cTp-e Interval Research Articles

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.

Association of Mild Hyperbilirubinemia with Decreased ECG-Based Ventricular Repolarization Parameters in Young Men.

Hyperbilirubinemia is associated with protection against various oxidative stress-mediated diseases. We aimed to investigate the association between bilirubin and novel electrocardiography (ECG)-based ventricular repolarization parameters. We enrolled 201 healthy men with mild hyperbilirubinemia (group 1) and 219 healthy men with normal bilirubin levels (group 2). The Tpeak-Tend (Tp-e) interval (defined as the interval from the peak of the T wave to the end of the T wave), corrected (c) Tp-e interval, QT interval, cQT interval, and Tp-e interval/QT interval ratio were measured from leads V5 and V6 with 20 mm/mV amplitude and 50 mm/second rate. The Tp-e interval, cTp-e interval, and Tp-e interval/QT interval ratio were significantly lower in group 1 compared with group 2. The cTp-e interval showed a significant negative correlation with total bilirubin, conjugated bilirubin, and unconjugated bilirubin. The cTp-e interval (odds ratio [OR], 0.900; P =.002) and Tp-e interval/QT interval ratio (OR, 0.922; P =.04) were significantly associated with mild hyperbilirubinemia. We showed the association of mild hyperbilirubinemia with decreased novel ECG-based ventricular repolarization parameters.

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.

Variation of the T-wave peak-end interval and heart rate variability values in healthy males and females at various hours of the same day, and relationship of them.

BackgroundThe prolongation of repolarization time between the myocardial epicardium and endocardial cells is closely related to malignant ventricular arrhythmias. The purpose of our study was to compare repolarization markers, namely, T‐wave peak‐end interval (Tp‐e), QT, corrected QT (QTc), Tp‐e/QT, Tp‐e/corrected QT (QTc), and Heart Rate Variability (HRV) values in healthy men and women and to investigate their daily variations.MethodsA total of 74 male and 78 female participants, being a government employee, and having no health problems, were included in the two study groups (males and females). A 24‐hour, 12‐lead Holter monitoring was performed on the volunteers. Then, the Tp‐e interval and QT interval were measured on recordings. cTp‐e and QTc were calculated by the use of Bazzet's formula.ResultsThere was no statistically significant difference between the groups in the cTp‐e interval at 07.00 pm; however, it was significantly lower in the female group as compared with the male group at 07.00 am and 01.00 pm. It was significantly higher in the female group at 01.00 am compared with the male group. There were statistically significant moderate negative correlations between Tp‐e intervals and a standard deviation of between two normal beats interval (SDNN) values at various hours of the same day.ConclusionThere were statistically significant differences in terms of Tp‐e and cTp‐e intervals at various hours of the same day in both groups. In addition, there were statistically significant moderate negative correlations between Tp‐e intervals and SDNN at various hours of the same day.

Abnormal Dispersion of Ventricular Repolarization as a Risk Factor in Patients with Human Immunodeficiency Virus: Tp-e Interval, Tp-e/QTc Ratio

Objective: In recent years, there has been worldwide recognition of the problems associated with Human Immunodeficiency Virus (HIV) infection and Acquired Immune Deficiency Syndrome (AIDS). The prevalence of cardiovascular disease in the HIV-infected population is increasing. Repolarization abnormalities, the significant contributor to life-threatening arrhythmias and mortality, are the most frequent electrocardiographic changes in this population. This study aimed to evaluate the changes in Tp-e interval, Tp-e/QT and Tp-e/corrected QT (QTc) ratios, and traditional electrocardiographic features of electrical dispersion in adults infected with HIV. Subjects and Methods: A total of 235 participants were selected in the current study. The HIV group consisted of 85 subjects (median age 36 years [25–48], and the control group included 150 individuals (median age 39 years [27–51]). Tp-e interval, Tp-e/QT and Tp-e/QTc ratios were measured by the 12-lead electrocardiogram. Results: Tp-e interval, cTp-e interval, and Tp-e/QT and Tp-e/QTc ratios were significantly higher in HIV patients compared to the control group (p = 0.006, p = 0.004, p = 0.003, and p = 0.002, respectively). In correlation analysis, there was inverse correlation between the mean cTp-e interval and CD4 count and Tp-e/QTc ratios and CD4 count (r = – 0.407, p < 0.001, r = – 0.416, p < 0.001, respectively). Besides, there was correlation between the mean cTp-e interval and high-sensitivity C-reactive protein (hsCRP) and Tp-e/QTc ratios and hsCRP (r = 0.403, p = 0.001, r = 0.406, p = 0.001, respectively). Conclusion: Our study revealed that the cTp-e interval, Tp-e/QT and cTp-e/QT ratios were prolonged and correlated to the severity of the disease in HIV-infected patients. Our findings may shed light on the cTp-e interval and Tp-e/QTc ratio and lead to further studies showing a relationship with ventricular arrhythmias and mortality in HIV-infected individuals.

