T(p-e)/QT ratio as an index of arrhythmogenesis

Effect of Heroin on Electrocardiographic Parameters

Fundamento

Atualmente, o vício em heroína é um problema de saúde preocupante, e as informações sobre os efeitos eletrocardiográficos da heroína são limitadas.

Objetivos

O objetivo do presente estudo é investigar os efeitos da dependência de heroína em parâmetros eletrocardiográficos.

Métodos

Um total de 136 indivíduos, incluindo 66 indivíduos que fumam heroína como grupo de estudo e 70 indivíduos saudáveis sem dependência de drogas como grupo de controle, foram incluídos no estudo. Indivíduos que injetam heroína foram excluídos. A avaliação eletrocardiográfica (ECG) dos usuários de heroína foi realizada e comparada com as do grupo controle. Além disso, os ECGs pré e pós-tratamento do grupo usuário de heroína foram comparados. Um valor de p<0,05 foi aceito como estatisticamente significativo.

Resultados

A frequência cardíaca (77,2±12,8 versus 71,4±11,2; p=0,02) foi maior no grupo usuário de heroína em comparação com o grupo controle. Os intervalos QT (341,50±25,80 versus 379,11±45,23; p=0,01), QTc (385,12±29,11 versus 411,3±51,70; p<0,01) e o intervalo do pico ao fim da onda T (Tpe) (65,41±10,82 versus 73,3±10,13; p<0,01) foram significativamente menores no grupo usuário de heroína. Nenhuma diferença foi observada entre os grupos com respeito às razões Tpe/QT e Tpe/QTc. Na análise de subgrupo do grupo usuário de heroína, os intervalos QT (356,81±37,49 versus 381,18±40,03; p<0,01) e QTc (382,06±26,41 versus 396,06±29,80; p<0,01) foram significativamente mais curtos no período pré-tratamento.

Conclusão

O vício em heroína afeta significativamente os intervalos de tempo QT, QTc e Tpe. Os efeitos de arritmia desses parâmetros já são conhecidos. Os parâmetros eletrocardiográficos desses indivíduos merecem mais atenção. (Arq Bras Cardiol. 2020; 115(6):1135-1141)

Cardiovascular risk assessment in children and adolescents with congenital solitary kidneys

Patients with solitary kidneys (SKs) are at risk of hypertension (HT) and associated end-organ damage. The authors aimed to evaluate whether children with congenital SKs (CSKs) have higher office, ambulatory, or central blood pressure (BP), increased arterial stiffness or left ventricular mass index, or any risk for arrhythmia. With this purpose, patients with CSK and healthy controls being followed up between January 2018 and June 2019 were enrolled in the study. Demographic, biochemical, and office blood pressure (BP) data were recorded. Then, ambulatory blood pressure monitoring (ABPM) and measurements of central BP (cBP), pulse wave velocity (PWV), and augmentation index (AIx@75) were obtained. Ventricular repolarization parameters were acquired by 12-lead electrocardiography. Left ventricular mass index (LVMI) and abdominal aortic stiffness parameters including strain, pressure strain elastic modulus (Ep), and normalized Ep (Ep*) were calculated with echocardiographic measurements. Finally, 36 children with CSK and 36 healthy controls were included. Serum creatinine, uric acid, total cholesterol levels, ABPM parameters, cBP levels, and PWV values were significantly higher, and eGFR levels were significantly lower in the CSK group. VR parameters, abdominal aortic stiffness indices, and LVMI were similar between the groups. CSK increased the risk of HT in ABPM (HT_ABPM ) by 6 times. PWV was significantly correlated with Ep and Ep* in cases with CSK. Determination of cBP and PWV along with 24-hour ABPM would be a useful tool in children with CSK.

Assessment of Structure, Function, and Rhythm of the Heart with Echocardiography and Electrocardiography in Adolescent Swimmers

The aim of this study was to evaluate the cardiac parameters by using electrocardiography and echocardiography in adolescent swimmers. Twenty-two adolescent swimmers and 22 gender- and age-matched sedentary controls admitted to our center between November 2018 and May 2019 were included in this study. In addition to demographical characteristics, participants were assessed via a 12-lead electrocardiography and two-dimensional echocardiography for cardiac function. On the echocardiography, end-systolic and end-diastolic interventricular septum, end-systolic and end-diastolic left ventricular posterior wall thicknesses, left atrial width, Tricuspid E, left ventricular mass and left ventricular mass index were higher in the swimmers when compared to the sedentary controls (P < 0.05). On the electrocardiography, Tp-e duration which reflects ventricular transmural repolarization, and Tp-e/QT and Tp-e/corrected QT ratios were higher in the swimmers than the sedentary controls (P < 0.05). In conclusion, swimming exercise in children leads to concentric thickening of left ventricle and induces an increase in Tp-e duration, and Tp-e/QT and Tp-e/corrected QT ratios, which are the novel markers for risk of ventricular arrhythmias.

Effects of Antipsychotics on Arrhythmogenic Parameters in Schizophrenia Patients: Beyond Corrected QT Interval

PURPOSE

Antipsychotic drugs have been implicated as risk factors for QT prolongation, which is a predictor of sudden cardiac death. However, the QT interval is considered an imperfect marker for proarrhythmic risk. Recently, improved methods, namely, QT dispersion (QTD), QTD ratio (QTDR), T wave peak-to-end interval (Tp-e), Tp-e/QT ratio and Tp-e/QTc ratio, have been regarded as proarrhythmic risk markers. We attempted to reevaluate the risk of sudden cardiac death due to antipsychotics use by measuring these improved evaluation methods.

PATIENTS AND METHODS

We retrospectively evaluated QTc, QTD, QTDR, Tp-e, Tp-e/QT ratio and Tp-e/QTc ratio from the medical records of 410 patients with schizophrenia diagnosed by the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision, or 5th Edition. Information on drugs administered was obtained from medical records. We investigated the correlation between each index on ECG and medication, such as antipsychotics, prescribed to participants with linear regression analysis. We also compared each index between 235 healthy controls and 235 patients matched for age and sex.

RESULTS

Positive correlations between QTc and levomepromazine and brexpiprazole were identified. Levomepromazine and lithium were positively correlated with QTD. Levomepromazine, quetiapine, asenapine, clozapine and carbamazepine were positively correlated with QTDR. Levomepromazine, olanzapine, brexpiprazole and lithium were positively correlated with Tp-e. Olanzapine, brexpiprazole and lithium were positively correlated with the Tp-e/QT ratio. Olanzapine, brexpiprazole and lithium were positively correlated with Tp-e/QTc ratio. Significant differences in all indexes were noted between the patients and healthy controls.

CONCLUSION

According to our results, the prediction of the risk of sudden cardiac death by each index was inconsistent. We should evaluate the predictive factor of ventricular arrhythmia according to various electrocardiogram indexes because QTc alone could not identify the risk of sudden cardiac death.

