Search Results (19)

Objective: Sodium–glucose cotransporter 2 (SGLT2) inhibitors, particularly empagliflozin, have attracted considerable attention because of their cardiovascular benefits beyond glycemic control. However, the interaction between empagliflozin and exercise-induced physiological cardiac remodeling in healthy individuals remains insufficiently understood. This study investigated the effects of different swimming exercise protocols (anaerobic, aerobic, and endurance), administered alone or in combination with empagliflozin, on cardiac structure and electrophysiology. Methods: Thirty-six male Sprague–Dawley rats were randomly assigned to six groups (n = 6 per group): anaerobic (An), aerobic (Ae), endurance (En), and the corresponding exercise groups combined with empagliflozin (An + Empa, Ae + Empa, and En + Empa). Empagliflozin was administered by oral gavage at a dose of 15 mg/kg/day for 30 days. Transthoracic echocardiography, electrocardiography (ECG), and gastrocnemius electromyography were performed at baseline and at the end of the study to assess cardiac remodeling, heart rate, and neuromuscular function. The study was carried out over a 30-day intervention period following ethics committee approval on 24 July 2024. Results: No significant between-group differences were observed in echocardiographic parameters before the intervention. On day 30, significant differences were identified among the groups in interventricular septal thickness at end-diastole (IVSd) (p = 0.027), left ventricular internal diameter at end-diastole (LVIDd) (p = 0.009), and end-diastolic volume (EDV) (p = 0.014). Bonferroni-corrected post hoc analysis showed that the aerobic exercise plus empagliflozin group differed from several exercise-only groups, particularly in parameters related to ventricular size and filling volume, including LVIDd and EDV (p < 0.008). On day 30, electrocardiographic repolarization-related parameters, including QT, QTc, JT, and Tpeak–Tend intervals, also differed significantly among the groups (all p < 0.05). In post hoc analysis, the anaerobic exercise group showed significant differences in QT and JT intervals compared with the aerobic and endurance groups (p < 0.008). In the anaerobic protocol, empagliflozin was associated with a reduction in heart rate compared with the corresponding control group (p = 0.019). No significant between-group differences were observed in EMG findings. Conclusions: Different exercise protocols induce distinct patterns of adaptation in cardiac structure and electrophysiology in healthy rats. Empagliflozin (15 mg/kg/day) may modulate exercise-induced cardiac responses in a modality-dependent manner; the most pronounced echocardiographic effects were observed in the aerobic protocol, whereas the effect on heart rate was observed in the anaerobic protocol. These findings highlight the need for longer-term and mechanistic studies to further clarify the effects of SGLT2 inhibitors on physiological cardiac remodeling. Full article

Background: Migraine is a neurological disorder affecting approximately 15% of the general population, and autonomic nervous system (ANS) dysfunction is a well-characterized feature of the condition. Sympathovagal imbalance during acute migraine attacks has been linked to cardiac electrical instability. This study aimed to evaluate atrial and ventricular myocardial repolarization markers in migraine patients at three serial electrocardiography (ECG) time points. Methods: A prospective observational cross-sectional study was conducted in a tertiary emergency department (ED), enrolling 70 migraine patients and 70 age- and sex-matched healthy controls. Three 12-lead ECGs were obtained per patient: during the migraine attack (within 60 min of ED admission), after analgesic treatment (verbal pain relief or Numeric Rating Scale [NRS] decrease greater than 4 points), and in the pain-free period (at least 24 h after the attack, within 7 days). Measured parameters included P-wave duration, P-wave dispersion, QT interval, QT dispersion, corrected QT (QTc) duration (Bazett formula), QTc dispersion, Tpeak–Tend (Tp-e) interval, Tp-e dispersion, and Tp-e/QTc ratio. ECGs were evaluated by two blinded emergency medicine specialists. Results: All repolarization markers were significantly higher in migraine patients than in controls (p < 0.05 for all). Comparing the first (ictal) with the second (post-treatment) measurements, all markers except P-wave dispersion decreased significantly (p < 0.05). All markers were significantly higher during the attack than in the pain-free period (p < 0.05 for all). Tp-e interval and Tp-e/QTc ratio showed a further significant reduction between the second and third measurements (p = 0.016 and p = 0.004, respectively). P-wave dispersion was significant only for the first-to-second comparison (p = 0.034) and did not differ significantly between the first and third (p = 0.137) or second and third (p = 0.725) measurements. Pulse rate was significantly higher in the migraine group than in controls (p = 0.012). Conclusions: Acute migraine attacks were associated with significant elevation of both atrial and ventricular repolarization markers, with near-normalization during pain-free periods. These findings are consistent with a proposed mechanism of ANS-mediated cardiac electrical instability during acute attacks, although direct confirmation in future studies is required. Clinicians managing acute migraine in the ED should consider ECG monitoring in patients with cardiovascular risk factors. For anesthesiologists and intensivists, the elevated Tp-e and Tp-e/QTc observed ictally indicate that preoperative ECG assessment in migraine patients may be warranted to guide anesthetic planning. Full article

