Myocardial perfusion single photon emission computed tomography (SPECT) and electrocardiogram(ECG) are crucial modalities in the evaluation of coronary artery disease(CAD) in clinical practice.

To evaluate the relationship between ventricular repolarization parameters, index of cardiac electrophysiological balance (iCEB) from basal electrocardiograms (ECG), and reversible ischemia findings on SPECT.

A total of 45 patients with reversible ischemia on 99m technetium-sestamibi (99mTc-MIBI) stress-rest myocardial perfusion SPECT and confirmed CAD by coronary angiography were included in the ischemia group. Forty-five patients with normal scans, matched by age and gender with the ischemia patient group, were included in the control group. The two-day 99mTc-MIBI SPECT protocol was performed with adenosine-pharmacologic stress. The presence of ischemia and reversible ischemia size (RIS) were recorded in the ischemia group. The summed stress scores (SSS) were recorded for the ischemia and control groups. The QRS, QTd, cQTd, Tp-Te, Tp-Te/QT, Tp-Te/cQT, iCEB (QT/QRS), and iCEBc (cQT/QRS) were calculated. Correlations between myocardial perfusion SPECT and ECG parameters were evaluated using the Spearman test. Predictors of reversible ischemia were assessed using logistic regression analysis.

The ischemia group showed significantly higher values for QRS duration (p = 0.018), cQTmax (p = 0.006), QTd (p = 0.002), and cQTd (p = 0.003). Tp-Te (p = 0.004), Tp-Te/QT ratio (p = 0.003), and Tp-Te/cQT ratio (p = 0.002) were significantly lower in the ischemia group. The multivariate analysis showed that hyperlipidemia, QRS duration, cQTd, and Tp-Te/QTc ratio were found as independent predictors of ischemia.

The Tp-Te/cQT ratio, QRS duration, and cQTd might be valuable predictors of reversible ischemia in SPECT, warranting further study.

In about 8% of survivors of sudden cardiac death, no structural or electrical heart disease can be identified. Some of these patients with idiopathic ventricular fibrillation (IVF) present ECG markers of early repolarization (Early Repolarization Syndrome, ERS). The Tpeak-Tend interval has been linked to increased arrhythmic risk in different clinical settings, such as Brugada syndrome or hypertrophic cardiomyopathy. As there is limited data about the relationship of Tpeak-Tend and arrhythmogenesis in IVF, respectively, its significance in risk stratification in ERS, the aim of this study was to investigate a possible correlation between sustained ventricular arrhythmia (VA) recurrences in these patients and the Tpeak-Tend interval.

We retrospectively investigated 56 consecutive IVF patients (64.3% male, mean age 37.8 ± 12.9 years) who received an implantable cardioverter-defibrillator for secondary prevention. Markers of early repolarization were present in 32.1% of cases. During a mean follow-up of 41.2 ± 35.8 months, 11 patients (19.6%) received in total 18 adequate ICD-therapies. Patients with VA recurrence showed longer Tpeak-Tend compared to arrhythmia-free patients (105 ± 14 ms vs. 91 ± 14 ms, p = 0.03). The combination of prolonged Tpeak-Tend (> 90 ms) and an early repolarization pattern was associated with a 12-fold increased risk of recurrent VA (p = 0.002).

Prolonged Tpeak-Tend was associated with VA recurrence in patients with survived IVF. This correlation was even more pronounced in IVF patients with early repolarization pattern. The Tpeak-Tend interval might play a future role in risk stratification of patients with ERS.

Type 2 diabetes (T2DM) is a chronic metabolic disorder that affects approximately 10.5% of the world's population and is an independent risk factor for cardiovascular complications, including sudden cardiac death (SCD). Inhibitors of sodium-glucose co-transporter type 2 (iSGLT2), particularly dapagliflozin, have emerged as promising treatments in patients with T2DM and with heart failure and chronic kidney disease, demonstrating the ability to significantly reduce major cardiovascular events. However, the exact mechanisms that promote the observed benefits are still not fully understood.

In this study, we sought to understand the mechanisms associated with the benefits of dapagliflozin by evaluating various electrophysiological parameters of the electrocardiogram (ECG) in patients with T2DM. A randomized, multicenter, prospective study with 174 patients with T2DM divided into two groups: one receiving dapagliflozin plus optimized guideline directed medical therapy (GDMT) and the other optimized GDMT without SGLT2 inhibitors. Clinical, electrocardiographic, laboratory, and echocardiographic evaluations were performed initially and after three months. Descriptive and inferential statistics were used, with a significance level of 0.05.

This study shows that in patients treated with dapagliflozin plus GDMT, a significant reduction in the duration of the interval from the peak of the T wave to the end of the T wave (TpTe), the QTc interval, and the ratio between the TpTe/QT intervals was observed, with no change in other electrocardiographic variables such as QT interval dispersion, JT peak interval, or changes in the QRS complex and T wave axes (QRS-T angle).

In patients with T2DM, dapagliflozin significantly shortened the TpTe and QTc intervals, as well as the TpTe/QT ratio. These results suggest a reduction in ventricular electrical remodeling, highlighting a potential cardioprotective effect of dapagliflozin.

https://clinicaltrials.gov/study/NCT06721442, identifier NCT06721442.

Various ventricular repolarization parameters are known to predict ventricular arrhythmias and mortality in various diseases. Although mortality in patients with heart failure with preserved ejection fraction (HFpEF) is similar to that in heart failure with reduced ejection fraction patients, studies on this subject are more limited. Therefore, it is important to evaluate the relationship between ventricular arrhythmias and mortality and ventricular repolarization parameters, especially the frontal plane QRS-T angle, in patients with HFpEF.

Electrocardiographic, echocardiographic, and laboratory data of 811 patients were evaluated, and the fQRST angle was calculated on ECG. The occurrence of ventricular tachycardia, ventricular fibrillation, or sudden death within a mean of 48 ± 12 months was recorded. Statistical significance was determined as p < 0.05.

A total of 811 patients were evaluated, 180 patients in the cardiac event group and 631 patients in the no cardiac event group. NT-proBNP, La size, La volume index, Tp-e time, Tp-e/QTc ratio, and fQRS-T angle were statistically significantly higher in the cardiac event group. NT-proBNP level and fQRS-T angle were found to be independent predictors of mortality in multivariate cox analysis. According to ROC analysis, when QRS-T angle has a cut-off value of 58.63, its sensitivity is 81.2, and its specificity is 79.3. Kaplan-Meier analysis also found that when the fQRS-T angle was > 58.63, mortality was higher than at narrower angles.

According to our study, the fQRS-T angle, which can be easily and inexpensively calculated on ECG, predicts long-term ventricular arrhythmias in patients with HFpEF.

Objective: This study evaluates the short-term cardiovascular effects of guanfacine treatment in children and adolescents with attention deficit/hyperactivity disorder (ADHD). The treatment's impact on novel electrocardiographic parameters was also investigated. Methods: In a retrospective study conducted between January 2023 and June 2024, 37 patients aged 6-18 years with ADHD underwent baseline and follow-up cardiac evaluations including electrocardiography (ECG) and blood pressure measurements. Novel ECG markers (QRS-T angle, QT dispersion, QTc dispersion, Tp-e interval, Tp-e dispersion, Tp-e/QT ratio, and Tp-e/QTc ratio) were analyzed alongside standard parameters such as heart rate, QT, and corrected QT (QTc) intervals. Guanfacine was initiated at 1 mg and titrated weekly until an optimal clinical response was achieved. Results: Guanfacine treatment led to a significant reduction in heart rate (-12.3 bpm; p < 0.001) and P wave axis (-12.3°; p = 0.038) and an increase in QT interval (+16.8 ms; p = 0.014). However, no significant changes were observed in blood pressure, QTc duration, or the novel ECG parameters. Importantly, the absence of any changes in these advanced markers supports the cardiovascular safety of guanfacine. Two patients experienced side effects (bradycardia and hypotension), leading to treatment discontinuation. ANCOVA analysis indicated that the duration between ECG evaluations significantly influenced the QT interval changes, emphasizing the importance of timing when monitoring cardiovascular effects. Conclusions: Guanfacine demonstrated minor, statistically significant effects on the selected cardiac parameters without clinically meaningful changes to or adverse impacts on the novel ECG markers investigated. As extended-release guanfacine has only been available in Türkiye for the management of ADHD for approximately two years, studies evaluating its clinical efficacy and side effects are critical for clinicians working in this field.

The most common cause of morbidity and mortality in type 1 diabetes mellitus is cardiovascular system involvement. Sudden death has been reported in type 1 diabetes mellitus patients. To analyse the use of the cardiac electrophysiological balance index in predicting ventricular arrhythmias in children with type 1 diabetes mellitus disease.