Effects of Short-Term Hydroxychloroquine Plus Moxifloxacin Therapy on Corrected QT Interval and Tp-e Interval in Patients With COVID-19.

BackgroundLimited data are available regarding hydroxychloroquine (HCQ) and moxifloxacin (MOX) in patients with possible coronavirus disease 2019, (COVID-19). Both drugs may increase risk of malignant ventricular arrhythmias associated with prolongation of QT interval.MethodsA total of 76 subjects with chest tomography findings compatible with COVID-19 pneumonia were enrolled in the study. Standard 12-lead electrocardiogram (ECG) was repeated on days 2 and 5 in patients receiving a combination of HCQ + MOX. Heart rate, QT interval, Tp-e interval, and Tp-e/QT ratio were measured.ResultsThe mean age of the patients was 61.7 ± 14.8 years and 54% had hypertension. Compared to day 2, ECG on day 5 showed significant increases in QT interval (370.8 ± 32.5 vs. 381.0 ± 29.3, respectively, P = 0.001), corrected QT (QTc) interval (424 (403 - 436) vs. 442 (420 - 468), respectively, P < 0.001), Tp-e interval (60 (55 - 70) vs. 65 (57 - 75), respectively, P < 0.001), cTp-e interval (72.2 ± 12.9 vs. 75.4 ± 12.7, respectively, P < 0.001). Moreover, a slight decrease in Tp-e/QT ratio was observed (0.17 ± 0.03 vs. 0.17 ± 0.02, P = 0.030). QTc was > 500 ms in 5% of the patients, and 8% of patients had an increase in QTc interval > 60 ms. Tp-e/QT ratio was > 0.23 in 4% of patients. Five patients died due to pulmonary failure without evidence of ventricular arrhythmia. No ventricular arrhythmia events, including torsades de pointes (TdP), were observed.ConclusionsHCQ + MOX combination therapy led to increases in QTc interval, Tp-e interval, and cTp-e interval. However, this therapy did not cause ventricular arrhythmia in the short-term observation.

The relationship between systolic pulmonary arterial pressure and Tp‐e interval, Tp‐e/QT, and Tp‐e/QTc ratios in patients with newly diagnosed chronic obstructive pulmonary disease

