QT Dispersion Research Articles

The association of the amounts of epicardial fat, P wave duration, and PR interval in electrocardiogram

BackgroundThe relationship of epicardial fat and cardiac arrhythmias has been described in many studies. The association of the amounts of epicardial fat and the characteristics of electrocardiogram (ECG) remains unclear. The purpose of this study was to elucidate the association between the amounts of epicardial fat and the characteristics of ECG. MethodsA total of 100 consecutive patients who received multi-detector computer tomography (MDCT) were enrolled. The amounts of epicardial fat, including total heart, total atria, total ventricles, right atrium (RA), right ventricle (RV), left atrium (LA), and left ventricle (LV) regions, were measured. The PR interval in lead II, the P wave duration in lead I, the characteristics of inter-atrial conduction block manifested in ECG, the corrected QT interval (QTc) and the QT dispersion of a 12‑lead ECG were measured manually by a computer caliper. ResultsThe PR interval was correlated with the amounts of epicardial fat including total heart, total atria, total ventricles, RA, RV, LA, and LV (R = 0.295, p = 0.003; R = 0.379, p < 0.001; R = 0.284, p = 0.003; R = 0.415, p < 0.001; R = 0.287, p < 0.001; R = 0.33, p < 0.001; R = 0.244, p = 0.014). The P wave duration of lead I was also correlated with the amounts of epicardial fat (R = 0.202, p = 0.043; R = 0.283, p = 0.004; R = 0.225, p = 0.024; R = 0.365, p < 0.001; R = 0.256, p = 0.001; R = 0.20, p = 0.046; R = 0.199, p = 0.048) but the QTc interval and the QT dispersion were not. Inter-atrial conduction block was also associated with the amounts of epicardial fat, including total atria, RA and LA in univariate analysis (odds ratio (OR): 1.04, 95% of confidence interval (CI): 1.01–1.06, p = 0.015; OR: 1.08, 95% CI: 1.02–1.15, p = 0.011; OR: 1.05, 95% CI: 1.01–1.10, p = 0.031). In multivariate analysis of linear regression, the amounts of RA epicardial fat was most significantly associated with the PR interval, and the P wave duration (β value: 1.30, 95% CI: 0.59–2.02, p < 0.001; β value: 0.81, 95% CI: 0.34–1.28, p = 0.001). In multivariate analysis of logistic regression, inter-atrial conduction block was also significantly associated with the amounts of RA epicardial fat (odds ratio (OR): 1.08, 95% CI: 1.02–1.15, p = 0.011). ConclusionsThe PR interval, P wave duration and inter-atrial conduction block were associated with the amounts of epicardial fat, which might imply an effect for arrhythmogenesis.

The assessment of electrophysiological indices and ECG parameters as predictors of fatal arrhythmias under ischemia/reperfusion setting in multivariate regression model.

IntroductionThere are many factors predisposing to arrhythmia. The reentry mechanism is determined by dispersion of repolarization, unidirectional conduction block and activation slowing which can be documented as QRS widening. Similarly, the duration of repolarization and heart rate could favor the triggered activity or afterdepolarization proarrhythmic mechanism. The great interest for clinically application is the evaluation of noninvasive markers of fatal arrhythmias such as Tpeak‐Tend interval, QT dispersion and others but often they give unsatisfactory or conflicting results.The aim of the study was to find out which of the electrophysiological indices and ECG parameters contribute significantly to the genesis of fatal arrhythmias under experimental coronary occlusion and reperfusion using multivariate regression model.MethodsUsing needle plunge electrodes unipolar electrograms were recorded in intramural ventricular layers of 24 anesthetized open‐chest cats. Activation times (ATs) as dV/dt min during QRS, end of repolarization times (RTs) as dV/dt max during ST‐T, and activation‐recovery intervals (ARIs) as the time interval between the ATs and RTs were measured in total of 88 myocardial leads. The global, apicobasal, border RT dispersions were calculated as electrophysiological indices. The data were obtained at baseline, at 1 and 30 min of coronary occlusion and at 1 and 30 min of reperfusion.ResultsThe ventricular tachycardia and/or ventricular fibrillation (VT/VF) arose in a total of 10 animals at 1–5 minutes after reperfusion onset. During ischemia RTs progressively decreased and ATs increased in the ischemic zone and then progressively restored during reperfusion (P&lt;0.05). The global, apicobasal, border dispersion of repolarization, QRS, Tpeak‐Tend intervals increased in all animals during ischemia and at the reperfusion onset (P&lt;0.05). Under ischemia/reperfusion episode, the VT/VF group of animals demonstrated the greater global, border, apicobasal dispersion of RT, RTs in nonischemic and ischemic areas, QRS and Tpeak‐Tend intervals, and the lower heart rate as compared with the nonVT/VF animals (P&lt;0.05). Using the multivariate logistic regression analysis we assessed the association between the dispersions of RT, RTs and ATs of ischemic and nonischemic zone under the 1 min of reperfusion and the occurrence of VT/VF. It was found that RTs of nonischemic zone (P=0.024) and global dispersion of RT (P=0.046) demonstrated significant association with the reperfusion VT/VF. The following ECG parameters as predictors of arrhythmias were tested (heart rate, Tpeak‐Tend, QRS and QTc intervals, Tpeak‐Tend/QT ratio). The QRS interval (P=0.01) and heart rate (P=0.009) were found to have the significant link with the occurrence of VT/VF.ConclusionThe multivariate regression model showed that the genesis of VT/VF was independently predicted by the repolarization duration in nonischemic area and the global dispersion of repolarization at the reperfusion onset. The QRS and heart rate were the independent ECG predictors of the occurrence of reperfusion VT/VF.Support or Funding InformationThe study was supported by the Program for Fundamental Research of RAS project № AAAA‐A17‐117012310154‐6, № AAAA‐A18‐118012290365‐2.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The effect of Huoxue-Yixin decoction combined with atorvastatin on NT-pro and QTd in patients with chronic heart failure