One hundred type 1 diabetes mellitus paediatric patients and 100 healthy children, divided into three groups according to their haemoglobin A1C levels, were included in the study. All participants were evaluated with transthoracic echocardiography, 12-lead electrocardiography, and 24-h Holter after a detailed physical examination. Systolic and diastolic function parameters, electrocardiography intervals, and heart rate variability parameters were evaluated.

The mean age in the type 1 diabetes mellitus and control groups was 11.52 (± 3.52) and 11.78 (± 3.45) years, respectively. In total, 57% of the type 1 diabetes mellitus group and 56% of the control group were male. The mean haemoglobin A1C value was 9.14% (± 1.79) and the disease duration was 3.71 years (± 3.13). The type 1 diabetes mellitus group had a higher QTc duration, deceleration time duration, A velocity, and a lower E/A ratio than the control group. In the type 1 diabetes mellitus group, Tpe, Tpe/QT ratio, QTc/QRS ratio, Tpe/QRS ratio, Tpe/(QT × QRS) ratio values were significantly higher than in the control group.

Children with type 1 diabetes mellitus are at risk for atrial and ventricular arrhythmias without valvular disease, ischemic heart disease, or diastolic dysfunction despite normal systolic function. No correlation was found between disease duration, metabolic control, autonomic function parameters, and arrhythmia risk; however, it was associated with diastolic function parameters.

The blood glucose levels in people with prediabetes mellitus (PDM) are regarded as too high to be normal but below the cutoff for diabetes mellitus (DM). Clinical indicators for PDM patients include impaired glucose tolerance (IGT), impaired fasting glucose (IFG), and/or hemoglobin A1c (HbA1c) levels between 5.7 and 6.4% (39-47 mmol/mol). PDM has been shown to raises the risk of cardiovascular disease (CVD) and mortality. Meanwhile, death and morbidity can be predicted by the new ventricular repolarization features of the electrocardiogram (ECG). Several studies have analyzed the connection between DM and the ventricular repolarization characteristics of ECG; however, few studies have examined the connection between PDM and these ventricular repolarization characteristics. This study evaluated the ECG ventricular repolarization parameters in individuals with PDM.

A retrospective case-control design was used. Randomly selected participants included 79 PDM patients (30 men, mean age: 39.7 ± 5.7 years) and 79 controls (30 men, mean age: 39.8 ± 5.2 years). ECG intervals analyzed were the distance from the beginning of the Q wave to the end of the T wave (QT), the distance between Q and S waves (QRS), the distance between the T wave's termination and point J (JT), and the distance between the peak and endpoint of the T wave (Tp-e), along with corrected and derived measures (corrected QT interval (QTc), the difference between the maximum and smallest QT intervals (QTd), corrected QTd (QTdc), corrected JT interval (JTc), Tp-e/QT, Tp-e/QTc, Tp-e/JT, Tp-e/JTc). Patient records were retrieved from the institution's database.

Both groups had comparable averages for age, gender, smoking, hyperlipidemia, body mass index (BMI), (p > 0.05 for each). Similarly, both groups had similar QT, QRS, and JT intervals. PDM patients had significantly greater heart rates (bpm), and QTc, QTd, QTdc, JTc, and Tp-e intervals (millisecond, ms) than the control group. The results were deemed significant when HbA1c levels were associated with every employed ECG measurement in our investigation.

In our study, the HbA1c value was shown to be moderately positively correlated with the heart rate and QTc, QTd, QTdc, JTc, and Tp-e intervals, all of which were determined to be significant. Additionally, the HbA1c value showed a weak positive correlation with Tp-e/QT, Tp-e/JT ratios, which were statistically significant. This study showed that patients with PDM are prone to ventricular arrhythmia in the early period of the disorder.

Some novel electrocardiographic (ECG) parameters, such as T-wave peak to T-wave end duration (Tp-Te) and Tp-Te/Q-T interval (QT) ratios, have recently been found to be associated with cardiac ischemia and effective in predicting ventricular arrhythmias and mortality. This study examined the association between ECG repolarization parameters and mortality in intensive care unit (ICU) patients. A total of 232 ICU patients were retrospectively categorized as survivors or nonsurvivors retrospectively. Laboratory, demographic, and ECG parameters were compared between the groups. A novel ECG score was measured using the QT interval, Tp-Te, and Tp-Te/QT ratio upon admission to the ICU. We compared the ECG score, Acute Physiologic and Chronic Health Evaluation II (APACHE II)-score, and APACHE II-ECG scores (the combination of APACHE II and ECG score) regarding mortality using a biostatistical program. The mean age of the 232 patients was 69.96 ± 18.01 years, and 49.1% were male. The nonsurvivor group was significantly older and had higher ECG, APACHE II, and APACHE II-ECG scores. Multivariate Cox regression analysis revealed that higher levels of all 3 scores were independent risk factors for mortality ([hazard ratio, HR (95% CI): 1.847 (1.305-2.615), P = .001], [HR (95%CI): 1.146 (1.071-1.225), P < .001], and [HR (95% CI): 1.181 (1.117-1.249), P < .001], respectively). Receiver operating curve analysis of these scoring systems for predicting mortality in the ICU revealed a stronger predictive value for the APACHE II-ECG score (AUC [95% CI]: 0.872 [0.824-0.919], P < .001, sensitivity: 88.7%, specificity: 73.3%). Kaplan-Meier survival analysis revealed the superiority of the APACHE II-ECG score in predicting the survival of ICU patients (log rank chi-square: 80.366, P < .001). Our study suggests combining ECG repolarization parameters with APACHE II score offers a new, more robust system for stronger mortality prediction in ICU patients.

Patients with anterior ST elevation myocardial infarction (STEMI) are vulnerable to life-threatening ventricular arrhythmia and arrhythmic death. This study aimed to investigate the predictive value of Tpeak-to-Tend (TpTe) and TpTe/QT ratio in patients with anterior STEMI on admission for the occurrence of in-hospital life-threatening ventricular arrhythmias and arrhythmic death.

This observational cross-sectional research was performed on patients with anterior STEMI who showed up within 12 hours of the beginning of symptoms and received the initial percutaneous coronary intervention (pPCI). The primary study endpoints included the assessment of sustained ventricular arrhythmias and all-cause/arrhythmic deaths throughout the hospitalization. Data collection involved clinical history, vital signs monitoring, ECG measurements, LVEF evaluation, and performance of pPCI procedures.

The studied patients had a mean age of 53 ± 11 years. Patients with arrhythmic events displayed a significant rise in QT dispersion, TpTe, TpTe/QT, and arrhythmic death rates (P < 0.05). A multivariate logistic regression examination revealed that HR (with an OR of 1.037 and a 95% CI of 1.004 to 1.071, P = 0.027), TpTe (with an OR of 1.025 and a 95% CI of 1.004 to 1.047, P = 0.022), and TpTe/QT (with an OR of 5.464 and a 95% CI of 2.027 to 14.726, P = 0.001) were found to be significant predictors of arrhythmic events or mortality.

In patients with anterior STEMI, TpTe and TpTe/QT ratio are significant predictors of in-hospital VA and arrhythmic death. Higher TpTe and TpTe/QT values are linked to a higher risk of these occurrences.

One of the metabolic effects of antiepileptic drugs (AEDs) is cardiac changes.

In our study, to investigate the cardiac effects of AED use; We looked at electrocardiography (ECG) samples performed on patients. By looking at ECG variables, we tried to determine their relationship with epileptic seizure types and antiepileptic drugs.

This prospective study was completed with a total of 50 epilepsy patients whose ECGs were recorded after exclusion criteria. The number of years the patients had epilepsy, the frequency of seizures, the duration of seizures, and the AEDs they used were recorded. Standard 12-lead ECG was applied to the patients, and QT intervals, Tp-e interval, Tp-e/QT ratio, and Tp-e/QTd ratio were measured.

Patients most commonly use levatiracetam, valproic acid (VPA), carbamazepine, and lamotrigine, respectively. The median seizure time of the patients was 120 seconds. There was no difference regarding ECG parameters among seizure types. Among the AED groups, Tp-e interval (P = 0.028), Tp-e/QT (P = 0.007), and Tp-e/QTd (P = 0.001) values were lower in those receiving lamotrigine.

It was determined that there were differences in cardiac repolarization parameters between AEDs. Lamotrigine had the highest confidence interval due to its low effect on the ECG and low potential to cause arrhythmia.

Clinical effects of subclinical hypothyroidism are not clearly understood. This study aims to investigate the effects of subclinical hypothyroidism (SH) on cardiac autonomic and conduction systems in children.

Forty-seven cases (25 female, 22 male) with SH aged between 3 and 17 years and 46 controls that were age, body mass index and sex matched, were included in the study. Heart rate variability (HRV) was used to evaluate cardiac autonomic function while QT dispersion, P dispersion and Tp-e measurements from ECGs to evaluate susceptibility to arrhythmia.