The risk of sudden cardiac death (SCD) and arrhythmias has been shown to be common in chronic obstructive pulmonary disease (COPD) subjects. We aimed to evaluate the markers of arrhythmia such as QT, QTc (corrected QT), Tp-e, and cTp-e (corrected Tp-e) intervals, Tp-e/QT ratio, and Tp-e/QTc ratio in newly diagnosed COPD subjects in both right and left precordial leads. The study group consisted of 74 subjects with obstructive respiratory function tests (RFTs). The control group consisted of 78 subjects who had nonobstructive RFTs. RFTs, electrocardiograms (ECG), and transthoracic echocardiograms (TTE) were performed, and QTR (QT interval in right precordial leads), QTL (QT interval in left precordial leads), Tp-eR (Tp-e interval in right precordial leads), and Tp-eL (Tp-e interval in left precordial leads) intervals; systolic pulmonary arterial pressure (sPAP); forced expiratory volume in one second (FEV1 )/forced vital capacity (FVC); and peripheral oxygen saturation(POS) values were measured. Tp-eR interval 85.82±5.34millisecond (ms) versus 62.87±3.55ms (t=31.29/p<.00001), cTp-eR interval 97.51±7.18ms versus 71.07±4.58ms (t=27.20/p<.00001), Tp-eR/QTR ratio 0.234±0.02 versus 0.164±0.01 (t=2.2/p=.014), and Tp-eR/QTcR ratio 0.201±0.01 versus 0.141±0.01 (t=1.92/p=.028) were statistically significantly higher in COPD subjects. There was a strong negative correlation between RFT and sPAP (sPAP, 29.93±5.1mmHg; and FEV1 /FVC, 63.78±3.33%, r=-.85/p<.00001). There was a moderate positive correlation between sPAP and Tp-eR. We found Tp-e and cTp-e intervals, Tp-e/QT ratio, and Tp-e/QTc ratio were significantly higher in the COPD patients than in the control group. In addition, in the COPD group, heart rate variability (HRV) parameters were significantly lower on ECG.

Can abnormal dispersion of ventricular repolarization be a predictor of mortality in arrhythmogenic right ventricular cardiomyopathy: The importance of Tp-e interval.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy characterized by ventricular arrhythmias and specific ventricular pathology. Repolarization abnormalities, the significant contributor to life-threatening arrhythmias and mortality, are frequently observed ECG changes in patients with ARVC. This study aimed to evaluate the changes in Tp-e interval, Tp-e/QT, Tp-e/QTc ratio, and traditional electrocardiographic features of electrical dispersion in patients with ARVC. A total of 105 participants were enrolled in the current study. The ARVC group consisted of 40 subjects (30 men, with a median of 35 (26-41) years), and the control group included of 65 age and sex-matched individuals (42 men, with a median of 37 (24-45) years). The Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio were measured by the 12-lead electrocardiogram. Tp-e interval, cTp-e interval, Tp-e/QT, and Tp-e/QTc ratio were significantly higher in ARVC patients compared to the control group (all p<0.001). Tp-e interval, cTp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio were significantly increased in deceased ARVC patients compared to the survival group (p=0.038, p<0.001, p=0.006, p=0.032, respectively). In the multivariate analysis, RV-FAC and cTp-e interval level (p<0.05 for each parameter) were associated with all-cause mortality [odds ratio 1.747 95% CI (1.012-3.018); p=0.045 and odds ratio 1.166, 95% CI (1.017-1.336); p=0.027, respectively]. Tp-e interval, cTp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio were prolonged in patients with NC. We revealed that abnormal dispersion of ventricular repolarization suggests the increased risk of mortality in ARVC.

Impact of cardiac rehabilitation on ventricular repolarization indexes in patients with rheumatid arthritis

ObjectiveAbnormalities in ventricular repolarization (VR) parameters have been associated with sudden cardiac death (SCD) in patients with rheumatoid arthritis (RA). The benefits of cardiac rehabilitation (CR) in patients with RA are well recognized. We aimed to assess its impact on VR indexes in patients with RA. MethodsThis study included 45 patients with RA (36 female, age 58 ± 5.5 years) and 50 age- and sex-matched otherwise healthy controls. Baseline electrocardiogram (ECG) recordings were used to compare VR parameters such as maximum and minimum QT intervals, and corrected, and dispersion (QTmax, QTmin, cQTmax, cQTmin, QTd, cQTd, respectively), JT and cJT intervals, Tp-e and cTp-e intervals, and Tp-e/QT and Tp-e/cQT ratios in patients with RA and healthy individuals. The effects of 6-week CR in patients with RA were also evaluated by comparing pre- and post-CR ECGs, exercise tolerance test (MET and VO2max) and RA characteristics (C-reactive protein (CRP), Disease Activity Score 28 (DAS28) and Health Assessment Questionnaire(HAQ)). ResultsIn comparison with the healthy individuals, the patients with RA had significantly higher cQTmax and QTmin intervals, QTd, cQTd, Tp-e and cTp-e intervals, and Tp-e/QT and Tp-e/cQT ratios. At the end of CR, all VR indexes (p < 005), except QTd, were significantly decreased as did the results for CRP, DAS28, and HAQ (all p < 0.05), and MET and VO2max (p < 0.05 for both) were significantly increased in patients with RA. ConclusionsCR may provide an improvement in the majority of VR indexes which are related with ventricular arrhythmia and SCD in patients with RA. Changes in ETT parameters and RA characteristics may contribute to improvement of several VR indexes such as cQTd, cJT and Tp-e intervals at the end of CR.