Assessment of Cardiac Arrhythmic Risk in Children With Covid-19 Infection

Coronavirus disease of 2019 (COVID-19) is a cause of significant morbidity and mortality worldwide. Although COVID-19 clinical manifestations are mainly respiratory, major cardiac complications are being reported. The mechanism of cardiac injury and arrhythmias is unclear. Also, drugs currently used to treat the COVID-19 may prolong the QT interval and may have a proarrhythmic propensity. The study aims to investigate the effects of COVID-19 infection with asymptomatic and mild symptoms on trans-myocardial repolarization parameters in children without treatment. A total of 105 COVID-19 patients were compared with 40 healthy children. The patient and control group data were compared by calculating the QT interval, corrected QT (QTc), QT dispersion (QTd), QTc dispersion (QTcd), Tp-e, Tp-e dispersion, Tp-e/QT ratio, and Tp-e/QTc ratio on the 12-lead surface electrocardiogram. The mean age was determined as 11.2 ± 0.3 years in the patient group, and 10.8 ± 2.1 years in the control group. In the COVID-19 group, QTd, QTcd, Tp-e, Tp-e dispersion, Tp-e/QT ratio and Tp-e/QTc ratio were statistically higher than the control group. The ventricular repolarization was impaired even in asymptomatic children with COVID-19 infection. These results suggest the need to further assess the long terms risks of prolonged QT dispersion in the setting of COVID-19 infection.

Utility of Normalized TdP Score System in Drug Proarrhythmic Potential Assessment: A Blinded in vitro Study of CiPA Drugs

Drugs that prolong QT may cause torsade de pointes (TdP). However, translation of nonclinical assessment of QT prolongation or hERG channel, targeted by QT-prolonging drugs, into clinical TdP risk has been insufficient to date. In this blinded study, we confirmed the utility of a Normalized TdP Score System in predicting drug-induced TdP risks among 34 drugs, including 28 with low, intermediate, and high TdP risks under the Comprehensive In Vitro Proarrhythmia Assay (CiPA) initiative plus six compounds with names blinded to the investigators, using the rabbit ventricular wedge assay. Concentration-dependent TdP scores were determined by drug-induced changes in QT, T_p-e , and proarrhythmias. Disclosure of the names and testing concentrations was made after completion of the experiments and report to the sponsors. Drugs' normalized TdP scores were calculated thereafter based on their respective free clinical maximum concentration (C_max ). Drugs' normalized TdP scores were calculated and ranked for 33 drugs, excluding 1 investigational drug, and the TdP risks of the 28 CiPA drugs were correctly distinguished according to their respective categories of low, intermediate, and high TdP risks under the CiPA initiative. Accordingly, we are able to propose the cutoff values of the normalized TdP scores at 1 × C_max : ≤ 0, > 0 to < 0.65 and ≥ 0.65, respectively, for low, intermediate, and high risk. This blinded study supports utility of our Normalized TdP Score System in predicting drug-induced TdP risks in 33 drugs, including 28 used for characterization of other assays under the CiPA initiative. However, these results need to be replicated in other laboratories.

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.

Importance of electrocardiographic markers in predicting cardiac events in children

ECG is a common diagnostic tool in medical practice. Sudden cardiac death (SCD) is a rare but devastating event. The most common cause of SCD in the young is a primary arrhythmic event, which is often produced by malignant ventricular arrhythmia. Several electrocardiographic markers for ventricular repolarization and depolarization have been proposed to predict this arrhythmic risk and SCD in children. Although many of these parameters can easily be used in clinical practice, some of them need specific techniques for interpretation. In this review, we summarized the current knowledge regarding the clinical importance and the ability of these ECG parameters to predict adverse cardiac events in the pediatric population.

Index of cardiac-electrophysiological balance and the effects of thrombolytic therapy on the electrocardiogram of patients with pulmonary embolism

OBJECTIVE

Different parameters on electrocardiograms (ECG) have been investigated to predict arrhythmia and mortality in patients with acute pulmonary embolism (APE). The acute effect of thrombolytic therapy (TT) on these parameters has not been investigated yet.

METHODS

We examined the data of 83 patients who were evaluated as high-risk APE and discharged from the hospital after TT. First, the high-risk APE patients' ECGs were compared with healthy control subjects (n = 55). After their admission and 24 hours later, the ECGs of patients with APE were compared. Heart rate, P-wave morphology, QRS duration, QT distance, Tp-e, and the index of cardiac electrophysiological balance (iCEB) were analyzed.

RESULTS

Although P maximum was not different between the groups' ECGs, heart rate, QT, QTc (corrected QT) interval, Tp-e intervals, Tp-e/QT ratio, and P wave dispersion were significantly higher in the APE group ( P values < 0.031). iCEB or iCEBc (corrected iCEB) values were lower in APE group ( P < 0.001). After TT, we determined a decrease in heart rate, Tp-e interval, and Tp-e/QT ratio ( P < 0.001). Although we detected a decrease in the QT and QTc interval and QT dispersion (QTd), QTd had no statistical significance (respectively P -value 0.013, 0.029, and 0.096). The iCEB and iCEBc levels were lower after TT ( P -value was 0.035 and 0.044 respectively).

CONCLUSION

The QT, QTc, Tp-e interval, Tp-e/QTc ratio, iCEB, and iCEBc values significantly decreased after TT. It may be thought that effective TT causes partial improvement in ventricular repolarization in an early period.

Assessment of Ventricular Repolarization in Sickle Cell Anemia Patients: The Role of QTc Interval, Tp-e Interval and Tp-e/QTc Ratio and Its Gender Implication

Background

Many specific and non-specific electrocardiographic abnormalities including ventricular arrhythmias have been reported in subjects with sickle cell anemia (SCA). In SCA patients, cardiac electrical abnormalities may be the leading cause of increased risk of arrhythmias. The corrected QT (QTc) interval, peak to the end of the T wave (Tp-e) interval and associated Tp-e/QTc ratio are promising measures of altered ventricular repolarization and increased arrhythmogenesis risk.

Aim

This study assessed ventricular repolarization abnormalities in subjects with SCA using the QTc interval, Tp-e interval and Tp-e/QTc ratio, and also evaluated the gender differences in these parameters, as well as their determinants.

Methods

Sixty subjects with SCA and 60 healthy control subjects, matched for age and gender, were studied. All participants underwent physical examination, hematological and biochemical evaluation, and 12-lead electrocardiography (ECG) recording. QT and Tp-e intervals were measured from the ECG, and the QTc interval was calculated using Bazett’s formula. Tp-e/QT and Tp-e/QTc ratios were also derived.