Standard deviation of the average of Normal-Normal intervals in 5-minute measurements was lower in the SH group compared to controls. No statistically significant differences were found in other time or frequency domain parameters. Maximum and minimum corrected QT intervals were longer in the SH group (p = 0.047 and p = 0.012, respectively); there were no significant differences in other ECG parameters.

Our study demonstrates that cardiac autonomic dysfunction and arrhyhtmogenesis shown as susceptibility to ventricular arrhythmia and longer intraatrial conduction times, appear in children with SH.

To our knowledge, this is the first study to show changes in cardiac autonomic function using heart rate variability in children with subclinical hypothyroidism (SH). We suppose that the fact that ventricular repolarization is longer in children with SH regardless of heart rate shows a predisposition to ventricular arrhythmia. Our study demonstrates that cardiac autonomic dysfunction and arrhythmogenesis shown as susceptibility to ventricular arrhythmia and longer intraatrial conduction times, appear in children with SH. We suggest that an evaluation regarding arrhythymia together with endocrinological follow-up is warranted when children are diagnosed with SH.

Dermatomyositis (DM) is a chronic multi-systemic inflammatory disorder of autoimmune origin, which has been associated with cardiovascular complications, including ventricular arrhythmias and sudden cardiac death. The Tp-e interval and Tp-e/QT ratio have been accepted as new markers for the assessment of myocardial repolarization and ventricular arrhythmogenesis. The aim of this study was to evaluate ventricular repolarization by using Tp-e interval and Tp-e/QT ratio in patients with DM, and to assess the relation with inflammation and autoimmunity. This study included 281 DM patients (180 females, 101 males; mean age 52.73 ± 15.80 years) and 281 control subjects (180 females, 101 males; mean age 53.38 ± 15.72 years). QTc, Tp-e interval and Tp-e/QT ratio were measured from the 12-lead ECG. The plasma level of blood routine test, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) was measured. These parameters were compared between groups. No statistically significant difference was found between two groups in terms of basic characteristics. In electrocardiographic parameters analysis, QTc, Tp-e interval and Tp-e/QT ratio were significantly increased in DM patients compared to the control group (441.44 ± 26.62 ms vs 422.72 ± 11.7 ms, 104.16 ± 24.34 ms vs 77.23 ± 16.25 ms and 0.27 ± 0.06 ms vs 0.20 ± 0.04 ms, all P value < 0.01). QTc, Tp-e interval and Tp-e/QT were positively correlated with NLR, CRP, and ESR (all P values < 0.01), and were increased in anti-Ro/SSA-52kD positive patients compared to those negative (452.33 ± 24.89 ms vs 438.55 ± 26.37 ms, 114.05 ± 22.68 ms vs 101.53 ± 24.13 ms, and 0.29 ± 0.06 ms vs 0.27 ± 0.05 ms, all P value < 0.01). Our study demonstrated that QTc, Tp-e interval, and Tp-e/QT ratio were increased in DM patients and were associated with inflammatory markers and anti-Ro/SSA-52kD positivity.

The risk of death is increased in acromegaly patients compared to the general population, and cardiovascular system-related complications are among the risk factors decreasing life expectancy. The Tp-e interval, which is the distance between the point where the T-wave peaks and ends on electrocardiography (ECG), shows ventricular rapolarization and, together with the Tp-e/QT and Tp-e/QTc ratios, these are relatively new tools that predict ventricular arrhythmia. We aimed to evaluate the ECG of acromegaly patients at the time of diagnosis and compare the results with current ECG findings.

The study included 103 acromegaly patients and 81 control subjects. Of the 103 patients, 41 patients had only baseline ECG, 23 patients had only current ECG and 39 patients had both baseline and current ECGs. Heart rate, QT interval and corrected QT (QTc) interval, Tp-e, Tp-e/QT, Tp-e/QTc values on the ECGs were measured by a cardiologist.

In the acromegaly patients with both baseline and current ECGs, heart rate, QRS duration, Tp-e, and Tp-e/QTc ratio were decreased. The decrease in these arrhythmia parameters was similar in active and remission patients. Compared to the control group, in acromegaly patients with only baseline ECG, heart rate, QTc interval, Tp-e, Tp-e/QT, and Tp-e/QTc were decreased.

Ventricular arrhythmia parameters improve with treatment in patients with acromegaly. The decrease in ventricular arrhythmia parameters was similar in active and remission patients, which can be explained by the significant decrease in IGF-1 levels compared to the time of diagnosis, even in patients with active disease.

This study aimed to determine whether there is a difference in the electrocardiography (ECG) measurements of healthy controls and rheumatoid arthritis (RA) patients and to predict whether they can be used to determine the risk of arrhythmia in patients.

The prospective study included 50 cardiac asymptomatic RA patients (38 males, 12 females; mean age: 46.8±9.1 years; range, 18 to 60 years) who met the 2010 American College of Rheumatology/European Alliance of Associations for Rheumatology RA criteria and 50 healthy volunteers (34 males, 16 females; mean age: 43.4±10.4 years; range, 18 to 60 years) as a control group between June 1, 2022, and August 31, 2022. Disease activity of the patients was calculated with the Disase Activity Score (DAS28). Heart rate, minimum and maximum QT intervals, QT dispersion, minimum and maximum P waves, P wave dispersion (Pd), minimum and maximum Tp-e intervals, Tp-e dispersion, minimum and maximum corrected QT (QTc) intervals, QTc dispersion, and the Tp-e/QTc ratio in ECGs were calculated.

The mean disease duration of the RA group was 9.09±5.74 years. The mean C-reactive protein level was 9.83±8.29, the mean erythrocyte sedimentation rate was 26.12±16.28 mm/h, and the mean DAS28 was 3.03±0.37. There was a statistically significant increase in the maximum P wave, Pd, maximum QT, QT dispersion, maximum QTc, QTc dispersion, maximum Tp-e, Tp-e dispersion, and Tp-e/QTc dispersion parameters in the RA group compared to the control group, while there was a significant decrease in the minimum P wave, minimum QT, and minimum QTc parameters.

In our study, the Pd, QTc dispersion, Tp-e dispersion, and Tp-e/QTc dispersion values of our patients, which indicate the risk of atrial and ventricular arrhythmia, were found to be significantly higher. This finding suggests that our patients had an increased risk of cardiac morbidity and mortality. Arrhythmias are the likely source of the increase in sudden cardiac death in RA, and these new indicators measured on ECG can be used as standardized cardiovascular morbidity and mortality indicators in the future.

In systemic sclerosis (SSc), fibrosis of the myocardium along with ongoing autoimmune inflammation can alter the electric function of the cardiac myocytes, which may increase the risk for ventricular arrhythmias and sudden cardiac death. We analyzed the electrocardiographic (ECG) variables describing ventricular repolarization such as QT interval, QT dispersion (QTd), T wave peak-to-end interval (Tpe), and arrhythmogeneity index (AIX) of 26 patients with SSc and 36 healthy controls. Furthermore, echocardiographic and laboratory parameters were examined, with a focus on inflammatory proteins like C-reactive ptotein (CRP), soluble intracellular adhesion molecule-1 (sICAM-1), soluble vascular adhesion molecule-1 (sVCAM-1), and progranulin (PGRN). The CRP, sICAM-1, and sVCAM-1 levels were positively correlated with the length of the QT interval. Although the serum PGRN levels were not increased in the SSc group compared to the controls, in SSc patients, the PGRN levels were positively correlated with the QT interval and the AIX. According to our results, we conclude that there may be a potential association between autoimmune inflammation and the risk for ventricular arrhythmias in patients with SSc. We emphasize that the measurement of laboratory parameters of inflammatory activity including CRP, PGRN, sVCAM-1, and sICAM-1 could be helpful in the prediction of sudden cardiac death in patients with SSc.

The electrocardiogram (ECG) is a valuable tool for interpreting ventricular repolarization. This article aims to broaden the diagnostic scope beyond the conventional ischemia-centric approach, integrating an understanding of pathophisiological influences on ST-T wave changes.

A review was conducted on the physiological underpinnings of ventricular repolarization and the pathophisiological processes that can change ECG patterns. The research encompassed primary repolarization abnormalities due to uniform variations in ventricular action potential, secondary changes from electrical or mechanical alterations, and non-ischemic conditions influencing ST-T segments.

Primary T waves are characterized by symmetrical waves with broad bases and variable QT intervals, indicative of direct myocardial action potential modifications due to ischemia, electrolyte imbalances, and channelopathies. Secondary T waves are asymmetric and often unassociated with significant QT interval changes, suggesting depolarization alterations or changes in cardiac geometry and contractility.