Background and Objectives: The interaction between the brain and heart has become more interesting in the last 20 years. The most common cardiac complications after stroke are myocardial infarction, heart failure, arrhythmias, electrocardiographic disturbances, repolarization disorders, and sudden cardiac death. The prolonged Tpeak–Tend interval is an indicator of the electrical heterogeneity of the myocardium (abnormal repolarization) that causes malignant arrhythmias. We aimed to investigate whether the Tpeak–Tend interval, which reflects the heterogeneity of repolarization, is prolonged in stroke and its relationship with short-term mortality. Materials and Methods: Individuals over the age of 18 who presented with hemorrhagic or ischemic stroke were included in the study. Demographic characteristics, laboratory and imaging findings of the patients were recorded. ECGs were obtained at the time of admission to the hospital and 24 h later. Patients were followed for in-hospital mortality. Results: 89 (82.4%) of the patients had ischemic stroke, 19 (17.6%) had hemorrhagic stroke. It was determined that Tp-eV2 and Tp-eV5 at hospital admission were significantly longer than the 24th hour values. A total of 92.01 (16.3) ms at Tp-eV2 admission, 84.1 (16.3) ms after 24 h (p = 0.003), 91.9 (7.3) msTp-eV5 at admission, and 81.6 (17.8) ms (p = 0.000) after 24 h. In multivariate logistic regression analysis of in-hospital mortality, Tp-eV2 (HR: 0.96 (95% CI 0.93–0.99) p = 0.008) was determined as an independent predictor among cardiovascular parameters. Conclusions: Tp-e intervals were prolonged in both leads V2 and V5 in patients with stroke. Prolongation of lead V2 in the Tp-e interval is an independent indicator of short-term mortality among cardiovascular parameters. Full article

(1) Background: Physical activity, altered metabolic parameters, and socio-economic status may affect electrocardiographic (ECG) parameters in children. However, a direct comparison of their effects on resting ECG has not yet been performed. (2) Methods: A total of 139 participants (60 male), aged 10–17 years, were recruited. Resting 1-minute ECG recordings and clinical and laboratory investigations were obtained, while socio-economic status and physical activity were assessed using a questionnaire. Associations between these factors and ECG parameters were analyzed using analysis of covariance (ANCOVA). (3) Results: Age, sex, metabolic syndrome, and physical activity significantly influenced the average RR interval (η² = 0.292, 0.070, 0.078, and 0.070, respectively). Similar effects were observed on the T_end–P interval. The PR, QRS, QTc, and T_peak–T_end intervals were moderately influenced by age (η² = 0.084, 0.056, 0.072, and 0.049, respectively). QTc was additionally affected by sex (η² = 0.060). None of the modifiable factors had any effect on depolarization or repolarization parameters. Socio-economic status had no significant effect on resting ECG. (4) Conclusions: Physical activity exerts similar effects on resting ECG in both sexes, while metabolic syndrome is an independent determinant of several ECG parameters. Further studies are warranted to clarify the clinical relevance of these findings. Full article

