TpTe Interval Research Articles

No Association Between T-peak to T-end Interval on the Resting ECG and Long-Term Incidence of Ventricular Arrhythmias Triggering ICD Interventions.

Background and ObjectivesPotential of using the T-peak to T-end (TpTe) interval as an electrocardiographic parameter reflecting the transmural dispersion of ventricular repolarization (TDR) to identify patients (pts.) with higher risk of malignant ventricular arrhythmias (MVA) for better selection of candidates for implantable cardioverter-defibrillator (ICD) in primary prevention (PP) of sudden cardiac death (SCD) remains controversial. The primary objective of this study was to investigate the relationship between the TpTe interval in patient’s preimplantation resting 12-lead electrocardiogram (ECG) and the incidence of MVA resulting in appropriate ICD intervention (AI). The secondary objective was to assess its relationship to overall mortality.MethodsA total of 243 consecutive pts. with severe left ventricular (LV) systolic dysfunction after myocardial infarction (MI) with a single-chamber ICD for PP of SCD from one implantation center were included. Excluded were all pts. with any other disease that could interfere with the indication of ICD implantation. Primarily investigated intervals were measured manually in accordance with accepted methodology. Data on ICD interventions were acquired from device interrogation during regular outpatient visits. Survival data were collected from the databases of health insurance and regulatory authorities.ResultsWe did not find a significant relationship between the duration of the TpTe interval and the incidence of MVA (71.5 ms in pts. with MVA vs. 70 ms in pts. without MVA; p = 0.408). Similar results were obtained for the corrected TpTe interval (TpTec) and the ratio of TpTe to QT interval (76.3 ms vs. 76.5 ms; p = 0.539 and 0.178 vs. 0.181; p = 0.547, respectively). There was also no significant difference between the duration of TpTe, TpTec and TpTe/QT ratio in pts. groups by overall mortality (71.5 ms in the deceased group vs. 70 ms in the survivors group; HR 1.01; 95% CI, 0.99–1.02; p = 0.715, 76.3 ms vs. 76.5 ms; HR 1.01; 95% CI, 0.99–1.02; p = 0.208 and 0.178 vs. 0.186; p = 0.116, respectively).ConclusionThis study suggests no significant association of overall or MVA-free survival with ECG parameters reflecting TDR (TpTe, TpTec) in patients with systolic dysfunction after MI and ICD implanted for primary prevention.

Beneficial effects of paricalcitol on cardiac dysfunction and remodelling in a model of established heart failure.

The synthetic vitamin D3 analogue paricalcitol acts as a selective activator of the vitamin D receptor (VDR). While there is evidence for cardioprotective effects of paricalcitol associated with the VDR pathway, less information is available about the structural and functional cardiac effects of paricalcitol on established heart failure (HF) and particularly its effects on associated electrophysiological or Ca2+ handling remodelling. We used a murine model of transverse aortic constriction (TAC) to study the effect of paricalcitol on established HF. Treatment was initiated 4 weeks after surgery over five consecutive weeks, and mice were sacrificed 9 weeks after surgery. Cardiac MRI (CMRI) was performed 4 and 9 weeks after surgery. Hearts were used for biochemical and histological studies and to isolate ventricular myocytes for electrophysiological and calcium imaging studies. CMRI analysis revealed that, compared with vehicle, paricalcitol treatment prevented the progression of ventricular dilation and hypertrophy after TAC and halted the corresponding decline in ejection fraction. These beneficial effects were related to the attenuation of intracellular Ca2+ mishandling remodelling, antifibrotic and antihypertrophic effects and potentially antiarrhythmic effects by preventing the reduction of K+ current density and the long QT, JT and TpTe intervals observed in HF animals. The results suggest that paricalcitol treatment in established HF hampers disease progression and improves adverse electrophysiological and Ca2+ handling remodelling, attenuating the vulnerability to HF-associated ventricular arrhythmias. Paricalcitol may emerge as a potential therapeutic option in the treatment of HF.