We advocate for a unified ECG analysis, recognizing primary and secondary ST-T changes, and their clinical implications. Our proposed analytical framework enhances the clinician's ability to discern a wide array of cardiac conditions, extending diagnostic accuracy beyond myocardial ischemia.

The leading cause of death in people living with HIV (PLWH) is cardiovascular disease, and the high prevalence of tobacco cigarette (TC) smoking is a major contributor. Switching to electronic cigarettes (ECs) has been promoted as a harm reduction strategy. We sought to determine if acute EC compared to TC smoking had less harmful effects on arrhythmogenic risk factors including acute changes in hemodynamics, heart rate variability (HRV), and ventricular repolarization (VR). In PLWH who smoke, changes in hemodynamics, HRV, and VR were compared pre/post acutely using an EC, TC, or puffing on an empty straw on different days in random order, in a crossover study. Thirty-seven PLWH (36 males, mean age 40.5 ± 9.1 years) participated. Plasma nicotine was greater after TC versus EC use (10.12 ± 0.96 vs. 6.18 ± 0.99 ng/mL, respectively, p = 0.004). HR increased significantly, and similarly, after acute EC and TC smoking compared to control. Changes in HRV that confer increased cardiac risk (LF/HF ratio) were significantly smaller after acute EC versus TC use, consistent with a harm reduction effect. In a post-hoc analysis of PLWH with and without positive concurrent recreational drug use as indicated by point of care urine toxicology testing, this differential effect was only seen in PLWH not currently using recreational drugs. Changes in VR were not different among the three exposures. In PLWH who smoke, EC compared to TC smoking resulted in smaller adverse changes in HRV. This differential effect was accompanied by a smaller increase in plasma nicotine, and was negated by concurrent recreational drug use. Additional studies are warranted in this vulnerable population disproportionately affected by tobacco-related health disparities.

Globally, cardiovascular diseases are still the leading cause of death. Numerous methods are used to diagnose cardiovascular pathologies; there is still a place for straightforward and noninvasive techniques, such as electrocardiogram (ECG). Depolarization and repolarization parameters, including QT interval and its derivatives, are well studied. However, the Tpeak-Tend interval is a novel and promising ECG marker with growing evidence for its potential role in predicting malignant arrhythmias. In this review, we discuss the association between the Tpeak-Tend interval and several cardiovascular diseases, including long QT syndrome, cardiomyopathies, heart failure, myocardial infarction, and obesity, which constitutes one of the risk factors for cardiovascular diseases.

Background: Overweight and obesity are important risk factors in the development of cardiovascular diseases. New repolarization markers, such as the Tpeak-Tend interval and JTpeak intervals, have not yet been profoundly studied in obese patients. The study aims to analyze whether, in patients with obesity and overweight, repolarization markers, including the Tpeak-Tend interval, are prolonged and simultaneously check the frequency of other ECG pathologies in a 12-lead ECG in this group of patients. Methods: A study group consisted of 181 adults (90 females and 91 males) with overweight and first-class obesity. The participants completed a questionnaire, and the ECG was performed and analyzed. Results: When analyzing the classic markers, only QT dispersion was significantly higher in obese people. The Tpeak-Tend parameter (97.08 ms ± 23.38 vs. 89.74 ms ± 12.88, respectively), its dispersion, and JTpeak-JTend parameters were statistically significantly longer in the obese group than in the controls. There were also substantial differences in P-wave, QRS duration, and P-wave dispersion, which were the highest in obese people. Tpeak-Tend was positively correlated with body mass and waist circumference, while JTpeak was with BMI, hip circumference, and WHR. Tpeak/JT was positively correlated with WHR and BMI. In backward stepwise multiple regression analysis for JTpeak-WHR, type 2 diabetes and smoking had the highest statistical significance. Conclusions: Only selected repolarization markers are significantly prolonged in patients with class 1 obesity and, additionally, in this group, we identified more pathologies of P wave as well as prolonged QRS duration.

Introduction Cancer chemotherapy regimens include multiple classes of adjuvant drugs as supportive therapy. Because of the concurrent intake of other drugs (like antiemetics, antidepressants, analgesics, and antimicrobials), there is a heightened risk for possible QT interval prolongation. There is a dearth of evidence in the literature regarding the usage of QT-prolonging anticancer drugs and associated risk factors that have the propensity to prolong QT interval. The purpose was to explore the extent of the use of QT-interval-prolonging drugs and potential QT-prolonging drug-drug interactions (QT-DDIs) in cancer patients attending OPD in a tertiary-care hospital. Methods This was a hospital-based, cross-sectional, observational study. Risk stratification of QT-prolonging drugs for torsades de pointes (TdP) was done by the Arizona Center for Education and Research on Therapeutics (AzCERT)/CredibleMeds-lists, and potential QT-DDIs were determined with four online DDI-checker-software. Results In 1331 cancer patients, the overall prevalence of potential QT-prolonging drug utilization was 97.3%. Ondansetron, pantoprazole, domperidone, and olanzapine were the most frequent QT-prolonging drugs in cancer patients. The top six antineoplastics with potential QT-prolonging and torsadogenic actions were capecitabine, oxaliplatin, imatinib, bortezomib, 5-fluorouracil, and bendamustine. Evidence-based pragmatic QTc interval prolongation risk assessment tools are imperative for cancer patients. Conclusion This study revealed a high prevalence of QT-prolonging drugs and QT-DDIs among cancer patients who are treated with anticancer and non-anticancer drugs. As a result, it's critical to take precautions, stay vigilant, and avoid QT-prolonging in clinical situations. Evidence-based pragmatic QTc interval prolongation risk assessment tools are needed for cancer patients.

High-altitude exposure changes the electrical conduction of the heart. However, reports on electrocardiogram (ECG) characteristics and potent prophylactic agents during high-altitude acclimatization and de-acclimatization are inadequate. This study aimed to investigate the effects of ubiquinol on electrophysiology after high-altitude hypoxia and reoxygenation.

The study was a prospective, randomized, double-blind, placebo-controlled trial. Forty-one participants were randomly divided into two groups receiving ubiquinol 200 mg daily or placebo orally 14 days before flying to high altitude (3900 m) until the end of the study. Cardiopulmonary exercise testing was performed at baseline (300 m), on the third day after reaching high altitude, and on the seventh day after returning to baseline.

Acute high-altitude exposure prolonged resting ventricular repolarization, represented by increased corrected QT interval (455.9 ± 23.4 vs. 427.1 ± 19.1 ms, P < 0.001) and corrected Tpeak-Tend interval (155.5 ± 27.4 vs. 125.3 ± 21.1 ms, P < 0.001), which recovered after returning to low altitude. Ubiquinol supplementation shortened the hypoxia-induced extended Tpeak-Tend interval (-7.7 ms, [95% confidence interval (CI), -13.8 to -1.6], P = 0.014), Tpeak-Tend /QT interval (-0.014 [95% CI, -0.027 to -0.002], P = 0.028), and reserved maximal heart rate (11.9 bpm [95% CI, 3.2 to 20.6], P = 0.013) during exercise at high altitude. Furthermore, the decreased resting amplitude of the ST-segment in the V3 lead was correlated with decreased peak oxygen pulse (R = 0.713, P < 0.001) and maximum oxygen consumption (R = 0.595, P < 0.001).

Our results illustrated the electrophysiology changes during high-altitude acclimatization and de-acclimatization. Similarly, ubiquinol supplementation shortened the prolonged Tpeak-Tend interval and reserved maximal heart rate during exercise at high altitude.

URL: www.chictr.org.cn; Unique identifier: ChiCTR2200059900.

Sodium-glucose co-transporter-2 (SGLT2) inhibitors added to optimal medical therapy have been shown to reduce the risk of cardiovascular death and recurrent heart failure (HF) hospitalization in HF patients. We aimed to evaluate the effect of SGLT2 inhibitors on the ventricular repolarization markers (VRM) in patients with HF with reduced ejection fraction (HFrEF).

51 patients with HFrEF who had symptoms New York Heart Association (NYHA) class II-IV despite optimal medical treatment and were added SGLT2 inhibitors to their treatment were included in the study. Electrocardiography (ECG) and laboratory results obtained before the treatment and at the first-month follow-up visit were compared. QT, QTc (corrected by Bazett formula), QT dispersion (QTd), QTc dispersion (QTc-d), Tpeak to Tend (Tp-e) interval, Tp-e/QT, and Tp-e/QTc ratios were measured and defined as VRM.

A significant decrease was observed in HR, QT, QTc intervals, and QTd compared to pre-treatment. While the mean Tp-e interval was 101.5 ± 11.7 ms before treatment, it decreased to 93.1 ± 12.7 ms after treatment (p < 0.001). There was a significant decrease in N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels after treatment [2859 ± 681vs.1266 ± 763, respectively (p < 0.001)] and QTd, Tp-e interval, and Tp-e/QTc ratio was positively correlated with the change in NT-proBNP level.