Results

QT and QTc intervals were prolonged in subjects with SCA. Tp-e interval, Tp-e/QT ratio and Tp-e/QTc ratio were prolonged in male SCA subjects, with a paradoxical shortening in female SCA subjects. Plasminogen activator inhibitor-1 (PAI-1) was an independent determinant of QTc, while body mass index (BMI) was an independent determinant of both Tp-e interval and Tp-e/QTc ratio.

Conclusion

Our results suggest an elevated risk for ventricular arrhythmogenesis in male SCA subjects. Furthermore, increased BMI and PAI-1 level are possible markers of ventricular repolarization abnormalities in SCA subjects.

The effect of low iron storage without Anaemia on electrocardiography

BACKGROUND

Low iron storage is a common health problem around the world. Although the association of low iron storage with cardiovascular events and various electrocardiographic parameters has been investigated, its association with fragmented QRS (fQRS), T_peak-T_end (Tp-e) interval, Tp-e/QT and Tp-e/QTc ratios, which are important criteria for repolarization, has not been studied in adults.

METHODS

A total of 201 female patients in the 18-50 age group with no history of chronic and cardiac disease or anaemia were included in the study. Patients were divided into 3 groups based on their ferritin levels. Twelve lead EKGs were obtained from each patient, and fQRS, Tp-e interval, Tp-e/QT and Tp-e/QTc ratios were calculated manually.

RESULTS

A total of 201 female patients with an average age of 37 ± 9 were included in the study. Group 1 (ferritin<15 ng/mL) consisted of 79 (39.3%) patients, Group 2 (ferritin 15-30 ng/mL) consisted of 64 patients (31.8%) and Group 3 (ferritin≥30 ng/mL) consisted of 58 (28.9%) patients. Tp-e interval was significantly higher in Group 1 compared to Group 2 and 3 (p < 0.001). A similar relationship was also observed between Tp-e/QT, Tp-e/QTc and fQRS (p < 0.001). A moderate, negative relationship was found in the correlation analysis of Tp-e, Tp-e/QT, Tp-e/QTc and fQRS with ferritin value [r = -0.519 (p = 0.001), r = -0.485 (p = 0.001), r = -0.540 (p = 0.001) and r = -0.345 (p = 0.001), respectively].

CONCLUSION

As a result of the study, it was found that low iron storage may increase arrhythmogenic susceptibility through increased fragmented QRS presence, increased Tp-e interval, Tp-e/QT and Tp-e/QTc ratios in healthy women of childbearing age.

Interpretation of arrhythmogenic effects of COVID-19 disease through ECG

OBJECTIVE

We aimed to detect the malignant arrhythmic potential of COVID-19 with surface electrocardiographic (ECG) markers.

MATERIAL AND METHOD

Of the ECG parameters PR, QT, QTc, QTd, TPe, and Tpe/QTc were measured in 51 COVID-19 patients and 40 in control subjects.

RESULTS

Compared to control group mean QTc (410.8 ± 24.3 msec vs. 394.6 ± 20.3 msec, p < .001) and Tpe/QTc (0.19 ± 0.02 vs. 0.18 ± 0.04, p = .036) and median QTd (47.52 vs. 46.5) values were significantly higher in COVID-19 patients. Troponin levels were significantly correlated with heart rate (r = 0.387, p = .006) but not with ECG parameters.

CONCLUSION

Several ventricular arrhythmia surface ECG predictors including QTc, QTd, and Tpe/QTc are increased in COVID-19 patients. Since medications used in COVID-19 patients have the potential to affect these parameters, giving importance to these ECG markers may have a significant contribution in decreasing disease-related arrhythmias.

Diabetic microvascular complications associated with myocardial repolarization heterogeneity evaluated by Tp-e interval and Tp-e/QTc ratio

INTRODUCTION

The heterogeneity in myocardial repolarization increases the risk of ventricular arrhythmias and sudden death in patients with diabetes mellitus (DM). The Tp-e interval and Tp-e/QTc ratio are found to be useful in the prediction of ventricular arrhythmias. In this study, we aimed to investigate the Tp-e interval and Tp-e/QTc ratio in diabetic patients with and without microvascular complications.

MATERIALS AND METHODS

This cross-sectional observational study included patients with type 2 DM who presented to the endocrinology outpatient clinic. Diabetic microvascular complications were evaluated. The Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio were also calculated.

RESULTS

A total of 240 patients with type 2 DM (148 patients had microvascular complications) were included in the study. Diabetic neuropathy rate was 30.4%, diabetic nephropathy rate was 38.4%, and diabetic retinopathy rate was 21.7%. Upon comparing patients according to Tp-e/QTc ratio, the median Tp-e/QTc interval of the group of patients with complications was 0.21 (0.19-0.23) and the median Tp-e/QTc ratio of the group of patients without complications was 0.19 (0.18-0.20) (p < 0.001). When patients were grouped according to the presence and severity of retinopathy, the Tp-e/QTc ratio was more prolonged in the proliferative retinopathy group [0.27 (0.23-0.30)] than the non-proliferative retinopathy group [0.20 (0.19-0.22), p < 0.001]. When patients were grouped according to the presence and severity of nephropathy, the Tp-e/QTc ratio was more prolonged in the macroalbuminuria and microalbuminuria group than the normoalbuminuric group [0.25 (0.21-0.30), 0.23 (0.19-0.24), and 0.19 (0.20-0.22), respectively, p = 0.002].

CONCLUSIONS

Our study is the first to demonstrate the association of the Tp-e interval and Tp-e/QTc ratio with the presence and severity of microvascular complications in patients with type 2 DM.

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.

ECG changes in patients with opioid use disorder; P-QT wave dispersion: a retrospective study

OBJECTIVE

We aimed to examine the electrocardiographic arrhythmia risk predictors in patients with opioid use disorder by P wave dispersion, QT dispersion, and by comparing Tp-e/QTc ratio with healthy controls.

METHODS

One hundred seventeen patients who were diagnosed with opioid use disorder according to DSM-5 criteria and who were hospitalized in 25 Aralık Gaziantep State Hospital AMATEM (Alcohol and substance addiction treatment center) service and a healthy control group consisting of 168 subjects were included in the study. Electrocardiography (ECG) scans of all participants were performed in the supine position and at rest. P wave dispersion, QT dispersion, and Tp-e/QTc ratio were calculated.

RESULTS

Of all the participants, 12 were women (4.21%), 273 (95.78%) were men. The mean age of all participants was 30.42 ± 9.36 years. No difference was found between the gender, mean age, marital status, educational level, and smoking status of the participants (p > 0.05). The entire patient group was using heroin. Heart rate of the patient group was calculated as 68.14 ± 13.26 beats per minute, being lower than healthy controls (p < 0.05). Although QT dispersion value was lower than healthy controls (p < 0.05); P wave dispersion did not differ between groups (p > 0.05).