Objective To observe the effect of Huoxue-Yixin decoction combined with atorvastatin on NT-pro and QTd in patients with chronic heart failure (CHF). Methods A total of 120 patients with chronic heart failure in our hospital from December 2016 to June 2017 were enrolled in this study. The subjects were randomly divided into the control group (n=60) and the treatment group (n=60). The control group were treated with conventional treatment, and the treatment group were treated with Huoxue-Yixin decoction combined with atorvastatin. The two groups were treated for 30 days. The NT-ProBNP, QTd, QTcd and LVESD, LVEDD, LVEF of the two groups before and after treatment were compared. Results The QTd at 2 d (45.6 ± 8.9 ms vs. 64.0 ± 18.2 ms, t=-7.029), 14 d (44.3 ± 6.8 ms vs. 55.7 ± 12.8 ms, t=-6.092) in the experiment group were significantly lower than those of control group (P<0.01). The level of QTcd at 2 d (50.8 ± 10.1 ms vs. 71.2 ± 19.8 ms, t=7.109), 14 d (48.1 ± 9.7 ms vs. 63.1 ± 13.1 ms, t=7.128) of the experiment group were significantly lower than those of control group (P<0.01). After treatment, the NT-ProBNP (494.58 ± 331.61 ng/L vs. 594.71 ± 382.65 ng/L, t=-1.532), LVESD (40.23 ± 3.13 mm vs. 49.72 ± 3.99 mm, t=-14.495) and LVEDD (58.22 ± 3.30 mm vs. 65.11 ± 3.95 mm, t=-10.720) of the treatment group were significantly lower than those of the control group (P<0.01). The LVEF (69.82% ± 4.72% vs. 50.34% ± 4.02%, t=-10.720) of the treatment group was significantly higher than the control group (P<0.01). Conclusions The Huoxue-Yixin decoction combined with atorvastatin can reduce the level of NT-ProBNP, QTd and QTcd in patients with CHF, can significantly improve cardiac function. Key words: Heart failure; Huoxue-Yixin decoction; N-terminal pro-brain natriuretic peptide; QT dispersion

Immediate and short term effects of percutaneous atrial septal defect device closure on cardiac electrical remodeling in children.

BackgroundThe beneficial effects of atrial septal defect (ASD) device closure on electrical cardiac remodeling are well established. The timing at which these effects starts to take place has yet to be determined.ObjectivesTo determine the immediate and short term effects of ASD device closure on cardiac electric remodeling in children.Methods30 pediatric patients were subjected to 12 lead Electrocardiogram immediately before ASD device closure, 24 h post procedure, 1 and 6 months after. The maximum and minimum P wave and QT durations in any of the 12 leads were recorded and P wave and QT dispersions were calculated and compared using paired T test.ResultsThe immediate 24 h follow up electrocardiogram showed significant decrease in P maximum (140.2 ± 6 versus 130.67 ± 5.4 ms), P dispersion (49.73 ± 9.01 versus 41.43 ± 7.65 ms), PR interval (188.7 ± 6.06 ms versus 182.73 ± 5.8 ms), QRS duration (134.4 ± 4.97 ms versus 127.87 ± 4.44), QT maximum (619.07 ± 15.73 ms versus 613.43 ± 11.87), and QT dispersion (67.6 ± 5.31 versus 62.6 ± 4.68 ms) (P = 0.001). After 1 month all the parameters measured showed further significant decrease with P dispersion reaching 32.13 ± 6 (P = 0.001) and QT dispersion reaching 55.0 ± 4.76 (P = 0.001). These effects were maintained 6 months post device closure.ConclusionPercutaneous ASD device closure can reverse electrical changes in atrial and ventricular myocardium as early as the first 24 h post device closure.