Assessment of the relationship between reperfusion success and T-peak to T-end interval in patients with ST elevation myocardial infarction treated with percutaneous coronary intervention.

Objective:T-peak–T-end (TPE) interval, which represents the dispersion of repolarization, is defined as the interval between the peak and end of the T-wave, and is associated with increased malignant ventricular arrhythmia and sudden cardiac death (SCD) in patients with ST elevation myocardial infarction (STEMI). Although prolonged TPE interval is associated with poor short- and long-term outcomes, even in patients with STEMI treated with successful primary percutaneous coronary intervention (pPCI), clinical, angiographic, and laboratory parameters that affect TPE remain to be elucidated. The aim of our study was to evaluate the potential relationship between prolonged TPE interval and reperfusion success using ST segment resolution (STR) in patients with STEMI undergoing pPCI.Methods:In the current study, 218 consecutive patients with STEMI who underwent pPCI were enrolled; after exclusion, 164 patients were included in the study population.Results:Patients were divided into two groups according to the presence of complete (STR%≥70) or incomplete (STR%<70) STR. Preprocedural corrected TPE (cTPEPRE;116±21 ms vs. 108±21 ms; p=0.027), postprocedural TPE (TPEPOST; 107±16 ms vs. 92±21 ms; p<0.001), and postprocedural cTPE (cTPEPOST; 119±19 ms vs. 102±17 ms; p<0.001) intervals were significantly longer in patients with incomplete STR than in patients with complete STR, whereas there was no statistically significant difference between the two groups in terms of pre- and postprocedural and corrected QT intervals. cTPEPRE and cTPEPOST were found to be independent predictors for incomplete STR.Conclusion:To our knowledge, this is the first study that evaluated the relationship between TPE interval and no-reflow defined by STR in patients with STEMI who were treated with pPCI.

A novel marker to determine arrhytmia risk in elite cyclists: T peak T end

In athletes, left ventricular hypertrophy is a physiological response upon routine active sports. If the hypertrophic cardiomyopathy is not diagnosed and treated, it can lead to sudden deaths in athletes. Not so much data is known whether or not it is favorable to use of Tp-e values in order to reflect the arrhythmia risks in asymptomatic elite cyclists. The aim of this study is to examine the risks of regular bike sport on potential arrhythmia in healthy active elite cyclists and veterans by using non-invasive cardiac tests. Study groups were: healthy volunteers (group 1, n=28, mean age 35.8±4.6), active cyclists (group 2, n=27, mean age 21±3.0), veteran cyclists (group 3, n=27, mean age 29.5±7.1 yr). All groups were underwent cardiological examinations, 12 derivation ECG records, transthoracic echocardiography investigations. Tp-e interval, Tp-e dispersion, corrected Tp-e interval, QT interval and Tp-e/QT ratio were calculated from ECG records. Tp-e intervals were measured with Tangent method, corrected Tp-e interval were measured with Bazett formula. Mean Tp-e interval results were as follows according to groups 1, 2, 3; 75.0±9.3, 88.1±7.0, 83.2±8.8 ms, respectively. The Tp-e interval, cTp-e interval, Tp- dispersion, QT interval, and SLI values were significantly higher in active cyclists than the veteran cyclists and the control group (p<0.05). Both cyclist groups had also significantly higher Tp-e interval, cTp-e interval, QT interval, Tp-e/QT, QRS time and SLI values than the control group (p<0.05). Furthermore, there were significant differences in Tp-e interval, cTp-e interval, Tp-e dispersion, QT interval and SLI values between the active and veteran cyclists (p<0.05). There were significant differences in Tp-e dispersion between active cyclists and control group or veteran cyclists (p< 0.01). Arrythmia related to Tp-e interval, Tp-e dispersion, corrected Tp-e interval and Tp-e/QT ratio are associated with long-term, intense bike sport training either in active cyclists or veterans. This can also be associated with left ventricular hypertrophy in active cyclists and remnant left ventricular hpertrophy in veterans.