Tp-Te interval and Tp-Te/QT ratio may be predictive of idiopathic ventricular tachycardia in patients with frequent outflow tract premature ventricular complexes

Background The aim of present study is to evaluate the predictive value of QTc dispersion, Tp-Te interval and Tp-Te/QT ratio for idiopathic monomorphic outflow tract ventricular tachycardia (VT) occurrence in patients with frequent idiopathic outflow tract premature ventricular complexes (PVCs). Methods A total of 180 patients (49.2 ± 13.6 years, 74 male) who had undergone outflow tract PVC ablation between 01 January 2015 and 01 November 2018 constituted our study population. Patients with isolated outflow tract PVC without any VT recording on Holter recordings and without any inducible VT at EPS were classified as isolated PVC group. Patients with any episode of VT that has the same morphology with outflow tract PVC were classified as nonsustained or sustained VT groups based on the duration of VT episode. QTc dispersion, Tp-Te and Tp-Te/QT ratio values were calculated and compared between groups. Results There were 116 patients with isolated PVC, 35 patients with nonsustained VT and 29 patients with sustained VT. QTc dispersion, Tp-Te and Tp-Te/QT ratio values were significantly lower in patients with isolated PVC compared to patients with nonsustained or sustained VT episodes. Tpeak to Tend interval greater than 110.5 msec on derivation V6 predicted VT occurrence with 93.8% sensitivity and 82.8% specificity. Tpeak to Tend/QT interval greater than 0.27 on derivation V6 predicted VT occurrence with 93.8% sensitivity and 0.81% specificity. Conclusion Tp-Te interval and Tp-Te/QT ratio on derivation V6 may aid in prediction of presence of outflow tract VT in clinical practice.

Effects of medications on ventricular repolarization in children with attention deficit hyperactivity disorder.

Attention deficit hyperactivity disorder (ADHD) is a multifactorial neurodevelopmental disorder that manifests during childhood. Methylphenidate (MPH), which is a psychostimulant drug, has been often prescribed for the treatment of ADHD in patients. It may increase the risk of fatal arrhythmias by impairing ventricular repolarization. Indicators of ventricular repolarization in ECG are intervals of QT, corrected QT (QTc), QT dispersion (QTd), T-peak to T-end (Tp-e), and Tp-Te/QTc ratio. We aimed to determine ventricular repolarization findings before and after MPH drug therapy in children with ADHD. The study retrospectively examined the medical records of 33 children aged 6-15 years who received MPH for ADHD and who had a control ECG one month after medication. The ECG parameters, heart rate, intervals of QRS, QT, QTc, QTd, Tp-Te, and Tp-Te/QTc ratio, were compared for each patient before and after drug therapy. No significant change was observed in heart rate, QRS, QT, QTc, and QTd interval in ECGs of patients after treatment but pre and posttreatment mean Tp-Te interval was 73.4 ± 9.72 ms and 79.7 ± 10.48 ms, and mean Tp-Te/QTc ratio was 0.17 ± 0.024 and 0.18 ± 0.023, respectively (P = 0.015, P = 0.028). Tp-Te intervals and Tp-Te/QTc ratios remained within normal values after treatment with MPH, but values were higher than baseline.

Cardiotoxicity by Anthracycline Regimen Chemotherapy Prolonged T Peak to T End Interval.

BackgroundMyocardial necrosis may occur due to anthracycline (doxorubicin/adriamycin) chemotherapy usage. Furthermore, myocardial necrosis can affect the heterogeneity of heart conduction system and lead to repolarization abnormalities. The aim of this study was to investigate the effect of cardiotoxicity caused by anthracycline to repolarization abnormalities measured by T peak to T end (TpTe) interval.MethodsThis was a single center prospective cohort study with linear regression from October 2018 to May 2019. The subjects of the study were breast cancer patients after completing administration of chemotherapy with fluorouracil, adriamycin and cyclophosphamide (FAC) regimen (containing anthracycline) for 6 months. Myocardial necrosis was assessed by high sensitive (hs)-troponin I, and the heterogeneity of repolarization was measured by TpTe interval.ResultsThis study involved 25 breast cancer patients after chemotherapy in the 6-month FAC regimen. The mean age is 46 ± 7 years, and the cumulative dose of anthracycline is 591 ± 52 mg/m2. The mean level of hs-troponin I is 90.5 ± 44.7 ng/L and the TpTe interval is 108.2 ± 10 ms. The results of linear regression analysis showed a positive correlation between hs-troponin I and TpTe interval (r: 0.421, P: 0.036) after controlling for one confounding variable (cumulative dose of anthracycline).ConclusionsCardiotoxicity caused by accumulative dose of anthracycline may lead to myocardial necrosis which was shown by elevated hs-troponin I levels. This process may lead to heterogeneity conduction system that affect the repolarization phase of cardiac cycle which was shown by increased TpTe interval.