CONCLUSION

It is thought that the patients with opioid use disorder are at risk for cardiac arrhythmia based on our findings. Therefore, physicians should be careful about cardiac rhythm and conduction problems while organizing any treatment of these patients.

Impaired repolarization parameters may predict fatal ventricular arrhythmias in patients with hypertrophic cardiomyopathy (from the CILICIA Registry)

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is significantly associated with high risk of fatal ventricular arrhythmias (VAs). Increased frontal QRST angle (fQRSTa), Tpe interval, and Tp-e/QTc ratio are described as ventricular repolarization parameters which are related to arrhythmias. In this study, we aimed to investigate the predictive value of these repolarization parameters for fatal VAs in patients with HCM.

METHODS

A total of 127 HCM patients (mean age: 47.9 ± 12.6 years; male:79) were enrolled in this retrospective study. All patients underwent transthoracic echocardiography. Moreover, the last electrocardiograms within 3 months prior to the fatal VA documentation were assessed. The primary outcome was the occurrence of fatal VAs including sustained ventricular tachycardia and ventricular fibrillation which were documented from implantable cardioverter defibrillator records.

RESULTS

There were documented fatal VAs in 37 (29.1%) patients during a mean follow-up time of 70.1 ± 22.6 months. The prevalence of fatal VAs was significantly higher in patients with fQRSTa ≥140 degrees (67.4 vs. 7.4%; p < 0.001) and in patients with Tp-e/QTc ratio ≥ 0.19 (61.5 vs. 6.7%; p < 0.001) as compared to others. High Tp-e/QTc ratio (hazard ratio: 1.564; 95% confidence interval: 1.086-4.796; p = 0.032) and high fQRSTa (hazard ratio: 1.864; 95% confidence interval: 1.106-8.745; p = 0.002) were found to be independent predictors of fatal VAs in HCM patients.

CONCLUSIONS

Wider fQRSTa, prolonged Tp-e interval, and increased Tp-e/QTc ratio may be associated with fatal VAs in HCM patients. In addition to traditional risk factors, these simple ECG parameters may provide valuable information during evaluation of sudden cardiac death risk in HCM patients.

Evaluation of electrocardiographic markers of cardiac arrhythmic events and their correlation with cardiac iron overload in patients with β-thalassemia major

Iron overload is associated with an increased risk of atrial and ventricular arrhythmias. Data regarding the relationship between electrocardiographic parameters of atrial depolarisation and ventricular repolarisation with cardiac T2* MRI are scarce. Therefore, we aimed to investigate these electrocardiographic parameters and their relationship with cardiac T2* value in patients with β-thalassemia major. In this prospective study, 52 patients with β-thalassemia major and 52 age- and gender-matched healthy patients were included. Electrocardiographic measurements of QT, T peak to end interval, and P wave intervals were performed by one cardiologist who was blind to patients' data. All patients underwent MRI for cardiac T2* evaluation. Cardiac T2* scores less than 20 ms were considered as iron overload. P wave dispersion, QTc interval, and the dispersions of QT and QTc were significantly prolonged in β-thalassemia major patients compared to controls. Interestingly, we found prolonged P waves, QT and T peak to end dispersions, T peak to end intervals, and increased T peak to end/QT ratios in patients with T2* greater than 20 ms. No significant correlation was observed between electrocardiographic parameters and cardiac T2* values and plasma ferritin levels. In conclusion, our study demonstrated that atrial depolarisation and ventricular repolarisation parameters are affected in β-thalassemia major patients and that these parameters are not correlated with cardiac iron load.

Correlation between apnea-hypopnea index and Tp-Te interval, Tp-Te/QT, and Tp-Te/QTc ratios in obstructive sleep apnea

Background

Obstructive sleep apnea (OSA) is a highly prevalent sleep disorder associated with important cardiovascular complications including ventricular arrhythmias. Tp‐Te interval, Tp‐Te/QT, and Tp‐Te/QTc ratios are repolarization indices representing ventricular arrhythmogenic potential. These parameters are associated with ventricular arrhythmias and sudden cardiac death. The aim of this study was to investigate the correlation between apnea–hypopnea index and Tp‐Te, Tp‐Te/QT, and Tp‐Te/QTc in OSA.

Methods

We screened a total of 280 patients who underwent overnight polysomnography (PSG) between the years 2012–2017 at our institution. Patients were assigned into four groups based on severity of apnea–hypopnea index: 70 with apnea–hypopnea index (AHI) <5 (control group), 71 with 5 ≤ AHI < 15, 63 with 15 ≤ AHI < 30, and 76 with AHI ≥ 30. Tp‐Te, Tp‐Te/QT, and Tp‐Te/QTc were measured.

Results

Compared to control group, repolarization parameters were significantly prolonged in other groups (Tp‐Te interval: 68.3 ± 6.8, 71.8 ± 6.3, 79.1 ± 5.5, and 85.1 ± 6.4 ms, p < .001; Tp‐Te/QT ratio: 167.5 ± 12.7, 181.7 ± 13.0, 202.2 ± 10.0 and 219.4 ± 13.5, p < .001; Tp‐Te/QTc ratio: 151.1 ± 16.6, 167.6 ± 16.6, 193.7 ± 14.4, and 225.5 ± 17.0, p < .001). There was a significant trend toward higher Tp‐Te, Tp‐Te/QT, and Tp‐Te/QTc across higher AHI categories. In a univariate regression analysis, body mass index, smoking status, Tp‐Te, and Tp‐Te/QTc were significantly associated with the severity of AHI in OSA. Tp‐Te (OR 1.629, 95% CI 1.393–1.906, p < .001), Tp‐Te/QTc (OR 1,333 95% CI 1.247–1.424, p < .001), and smoking status (OR 5.771, 95% CI 1.025–32.479, p = .047) were found to be significant independent predictors of severity of AHI in a multivariate analysis, after adjusting for other risk parameters.

Conclusions

Our study showed that Tp‐Te, Tp‐Te/QT, and Tp‐Te/QTc were prolonged in patients with OSA. There was significant correlation between apnea–hypopnea index and these parameters.

Disease severity affects myocardial functions in patients with treatment-naive early rheumatoid arthritis

OBJECTIVES

The cross-sectional study aimed to assess myocardial functions using global longitudinal strain (GLS) echocardiography and arrhythmia parameters with treatment naive newly diagnosed rheumatoid arthritis (RA) and no clinical evidence of cardiovascular disease (CVD).

METHODS

Seventy seven newly diagnosed treatment-naive RA patients were enrolled. Disease severity was evaluated according to rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA) positivity, and Disease Activity Score 28 C-reactive protein (DAS28 CRP). Myocardial functions were assessed using conventional echocardiography and GLS technique and electrocardiogram parameters cQT and Tp-e/cQT.