Evaluation of the Tp-e Interval and Tp-e/QT Ratio in Patients with Mitral Annular Calcification

Objective: Mitral annular calcification (MAC) is regarded as a manifestation of cardiovascular disease. Recent studies have shown that prolongation of the interval between the peak and end of the T wave on electrocardiogram (Tp-e), which is accepted as an index of transmural dispersion of ventricular repolarization, and the Tp-e/QT ratio are associated with ventricular arrhythmias. In the present study, we aimed to evaluate ventricular repolarization using the Tp-e interval and Tpe/ QT ratio in patients with MAC. Methods: Fifty patients with MAC (27 females and 23 males; mean age 71.6 ± 8.0 years) and 50 patients without MAC (26 females and 24 males; mean age 69.3 ± 6.2 years) were included in this study. Maximum and minimum QT and Tp-e intervals as well as corrected values according to heart rate were calculated using a 12- lead electrocardiogram. QT dispersion and Tp-e/QT ratios were calculated. All parameters were compared between the two groups. Results: Patients with MAC had significantly higher Tp-e (75.8 ± 11.6 vs. 62.1 ± 8.7; p<0.001) and cTp-e intervals (84.9 ± 14.3 vs. 67.5 ± 9.7; p<0.001), Tp-e/QT (0.19 ± 0.02 vs. 0.15 ± 0.02; p<0.001) and cTp-e/QT ratios (0.19 ± 0.03 vs. 0.15 ± 0.02; p<0.001), and cQT values (390.1 ± 31.5 vs. 373.8 ± 26.1; p=0.006) compared with the control subjects. There were positive correlations between E/Em ratio and cTp-e interval (r=0.396; p=0.004) and between the E/Em ratio and cTp-e/QT ratio (r=0.535; p<0.001) in the MAC group. Conclusion: Our findings indicate that the patients with MAC had higher Tp-e and cTp-e intervals and Tp-e/QT and cTp-e/QT ratios compared with the subjects without MAC.

The Relationship between Ventricular Repolarization Indexes and Neutrophil to Lymphocyte Ratio in Patients with Slow Coronary Flow

Objective: Slow coronary flow (SCF) is characterized by angiographically normal coronary arteries with delayed opacification of the distal vasculature. The peak to the end of the electrocardiographic T wave (Tp-e) may correspond to the transmural dispersion of repolarization and that increased Tp-e interval and Tp-e/QT ratio are associated with ventricular arrhythmias. Neutrophil to lymphocyte ratio (NLR) is a new inflammatory marker using for cardiovascular risk prediction. The aim of this study was to evaluate the relationship between ventricular repolarization and inflammation in patients with SCF. Methods: Forty-six SCF patients and 44 controls were enrolled to the study. Coronary flow rates were measured by Thrombolysis in Myocardial Infarction frame count (TFC). Tp-e interval and Tp-e/QT ratio were measured from a 12-lead electrocardiogram, and Tp-e interval was corrected for heart rate (cTp-e). NLR was calculated as the ratio of neutrophil to lymphocyte count. These parameters were compared between groups. Results: Corrected Tp-e interval and Tp-e/QT ratio were significantly higher in SCF patients (94.5 ± 14.9 vs 88.1 ± 6.3 ms, 0.23 ± 0.03 vs 0.21 ± 0.02; P=0.009, and P=0.002, respectively). Also, NLR was increased in SCF patients (2.40 ± 0.9 vs 1.67 ± 0.5, P<0.001). The cTp-e was significantly correlated with mean TFC and NLR (r=0.50, p<0.001 and, r=0.37, p<0.001, respectively). Tp-e/QT ratio was significantly correlated with mean TFC and NLR (r=0.48, P<0.001 and r=0.28, P=0.006, respectively). Conclusion: Our study revealed that cTp-e interval and Tp-e/QT ratio were increased in SCF patients. These new electrocardiographic ventricular repolarization indexes were significantly correlated with the mean TFC and NLR.