Is there a relationship between epicardial fat tissue thickness and Tp-Te/QT ratio in healthy individuals?

IntroductionEpicardial fat is a tissue that releases many proinflammatory and atherogenic mediators, with endocrine and paracrine effects on the heart. In this study, the implication of the EFT thickness (EFTt) on transmural dispersion of repolarisation (TDR) was analysed utilizing the T-wave peak to end interval (Tp-Te), the Tp-Te dispersion (Tp-Te (d)), and the Tp-Te/QT ratio.Material and methodsOne thousand seven hundred and thirteen subjects were enrolled in the research. The subjects were chosen to be healthy individuals, without any cardiovascular/systemic disorders or risk factors for atherosclerosis. Transthoracic echocardiography (TTE) was applied to all subjects, and EFTt was measured in both diastole and systole. The ECG measurements were taken from standard 12-lead surface ECG.ResultsCorrelation analysis revealed that the EFTt is highly associated with the Tp-Te interval, Tp-Te/QT ratio, Tp-Te (d), increasing age, body mass index (BMI), body surface area (BSA), left ventricular (LV) mass, LV mass index, plasma glucose during fasting, triglycerides, and low-density lipoprotein cholesterol.ConclusionsThe study results showed that increased EFTt was associated with increased TDR values of Tp-Te, Tp-Te (d), and Tp-Te/QT ratio, even in the absence of other factors that could increase TDR and EFTt. Therefore, it can be stated that increased EFTt may cause an increase the risk for ventricular arrhythmia.

The relation of frontal QRS-T angle with syntax score in patients with ST segment elevation myocardial infarction

Aim: Current data regarding the relation between the Frontal QRS-T (FQRST) angle and the atherosclerotic burden is limited. This study purposed to investigate the relation between FQRST angle and the Syntax (SX) score in subjects presenting with STEMI. Material and Methods: Forty-nine patients who were admitted to the coronary care unit of a tertiary-care hospital for acute STEMI and underwent successful revascularization of the infarct related artery were included in this retrospective analysis. FQRST angle, QTc, and T peak- T end (TpTe) intervals were obtained from the presenting electrocardiogram (ECG). ECG was repeated 30 minutes after revascularization. The SX score was calculated using dedicated software. The study population was then divided into 3 tertiles based on the SYNTAX trial results as follows: SX score ≤ 22 (Low SX score, n=34), SX score ≥ 23 and 33 (Intermediate SX score, n=8), and those with an SX score ≥ 33(High SX score, n=7).Results: Median FQRST angle of the subjects with an SX score ≥ 33 was significantly wider than those with an SX score 22 had a longer TpTe interval than those with an SX score ≤ 22 points. SX score was significantly correlated with the FQRST angle (r=0.691, p 0.001) and TpTe interval (r=0.579, p 0.001).Conclusion: FQRST angle obtained from the admission surface ECG of the subjects with acute STEMI might reflect the extent and severity of the CAD, as demonstrated by the SX score. Moreover, FQRST angle may be useful in determination of the success of the revascularization in STEMI subjects.

Predictors of impending cardiac arrhythmias by electrocardiographic markers in proven obstructive sleep apnea patients

Background: Obstructive sleep apnoea is proved to be one of the causes of sudden cardiac death due to undocumented transient cardiac arrhythmias.So we studied the changes in various electrocardiographic parameters (P wave duration, QRS duration and Tpeak to Tend interval) and its association with increasing severity of OSA by AHI to predict the risk of impending cardiac atrial and ventricular arrhythmias in these patients. Objective: This study compares the risk of impending cardiac arrhythmias by electrocardiographic parameters with the increasing severity of obstructive sleep apnoea by AHI (apnoea-hypopnea index) in polysomnnography. Methodology: The study was conducted in a rural based teaching tertiary care hospital in Puducherry,India. The electrocardiogram(ECG) of the 30 proven OSA patients were analysed for parameters like P wave duration, QRS duration and peak of T wave to end of T wave interval. Any deviation from the normal duration is recorded and compared with the severity of OSA by AHI to estimate the risk of arrhythmogenicity Results: Out of 30 OSA patients in the study group 7 (23.3%) were found to have mild OSA [i.e AHI= 5 TO 14 events/hr] , 6 (20%) were found to have moderate OSA [i.e AHI=15 to 29 events/hr] and 17(56.7%) were found to have severe OSA[i.e AHI=30 and above]. The p value is significant [ Conclusion: We concluded that the increase in duration of P wave, QRS duration and prolongation of Tp-Te interval in electrocardiogram is associated with increasing severity of obstructive sleep apnoea tends to possess significant risk of developing impending cardiac atrial and ventricular arrhythmias respectively which can be attributed to one of the causes of sudden cardiac death in OSA patients.