Background/Objectives: Immune checkpoint inhibitor (ICI)-associated cardiovascular adverse events are relatively uncommon; they can be life-threatening, particularly when involving malignant ventricular arrhythmias. Electrocardiographic markers such as P-wave dispersion (PWD), QT dispersion (QTd), T-peak to T-end (Tp-e) interval, and Tp-e/QT and Tp-e/QTc ratios have been linked to an elevated risk of both atrial and ventricular arrhythmias and sudden cardiac death across various cardiac conditions. Monitoring these parameters may aid in identifying the risk of arrhythmogenic events in cancer patients undergoing ICI therapy. Methods: This retrospective cohort study analyzed 42 patients with cancer who received ICI therapy and had serial 12-lead electrocardiograms (ECGs) performed at baseline and at three-month intervals during the first year of treatment, from May 2022 to November 2023. ECG parameters including PWD, QTd, Tp-e interval, and Tp-e/QT and Tp-e/QTc ratios were measured and compared between baseline and follow-up time points. Results: The median follow-up duration was 5.3 months (range: 0.5–18.9 months). No statistically significant differences were observed in any of the ECG parameters between baseline and subsequent measurements (p > 0.05). One patient developed atrial fibrillation during the third month of treatment. Additionally, one patient exhibited a left anterior fascicular block, and another experienced frequent ventricular extrasystoles. No malignant ventricular arrhythmias were reported throughout the study period. Conclusions: This study found no significant changes in electrocardiographic markers associated with arrhythmia risk during ICI treatment. Larger, multicenter, prospective studies with extended follow-up are warranted to further elucidate the cardiovascular safety profile of ICIs. Full article

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, Full article

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. Full article

A noninvasive tool for cardiovascular risk stratification has not yet been established in the clinical routine analysis. Previous studies suggest a prolonged T_peak-T_end interval (the interval from the peak to the end of the T-wave) to be predictive of death. This meta-analysis was designed to systematically evaluate the association of the T_peak-T_end interval with mortality outcomes. Medline (via PubMed), Embase and the Cochrane Library were searched from 1 January 2008 to 21 July 2020 for articles reporting the ascertainment of the T_peak-T_end interval and observation of all-cause-mortality. The search yielded 1920 citations, of which 133 full-texts were retrieved and 29 observational studies involving 23,114 patients met the final criteria. All-cause deaths had longer T_peak-T_end intervals compared to survivors by a standardized mean difference of 0.41 (95% CI 0.23–0.58) and patients with a long T_peak-T_end interval had a higher risk of all-cause death compared to patients with a short T_peak-T_end interval by an overall odds ratio of 2.33 (95% CI 1.57–3.45). Heart rate correction, electrocardiographic (ECG) measurement methods and the selection of ECG leads were major sources of heterogeneity. Subgroup analyses revealed that heart rate correction did not affect the association of the T_peak-T_end interval with mortality outcomes, whereas this finding was not evident in all measurement methods. The T_peak-T_end interval was found to be significantly associated with all-cause mortality. Further studies are warranted to confirm the prognostic value of the T_peak-T_end interval. Full article

Background: Brugada syndrome (BrS) is diagnosed in patients with ST-segment elevation with coved-type morphology in the right precordial leads, occurring spontaneously or after provocative drugs. Due to electrocardiographic (ECG) inconsistency, provocative drugs, such as sodium-channel blockers, are useful for unmasking BrS. Ajmaline is superior to flecainide and procainamide to provoke BrS. Prolonged T-peak to T-end (TpTe) is associated with an increased risk of ventricular arrhythmia and sudden cardiac death in Brugada syndrome patients. Objective: This study aimed to investigate the predictive value of T-peak to T-end interval and corrected T-peak to T-end interval for predicting the positive response of the ajmaline challenge test in suspected Brugada syndrome patients. Methods: Patients who underwent the ajmaline test in our center were enrolled. Clinical characteristics and electrocardiographic parameters were analyzed, including TpTe, corrected TpTe, QT, corrected QT(QTc) interval, and S-wave duration, compared with the result of the ajmaline challenge test. Results: The study found that TpTe and corrected TpTe interval in suspected BrS patients were not significantly associated with a positive response to the ajmaline challenge test. Conclusions: The T-peak to T-end interval and corrected T-peak to T-end interval could not predict the positive response of the ajmaline challenge test in suspected Brugada syndrome patients. Full article

In many recent studies, high sugar intake has been shown to have harmful effects on the cardiovascular system, especially in children. This study aimed to check the association between sugar intake and T-peak to T-end interval, an electrocardiogram (ECG) parameter associated with a higher risk of early afterdepolarizations and ventricular arrhythmias in young athletes. The study participants were 96 young athletes aged 7–15, 34 girls and 62 boys trained in various sports. ECGs were performed on all participants and analyzed for the duration of the period from the peak of the T-wave to the end of the T-wave. The data on years of training and training hours per week, type of sport, age, height, and weight were taken, as well as the child’s sugar intake per day. The cut-off was a minimum of 30 g of concentrated sugar in sweets or drinks. The group of children that consumed sugar had, on average, a significantly longer duration of the T-peak to T-end (TpTe) interval. There is an association between sugar intake and the duration of the T-peak to T-end (TpTe) interval. In our case study, it was demonstrated that the benefit of playing sports cannot compensate for the harm of overconsumption of sugar, so an important public health target would be to lower sugar intake in children’s diets (particularly in the diets of young athletes). It would be necessary to determine interventions and activities that would affect the reduction in sugar intake from early childhood. Aside from the fact that overconsumption of sugar is associated with human health issues, there are many environmental benefits of reducing sugar production and consumption. Full article

