeak-end/QT, Tpeak-end/corrected QT ratios and heart rate variability according to decades in the healthy male subjects aged between 30 and 79 years.

BACKGROUND: Heart rate variability (HRV) is a predictor of cardiac autonomic functions. Ventricular repolarization markers can indicate ventricular arrhythmias. We aimed to evaluate variations of HRV and these repolarization markers in five healthy male groups between age 30 and 79 years according to decades. MATERIALS AND METHODS: The study group consisted of 500 healthy male subjects between October 2018 and May 2019. The male subjects were divided into five categories according to their ages. Then, electrocardiograms (ECG), transthoracic echocardiograms (TTE), and treadmill exercise test (TET) were performed. T-wave peak-end (Tp-e) interval was defined as the time between the peak point and end of T-wave. Tp-e, corrected Tp-e (cTp-e), QT, and corrected QT (QTc) were measured from the resting ECGs and HRV temporal parameters (SDNN, SDNN Index, SDANN Index, RMSSD, sNN50, and pNN50), and HRV frequency parameters (VLF, LF, HF, and LF/HF) were obtained from 24-hour Holter monitorization recordings. One-way ANOVA test was used for the differences between the groups. Pearson correlation test was used to determine the correlations between the values of all groups. RESULTS: Considering the repolarization parameters, there are significant differences in five groups in terms of Tp-e interval, but not Tp-e/QT and Tp-e/QTc ratios. Considering the HRV parameters, there were statistically significant differences between the five male healthy groups in terms of HRV temporal parameters and there are no significant differences in terms of HRV frequency parameters. CONCLUSION: As the age increases, basal Tp-e interval increases and HRV temporal parameters decrease significantly in the male subjects aged between 30 and 79 years, but HRV frequency parameters do not change.

Influence of disease severity and cardiac autonomic tone on ventricular repolarization and dispersion in electrocardiographic assessment of patients with systemic lupus erythematosus.

BACKGROUND: There are no data on the influence of disease severity and cardiac autonomic tone on ventricular repolarization and dispersion in 24-hour Holter monitoring in systemic lupus erythematosus (SLE). METHODS: Consecutive 92 SLE and 51 healthy subjects were studied. The standard 12-lead electrocardiography (ECG), Holter monitoring with heart rate turbulence (HRT) and QT, Tp-e and Tp-e/QT ratio assessment (including corrected values) were performed. Subjects with conditions causing repolarization abnormalities or insufficient number of beats suitable for QT evaluation were excluded (17 SLE and 8 controls). RESULTS: Finally, 75 SLE and 43 sex- and age-matched controls were included to the study. In SLE patients, the median disease severity score (Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SLICC/ACR-DI)) was 3.0. The mean values of QTc, cTp-e and cTp-e/QTc were significantly higher in SLE patients than in controls. QTc ≥ 460 ms was observed in 18.7% of patients using standard ECG and in 58.7% using Holter monitoring. With Holter monitoring, patients with SLICC/ACR-DI >3.0 presented longer QTc than those with SLICC/ACR-DI ≤3.0 (418±15 vs. 409 ± 16, p = 0.04), while cTp-e and cTp-e/QTc values were similar. Patients with abnormal HRT presented longer cTp-e and higher cTp-e/QTc than those with normal HRT (92 ± 52 vs. 71 ± 16 ms, p = 0.04; 0.244 ± 0.126 vs. 0.187 ± 0.035, p = 0.03), while QTc values were similar. No differences in QT and Tp-e parameters were observed according to disease duration. CONCLUSION: In SLE patients, Holter monitoring revealed QTc prolongation more frequently than standard ECG. Longer QTc values were observed in patients with more advanced disease, while increased cTp-e and cTp-e/QTc were related to cardiac autonomic dysfunction expressed by abnormal HRT.

Effects of valproate, carbamazepine and levetiracetam on Tp-e interval, Tp-e/QT and Tp-e/QTc ratio.

BACKGROUND AND PURPOSE: To evaluate P-wave dispersion before and after antiepileptic drug (AED) treatment as well as to investigate the risk of ventricular repolarization using the Tpeak-Tend (Tp-e) interval and Tp-e/QT ratio in patients with epileptic disorder. METHODS: A total of 63 patients receiving AED therapy and 35 healthy adults were included. ECG recordings were obtained before and 3 months after anti-epileptic treatment among patients with epilepsy. For both groups, Tp-e and Tp-e/QT ratio were measured using a 12-lead ECG device. RESULTS: Tp-e interval, Tpe/QT and Tp-e/QTc ratios were found to be higher in the patient group than in the control group (p<0.05, for all), while QTmax ratio was significantly lower in the patient group. After 3 months of AED therapy, significant increases in QT max, QTc max, QTcd, Tp-e, Tp-e/QT, and Tp-e/QTc were found among the patients (p<0.05). When the arrhythmic effects of the drugs before and after treatment were compared, especially in the valproic acid group, there were significant increases in Tp-e interval, Tp-e/QT and Tp-e/QTc values after three months of treatment (p<0.05). Carbamazepine and levetiracetam groups were not statistically significant in terms of pre- and post-treatment values. CONCLUSION: It was concluded that an arrhythmogenic environment may be associated with the disease, and patients who received AED monotherapy may need to be followed up more closely for arrhythmia.