A new electrocardiographic parameter associated with sudden cardiac death in pulmonary sarcoidosis.

IntroductionThe interval from the peak to the end of the electrocardiographic T wave (Tp–Te) may correspond to malignant ventricular arrhythmias. In this study we aimed to assess Tp–Te variability and investigate the transmural dispersion of repolarisation in pulmonary sarcoidosis disease without proofed cardiac involvement.Material and methodsThis was a retrospective case-control study that included patients who had a pathologic and radiologic diagnosis of sarcoidosis. All data of the patients’ demographic features and electrocardiographs were analysed.ResultsWe enrolled 78 patients with sarcoidosis and 54 healthy volunteers as controls in our study. Men comprised 36% of the sarcoidosis group and 27% of controls. The mean age in the sarcoidosis and control group was 45.4 ±8.7 years (range: 23–58 years) and 44.6 ±11.9 years (range: 21–73 years), respectively. There was no significant difference between the groups for age or sex (p = 0.654, p = 0.246, respectively). There was a significant increase in Tp–Te results in all precordial leads in the sarcoidosis group compared with the control group (p < 0.05).ConclusionsPulmonary sarcoidosis is suspected to have cardiac involvement; therefore, we need to develop new approaches. We present strong evidence that Tp–Te intervals were increased in patients with pulmonary sarcoidosis, which suggests that there may be a link between sarcoidosis and ventricular arrhythmias without proofed cardiac involvement.

Prolonged Tpeak -Tend interval is a risk factor for sudden cardiac death in adults with congenital heart disease.

ObjectiveAdult congenital heart disease (ACHD) patients are at risk of sudden cardiac death (SCD). However, methods for risk stratification are not yet well‐defined. The Tpeak‐Tend (TpTe) interval, a measure of dispersion of ventricular repolarization, is a risk factor for SCD in non‐ACHD patients. We aim to evaluate whether TpTe can be used in risk stratification for SCD in ACHD patients.DesignFrom an international multicenter cohort of 25 790 ACHD patients, we identified all SCD cases. Cases were matched to controls by age, gender, congenital defect, and (surgical) intervention.Outcome MeasuresTpTe was measured on a standard 12‐lead ECG. The maximum TpTe of all ECG leads (TpTe‐max), mean (TpTe‐mean), and TpTe dispersion (maximum minus minimum) were obtained. Odds ratios (OR) for SCD cases vs controls were calculated using conditional logistic regression analysis.ResultsECGs were available for 147 cases (median age at death 33.5 years (quartiles 26.2, 48.7), 66% male) and 267 controls. The mean TpTe‐max was 97 ± 24 ms in cases vs 84 ± 17 ms in controls (P < .001); TpTe‐mean was 70 ± 16 vs 63 ± 10 ms (P < .001); and dispersion was 51 ± 22 ms vs 41 ± 16 ms (P = .02), respectively. Assessing each ECG lead separately, TpTe in lead aVR predicted SCD most accurately. TpTe in lead aVR was 71 ± 23 ms in cases vs 61 ± 13 ms in controls (P < .001). After adjusting for impaired ventricular function, heart failure symptoms, and prolonged QRS duration, the OR of SCD of TpTe in lead aVR at an optimal cutoff of 80 ms was 5.8 (95% CI 2.7‐12.4, P < .001).ConclusionsThe TpTe interval is associated with SCD in ACHD patients. Particularly, TpTe in lead aVR can be used as an independent risk factor for SCD in ACHD patients and may, therefore, add precision to current risk prediction models.