The addition of SGLT2 inhibitors to optimal medical therapy in HFrEF patients positively changes VRM (QT, QTc, QTd, Tp-e, and Tp-e/QTc).

QT interval dispersion, which reflects the regional heterogeneity of ventricular repolarization, increases during electroconvulsive therapy (ECT). Tpeak-Tend (TpTe) is considered a new marker of the transmural dispersion of ventricular repolarization (TDR). This study aimed to evaluate the effect of remifentanil on TpTe during ECT.

Forty-two patients who were scheduled to undergo ECT with American Society of Anesthesiologists physical status I or II randomly received 0.1 μg/kg remifentanil (group R: n = 21) or saline (group C: n = 21). After the induction of general anesthesia, we measured the TpTe, TpTe/QT, TpTe/QTc, TpTe/RR, TpTe/√RR and TpTe/3√RR every minute during ECT (QT: QT interval, QTc: corrected QT interval, RR: RR interval). Statistical analysis was performed using two-way analysis of variance (ANOVA).

Immediately (T0) and 1 min (T1) after electrical stimulation, the RRs (group C: T0; 654.2 ± 145.9 ms, T1; 657.3 ± 114.8 ms, group R: T0; 849.6 ± 249.3 ms, T1; 885.4 ± 213.6 ms, p < 0.05) were significantly increased, while systolic (group C: T0; 177.1 ± 35 mmHg, group R: T0; 129 ± 27.2 mmHg, p < 0.05) and diastolic blood pressures (group C: T0; 107.1 ± 22.4 mmHg, T1; 101.3 ± 23.2 mmHg, group R: T0; 75.4 ± 19.3 mmHg, T1; 80.6 ± 18.3 mmHg, p < 0.05) were significantly decreased in group R compared to group C. The TpTe/RR was significantly lower at T1 in group R compared to group C (group C: 101.5 ± 28.2, group R: 76.8 ± 21.8, p < 0.05). However, there was no significant difference in TpTe, TpTe/QT, TpTe/QTc, TpTe/√RR or TpTe/3√RR between the two groups throughout the study.

Pretreatment with remifentanil suppressed the increase of TpTe/RR after electrical stimulation. Our results imply that remifentanil may lead to a decrease in TDR during ECT.

This trial was registered with the University Hospital Medical Information Network (registration number: UMIN000051958).

Whether sodium-glucose cotransporter-2 inhibitors (SGLT2is) reduce ventricular arrhythmias and sudden cardiac death is controversial. Ventricular repolarization heterogeneity is associated with ventricular arrhythmias; however, the effect of SGLT2is on ventricular repolarization in patients with heart failure with reduced ejection fraction (HFrEF) has not been fully investigated. We prospectively evaluated 31 HFrEF patients in sinus rhythm who were newly started on dapagliflozin 10 mg/day. Changes in QT interval, corrected QT interval (QTc), QT dispersion (QTD), corrected QTD (QTcD), T peak to T end (TpTe), TpTe/QT ratio, and TpTe/QTc ratio were evaluated at 1-year follow-up. QT interval, QTc interval, QTD, QTcD, TpTe, and TpTe/QTc ratio decreased significantly at 1-year follow-up (427.6 ± 52.6 ms vs. 415.4 ± 35.1 ms; p = 0.047, 437.1 ± 37.3 ms vs. 425.6 ± 22.7 ms; p = 0.019, 54.1 ± 11.8 ms vs. 47.6 ± 14.7 ms; p = 0.003, 56.0 ± 11.2 ms vs. 49.4 ± 12.3 ms; p = 0.004, 98.0 ± 15.6 ms vs. 85.5 ± 20.9 ms; p = 0.018, and 0.225 ± 0.035 vs. 0.202 ± 0.051; p = 0.044, respectively). TpTe/QT ratio did not change significantly (0.231 ± 0.040 vs. 0.208 ± 0.054; p = 0.052). QT interval, QTD, and TpTe were significantly reduced 1 year after dapagliflozin treatment in patients with HFrEF. The beneficial effect of dapagliflozin on the heterogeneity of ventricular repolarization may contribute to the suppression of ventricular arrhythmias.Registry information https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000049428 . Registry number: UMIN000044902.

Congenital long QT syndrome (LQTS) carries an increased risk for syncope and sudden death. QT prolongation promotes ventricular extrasystoles, which, in the presence of an arrhythmia substrate, might trigger ventricular tachycardia degenerating into fibrillation. Increased electrical heterogeneity (dispersion) is the suggested arrhythmia substrate in LQTS. In the most common subtype LQT1, physical exercise predisposes for arrhythmia and spatiotemporal dispersion was therefore studied in this context. Thirty-seven patients (57% on β-blockers) and 37 healthy controls (mean age, 31 vs. 35; range, 6-68 vs. 6-72 yr) performed an exercise test. Frank vectorcardiography was used to assess spatiotemporal dispersion as Tampl, Tarea, the ventricular gradient (VG), and the Tpeak-end interval from 10-s signal averages before and 7 ± 2 min after exercise; during exercise too much signal disturbance excluded analysis. Baseline and maximum heart rates as well as estimated exercise intensity were similar, but heart rate recovery was slower in patients. At baseline, QT and heart rate-corrected QT (QTcB) were significantly longer in patients (as expected), whereas dispersion parameters were numerically larger in controls. After exercise, QTpeakcB and Tpeak-endcB increased significantly more in patients (18 ± 23 vs. 7 ± 10 ms and 12 ± 17 vs. 2 ± 6 ms; P < 0.001 and P < 0.01). There was, however, no difference in the change in Tampl, Tarea, and VG between groups. In conclusion, although temporal dispersion of repolarization increased significantly more after exercise in patients with LQT1, there were no signs of exercise-induced increase in global dispersion of action potential duration and morphology. The arrhythmia substrate/mechanism in LQT1 warrants further study.NEW & NOTEWORTHY Physical activity increases the risk for life-threatening arrhythmias in LQTS type 1 (LQT1). The arrhythmia substrate is presumably altered electrical heterogeneity (a.k.a. dispersion). Spatiotemporal dispersion parameters were therefore compared before and after exercise in patients versus healthy controls using Frank vectorcardiography, a novelty. Physical exercise prolonged the time between the earliest and latest complete repolarization in patients versus controls, but did not increase parameters reflecting global dispersion of action potential duration and morphology, another novelty.

Coeliac disease is an autoimmune intestinal disease that develops with permanent intolerance to gluten and similar cereal proteins. It can damage to many tissues, including myocardium, by autoimmune mechanisms. In our study, we aimed to investigate the effect of coeliac disease on cardiac electrical activity by comparing the Tp-e interval and Qt dispersion values of coeliac patients with healthy children.

Fifty-seven coeliac patients and 57 healthy children were included in the study. Sociodemographic findings, physical examinations, symptoms, laboratory values, dietary compliance, endoscopy, and pathological findings were recorded into a standardised form. Electrocardiogram parameters were calculated, and echocardiography findings were noted.

No statistically significant difference was found between the two groups in terms of age, gender, heart rate, electrocardiogram parameters such as p wave, PR interval, QRS complex, QT interval, and QTc values. Tp-e interval, Tp-e / QT ratio, and Tp-e / QTc ratio were statistically significantly higher in the patient group compared to the control group. Ejection fraction and fractional shortening values were significantly lower in the patient group compared to the control group. In the patient group, Tp-e interval, Tp-e / QT ratio, Tp-e / QTc ratio, and QTc dispersion were statistically significantly higher in patients with tissue transglutaminase IgA positive compared to patients with tissue transglutaminase IgA negative.

Our study gives important findings in terms of detecting early signs of future cardiovascular events in childhood age group coeliac patients.

Introduction Multisystem inflammatory syndrome in children (MIS-C) is characterized by hyperinflammation, heart involvement, and multiorgan failure, which develop following coronavirus disease 2019. Ventricular arrhythmias have been identified during this syndrome. It is known that the risk of ventricular arrhythmia is associated with ventricular repolarization changes. The aim of this study was to investigate the corrected QT interval, QT dispersion, T wave peak-to-end interval, and T-peak to T-end/corrected QT ratio in MIS-C. Methods The study included 35 patients diagnosed with MIS-C and 35 subjects as the control group. The ventricular diameters, ejection fraction, valve insufficiency, and coronary artery were examined in both groups using echocardiography. Corrected QT interval, QT dispersion, T wave peak-to-end interval, and T-peak to T-end/corrected QT ratio were determined by 12-lead electrocardiogram. Results The patient group had increased corrected QT interval (p<0.05), QT dispersion (p = 0.001), T-peak to T-end interval (p=0.001), and T-peak to T-end/corrected QT ratio (p = 0.001) compared to the control group. Moreover, there was a correlation between increased QT dispersion, T-peak to T-end, T-peak to T-end/corrected QT ratio, and decreased ejection fraction (r = -0.51 and p = 0.001, r = -0.71 and p < 0.001, r = -0.69 and p < 0.001, r = -0.56 and p < 0.001, respectively). Conclusions Our study demonstrated increased QTc interval, QT dispersion, T-peak to T-end interval, T-peak to T-end/corrected QT ratio in MIS-C. This result may indicate an increased risk of ventricular arrhythmia for these patients.