In myocardial ischemia, melatonin confers antiarrhythmic action, but its electrocardiographic expression is unclear. We aimed to evaluate the effects of melatonin treatment on electrocardiogram (ECG) parameters reflecting major arrhythmogenic factors and to test the association of these parameters with ventricular fibrillation (VF) incidence. Myocardial ischemia was induced by 40 min coronary artery occlusion in 25 anesthetized pigs. After induction of ischemia, 12 and 13 animals were given melatonin or placebo, respectively. Twelve-lead ECGs were recorded and durations of QRS, QT, Tpeak-Tend intervals and extrasystolic burden were measured at baseline and during occlusion. During ischemia, VF episodes clustered into early and delayed phases (<10 and >20 min, respectively), and QRS duration was associated with VF incidence. QT interval and extrasystolic burden did not differ between the groups. The Tpeak-Tend interval was progressively prolonged, and the prolongation was less pronounced in the treated animals. QRS duration increased, demonstrating two maxima (5–10 and 25 min, respectively). In the melatonin group, the earlier maximum was blunted, and VF development in this period was prevented. Thus, acute melatonin treatment prevented excessive prolongation of the QRS and Tpeak-Tend intervals in the porcine myocardial infarction model, and QRS duration can be used for the assessment of antiarrhythmic action of melatonin. Full article

Background: Pregnancy is a condition in which new cardiac arrhythmias can occur or prior undiagnosed arrhythmias may provide symptoms. The occurrence of severe ventricular arrhythmias and polymorphic ventricular tachycardia that may lead to fainting or sudden cardiac death is promoted by the prolongation of the QTc interval. The post-partum adaptation period is the most arrhythmogenic. TpTe (Tpeak-Tend interval) is a novel marker of arrhythmogenesis by many considered a more sensitive marker than QTc. Objective: The aim of our work was to determine the TpTe interval (Tpeak-Tend) in women in the first, second and third trimester of pregnancy and the post-partum period. Materials and Methods: The study group consisted of 128 women in pregnancy or postpartum and a control group of 32 non-pregnant women. A standard 12-lead ECG (electrocardiograph) recording with evaluation of the duration of TpTe and QTc was performed in all patients. Results: In comparison to the non-pregnant women, higher values of QTc and TpTe were observed starting in the first trimester with highest values observed in the postpartum period. Mean duration of TpTe interval during pregnancy (81.59 ± 5.92 ms) and in the whole study group (pregnancy + postpartum) (85.46 ± 6.45 ms) was significantly longer (p < 0.001) compared to the TpTe interval in the control group (74.06 ± 6.14 ms). During pregnancy and postpartum, the increase in the TpTe interval in comparison to the increase in the QTc parameter (31.10% vs. 4.18%) was significantly higher (p < 0.001). Conclusions: The study showed an increase in the duration of the TpTe interval and QTc parameter during pregnancy and postpartum with the highest values in the postpartum period. TpTe interval increase was significantly higher compared to QTc increase during pregnancy and postpartum. Changes of TpTe interval were not associated with any clinical outcome or measure of arrythmia burden. Further studies are needed in order to see the clinical significance of these ECG findings, in particular for larger groups of patients with automatic measurement in correlation with echocardiography Full article