Usefulness of Tp-Te interval and Tp-Te/QT ratio in the prediction of ventricular arrhythmias and mortality in acute STEMI patients undergoing fibrinolytic therapy

Background and aimAcute ST-elevation myocardial infarction (STEMI) is associated with fatal and non-fatal ventricular arrhythmic events (VAE). Although primary percutaneous intervention (PCI) is first-line treatment in STEMI, fibrinolytic therapy (FT) is still widely used in many countries. Tp-Te interval; Tp-Te/QT ratio and QT dispersion (QTd) are novel markers of ventricular repolarization (VR) and associate with VAE and mortality. Hereby, we assessed Tp-Te, QTd and Tp-Te/QT in acute STEMI patients undergoing FT and analyzed their relationship with post-FT VAE, and arrhythmic and overall deaths. MethodsA total of 207 consecutive STEMI patients treated with FT were retrospectively evaluated. Patients were divided in Group 1 (non-VAE group) and Group 2 (VAE group). ECG, clinical and demographic data were noted. Relationship between the pre-FT electrocardiographic parameters of VR and post-FT VAE, arrhythmic and overall death was evaluated. ResultsTp-Te, Tp-Te/QT and QTd were significantly higher in Group 2 compared to Group 1 (p < 0.05). Tp-Te, Tp-Te/QT, QTd, QTc and left ventricular ejection fraction (LVEF) predicted VAE. Tp-Te/QT and LVEF predicted arrhythmic death (1.05; 95% CI 1.01–1.08; p = 0.031 and 0.87; 95% CI 0.72–0.96; p = 0.040; respectively). In ROC analysis, cut-off for Tp-Te/QT to predict VAE was >0.305 with 87.5% sensitivity and 60.1% specificity (AUC: 0.90; 95% CI: 0.85–0.95; p < 0.001), and to predict arrhythmic death was >0.315 with 83.3% sensitivity and 62% specificity (AUC: 0.70; 95% CI: 0.60–0.81; p = 0.018). ConclusionTp-Te, Tp-Te/QT, QTc, QTd and LVEF are independent predictors of post-FT VAE in acute STEMI. Tp-Te/QT ratio is associated with VA-related deaths.

Markers of ventricular repolarization as an additional non-invasive electrocardiography parameters for predicting ventricular tachycardia/fibrillation in patients with Brugada Syndrome – A systematic review and meta-analysis

BackgroundControversies surrounded the management of asymptomatic Brugada syndrome. Prognostication using electrophysiology study (EPS) is disputable. Non-invasive parameters may be a valuable additional tool for risk stratification. We aim to evaluate the use markers of ventricular repolarization including Tpeak-to-Tend (TpTe), Tpe Dispersion, TpTe/QT ratio, and QTc interval as additional non-invasive electrocardiography parameters for predicting ventricular tachycardia/fibrillation in patients with Brugada syndrome. MethodsWe performed a comprehensive search on TpTe, Tpe Dispersion, TpTe/QT ratio, and QTc interval as a predictor for ventricular tachycardia(VT)/fibrillation(VF)/aborted sudden cardiac death/appropriate ICD shock in patients with Brugada syndromes up until October 2018. ResultsWe included ten studies in the qualitative synthesis and eight studies in meta-analysis. There were a total of 2126 subjects from ten studies. We found that TpTe interval (mean difference 11.97 m s [5.02–18.91]; p < 0.001; I2 80% possibly on ≥80–100 m s and maximum QTc interval (mean difference 11.42 m s [5.90–16.93], p < 0.001; I2 28%) were the most potential ECG parameters to predict VT/VF/AT/SCD. Tpe dispersion and TpTe/QT ratio have a high heterogeneity. Upon sensitivity analysis, there is no single study found to markedly affect heterogeneity of Tpe dispersion and TpTe/QT ratio. Removal of a study reduced maximum QTc interval heterogeneity to 0%. ConclusionsMeasurement of TpTe interval, Tp-e dispersion, TpTe/QT ratio, and QTc interval on ECG emerge as a promising prognostication tool which needs further investigations with a more standardized method, outcome, and cut-off points. As for now, only maximum QTc interval has a reliable result with low heterogeneity sufficiently reliable for prognostication.

Assessment of Tp-Te Interval and Tp-Te/Qt Ratio in Patients with Aortic Aneurysm.