Dapagliflozin is an agent that has both antihyperglycemic effects and is significantly associated with a lower risk of cardiovascular events in patients with diabetes mellitus (DM). However, there is insufficient data and information about the effect of dapagliflozin on electrocardiographic (ECG) parameters.

The effects of dapagliflozin on ventricular repolarization parameters have not been fully elucidated yet. This study aimed to investigate whether dapagliflozin has a positive effect on ventricular repolarization heterogeneity parameters in patients with type 2 DM.

We retrospectively enrolled 140 patients with a known diagnosis of type 2 DM who were newly prescribed dapagliflozin in addition to standard anti-diabetic therapy. The patients were divided into two groups according to whether they had cardiovascular disease (CVD). The effect of dapagliflozin treatment on ventricular repolarization parameters (frontal plane QRST angle, Tp-e interval, Tp-e/QTc, QTc, and QTc dispersion) was investigated, patient groups were compared before and after treatment.

Among 140 patients, 70 (50 %) had CVD and 70 (50 %) did not have CVD. Dapagliflozin treatment resulted in significant reductions in ventricular repolarization parameters over the study period in the CVD group with diabetes. Mean fQRST angle, Tp-e interval, Tp-e/QTc, QTc, and QTc dispersion were significantly lower than baseline values at 6-month follow-up visits in the CVD group (61.61 ± 9.22° vs 52.55 ± 8.31°, 74.45 ± 16.06 msec vs 63.27 ± 13.99 msec, 0.19 ± 0.03 vs 0.16 ± 0.03, 384.12 ± 47.93 msec vs 356.15 ± 43.31 mesc, 55.28 ± 5.50 msec vs 48.08 ± 6.48 msec for all pairwise comparisons p < 0.001).

Similar antihyperglycemic effects were found with dapagliflozin treatment in patients with and without CVD. However, significant reductions in ventricular repolarization parameters were observed only in patients with CVD.

The present study aimed to compare electrocardiographic (ECG) parameters of amputee football players (AF) with football players without disability (FP) and sedentary individuals without disability (SI).

A total of 32 participants (AF = 9, FP = 11, SI = 12) were included in the study. ECG parameters including P-wave amplitude, P-wave duration, PR interval, QRS duration, RR interval, QT interval, corrected-QT interval (QTc), ST segment duration, Tp-e duration, Tp-e/QT and Tp-e/QTc ratios were assessed in all the study participants by using a 12-lead ECG device. OneWay ANOVA Test was used for statistical analysis.

Of all ECG parameters, P-wave amplitude and QTc were significantly higher in the AF group in comparison to FP and SI groups. QRS duration was found to be lower in the AF group when compared to FP and SI groups. Myocardial repolarization parameters including Tp-e duration, Tp-e/QT and Tp-e/QTc ratios were similar between groups, as were other parameters such as P-wave duration, PR interval, RR interval, QRS duration and QT interval.

It was found that some ECG parameters of amputee football players differ from those with non-disabled players and non-disabled sedentary individuals. These different parameters were within normal limits.

Cardiac complications due to anthracycline treatment may become evident several years after chemotherapy and are recognized as a serious cause of morbidity and mortality in cancer patients or childhood cancer survivors.

We analyzed ventricular repolarization parameters in electrocardiography for pediatric acute lymphoblastic leukemia patients during chemotherapy and in long-term follow-up. To establish the reference values of ventricular repolarization parameters in children, we retrospectively summarized the Tpe interval, QT interval, QTc interval, and Tpe/QT ratio in healthy Japanese children.

Electrocardiography data recorded from students in 1st and 7th grades were randomly selected from a database maintained by the school-based screening system in the Oita city cohort, Japan. Subsequently, chronological data of the Tpe/QT ratio in 17 pediatric patients with acute lymphoblastic leukemia were analyzed over time.

The mean ± standard deviation of the Tpe interval in 1st and 7th graders was 70 ± 7 and 78 ± 17 ms, respectively, while the mean ± standard deviation of the Tpe/QT ratio was 0.21 ± 0.02 and 0.22 ± 0.02 ms, respectively. During the intensive phase of treatment, the Tpe/QT ratios of 3 high-risk patients among the 17 patients with acute lymphoblastic leukemia exceeded the upper limit.

The Tpe/QT ratio has a potential clinical application in predicting the risk of long-term ventricular arrhythmia of cancer patients or childhood cancer survivors from childhood to adulthood.

The most common cause of death in patients with Duchenne muscular dystrophy (DMD) is cardiomyopathy. Our aim was to investigate the relationship between the Tpeak-Tend (Tp-e) interval and the premature ventricular contraction (PVC) burden and therefore early arrhythmic risk and cardiac involvement in DMD patients. Twenty-five patients with DMD followed by pediatric cardiology were included in the study. Those with a frequency of <1% PVC in the 24 h Holter were assigned to Group 1 (n = 15), and those with >1% were assigned to Group 2 (n = 10). Comparisons were made with healthy controls (n = 27). Left ventricular ejection fraction (LVEF) was lowest in Group 2 and highest in the control group (p < 0.001). LV end-diastolic diameter was greater in Group 2 than in Group 1 and the control group (p = 0.005). Pro-BNP and troponin levels were higher in Group 1 and Group 2 than in the control group (p = 0.001 and p < 0.001, respectively). Tp-e interval was longer in Group 2 compared to Group 1 and the control group (p < 0.001). The LVEF (OR 0.879, 95% CI 0.812-0.953; p = 0.002) and Tp-e interval (OR 1.181, 95% CI 1.047-1.332; p = 0.007) were independent predictors of PVC/24 h frequency of >1%. A Tp-e interval > 71.65 ms predicts PVC > 1%, with a sensitivity of 80% and a specificity of 90% (AUC = 0.842, 95% CI (0.663-1.000), p = 0.001). Determination of Tp-e prolongation from ECG data may help in the determination of cardiac involvement and early diagnosis of arrhythmic risk in DMD.

Background and Objectives: Smokeless tobacco (ST) use has recently become an alternative to cigarettes, and it has been concluded that ST is at least as harmful as cigarettes. ST use is thought to play a role in the pathogenesis of arrhythmia by affecting ventricular repolarization. In this study, we aimed to examine the relationships of Maras powder (MP), one of the ST varieties, with epicardial fat thickness and new ventricular repolarization parameters, which have not previously been described. Materials and Methods: A total of 289 male individuals were included in this study between April 2022 and December 2022. Three groups, 97 MP users, 97 smokers, and 95 healthy (non-tobacco), were compared according to electrocardiographic and echocardiographic data. Electrocardiograms (ECG) were evaluated with a magnifying glass by two expert cardiologists at a speed of 50 m/s. Epicardial fat thickness (EFT) was measured by echocardiography in the parasternal short- and long-axis images. A model was created with variables that could affect epicardial fat thickness. Results: There were no differences between the groups regarding body mass index (p = 0.672) and age (p = 0.306). The low-density lipoprotein value was higher in the MP user group (p = 0.003). The QT interval was similar between groups. Tp-e (p = 0.022), cTp-e (p = 0.013), Tp-e/QT (p =0.005), and Tp-e/cQT (p = 0.012) were higher in the MP user group. While the Tp-e/QT ratio did not affect EFT, MP predicted the epicardial fat thickness (p < 0.001, B = 0.522, 95%CI 0.272-0.773). Conclusions: Maras powder may play a role in ventricular arrhythmia by affecting EFT and causing an increase in the Tp-e interval.

The effect of frontal QRS-T angle, Tp-e and Tp-e/QT ratio on cardiac events have been shown in many studies. In this study, we aimed to determine the prognostic value of frontal QRS-T angle, TPe and Tp-e/QT ratio on ICD shock in patients who had ICD (Implantable Cardioverter Defibrillator) implanted due to heart failure with reduced ejection fraction (HFrEF).

158 patients with HFrEF who had previous ICD implantation were retrospectively analyzed. 27 patients were found to have an appropriate shock. Frontal QRS-T angle, Tp-e interval, Tp-e/QT ratio were calculated by evaluating the basal ECG records of the patients. Comparisons of these arrhythmogenic predictors were made in patients with and without ICD shock at follow-up.