Prognostic value of Tpeak-Tend interval in patients with acute pulmonary embolism.

BackgroundThe aim of this study was to examine the Tpeak-Tend (Tpe/corrected Tpe) interval, which is an indicator of transmural myocardial repolarization, measured non-invasively via electrocardiogram in patients with acute pulmonary embolism (PE), and to investigate the relationship with 30-day mortality and morbidity.MethodsThe study included 272 patients diagnosed with acute PE, comprising 154 females and 118 males, with a mean age of 63.1 ± 16.8 years. Tpe/cTpe intervals were calculated from the electrocardiograms with a computer program after using a ruler or vernier caliper manual measuring tool to obtain highly sensitive measurements. The relationship between the electrocardiogram values and 30-days mortality and morbidity were measured.ResultsThe study group was divided into three groups according to cTpe intervals: Group 1, < 113 ms; Group 2, 113–133 ms; and Group 3, > 133 ms. White blood cell count and troponin T levels, corrected QT intervals with QRS complex durations, percentage of right ventricle dilatation with right/left-ventricular ratio, 30-day death, and combinations of these values were seen at a higher rate in Group 3 patients compared to the other groups. Kaplan–Meier analysis showed that the cTpe interval measured at > 126 ms could be used as a cut-off value in the prediction of mortality and morbidity. The cTpe cut-off values of 126 ms had sensivity, specificity, negative predictive value, and positive predictive value of 80.56 %, 59.32 %, 95.2 %, and 23.2 %, respectively.ConclusionscTpe interval could be a useful method in early risk stratification in patients with acute PE.

Evaluation of Electrocardiographic T-peak to T-end Interval in Subjects with Increased Epicardial Fat Tissue Thickness.

BackgroundThe association between periatrial adiposity and atrial arrhythmias has been shown in previous studies. However, there are not enough available data on the association between epicardial fat tissue (EFT) thickness and parameters of ventricular repolarization. Thus, we aimed to evaluate the association of EFT thickness with indices of ventricular repolarization by using T-peak to T-end (Tp-e) interval and Tp-e/QT ratio.MethodsThe present study included 50 patients whose EFT thickness ≥ 9 mm (group 1) and 40 control subjects with EFT thickness < 9 mm (group 2). Transthoracic echocardiographic examination was performed in all participants. QT parameters, Tp-e intervals and Tp-e/QT ratio were measured from the 12-lead electrocardiogram.ResultsQTd (41.1 ± 2.5 vs 38.6 ± 3.2, p < 0.001) and corrected QTd (46.7 ± 4.7 vs 43.7 ± 4, p = 0.002) were significantly higher in group 1 when compared to group 2. The Tp-e interval (76.5 ± 6.3, 70.3 ± 6.8, p < 0.001), cTp-e interval (83.1 ± 4.3 vs. 76±4.9, p < 0.001), Tp-e/QT (0.20 ± 0.02 vs. 0.2 ± 0.02, p < 0.001) and Tp-e/QTc ratios (0.2 ± 0.01 vs. 0.18 ± 0.01, p < 0.001) were increased in group 1 in comparison to group 2. Significant positive correlations were found between EFT thickness and Tp-e interval (r = 0.548, p < 0.001), cTp-e interval (r = 0.259, p = 0.01), and Tp-e/QT (r = 0.662, p < 0.001) and Tp-e/QTc ratios (r = 0.560, p < 0.001).ConclusionThe present study shows that Tp-e and cTp-e interval, Tp-e/QT and Tp-e/QTc ratios were increased in subjects with increased EFT, which may suggest an increased risk of ventricular arrhythmia.