BACKGROUND:Arrhythmic disorders in the aortic aneurysm (AA) have been rarely reported.AIM:The study aimed to assess the repolarisation indices of ventricular arrhythmia (VA) (mainly Tp-Te interval and Tp-Te/QT ratio) in patients with AA.METHODS:A group of 98 patients with AA and 75 patients as control were recruited. Many of indices of ventricular arrhythmia were assessed.RESULTS:Many of indices like QT, QTc, QTpc, Tp-Te/QT, Tp-Te/QTc, Tp-Tec/QTc, S-Tp, S-Tpc, S-Te, S-Tec and fQRS were found to be significantly different in AA group (for all P < 0.05). However, QTp, mean Tp-Te and Tp-Tec were not found different (for all P < 0.05). Aortic diameter (Ao-D) was found to have a positive correlation with QTc, QTpc, S-Tp, S-Tpc, S-Te, S-Tec, fQRS (for all P < 0,05) and negative correlation withTp-Te/QT (P = 0.047). The best cut-off level for prediction of Tp-Te ≥100 ms was found the Ao-D > 43.5 mm in ROC analysis (AUC: 0.69; P = 0.151) with sensitivity 60% and specificity 79.6%.CONCLUSIONS:Although our study did not find any differences for mean Tp-Te interval between groups, many of other indexes of TDR were found to be significantly different. Ao-D was found to have significant correlations with many indices.

Comparing of Tp-Te Interval and Tp-Te/Qt Ratio in Patients with Preserved, Mid-Range and Reduced Ejection Fraction Heart Failure.

BACKGROUND:Heart failure (HF) is classified in three class: HF with preserved EF (HFpEF); normal or LVEF ≥ 50%, HF with reduced EF (HFrEF); LEVF < 40% and newly HF mid-range EF (HFmrEF); LVEF 40-49%. On Electrocardiography (ECG) T wave, Tpeak-Tend (Tp-Te) interval reflects transmural dispersion of repolarisation (TDR) which of these indexes have been proposed as predictors of risk for ventricular arrhythmia (VA) in many cardiac diseases.AIM:Aim of this study to asses these indices of TDR among three HF class.METHODS:Total of 192 patients were included in this study.RESULTS:Many of indices like Tp-Te, Tp-Te/QT wasn’t different between groups (P > 0.05). But mean Q-Tpeak (QTp), S-Tend (S-Te) and S-Tpeak (S-Tp) were found significantly different between groups (P < 0.05). Again S-Te was found different according to having fragmented QRS (fQRS) on ECG (P = 0.031). Comparing to mitral inflow E/A parameters showed significant differences for Tp-Te, Tp-Tec, Tp-Te/QT, Tp-Te/QTc and Tp-Tec/QTc parameters. Finally, we found correlations between S-Te and white blood cell (WBC) (r = - 0.171; P = 0.037) and S-Tp and WBC (r = - 0.170; P = 0.038) and between S-Te and fQRS (r = 0.158; P = 0.031).CONCLUSIONS:We didn’t find differences for many of indices of TDR like Tp-Te interval between groups except QTp, S-Te, S-Tp intervals. Also, S-Te and fQRS showed significant correlation. For prediction of ventricular arrhythmia and cardiovascular death newer indexes on ECG are needed to be established in the future which will make us facilitate to distinguish high risk patients.

Electrocardiographic measures of ventricular repolarization dispersion and arrhythmic outcomes among ST elevation myocardial infarction patients with pre-infarction angina undergoing primary percutaneous coronary intervention.

Arrhythmias are considered one of the major causes of death in ST elevation myocardial infarction (STEMI), particularly in the early in-hospital phase. Pre-infarction angina (PIA) has been suggested to have a protective role. To study the difference in acute electrocardiographic findings between STEMI patients with and without PIA and to assess the in-hospital arrhythmias in both groups. We prospectively enrolled 238 consecutive patients with STEMI. Patients were divided into two groups: those with or without PIA. ECG data recorded and analyzed included ST-segment resolution (STR) at 90min, corrected QT interval (QTc) and dispersion (QTD), T-peak-to-T-end interval (Tp-Te), and dispersion and Tp-Te/QT ratio. In-hospital ventricular arrhythmias encountered in both groups were recorded. Predictors of in-hospital arrhythmias were assessed among different clinical and electrocardiographic parameters. Of the 238 patients included, 42 (17%) had PIA and 196 (83%) had no PIA. Patients with PIA had higher rates of STR (p<0.0001), while patients with no PIA had higher values of QTc (p=0.006), QTD (p=0.001), Tp-Te interval (p=0.001), Tp-Te dispersion (p<0.0001), and Tp-Te/QT ratio (p=0.01) compared to those with angina preceding their incident infarction (PIA). This was reflected into significantly higher rates of in-hospital arrhythmias among patients with no PIA (20% vs. 7%, p=0.04). Furthermore, longer Tp-Te interval and higher Tp-Te/QT ratio independently predicted in-hospital ventricular arrhythmias. Pre-infarction angina patients had better electrocardiographic measures of repolarization dispersion and encountered significantly less arrhythmic events compared to patients who did not experience PIA.