RESULTS

Twenty three patients had severe disease while 54 patients were non-severe. The Left Ventricle GLS (17.98 ± 1.24 vs 21.29 ± 1.03, P < .001), cQT (428.71 ± 9.05 vs 394.61 ± 17.83, P < .001), Tp-e/cQT (0.19 ± 0.02 vs 0.16 ± 0.01, P < .001) for severe RA patients was reduced compared to RA non-severe patients. Penalized maximum likelihood estimation logistic regression analysis revealed LVGLS as the only significantly independent predictor of severe RA disease (OR 0.70, CI 95% 0.52-0.92, P = .001). Receiver operating characteristic (ROC) curves of the LVGLS was revealed 19.9 as GLS discriminative value with 88.8% positive predictive value for predicting severity. Severe RA risk increases when log-odds value was over 0, corresponds to LVGLS value less than 18 by partial effect plots.

CONCLUSION

RA severity was associated with lower LV systolic myocardial function and increased arrhythmia parameters. Only LVGLS was significantly independent predictor of RA disease severity.

Effect of different general anaesthetics on ventricular repolarisation in robot-assisted laparoscopic prostatectomy

BACKGROUND

Ventricular repolarisation is affected differently by the types of anaesthetics used. This study aimed to compare the effect of different types of anaesthetics on ventricular repolarisation during robot-assisted laparoscopic radical prostatectomy (RALP).

METHODS

Sixty-nine patients were randomly assigned in a 1:1:1 ratio to the Sevoflurane (sevoflurane/remifentanil), Desflurane (desflurane/remifentanil) or total intravenous anaesthesia (TIVA [propofol/remifentanil]) groups; however, only 67 patients completed the study. The primary outcome was heart rate-corrected QT (QTc) interval collected at nine time points during RALP. Bazett's (QTcB) and Fridericia's (QTcF) formulae were used for QT interval correction. The secondary outcomes were Tpeak-Tend (Tp-e) interval and Tp-e/QT ratio that were collected at the same time points.

RESULTS

The QTcB and QTcF intervals were significantly prolonged during surgery in all groups; however, these values showed significant intergroup differences with time. After assuming the Trendelenburg position, the QTcB and QTcF intervals were significantly longer in the Desflurane group than in the other two groups, and this prolongation continued until the end of surgery. Intra-operatively, the QTcB and QTcF intervals exceeded 450 ms in six and five patients, respectively, in the Desflurane group, but in none in the TIVA group. Moreover, the incidence of intra-operative QTc interval prolongation >20 ms and >60 ms was significantly higher in the Desflurane group than in the TIVA group. There were no significant differences in Tp-e intervals and Tp-e/QT ratio among the three groups during surgery.

CONCLUSIONS

To minimise QTc interval prolongation during RALP, TIVA with propofol/remifentanil is recommended for general anaesthesia.

Myocardial Repolarization Parameters and Neutrophil-to-Lymphocyte Ratio are Associated with Cardiotoxicity in Carbon Monoxide Poisoning

The present study aims to examine the clinical values of complete blood count (CBC) bioindicators and corrected QT (QT_c), T_peak - T_end interval (T_p-e), T_{peak dispersion} (T_{p disp}), and T_p-e/QT ratio that are the parameters of myocardial repolarization (M-rep) for cardiotoxicity, which develops due to acute carbon monoxide (CO) intoxication in patients admitted to the emergency service. This retrospective, cross-sectional, observational, and single-center study was conducted between April and June 2019. Statistical analysis was performed using the SPSS 23.0 software. Data of 234 participants were analyzed. Of these, 54.9% (n = 129) were female. Neutrophil-to-lymphocyte ratio (NLR), QT_c, T_p-e values were significantly high in the CO intoxication group (p < 0.001, p < 0.001, and p < 0.001, respectively), whereas T_p-e/QT_c ratio was significantly lower in the CO intoxication group than that in the control group (p < 0.001). NLR, T_p-e, T_{p disp} values were significantly high in the myocardial injury (M-inj) group (p < 0.001, p = 0.003, and p = 0.018, respectively). Furthermore, T_p-e/QT_c ratio was significantly low in the M-inj group (p = 0.002). M-rep parameters and NLR are associated with CO intoxication and the development of M-inj. Moreover, these bioindicators and can provide clinicians an early indication of M-inj.

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 Objectives

Potential 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.

Methods

A 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.

Results

We 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).

Conclusion

This 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.

Investigation of the Value of T peak to T end and QTc Intervals as Electrocardiographic Arrhythmia Susceptibility Markers in Acute Ischemic Stroke

INTRODUCTION

Arrhythmias are one of the most common causes of mortality in patients with acute ischemic stroke (AIS). This study aimed to investigate the relationships of arrhythmia susceptibility markers (QT, QTc, Tpe, Tpe-D, Tpe/QT, and Tpe/QTc) with the localization and volume of the ischemic area, the National Institutes of Health Stroke Scale (NIHSS) scores, and troponin levels in AIS.

METHODS

Patients diagnosed with AIS in the emergency department in the period from 01 November 2016 to 31 March 2019 were retrospectively reviewed. Patients admitted to the emergency department with no pathological ECG findings were included. The measurements of QT, QTc, Tpe, Tpe-D, Tpe/QTc, and Tpe/QT were performed under a digital microscope. The NIHSS scores, troponin values, and the ischemic area volume based on the diffusion-weighted magnetic resonance imaging findings at the time of admission were found.

RESULTS

A total of 135 patients, comprising 70 AIS patients and 65 individuals as controls, were included in the study. The male/female ratio was 73/62 and the mean age was 68.51±10.80 years. All of the ECG parameters in the AIS group and the control group were statistically significantly different between the groups except Tpe-D (p=0.454) (For QT, QTc, Tpe, Tpe/QTc, and Tpe/QT; p=0.003, 0.022, <0.001, 0.001, 0.001; respectively). QT, QTc, Tpe, Tpe/QTc, and Tpe/QT values were not significantly different between the groups with a NIHSS score of ≤5 and >5 (p=0.480, 0.688, 0.663, 0.512, 0.333, respectively).

CONCLUSIONS

Arrhythmia susceptibility markers including QT, QTc, Tpe, the values of Tpe-D, Tpe/QT, and Tpe/QTc are different in AIS patients compared to the individuals in the control group; therefore, these parameters can be included among the other parameters of close cardiac monitoring.

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 ± 4.6 vs. 70.9 ± 4.8; p < .001), Tp-e / QT ratio (0.21 ± 0.01 vs. 0.19 ± 0.01; p < .001) and Tp-e/QTc ratio (0.19 ± 0.01 vs.0.17 ± 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.

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

Background

Limited 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.

Methods

A 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.

Results

The 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.

Conclusions

HCQ + 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.