Evaluation of TP-E Interval and TP-E/QT Ratio in Panic Disorder.

Background and Objectives: The autonomic nervous system (ANS) is involved in panic disorders. ANS dysfunction has been shown to be associated with ventricular arrhythmia and increased heterogeneity of ventricular repolarization. However, there remains limited evidence of the relationship between panic disorders and ventricular depolarization markers, including the Tp-e interval and Tp-e/QT ratio. This study aimed to evaluate ventricular repolarization parameters in patients with panic disorder. Materials and Methods: In total, 40 patients with panic disorder, diagnosed using the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria, were included in the study group. The control group comprised of 50 age- and sex-matched healthy individuals. A standard 12 lead electrocardiogram was recorded on all participants, and heart rate, QT interval, QRS duration, Tp-e interval, and Tp-e/QT ratio were measured. Results: QRS durations and QT intervals were similar in the study and control groups. Compared to the control group, QTd, Tp-e, and cTp-e intervals as well as Tp-e/QT and Tp-e/QTc ratios were significantly increased in patients with panic disorder (p < 0.05 for all). In the study group, the Severity Measure for Panic Disorder-Adult score had a significant positive correlation with the Tp-e interval (r = 0.369, p < 0001), cTp-e interval (r = 0.531, p < 0.001), Tp-e/QT ratio (r = 0.358, p = 0.001), and Tp-e/QTc ratio (r = 0.351, p = 0.001). Conclusion: These findings indicate that panic disorders are associated with increased ventricular repolarization heterogeneity, which may be attributed to ANS dysregulation.

Evaluation of Tp-e interval and Tp-e/QT ratio in major burn patients.

INTRODUCTION: Major burn injury is an acute stress reaction with systemic effects. Major burn injury has been associated with a number of cardiovascular dysfunctions, including ventricular arrhythmias. The mechanism of increased ventricular arrhythmias in burn patients uncertain. The aim of the present study was to evaluate the ventricular repolarization by using the Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio as candidate markers of ventricular arrhythmias in patients with major burn patients. In addition, the relationship between the repolarization parameters and the CRP(C-reactive protein) and ABSI(Abbreviated Burn Severity Index) score was investigated. METHODS: 55 major burn patients, 55 age and sex matched healthy subjects were included in the study between January 2017 and September 2019. The risk of ventricular arrhythmias was evaluated by calculating the electrocardiographic Tp-e and QT interval, corrected QT(QTc), Tp-e/QT and Tp-e/QTc ratios. ABSI score was calculated in burn patients. Left ventricular functions were evaluated by echocardiography. RESULTS: Tp-e interval (80.7 ±â€¯5.7 vs. 67.4 ±â€¯5.7; p < 0.001), Tp-e/QT ratio (0.21 ±â€¯0.01 vs. 0.18 ±â€¯0.01; p < 0.001) and Tp-e/QTc ratio (0.20 ±â€¯0.01 vs.0.17 ±â€¯0.01; p < 0.001) were significantly higher in major burn patients than the control group. There was a significant positive correlation between Tp-e interval, Tp-e/QTc ratio and ABSI score in major burn patients (r = 0.870, p < 0.001, r = 0.312, p = 0.020 consecutively). CONCLUSION: Our study showed for the first time in literature that the Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio, which were evaluated electrocardiographically in major burn patients, were prolonged compared with normal healthy individuals. A positive correlation was determined between repolarization parameters and ABSI score. Whether these changes increase the risk of ventricular arrhythmia deserve further studies. TAKE-HOME MESSAGE: Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio, which were evaluated electrocardiographically in major burn patients, were prolonged compared with normal healthy individuals and a positive correlation was found between these repolarization parameters and burn severity.

P wave dispersion, Tpeak-Tend interval, and Tp-e/QT ratio in children with psoriasis.