Research Progress in Formation and Application of Tp-Te Interval

Tp-Te interval refers to the duration from the peak to the end time points of T wave in electrocardiogram. Tp-Te interval is an electrocardiogram index reflecting mail-gnant ventricular arrhythmia, while Tp-Te interval mainly reflects ventricular transmural repolarization dispersion. The increase of ventricular transmural repolarization dispersion makes it easy to appear depolarization after repolarization, and forms functional conduction block between different regions, which leads to malignant arrhythmias. In this review we discuss how these markers have demonstrated to be effective to predict malignant arr- hythmias in medical conditions such as long and short QT syndromes, Brugada syndrome and so on. However, the same results have not been found in all conditions. Further studies are needed to reach a global consensus in order to incorporate these VR parameters in risk stratification of these patients.

Correlation between Tp-Te Interval and Myocardial Blush Grade Value in Anterior ST Elevation Myocardial Infarction Patient

Background: Clinical manifestations of coronary herat disease (CHD) may be an ST-Elevation Myocardial Infarction (STEMI). In STEMI condition, there is a metabolic disorder and ion exchange disturbance which causes dispersion of transmural repolarization, as well as micro coronary circulation disturbance involving mechanism of microvascular dysfunction. The Tp-Te interval is an electrocardiogram paramener that could be described as the transmural dispersion of repolarization. Assessment of Myocardial Blush Grade (MBG) is a coronary angiography densitometry method that can be used to assess microvascular dysfunction. This study aims to examine the correlation between Tp-Te interval and MBG in anterior STEMI.Methods: The research desgin is cross sectional. Data were taken consecutive from August to November 2017. The Tp-Te interval assessment was performed on the basis of an electrocardiogram record from the subjects. The MBG value assessment was performed using a Quantitative Blush Evaluator (QuBE) computer program based on coronary angiography. The Tp-Te interval is divided into 2 groups: Tp-Te interval &gt; 94 ms and Tp-Te interval ≤ 94 ms. The MBG values are divided into 3 groups: MBG QuBE 1, MBG QuBE 2 and MBG QuBE 3. The assessment of Tp-Te interval and MBG value was performed by observer in intra-observer which were acknowledged based on Kappa and blindness conformity test results against patient clinical data. Pearson correlation test was used to analyze the correlation between Tp-Te interval and MBG value, while logistic regression test was used for multivariate test.Results: Of the total 32 study subjects, there were 23 subjects with Tp-Te interval &gt;94 ms and 9 subjects with Tp-Te interval ≤94 ms. There was a negative correlationwith moderate strength between the Tp-Te interval and the MBG value in the anterior STEMI patients (r =-0.501, p =0.004). There was a prevalence ratio of 4.304 between Tp-Te interval &gt;94 milliseconds against MBG QuBE 1 (95%CI: 1.264-14.658, p &lt;0.001). Multivariate tests showed Tp-Te intervals consistently as independent risk factors for MBG values in subjects with anterior STEMI.Conclusion: There is a negative correlation with moderate strength between the Tp-Te interval and the MBG value in the anterior STEMI patients.

Electrocardiographic Analysis of Repolarization Changes in South Indian Children with Kawasaki Disease after the Acute Phase of Illness.