Relationship With Calcium, Nutrition Risk, QTc Interval, Tp-e Interval, and Tp-e/QTc Ratio of Critical Care Patients

BACKGROUND

To our knowledge, there are studies related to QTc interval in critical care patients whose nutrition scores are evaluated but no studies evaluating T-wave peak and end interval (Tp-e interval), Tp-e/QT ratio, and Tp-e/QTc ratio, used to evaluate cardiac arrhythmia risk and ventricular repolarization change rates. Therefore, we aimed to investigate whether there is a change in Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio in patients whose nutrition scores are evaluated.

METHODS

This study was planned as a retrospective cross-sectional study. Forty-four patients with a risk score of ≤3 were defined as low-risk group, and 45 patients with a score of ≥4 were defined as high-risk group. Forty-five healthy patients of similar age and gender were included in the control group. All patients underwent 12-lead electrocardiography (ECG). The Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio were measured on ECG. The study data were grouped as patients with high Nutritional Risk Screening 2002 (NRS-2002) risk score, low NRS-2002 risk score, and healthy control.

RESULTS

QTc interval, Tp-e interval, and Tp-e/QTc ratios were significantly higher in patients with high nutrition risk. In a correlation analysis, Tp-e interval and Tp-e/QTc ratio were found to be independently associated with calcium, corrected calcium, and serum albumin level.

CONCLUSION

QTc interval, Tp-e interval, and Tp-e/QTc ratios are significantly increased in patients with high nutrition risk score compared with healthy people and are independently associated with calcium and serum albumin levels; thus, they can be used more effectively in the follow-up of cardiac fatal arrhythmias.

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

Introduction

Epicardial 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 methods

One 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.

Results

Correlation 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.

Conclusions

The 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.

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.

Effect of angiotensin/neprilysin inhibition on ventricular repolarization and clinical arrhythmogenesis

Background: The most common reason for sudden cardiac death in heart failure is malign ventricular arrhythmias. LCZ 696 improves hospitalization and sudden cardiac death outcomes in heart failure, however mechanisms in preventing sudden cardiac death are still unknown. There is little information available assessing effect of LCZ 696 on Tp-e interval and related calculations. In this study, we aimed to investigate the impact of Sacubitril/valsartan therapy on Tp-e interval, Tp-e/QT ratio and Tp-e/QTc ratio in heart failure patients and its reflections on clinical arrhythmogenesis. Methods: The study was designed as a prospective observational fashion. 265 patients with implantable cardioverter-defibrillator (ICD), who were on regular follow up at Samsun Training and Research Hospital Outpatient Heart Failure Clinic, were validated for the study. Clinical, echocardiographic, electrocardiogram and device data before initiation and six months after dose optimizing were obtained. Results: Stroke volume, cardiac output and ejection fraction significantly improved after LCZ 696 treatment. T wave related parameters, QT and QTC intervals significantly diminished. Furthermore, there was a negative correlation between baseline Tp-e interval duration and the absolute percentile increase of stroke volume(r:-0.234, p: 0.042) and cardiac output (r: -0.240, p: 0.037). Conclusion: In our study, switching Renin-Angiotensin-Aldosterone-System inhibitor with Angiotensin receptor/neprilysin inhibitor was associated with increase in left ventricle performance and decrease of sustained ventricular arrhythmias that required ICD shocks. These positive findings were accompanied by improvements in surface electrocaridogram changes such as Tp-e and related indices.

Wet Cupping Therapy Improves the Parameters of Ventricular Repolarization

BACKGROUND

Cupping therapy (CT) is an ancient medical treatment since antiquity and is used for the treatment of such various disease states as contagious diseases, chronic or acute inflammatory disease, and autoimmune disorders. Ventricular repolarization is represented by QT and corrected-QT (QTc) intervals from surface electrocardiography.

OBJECTIVES

As novel repolarization parameters, Tpeak-toTend (Tp-Te) interval, and Tp-Te/QT and Tp-Te/QTc ratios are suggested to correlate better with ventricular arrhythmia risk in various clinical conditions than sole QT and QTc intervals. In this study, we aimed to determine whether these parameters changed significantly after CT in healthy individuals.

METHODS

One hundred and twenty participants (57 women and 63 men; mean age: 49.0 ± 13.0 years) participated in this study. ECGs strips were recorded 1 hour before and 1 hour after CT from each participant, and relevant ECG parameters were compared.

RESULTS

Tp-Te interval [69.51 ± 11.54 msec vs 63.15 ± 10.89 msec, p = 0.001], Tp-Te/QT ratio [0.191 ± 0.030 vs 0.174 ± 0.031, p = 0.002] and Tp-Te/QTc ratio [0.175 ± 0.030 vs 0.159 ± 0.026, p = 0.001] were found to be significantly decreased 1 hour after the procedure compared with the pre-procedure values. However, no statistically significant change was observed in mean heart rate, QT and QTc intervals, QT/QRS and cQT/QRS, and frontal QRS/T angle after the procedure compared with the same parameters before the procedure (p > 0.05).

CONCLUSIONS

In accordance with the results of our study, it is plausible to conclude that CT may exert cardioprotective effect. However, larger scale prospective studies are needed to support our findings.

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.

Effect of Methadone on Cardiac Repolarization in Japanese Cancer Patients: A Longitudinal Study

INTRODUCTION

Methadone is known to prolong the QT interval, which could induce lethal arrhythmias such as torsades de pointes. To determine the risk of ventricular arrhythmias in cancer patients using methadone, we measured QT dispersion (QTD) and Tpeak-Tend (TpTe) before and after methadone administration and evaluated the correlations between methadone dosage and cardiac repolarization.

METHODS

We conducted a retrospective observational study with 19 patients undergoing follow-up for cancer pain with methadone. Electrocardiogram (ECG) recordings were obtained from the patients at methadone initiation and 1 week, 1 month, and 2 months later. The QT, corrected QT (QTc), QTD, QTc dispersion (QTcD), TpTe, TpTe/QT, and TpTe/QTc were measured manually via ECG records and analyzed using a repeated measures one-way ANOVA. The correlations between these ECG parameters and each methadone dosage were determined using Spearman's rank correlation coefficient.

RESULTS

The QTD, QTcD, TpTe/QT, and TpTe/QTc remained unchanged, while TpTe was prolonged significantly at 2 months (initiation: 82 ± 17 ms; 2 months: 106 ± 20 ms, p = 0.018). In addition, there was a positive correlation between TpTe and methadone dosage (rs = 0.4, p = 0.041).

CONCLUSIONS

The findings suggested that small or modest doses of methadone could exert dose-dependent effects on cardiac repolarization in cancer patients.

TRIAL REGISTRATION

UMIN Clinical Trials Registry, UMIN000034519.