When 158 patients with previous ICD implantation were analyzed in two groups with and without ICD shock, the number of patients with frontal QRS-T angle >120°, Tp-e interval > 105 ms, Tp-e/QT > 0.2 in the shock group (n: 27) was found to be high with a different significance (p:<0.01, p:<0.01, p:<0.01). There was no significant difference between the two groups regarding other ECG parameters such as QRS duration, QT interval, PR interval, fragmented QRS and positive T wave. In addition, more amiodarone use was observed in the shock group, and more hyperlipidemia cases were observed in the non-shocked group (p:0.01; p:<0.01).

Increased frontal QRS-T angle, Tp-e interval, and Tp-e/QT ratio are arrhythmogenic parameters and predict appropriate ICD shock.

Introduction It has been shown that cardiac functions begin to deteriorate in growth hormone (GH) deficiency even in childhood. However, little is known about how GH deficiency affects arrhythmogenesis. The aim of this study was to evaluate the parameters of P wave dispersion (Pd), QT dispersion (QTd), corrected QT (QTc) dispersion (QTcd), T wave peak-to-end (Tp-e) interval, Tp-e/QT ratio, and Tp-e/QTc ratio in children with GH deficiency. This study also aimed to evaluate the relationship of these parameters with insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 (IGFBP-3). Method In the study, records of children diagnosed with GH deficiency in Adana City Training and Research Hospital Pediatric Endocrine Outpatient Clinic between September 2021 and December 2022 were retrospectively reviewed. The control group consisted of children in the same age group who applied to the Emergency Outpatient Clinic with a complaint of chest pain and no pathological finding was detected. The electrocardiograms (ECGs) of all patients were retrospectively evaluated. Results There were a total of 82 children in the study, 41 of whom were diagnosed with GH deficiency and 41 in the healthy control group. The age and male/female ratio of children with GH deficiency were similar to those in the control group (p>0.05). There were 27 (66%) children with complete GH deficiency and 14 (34%) children with partial GH deficiency. P wave dispersion was similar in both GH-deficient children and control group children. It was also similar in children with complete and partial GH deficiency (p>0.05). QT and QTc dispersions were found to be increased in children with GH deficiency, although not statistically significant, compared to the control group (p>0.05). Tp-e interval, Tp-e/QTmax (longest QT interval), and Tp-e/QTcmax (longest QTc interval) ratios were increased in children with GH deficiency compared to the control group (p=0.001, p=0.003, and p=0.001, respectively). QT and QTc dispersion, Tp-e interval, Tp-e/QTmax, and Tp-e/QTcmax ratios were found to be increased in children with complete GH deficiency compared to children with partial GH deficiency, but the difference was not significant (p>0.05). No correlation was found between these ECG parameters and IGF-1, IGFBP-3, and peak GH levels after stimulation tests (p>0.05). Conclusion We found in our study that the Tp-e interval was longer and Tp-e/QT and Tp-e/QTc ratios were increased in children with GH deficiency. These results suggest that the risk of ventricular arrhythmias in children with GH deficiency may start to increase from childhood. However, further prospective studies are needed to confirm our results.

Cardiac involvement is common in systemic sclerosis occurring in up to 80% of patients. Primary myocardial dysfunction results from impairment of coronary microvascular circulation, myocardial inflammation and fibrosis with the prevalence of atherosclerosis remaining contradictory.

This review presents the various aspects of cardiac involvement in SSc from a pathophysiological, clinical, diagnostic and therapeutic standpoint. Imaging modalities with emerging role in the understanding of mechanisms and prompt diagnosis of myocardial fibrosis namely cardiac magnetic resonance are also discussed.

Cardiac involvement in SSc - and particularly primary myocardial disease - remains a challenge as clinical symptoms manifest in advanced stages of heart failure and convey poor prognosis. Over the last years the introduction of sophisticated imaging methods of myocardial function has resulted in a better understanding of the underlying pathophysiological processes of myocardial damage such as microvasculopathy, inflammation, diffuse or focal fibrosis. Such developments could contribute to the identification of patients at higher risk for subclinical heart involvement for whom diligent surveillance and prompt initiation of therapy with cardioprotective and/or immunosuppressive drugs coupled with invasive interventions namely radiofrequency ablation, implantable cardioverter-defibrillator when indicated, may improve long-term outcomes.

Premature ventricular complexes are common in healthy individuals' ambulatory monitoring. The index of cardiac-electrophysiological balance may predict malignant ventricular arrhythmias. This study investigated the relation between Premature ventricular complex burden and index of cardiac-electrophysiological balance in 24-h Holter monitoring.

A total of 257 patients who were admitted to a cardiology outpatient clinic without structural heart disease and underwent 24-h Holter monitoring were included in the study. Demographic features, laboratory parameters, and electrocardiographic and echocardiographic values of all patients were obtained from the hospital database. Patients were categorized into the following four groups according to their premature ventricular complex burden: ≤5% premature ventricular complexes as group 1, >6 and ≤10% premature ventricular complexes as group 2, >11 and ≤20% premature ventricular complexes as group 3, and >20% premature ventricular complexes as group 4. QRS, QT, and T peak to end interval were measured by resting electrocardiography. QT interval was corrected using Bazett's formula. T peak to end interval/QT, T peak to end interval/corrected QT interval, index of cardiac-electrophysiological balance, and corrected index of cardio-electrophysiological balance ratios were calculated.

There was no significant difference between groups regarding cardiovascular risk factors. In group 4, beta-blocker usage was significantly higher, and the serum magnesium levels were significantly lower than in other groups. There was no difference in QT duration or index of cardiac-electrophysiological balance values; however, corrected index of cardio-electrophysiological balance was significantly lower in the highest premature ventricular complex group (5.1, 5.1, 4.8, 4.7, p=0.005). In multivariate backward logistic regression analyses, it was found that lower corrected index of cardio-electrophysiological balance, lower serum magnesium levels, lower serum creatinine levels, larger left atrium size, and higher T peak to end interval were associated with higher premature ventricular complexes.

Corrected index of cardio-electrophysiological balance is a novel and noninvasive marker that can predict premature ventricular complex burden in patients with structurally normal hearts.

Cardiovascular disease (CVD) is the most common cause of death in patients with renal diseases. Cardiac arrhythmia and sudden cardiac death are particularly important, and the burden is higher in patients on hemodialysis. The aim of this study is to compare specific ECG changes as markers of arrhythmias in patients with CKD and patients with end-stage renal disease (ESRD); all without clinically manifest heart disease, with normal control subjects.

Seventy-five ESRD patients on regular hemodialysis, 75 patients with stage 3-5 CKD and 40 healthy control subjects were included. All candidates were subjected to thorough clinical evaluation and laboratory tests including serum creatinine, glomerular filtration rate calculation, serum potassium, magnesium, calcium, phosphorus, iron, parathyroid hormone, and total iron binding capacity (TIBC). Resting twelve-lead ECG was done to calculate P wave dispersion (P-WD), corrected QT interval, QTc dispersion, Tpeak-Tend interval (Tp-e), and Tp-e/QT. Patients with ESRD had a significantly higher QTc dispersion (p < 0.001) and P-WD (p = 0.001) when compared to the other 2 groups. In the ESRD group, males had a significantly higher P-WD (p = 0.045), insignificantly higher QTc dispersion (p = 0.445), and insignificantly lower Tp-e/QT ratio (p = 0.252) as compared to females. Multivariate linear regression analysis for ESRD patients showed that serum creatinine (β = 0.279, p = 0.012) and transferrin saturation (β =  - 0.333, p = 0.003) were independent predictors of increased QTc dispersion while ejection fraction (β = 0.320, p = 0.002), hypertension (β =  - 0.319, p = 0.002), hemoglobin level (β =  - 0.345, p = 0.001), male gender (β =  - 0.274, p = 0.009) and TIBC (β =  - 0.220, p = 0.030) were independent predictors of increased P wave dispersion. In the CKD group, TIBC (β =  - 0.285, p = 0.013) was an independent predictor of QTc dispersion while serum calcium (β = 0.320, p = 0.002) and male gender (β =  - 0.274, p = 0.009) were independent predictors of Tp-e/QT ratio.

Patients with stage 3-5 CKD and those with ESRD on regular hemodialysis exhibit significant ECG changes that are considered substrates for ventricular as well as supraventricular arrhythmias. Those changes were more evident in patients on hemodialysis.

To investigate changes in cardiac repolarization abnormalities (heart rate-corrected QT [QT_c ] [primary endpoint], T-wave abnormalities) and heart-rate variability measures in people with type 1 diabetes during insulin-induced hypoglycaemia followed by recovery hyperglycaemia versus euglycaemia.

In a randomized crossover study, 24 individuals with type 1 diabetes underwent two experimental clamps with three steady-state phases during electrocardiographic monitoring: (1) a 45-minute euglycaemic phase (5-8 mmol/L), (2) a 60-minute insulin-induced hypoglycaemic phase (2.5 mmol/L), and (3) 60-minute recovery in either hyperglycaemia (20 mmol/L) or euglycaemia (5-8 mmol/L).