Background Cardiac involvement in children with Kawasaki disease (KD) may present with repolarization abnormalities which are associated with increased risk of ventricular arrhythmias and sudden cardiac events. Methods Twenty children with history of KD without cardiac involvement in the acute phase were recruited along with age and sex-matched controls. Twelve-lead ECG was obtained from both groups using CARDIART 610T ECG system at 25 mm/sec and 50 mm/sec paper speed. ECG was repeated in 19 children in the study group after 9 ± 2 months. Measurements (QT dispersion (QTd), T-wave peak to end (Tp-Te) interval, and Tp-Te/QT ratio) were made using standard digital calipers. Statistical analysis was performed with student t-test and analysis of variance (ANOVA) using SSPS version 17.0. Results The mean value of QTd in the first ECG in cases was significantly high: 43.15 ± 14.13 versus 29.47 ± 8.637 in the controls (p = 0.001). The follow-up ECG in 19 cases showed a mean value of 46.26 ± 16.25 versus 43.89 + −14.53 at baseline (p = 0.440). QTd was increased in the follow-up ECG but was not statistically significant. There was no statistical significance seen in the Tp-Te interval and Tp-Te/Qt ratio as observed in Lead II and Lead V5. Conclusion Significant increase in the QTd in children with KD indicates repolarization changes in the myocardium even in the absence of clinical carditis. The persistence of this change on follow-up could indicate a possible increased risk for ventricular arrhythmia and warrants long term assessment of the cardiovascular status.

T wave peak-to-end interval in COPD.

IntroductionThe interval from the peak to the end of the electrocardiographic (ECG) T wave (Tp–Te) can estimate cardiovascular mortality and ventricular tachyarrhythmias.ObjectivesIn this study, we aimed to define a new ECG parameter in patients with COPD.MethodsThis was a cross-sectional observational study that included COPD patients who were diagnosed previously and followed up in the outpatient clinic. All data of the patients’ demographic features, history, spirometry, and electrocardiographs were analyzed.ResultsWe enrolled 134 patients with COPD and 40 healthy volunteers as controls in our study. Patients already known to be having COPD who were under follow-up for their COPD and diagnosed as having COPD according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria were included. Men comprised 82.8% of the COPD group and 73.2% of controls. The mean age in the COPD and control group was 60.2±9.4 and 58.2±6.7 years, respectively. There was no significant difference between the groups for age or sex (p=0.207, p=0.267, respectively). There were 46 (34.3%) patients in group A, 23 (17.2%) patients in group B, 26 (19.4%) patients in group C, and 46 (29.1%) patients in group D as COPD group. There was a significant increase in Tp–Te results in all precordial leads in the COPD group compared with the control group (p<0.05). Precordial V4 lead has the most extensive area under the curve (0.831; sensitivity 76.5%, specificity 89.6%).ConclusionWe present strong evidence that Tp–Te intervals were increased in patients with COPD, which suggests that there may be an association between COPD and ventricular arrhythmias and cardiac morbidity.

Elevated LV Mass and LV Mass Index Sign on the Athlete's ECG: Athletes' Hearts are Prone to Ventricular Arrhythmia.

Objectives: Intense exercise elevates all heart chambers’ dimensions, left ventricular mass (LV mass), and left ventricular mass index (LV mass index). The relationship between increased ventricular arrhythmias and sudden cardiac death with LV dilatation and elevated LV mass has been previously demonstrated. We investigated whether sports-related LV dilatation and elevated LV mass and LV mass index cause an increase in ventricular repolarization heterogeneity. Patients and Methods: This prospective observational study recruited 565 participants. There were 226 (female: 28) athletes and 339 (female: 45) healthy controls between 17 and 42 years of age. They were evaluated using 12-lead-electrocardiography and transthoracic echocardiography. Electrocardiograms were obtained at a rate of 50 mm/s and an amplitude of 10 mV, including at least 3 QRS complexes for each derivation. They were taken with 12 standard deviations. Transmural dispersion of repolarization indexes (TDR) (Tp-Te interval, Tp-Te/QT ratio and Tp-Te/QTc ratio, Tp-Te(d)) were measured from precordial derivations. Measurements weretakenwith a program which was generated with MATLAB codes. Results: Tp-Te interval, Tp-Te/QT ratio, Tp-Te/QTc ratio, Tp-Te(d), PW (posterior wall thickness), IVS (interventricular septal thickness), LVEDD (left ventricular end-diastolic diameter), LV mass (left ventricular mass), and LV mass index (left ventricular mass index) for the athlete group were significantly higher than for the control group. Correlation analyses revealed that TDR indexes significantly correlated with PW, IVS, LVEDD, LV mass, and LV mass index. Conclusion: LV mass and LV mass index increase in well-trained athletes, and this increase leads to an increase in TDR indexes. The increased frequency of ventricular arrhythmia and sudden cardiac death may be explained with increasing ventricular repolarization heterogeneity in these individuals.