Using bio-impedance to deduce some hemodynamic parameters combined with some short-term ECG temporal dispersion intervals, and measuring myocardial depolarization, intraventricular conduction, and repolarization. A total of 65 in-hospital patients (M/F:35/30) were enrolled, 39 with HFrEF and 26 HFpEF, in New York Heart Association (NYHA) class IV. Stroke volume (SVI), cardiac indexes (CI), left ventricular ejection fraction (LVEF_BIO), end diastolic volume (LV-EDV), and other systolic and diastolic parameters were noninvasively obtained at enrollment and at hospital discharge. At the same time, QR, QRS, QT, ST, Tpeak-Tend (Te) interval mean, and standard deviation (SD) from 5 min ECG recordings were obtained. At baseline, HFrEF patients reported significantly lower SVI (p < 0.05), CI (p < 0.05), and LVEF (p < 0.001) than HFpEF patients; moreover, HFrEF patients also showed increased LV-EDV (p < 0.05), QR, QRS, QT, ST, and Te means (p < 0.05) and standard deviations (p < 0.05) in comparison to HFpEF subjects. Multivariable logistic regression analysis reported a significant correlation between hospital mortality and Te mean (odds ratio: 1.03, 95% confidence limit: 1.01–1.06, p: 0.01). Fifty-seven percent of patients were considered responders to optimal medical therapy and, at discharge, they had significantly reduced NT-proBNP, (p < 0.001), heart rate (p < 0.05), and Te_SD (p < 0.001). LVEF, obtained by transthoracic echocardiography, and LVEF_BIO were significantly related (r: 0.781, p < 0.001), but these two parameters showed a low agreement limit. Noninvasive hemodynamic and ECG-derived parameters were useful to highlight the difference between HFrEF and HFpEF and between responders and nonresponders to the optimal medical therapy. Short-period bioimpedance and electrocardiographic data should be deeply evaluated to determine possible advantages in the therapeutic and prognostic approach in severe CHF. Full article

Background and Objectives: Early repolarization pattern (ERP) has recently been shown to be related with an increased risk of ventricular arrhythmias in susceptible individuals. Materials and Methods: We studied the ERP-associated ECG changes, with potential clinical relevance, in 220 young (age 22.1 ± 1.6 years), healthy, male subjects using 12-lead ECG recordings. A total of 38 subjects (17.3%) fulfilled the diagnostic criteria for ERP, and a total of 90 ECG characteristics were compared between the groups of subjects with and without ERP. Results: None of the ECGs were pathological, and 22 ECG parameters differed significantly (p < 0.05) between the subjects with and without ERP. Among them, the P wave-related parameters (e.g., average P wave duration: 101.5 ± 9.2 ms vs. 106.8 ± 9.9 ms, p = 0.004) and the presence of fragmented QRS complexes (67.6% vs. 92.1%, p = 0.002) revealed a potential propensity for atrial and ventricular arrhythmogenesis. The time-domain parameters of repolarization, those not corrected for QRS duration, showed shorter values (e.g., Tpeak-Tend interval: 70.9 ± 8.1 ms vs. 67.8 ± 8.0 ms, p = 0.036), reflecting the accelerated repolarization. Conclusions: Certain ECG characteristics seem to be more associated with ERP. The clinical significance of this finding at the individual level needs further prospective investigations. Full article

Background: The changes in the period of ventricular repolarization, i.e., QT interval, QTp (Q-Tpeak) and TpTe interval (Tpeak–Tend), make it possible to assess the electrical instability of the heart muscle, which may lead to the development of life-threatening ventricular arrhythmia. The aim of the study was to determine and evaluate the use of differences in T-wave morphology and durations of repolarization period parameters (QT, TpTe) in resting ECGs for children with ventricular arrhythmias. Methods: The retrospective analysis was made of the disease histories of 80 examined children with resting ECGs, which were admitted to the Children’s Cardiology Department. The study group consisted of 46 children aged 4 to 18 with ventricular arrhythmias and the control group consisted of 34 healthy children between 4 and 18 years of age, with no arrhythmias. Results: The duration of the TpTe interval was significantly (p < 0.001) longer in the group of children with ventricular arrhythmia with abnormal T-wave (bactrian/bifid, humid/biphasic) compared to the TpTe interval in children with ventricular arrhythmia with the normal repolarization period. The duration of the TpTe (p < 0.001), QTcB (p < 0.001) and QTcF (p < 0.001) intervals were significantly longer in the group of children with ventricular arrhythmias and with abnormal T-wave compared to the values of the TpTe, QTcB, and QTcF intervals of the control group with normal morphology of the repolarization period. Only the duration of the TpTe interval was significantly (p = 0.020) longer in the group of children with ventricular arrhythmia without clinical symptoms. Conclusions: Children with benign ventricular arrhythmias recorded on a standard ECG with prolonged TpTe and QT intervals and abnormal T-wave morphology require systematic and frequent cardiac check up with long term ECG recordings due to the possibility of future more severe ventricular arrhythmias. Further follow-up studies in even larger groups of patients are necessary to confirm the values of these repolarization parameters in clinical practice. Full article