Investigation of the effect of epicardial adipose tissue thickness on cardiac conduction system in children with type 1 diabetes mellitus

Objectives Investigation of the association between epicardial adipose tissue thickness (EATT) and P-wave dispersion (Pd), QT dispersion (QTd), corrected QT dispersion (QTcd) and Tp-e interval in children with Type 1 Diabetes Mellitus (T1DM) was aimed. Methods Forty-one children with T1DM and 41 age- and gender-matched healthy children were included in the study. Demographical characteristics of all cases were examined. In echocardiography; in addition to conventional echocardiographic measurements, end-systolic EATT was measured from right ventricular free wall. In electrocardiogram; Pd, QTd, QTcd and Tp-e interval durations, as well as Tp-e/QT and Tp-e/QTc ratios were calculated. Correlation values between EATT and electrocardiographic parameters were also noted. Results Mean age of the patient group was determined to be 12.43 ± 3.04 years and that of the control group was determined to be 12.08 ± 2.56 years. There was no significant difference between the groups in regard to age, gender, body weight, height and body mass index. In the patient group; EATT, Pd, QTd, QTcd and Tp-e interval were determined to be significantly higher compared to the control group. In the patient group, no significant correlation was determined between EATT and Pd, QTd, QTcd and Tp-e. However, when both patient and control groups were evaluated together, a statistically significant positive correlation was determined between EATT and Pd, QTd, QTcd and Tp-e. Conclusions In children with T1DM, an increase in epicardial adipose tissue thickness and in risk of cardiac arrhythmias has been demonstrated. To reveal the possible unfavorable effects of EATT on cardiac conduction system in T1DM patients needs further studies.

The relationship between electrocardiographic data and mortality in children diagnosed with dilated cardiomyopathy

The mortality causes of patients followed up due to dilated cardiomyopathy (DCM) include complications related to heart failure, ventricular arrhythmia, and transplantation. This study aims to evaluate the electrocardiographic findings of patients diagnosed with dilated cardiomyopathy and determine its relationship with mortality. The electrocardiographic, clinical, and laboratory findings of patients diagnosed with dilated cardiomyopathy between January 1, 2012, and September 1, 2018, in our university's pediatric cardiology department were retrospectively evaluated. The electrocardiographic findings of surviving and exitus dilated cardiomyopathy patients were compared and their effect on mortality was investigated. Twelve of the total 85 patients diagnosed with dilated cardiomyopathy were deceased. According to the electrocardiographic findings of surviving and exitus patients, there was a statistically significant difference in terms of P maximum (Pmax), P dispersion (Pdis), QT dispersion (QTdis), QTc maximum (QTcmax), QTc dispersion (QTcdis), Tp-e maximum (Tp-emax), Tp-e dispersion (Tp-edis), and QRS time. Hypertrophy and ischemia findings of electrocardiography were also statistically significant. There was a statistically significant difference between the two groups according to the echocardiographic findings of left ventricular ejection fraction (LVEF), left ventricular shortening fraction (LVSF), left ventricular end-diastolic diameter (LVEDd), and left ventricular end-systolic diameter (LVESd) measurements. It is well known that children diagnosed with dilated cardiomyopathy are at greater risk of arrhythmia compared with normal children. Although previous studies have determined the relationship between mortality and a limited number of electrocardiographic findings, especially in adults, the relationship between electrocardiography findings of children diagnosed with DCM and mortality has not been investigated before in such detail, as in our study.Conclusion: In this study, the significant difference between the electrocardiographic data of deceased and surviving dilated cardiomyopathy patients suggests that electrocardiographic data should be evaluated in detail in order to determine the low and high risk of mortality in patients with dilated cardiomyopathy.What is Known:• Previous studies on the relationship between limited electrocardiography data of adult patients diagnosed with DCM and mortality have been determinedWhat is New:• ECG data has not been investigated in such detail in child DCM patients, as in our study.

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 electrocardiographic parameters in patients with epileptic seizure

The aim of the study is to evaluate the changes in electrocardiographic parameters, including QTc dispersion (QTcd), Tpeak-Tend (Tp-e)/QTc ratio and P-wave dispersion (Pd), during the period without seizure activation in patients, presented to the emergency department (ED) with epileptic seizures. This prospective case-control study was conducted between January 2017 and January 2018. Patients, over 18 years old and presented to the ED with epileptic seizure, were consecutively included in the study. Interictal period ECGs of patients were obtained at least 2 hours after the end of the postictal period. ST-segment changes, QT interval, corrected QT interval (QTc), QTd, Pd, Tp-e, Tp-e dispersion (Tp-ed), Tp-e/QTc ratio and arrhythmias were evaluated in interictal ECGs. A total of 103 epileptic patients and 31 control cases were included in the study. Heart rate, QTc, QTcd, Pd, Tp-ed and Tp-e/QTc ratio were significantly higher in the epilepsy group than in the control group (p < 0.05 for all values). No statistically significant difference in those parameters was observed between the patients with known epilepsy and the patients who had seizure for the first time. There was also no statistically significant difference between patients who had recurrent seizures during the observation period and who did not. The patients with epileptic seizures had increased Pd, QTd, QTcd, Tp-ed and Tpe/QTc ratio during interictal period compared to healthy subjects. These electrocardiographic changes might be associated with an increased risk of dysrhythmia. However, prospective large cohorts with short- and long-term follow-up are needed for clinical reflections.

Evaluation of cardiac autonomic nervous system in patients with ankylosing spondylitis using 12-lead electrocardiography and Holter monitoring

OBJECTIVES

Ankylosing spondylitis (AS) is associated with increased risk of cardiovascular problems, including complications such as conduction defects and arrhythmias, which might lead to increased morbidity and/or mortality. The objective of the present study is to evaluate the electrocardiographic (ECG) parameters, including T-peak to T-end intervals (Tpe), Tpe/corrected QT (QTc) ratio, heart rate variability (HRV), and heart rate turbulence (HRT) in AS patients.

METHODS

Seventy-six AS patients and 55 control subjects were included in the study. 12-lead ECG and 24-h Holter monitoring recordings were obtained. Tpe and Tpe/QTc were measured using the 12-lead ECG and HRV and HRT parameters were assessed using 24-h Holter ECG recordings. Subjects were assigned into three groups based on their HRT parameters (Tonset (TO) and Tslope (TS)) (HRT-0, normal TO or TS; HRT-1, abnormal TO or TS; HRT-2, abnormal TO and TS).

RESULTS

Tpe was prolonged and Tpe/QTc ratio was higher in AS patients (p < 0.001 for both). Moreover, Tpe and Tpe/QTc ratio significantly correlated with disease duration. All HRV parameters (VLF, LF, HF, SDNN, SDANN, ASDNN, rMSSD, pNN50) were decreased in AS patients in comparison with those in control subjects (p < 0.05 for all parameters). Controls were significantly more likely to have normal TO and TS (82% vs 53%, p < 0.001). There was negative correlation between Holter parameters and disease duration, as well as Tpe and Tpe/QTc ratio (p < 0.05 for all parameters).