Exercise-Induced Repolarization Changes in Patients with Isolated Myocardial Bridging.

BackgroundAlthough myocardial bridging (MB) is defined as an angiographic phenomenon with a benign course, it has also been associated with adverse cardiovascular events. The effects of exercise on myocardial repolarization in patients with MB were tested in this study, with Tp-e and Tp-e/QT repolarization indexes.Material/MethodsA total of 50 patients in whom isolated MB was diagnosed at coronary angiography (CAG) (Group I) and 48 patients with normal CAG results (Group II) were included in this study. The participants underwent treadmill exercise stress testing according to the Bruce protocol. QT dispersion (QTd) was defined as the minimum QT interval subtracted from the maximum. The Tp-e interval was defined as the difference between the QT and the QT peak time period. QTd and Tp-e intervals were calculated for all patients before and after exercise testing and differences between groups were compared.ResultsAt peak exercise, QTd and cQTd showed a significant increase in comparison to baseline values in the group of patients with myocardial bridges. Significant increases were also found with exercise in the Tp-e, cTp-e durations and Tp-e/QT ratio of the MB patient group in comparison to the baseline values. On the other hand, significant differences in QTd, cQTd, Tp-e, cTp-e intervals, and Tp-e/QT ratio during peak exercise in comparison with baseline values were not detected in the control group (p>0.05).ConclusionsSignificant increases in QTd, cQTd, Tp-e and cTp-e intervals and Tp-e/QT ratio were detected in the MB patients during exercise testing.

Effects of the coronary collateral circulation on the Tp-e interval and Tp-e/QT ratio in patients with stable coronary artery disease.

The clinical utility of the Tp-e interval and Tp-e/QT ratio in the risk stratification of ventricular arrhythmic events is controversial. Therefore, we investigated the impact of CCC on these electrocardiographic indexes in the course of stable CAD. Two hundred three consecutive patients with stable CAD who underwent coronary angiography and had documented total occlusion of one of the major coronary arteries were enrolled in this prospective cross-sectional study. The Tp-e interval and Tp-e/QT ratio were measured by 12-lead electrocardiogram. The Tp-e interval, cTp-e interval, Tp-e/QT ratio, and cTp-e/QT ratio were lower in the grade 3 CCC group compared with the others in all leads. Multivariate linear regression analyses was performed to identify the clinical factors affecting the cTp-e interval and was indicated that age (β = 0.261, P < 0.001), male sex (β = 0.334, P < 0.001), poor Rentrop grade (β = -0.228, P < 0.001), and NLR (β = 0.137, P = 0.027) were independent predictors of a prolonged cTp-e interval. It could be concluded that the decreased dispersion of ventricular repolarization might contribute to the lower incidence of ventricular arrhythmias and SCD in CAD patients with a good CCC.

Effect of Smoking on Tp-e Interval, Tp-e/QT and Tp-e/QTc Ratios as Indices of Ventricular Arrhythmogenesis

Smoking may lead to ventricular arrhythmias and sudden cardiac death via altering ventricular recovery time dispersion indices such as QT interval and QT dispersion (QTd). The Tp-e/QT and Tp-e/QTc ratios are also known as predictors of ventricular arrhythmogenesis. The aim of this study was to evaluate the relationship between cigarette smoking and ventricular repolarisation dispersion using these novel electrocardiographic parameters. One hundred and twenty-one chronic smokers and 70 age- and sex-matched non-smoker controls were included in our study. The Tp-e interval and Tp-e/QT ratio were measured by 12-lead electrocardiogram, and corrected for heart rate. QTd (34.2 ± 8.4, 27.2 ± 10.4, P<0.001) and corrected QTd (37.3 ± 8.9, 29.8 ± 11.2, P<0.001) were significantly increased in the smokers compared to the non-smoker control group. The Tp-e interval (76.5 ± 6.3, 70.3 ± 6.8, P<0.001), cTp-e interval (83.5 ± 8.0, 77.1 ± 8.7, P<0.001), Tp-e/QT (0.20 ± 0.03, 0.19 ± 0.02, P<0.001) and Tp-e/QTc ratios (0.19 ± 0.02, 0.17 ± 0.02, P<0.001) were increased in the patient group when compared to the controls. Significant positive correlations were also found between the level of smoking with the cTp-e interval (r=0.836, P<0.001), and Tp-e/QT (r=0.714, P<0.001) and Tp-e/QTc ratios (r=0.448, P<0.001). We found in our study that cTp-e interval, Tp-e/QT and Tp-e/QTc ratios were increased in smokers and significantly correlated to the amount of smoking.