BACKGROUND: Psoriasis is a chronic inflammatory, multi-system disease that often begins in childhood and characterised by inflammatory skin, nails, scalp, and joint manifestations. The inflammation in psoriasis may promote some effect on the cardiac conduction system. OBJECTIVE: The aim of this study is to investigate myocardial repolarisation anomaly on the conducting system in the paediatric psoriasis using P wave dispersion, Tpeak-Tend interval, and Tp-e/QT ratio. METHODS: Forty-two patients diagnosed with psoriasis and 37 age- and sex-matched healthy children were enrolled in the study. Electrocardiographic parameters in psoriasis and control group were recorded from an electrocardiogram for each patient. RESULTS: The results indicated that the parameters including Pdis, QTc dis, Tp-e dis interval, and Tp-e max/QTmax ratios, which are known to be key indicators for the prediction of severe atrial or ventricular arrhythmia and sudden cardiac death and also important parameters used as the indicators for the non-invasive evaluation of the transmural heterogeneity were significantly longer in the study group compared to the control group (p < 0.05). CONCLUSIONS: This study includes the evidence linking psoriasis with increased myocardial repolarisation heterogeneity. These findings suggest that this patient population may be at an increased risk for arrhythmias. Our findings may be a basis for further studies.

Tp-e interval and Tp-e/QT ratio and their association with left ventricular diastolic dysfunction in Fabry disease without left ventricular hypertrophy.

INTRODUCTION: In the early stage of the Fabry disease, diastolic dysfunction can occur before left ventricular hypertrophy (LVH). Cardiovascular complications, most of which are seen as malignant arrhythmias and heart failure, are the leading causes of death in these patients. The aim of the present study was to assess repolarization parameters of Fabry patients in early stage (without LVH) and to show the relationship between these parameters and left ventricular diastolic dysfunction. METHODS: This cross-sectional single center study was carried out with newly diagnosed 23 Fabry patients and 20 healthy individuals, between April 2016 and September 2019. Diagnosis of Fabry disease was based on a measurement of enzyme activity in leukocytes and was confirmed by genetic analysis. Basic, demographic and clinical features were reviewed. The risk of ventricular arrhythmia was evaluated by calculating the electrocardiographic, the Tp-e and QT interval, corrected QT (QTc), Tp-e/QT and Tp-e/QTc ratios. Left ventricular systolic and diastolic dysfunctions were evaluated using echocardiography. RESULTS: Tp-e interval (86.9 ±â€¯6.2 vs. 73.8 ±â€¯6.3 ms; p < 0.001), Tp-e/QT ratio (0.23 ±â€¯0.008 vs. 0.21 ±â€¯0.01; p < 0.001) and Tp-e/QTc ratio (0.21 ±â€¯0.007vs. 0.18 ±â€¯0.017; p < 0.001) were significantly higher in Fabry patients than the control group. There was a significant positive correlation between Tp-e interval and E/e' ratio (r = 0.626, p = 0.003) and Tp-e/QTc ratio and E/e' ratio (r = 0.578, p = 0.008) in Fabry patients. CONCLUSION: Our study showed that the Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio, which are evaluated electrocardiographically in patients with pre-hypertrophic Fabry patients, are prolonged compared to normal healthy individuals. The most significant finding was the positive correlation found between repolarization parameters and LV diastolic dysfunction. These results may be indicative of an early subclinical cardiac involvement in Fabry patients, considering the diastolic dysfunction severity.

Acute effects of electronic cigarette smoking on ventricular repolarization in adults.

BACKGROUND: Electronic cigarette (e-cigarette) use is constantly increasing. However, the association between e-cigarette use and ventricular arrhythmia is unknown. Thus, in this study, we aimed to evaluate the markers of ventricular repolarization such as QT interval, corrected QT (QTc), QT dispersion (QTd), peak-to-end interval of the T wave (Tp-e), corrected Tp-e and Tp-e/QT ratios in e-cigarette users. METHODS: The study population consisted 36 e-cigarette users and 40 healthy subjects. Ventricular repolarization parameters were obtained from 12-lead resting electrocardiogram. Ventricular repolarization parameters of the groups were compared. RESULTS: Basal demographic and laboratory data were similar in both groups. According to the electrocardiographic parameters, the Tp-e interval, corrected Tp-e, and Tp-e/QT ratio were significantly higher in individuals using e-cigarettes than in control subjects [74.9±6.4 milliseconds (ms) vs. 80.1±4.1ms, <0.001; 82.9±7.5 ms vs. 87.8±6.3 ms, p=0.003; 0.20±0.01 vs. 0.21±0.01, p=0.002; respectively]. CONCLUSION: This is the first study to show the disruption of ventricular repolarization properties in e-cigarette users. E-cigarette use in terms of public health leads to augmentation of transmural dispersion of repolarization, which may be potential indicator of ventricular arrhythmogenesis.