All measured markers of arrhythmic risk indicated increased risk during hypoglycaemia. These findings were accompanied by a decrease in vagal tone during both hyperglycaemia and euglycaemia clamps. Compared with baseline, the QT_c interval increased during hypoglycaemia, and 63% of the participants exhibited a peak QT_c of more than 500 ms. The prolonged QT_c interval was sustained during both recovery phases with no difference between recovery hyperglycaemia versus euglycaemia. During recovery, no change from baseline was observed in heart-rate variability measures.

In people with type 1 diabetes, insulin-induced hypoglycaemia prolongs cardiac repolarization, which is sustained during a 60-minute recovery period independently of recovery to hyperglycaemia or euglycaemia. Thus, vulnerability to serious cardiac arrhythmias and sudden cardiac death may extend beyond a hypoglycaemic event, regardless of hyperglycaemic or euglycaemic recovery.

Ischemia due to microvascular dysfunction may be responsible for the heterogeneity of ventricular repolarization in coronary slow flow. To our knowledge, there is no study in which QT interval, Tp-Te interval, index of cardiac-electrophysiological balance (iCEB), and frontal QRS-T angle were evaluated together in patients with CSF. In this study, we examined for the first time the relationship between all these myocardial repolarization parameters and CSF.

The study group included 178 patients (99 female, mean age: 50.6 ± 8.6 years) with isolated CSF without stenotic lesions and with angiographically proven normal coronary arteries. The control group included 120 patients (71 female, mean age: 49.3 ± 9.4 years) with normal coronary angiography. QRS duration, QT interval, QTc interval, Tp-Te interval, Tp-Te/QT, Tp- Te/QTc, iCEB score, and frontal QRS-T angle were calculated from 12‑lead ECGs.

There was no significant difference in demographic parameters between the two groups. Compared with the control group, patients with CSF had significantly longer QTmax duration, QT dispersion, Tp-Te interval, and higher iCEB score, wider frontal QRS-T angle.

In our study, we found that many of the ventricular repolarization parameters were adversely affected in patients with CSF. Impaired parameters may be associated with the risk of malignant ventricular arrhythmias.

Empagliflozin is a new antidiabetic drug with positive effects on glucose regulation and the prevention of cardiovascular diseases (CVD). The effect of empagliflozin on arrhythmias has not been adequately studied. The index of cardio-electrophysiological balance (iCEB) is a popular marker used to predict ventricular arrhythmias. Therefore, in our study, we aimed to examine the effect of empagliflozin on iCEB and iCEBc in patients with type 2 diabetes mellitus (T2DM) without heart failure (HF).

A total of 70 patients were included in the study prospectively. Electrocardiographic and echocardiographic evaluations of all patients were reviewed at baseline and the end of the third month.

The median age of the patients was 57 (43-68 IQR), and 30 (42.9%) were male. Tp-e (100 [88-120] vs. 94 [82-105], p = .01), Tp-e/QT (0.27 [0.25-0.33] vs. 0.25 [0.23-0.30], p = .001) were significantly shorter after treatment. iCEB (4.24 [3.8-4.5] vs. 3.92 [3.79-4.42], p = .009) and iCEBc (4.78 [4.25-4.92] vs. 4.48 [4.0-4.71], p = .001) values decreased significantly after treatment compared to baseline.

Tp-e, Tp-e/QT, iCEB, and iCEBc values decreased within physiological limits in patients with T2DM without HF. This result may be associated with a reduced risk of potential ventricular arrhythmias.

Inflammatory bowel disease (IBD), a multisystemic inflammatory disorder, has been associated with increased risk of cardiovascular problems, including complications such as conduction defects and arrhythmias. Therefore, the early assessment of the risk factors predisposing to ventricular arrhythmias is crucial, since it can improve clinical outcomes. The objective of the present study is to evaluate ventricular repolarization by using Tp‑e interval and Tp-e/QTc ratio as candidate markers of ventricular arrhythmias in patients with IBD.

The presented study was designed as a single-center prospective cohort study. The study population consisted of 175 patients with IBD and 175 healthy volunteers. The Tp‑e interval, corrected QT (QTc), and Tp-e/QTc ratio were measured from the 12-lead electrocardiogram. These parameters were compared between groups.

The groups were similar in terms of electrocardiographic findings such as heart rate, QRS interval, and QTc interval. However, Tp‑e interval (87.0 ms, interquartile range, IQR 81.0-105.0 ms vs. 84.0 ms, IQR 74.0-92.0 ms; p < 0.001) and Tp-e/QTc ratio (0.21 ± 0.04 vs. 0.19 ± 0.05; p < 0.001) were significantly increased in IBD patient group compared to control group. Notably, a positive correlation was demonstrated between Tp‑e interval, Tp-e/QTc ratio and disease duration (Spearman's Rho = 0.36, p < 0.001 for Tp‑e; Spearman's Rho = 0.28, p < 0.001 for Tp-e/QTc).

This study demonstrated that IBD patients are at increased risk of disrupted ventricular repolarization (increased Tpe, Tpe/QTc ratio). In addition, a positive correlation was demonstrated between Tp‑e interval, Tp-e/QTc ratio, and disease duration. Therefore, IBD patients, especially those with long-standing diseases, should be more closely screened for ventricular arrhythmias.

Renal transplant recipients are at risk for ventricular arrhythmia and sudden death. To assess that risk, we compared the ventricular repolarization markers of pediatric renal transplant recipients with those of healthy children.

We included 30 children and adolescents who were followed for at least 6 months after renal transplant; 30 age- and sex-matched children were included for the control group. Demographic features, medications, and laboratory findings were recorded. Blood pressure measurements, ventricular repolarization indexes including QT dispersion, corrected QT dispersion, T-wave peak-to-end interval dispersion, the T-wave peak-to-end interval∕QT ratio, the T-wave peak-to-end interval∕corrected QT ratio, left ventricular mass index, and relative wall thickness were compared between groups. In addition, the correlations of ventricular repolarization indexes with other variables were evaluated.

Blood pressure standard deviation scores, the mean heart rate, QT dispersion, corrected QT dispersion, the T-wave peak-to-end interval∕QT ratio, the T-wave peak-to-end interval/corrected QT ratio, left ventricular mass index, and relative wall thickness values were significantly higher in renal transplant patients, whereas T-wave peak-to-end interval dispersion, ejection fraction, and fractional shortening were similar between groups. Although ventricular repolarization indexes were similar in patients with and without left ventricular hypertrophy, only corrected QT dispersion was significantly higher in patients with hypertension (P = .006). The only variable that significantly predicted prolonged corrected QT dispersion was the systolic blood pressure standard deviation score (P = .005, β = .403).

Ventricular repolarization anomalies, hypertension, left ventricular hypertrophy, and cardiac geometry irregularity may be observed after renal transplant in pediatric recipients despite acceptable allograft functions and normal serum electrolyte levels. Control of systolic blood pressure would decrease the risk of ventricular repolarization abnormalities, namely, the corrected QT dispersion. Follow-up of cardiovascular risks with noninvasive methods is recommended in all pediatric renal transplant recipients.

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

Premature ventricular contraction is generally known as benign in the absence of structural heart disease; however, premature ventricular contraction-induced left ventricular systolic dysfunction or ventricular arrhythmias are defined in some cases. Ventricular repolarization duration differs between myocardial cells, which causes myocardial electrical heterogeneity and is thought to be responsible for ventricular arrhythmias. In our study, we aimed to evaluate the association of ventricular repolarization parameters including Tp-Te interval, Tp-Te/QT ratio, and QRS-T angle with premature ventricular contraction frequency in patients with premature ventricular contraction burden.

A total of 80 subjects who were admitted to our cardiology department and underwent 24-h electrocardiography Holter monitoring were included. Patients were divided into two groups: group 1 is defined as premature ventricular contraction burden that had frequent premature ventricular contraction ≥1% in 24-h Holter monitoring, and group 2 is defined as rare premature ventricular contraction <1% in 24-h Holter monitoring.

Tp-Te interval and Tp-Te/QT ratio are statistically significantly prolonged in the premature ventricular contraction burden group than in the control group (85.3±13.9 vs. 65.7±11.9, p<0.001; 0.19±0.03 vs. 0.15±0.02, p<0.001, respectively). QRS-T angle was statistically significantly abnormal in the premature ventricular contraction burden group (p=0.024).

Increased Tp-Te interval and widened QRS-T angle are associated with ventricular arrhythmias and might be used for the prediction of premature ventricular contraction burden in patients with premature ventricular contraction in electrocardiography in the absence of 24-h Holter monitoring.