Evaluation of Tp-e interval and Tp-e/QT ratio in patients with ankylosing spondylitis

Objectives. Ankylosing spondylitis (AS) is a chronic multi-systemic inflammatory rheumatic disorder. Several studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (Tp-e) may correspond to the transmural dispersion of repolarization and that increased Tp-e interval and Tp-e/QT ratio are associated with malignant ventricular arrhythmias. The aim of this study was to evaluate ventricular repolarization by using Tp-e interval and Tp-e/QT ratio in patients with AS, and to assess the relation with inflammation.Methods. Sixty-two patients with AS and 50 controls were included. Tp-e interval and Tp-e/QT ratio were measured from a 12-lead electrocardiogram, and the Tp-e interval corrected for heart rate. The plasma level of high sensitive C-reactive protein (hsCRP) was measured. These parameters were compared between groups.Results. In electrocardiographic parameters analysis, QT dispersion (QTd) and corrected QTd were significantly increased in AS patients compared to the controls (31.7 ± 9.6 vs 28.2 ± 7.4 and 35.8 ± 11.5 vs 30.6 ± 7.9 ms, P = 0.03 and P = 0.007, respectively). cTp-e interval and Tp-e/QT ratio were also significantly higher in AS patients (92.1 ± 10.2 vs 75.8 ± 8.4 and 0.22 ± 0.02 vs 0.19 ± 0.02 ms, all P values <0.001). cTp-e interval and Tp-e/QT ratio were significantly correlated with hsCRP (r = 0.63, P < 0.001 and r = 0.49, P < 0.001, respectively).Conclusions. Our study revealed that Tp-e interval and Tp-e/QT ratio were increased in AS patients. These electrocardiographic ventricular repolarization indexes were significantly correlated with the plasma level of hsCRP.

Effects of Coronary Collateral Circulation on Tp-e interval, Tp-e/QT and Tp-e/QTc Ratios in Coronary Artery Disease Patients

Background: Coronary collateral circulation (CCC) identifies the severity of ischemic myocardial injury. Tp-e/QT ratio and Tp-e/QTc ratio are known as indicators of ventricular arrhythmogenesis. Aim of our study was to assess the effect of CCC on ventricular arrhythmogenesis in coronary artery disease patients using these new markers. Methods: Fifty five patients who have at least one occluded major coronary artery were included in our study. Study population were divided into two groups according to the Rentrop collateral scoring system with poor (Rentrop score 0-1, n1⁄426) and good (score 2-3, n1⁄429) CCC. We collected fasting blood samples before the coronary angiography. Results: QT dispersion (QTd) (27.8 4.5, 25.6 3.9 P1⁄40.011), corrected QTd (33.3 7.4, 30.8 5.8, P1⁄40.017), cTp-e interval (84.5 7.5, 72.0 5.7, P<0.001), Tp-e/QT (0.26 0.03, 0.18 0.03, P<0.001) and Tp-e/QTc ratios (0.21 0.02, 0.15 0.03, P<0.001) were significantly higher in good CCC patients compared to poor group. We found significant positive correlations between the collateral score with Tp-e/QT and Tp-e/QTc ratios (r1⁄40.444, P<0.001, r1⁄40.418, P<0.001, respectively). Conclusion:We found higher cTp-e interval, Tp-e/QT and Tp-e/QTc ratios in patients with good CCC than in poor CCC. We consider that cTp-e interval, Tp-e/QT and Tp-e/QTc ratios are likely to be useful indices of ventricular arrhythmias in coronary artery disease patients, especially who have good CCC. PP-155