CONCLUSIONS

This study demonstrated that AS patients have disrupted ventricular repolarization (increased Tpe, Tpe/QTc ratio). Results suggest a decreased cardiac impact of the parasympathetic system in AS patients. Key Points • This study demonstrated that AS patients have disrupted ventricular repolarization. • The study also finds that heart rate turbulence and heart rate variability are impaired in AS patients. • Impaired Holter and ECG parameters may be one of the high cardiovascular risk factors in AS patients.

Tobacco and electronic cigarettes adversely impact ECG indexes of ventricular repolarization: implication for sudden death risk

Tobacco cigarette smoking is associated with increased sudden death risk, perhaps through adverse effects on ventricular repolarization. The effect of electronic (e-)cigarettes on ventricular repolarization is unknown. The objective of the study was to test the hypothesis that tobacco cigarettes and e-cigarettes have similar adverse effects on electrocardiogram (ECG) indexes of ventricular repolarization and these effects are attributable to nicotine. ECG recordings were obtained in 37 chronic tobacco cigarette smokers, 43 chronic e-cigarette users, and 65 nonusers. Primary outcomes, Tpeak to Tend (Tp-e), Tp-e/QT ratio, and Tp-e/QTc ratio, were measured in tobacco cigarette smokers pre-/post-straw control and smoking one tobacco cigarette and in e-cigarette users and nonusers pre-/post-straw control and using an e-cigarette with and without nicotine (different days). Mean values of the primary outcomes were not different among the three groups at baseline. In chronic tobacco cigarette smokers, all primary outcomes, including the Tp-e (12.9 ± 5.0% vs. 1.5 ± 5%, P = 0.017), Tp-e/QT (14.9 ± 5.0% vs. 0.7 ± 5.1%, P = 0.004), and Tp-e/QTc (11.9 ± 5.0% vs. 2.1 ± 5.1%, P = 0.036), were significantly increased pre-/post-smoking one tobacco cigarette compared with pre-/post-straw control. In chronic e-cigarette users, the Tp-e/QT (6.3 ± 1.9%, P = 0.046) was increased only pre/post using an e-cigarette with nicotine but not pre/post the other exposures. The changes relative to the changes after straw control were greater after smoking the tobacco cigarette compared with using the e-cigarette with nicotine for Tp-e (11.4 ± 4.4% vs. 1.1 ± 2.5%, P < 0.05) and Tp-e/QTc (9.8 ± 4.4% vs. -1.6 ± 2.6%, P = 0.05) but not Tp-e/QT(14.2 ± 4.5% vs. 4.2 ± 2.6%, P = 0.061) . Heart rate increased similarly after the tobacco cigarette and e-cigarette with nicotine. Baseline ECG indexes of ventricular repolarization were not different among chronic tobacco cigarette smokers, electronic cigarette users and nonusers. An adverse effect of acute tobacco cigarette smoking on ECG indexes of ventricular repolarization was confirmed. In chronic e-cigarette users, an adverse effect of using an e-cigarette with nicotine, but not without nicotine, on ECG indexes of ventricular repolarization was also observed.NEW & NOTEWORTHY Abnormal ventricular repolarization, as indicated by prolonged Tpeak-end (Tp-e), is associated with increased sudden death risk. Baseline ECG indexes of repolarization, Tp-e, Tp-e/QT, and Tp-e/QTc, were not different among tobacco cigarette (TC) smokers, electronic cigarette (EC) users, and nonsmokers at baseline, but when TC smokers smoked one TC, all parameters were prolonged. Using an electronic cigarette with nicotine, but not without nicotine, increased the Tp-e/QT. Smoking induces changes in ECG indexes of ventricular repolarization associated with increased sudden death risk.

Effects of Septoplasty on Tp-e Interval and Tp-e/QT Ratio in Patients With Nasal Septal Deviation

OBJECTIVES

There are multiple nasal airway pathologies leading to upper airway obstruction, and one of the most common ones is nasal septum deviation (NSD). Our study aimed to evaluate the effect of nasal septal surgery in patients with NSD on ventricular arrhythmogenesis using the novel electrocardiographic parameters, Tp-e interval, and Tp-e/QT ratio.

METHODS

This retrospective cross-sectional study included 102 consecutive patients diagnosed with NSD. All participants completed a validated outcomes instrument (the NOSE scale), echocardiographic and electrocardiographic evaluation before and 3 months after septoplasty. The degree of nasal septal deviation was evaluated with the Dreher classification.

RESULTS

All of the electrocardiography parameters (except heart rate and QTmin) were significantly decreased with the septoplasty operation. Electrocardiographic parameters have significantly decreased especially in marked NSD patients. (Δ = difference between the preoperative and postoperative values) ΔNOSE was positively correlated both ΔcTp-e (r = 0.348, P < .001) and ΔcTp-e/QT values (r = 0.536, P < .001).

CONCLUSION

Consequently, marked NSD was associated with increased risk of arrhythmogenesis, which were too much improved after septoplasty. So, treatment of especially marked NSD not only reduces otolaryngological complaints, but also leads to improvement of ventricular repolarization parameters.

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.

Electrocardiographic markers for the prediction of ventricular arrhythmias in patients with systemic sclerosis

SSc is an autoimmune disease characterized by microvascular damage, endothelial dysfunction and fibrosis of the skin and the internal organs. Cardiac manifestation in patients with SSc is one of the major organ involvements. Approximately 20% of SSc patients suffer from primary cardiovascular disease and another 20% may have secondary cardiac involvement. Although cardiac arrhythmias are mostly linked to myocardial fibrosis, atrioventricular conduction abnormalities are secondary to the fibrosis of the pulse conduction system. Despite the severe consequences of ventricular rhythm disturbances in patients with SSc, the exact role of electrocardiographic markers in the prediction of these arrhythmias has not yet been clearly elucidated. Therefore, the question is whether certain ECG parameters reflecting ventricular repolarization may help to recognize scleroderma patients with increased risk for ventricular arrhythmias and sudden cardiac death.

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.

Risk stratification in hypertrophic cardiomyopathy

Sudden cardiac death (SCD) is the most devastating complication of hypertrophic cardiomyopathy (HCM). The greatest challenge in the management of HCM is identifying those at increased risk, since an implantable cardioverter-defibrillator (ICD) is a potentially life-saving therapy. We sought to summarize the available data on SCD in HCM and provide a clinical perspective on the current differing and somewhat conflicting data on risk stratification, with balanced guidance regarding rational clinical decision-making. Additionally, we sought to determine the status of the current implementation of guidelines compiled by HCM experts worldwide. The HCM Risk-SCD model helps improve the risk stratification of HCM patients for primary prevention of SCD by calculating an individual risk estimate that contributes to the clinical decision-making process. Improved risk stratification is important for decision-making before ICD implantation for the primary prevention of SCD.