QTc ınterval is prolonged in Wilson’s disease with neurologic ınvolvement

Background Neurologic and liver involvement in Wilson’s disease (WD) is well-documented, however, few reports demonstrated cardiac involvement. Tpe and Tpe/QT are new measures of ventricular repolarization which were recently suggested as predictor of arrythmogenesis. We aimed to evaluate ventricular depolarization and repolarization parameters including QT, QTc, Tpe intervals, Tpe/QT, Tpe/QTc ratios, and QT dispersion (QTd) in patients with WD.Materials and methods Thirty-five patients with WD and 30 healthy controls were included in the study. Patients were evaluated by a neurologist in addition to MR imaging. Twenty-one of 35 patients were diagnosed as neuroWilson (NW), whereas 14 patients as non-NW. ECG recordings were obtained using a 12-lead commercial device (Cardiac Science, Burdick s500,USA). All patients underwent standard echocardiographic evaluation. These two groups of patients and healthy controls were compared.Results There were no difference between patients with WD and healthy controls in terms of age sex, BMI, liver, and kidney functions where as patients with WD were anemic and thrombocytopenic. Left atrial, ventricular dimensions, left ventricular systolic, and diastolic functions were similar between patients and healthy control. QT interval was prolonged in patient group, however, QTc, Tpe intervals, Tpe/QT, and Tpe/QTc ratios and QTd did not differ between groups. When patients with NW and non-NW were compared, both QT and QTc intervals were significantly longer in patients with NW, however, Tpe interval, Tpe/QT and Tpe/QTc ratios, and QTd did not differ.Conclusion QT and QTc intervals are prolonged in patients with Wilson’s disease and neurologic involvement.

The Correlation between QT Dispersion and Severity of Pulmonary Valve Stenosis

AbstractBackground: The heart rate-corrected QT interval (QTc) and QTc dispersion (QTcd) are prolonged and associated with ventricular arrhythmia and an increase in sudden death in a variety of diseases such as coronary heart disease, heart failure, hypertension and diabetes mellitus.Objective: Study of the relation between QTcd, QT interval and QTc and severity of pulmonary stenosis.Methods: A prospective observational cohort single center study in a period of 10 months starting from June 2016 to March 2017 at Cardiovascular Medicine Department, Tanta University Hospitals in Gharbia Governorate, Egypt. The study enrolled 50 subjects of both genders; 40 patients who were diagnosed with pulmonary stenosis & 10 subjects matched in age, sex, weight and body surface area as a control group. Resting 12-lead electrocardiogram was recorded. QT interval was measured manually and corrected using Bazett's formula. Patients were divided into groups with mild, moderate and severe pulmonary valve stenosis and a control group according to peak pressure gradient across pulmonary valve.Results: In all observed cases, mean QTc was higher in severe pulmonary valve stenosis than in controls (448.67±28.0 ms vs. 404.0±19.55ms, p=0.001) and QTcd was higher in mild, moderate (51.75±2.18 & 69.23±6.07ms respectively) and severe pulmonary valve stenosis (79.27±6.73ms) than in controls (46.20±5.49ms) (p=0.001).Conclusion: In patients with pulmonary valve stenosis, mean QTc and QTcd are positively correlated to peak pressure gradient across pulmonary valve and are significantly increased in patients with severe pulmonary valve stenosis.

Atrial and Ventricular Electrocardiographic Dromotropic Disturbances in Down Syndrome Patients with Structurally Normal Heart: A Cross-Sectional Study

Background: We designed a cross-sectional study to determine electrocardiographic disorders in Down syndrome patients with congenitally normal hearts in a bid to predict fatal cardiac arrhythmia in the future. Materials and Methods: We investigated 60 children with DS without congenital abnormal hearts. Sixty healthy juveniles were also included in the study as a control group. Physical examination, electrocardiography, and echocardiography were performed in all subjects. Corrected QT interval (QTc) was measured according to Bazett’s formula. Results: Patients with DS consisted of 32 males (53.33%), and 28 females (46.66%), aged 6–13 (9.21 ± 6.24) years old. Healthy subjects comprised 31 males (51.66%), and 29 females (48.33%) with a mean age of 9.15 ± 5.01. The two groups were significantly different in terms of heart rate (P=0.006), maximum P-wave duration (P=0.001), and P-wave dispersion (PWd, P=0.0001). There was no statistically significant difference regarding minimum P-wave duration (P=0.176). The patients with DS had a greater maximum QTc interval, QT dispersion, and corrected QT interval dispersion (QTc-d) than the healthy control subjects (P=0.001). However, there was no difference in maximum QT interval and minimum QTc interval between the two groups (P=0.67 and P=0.553, respectively). A positive correlation was found between age, heart rate, and all electrocardiographic variables. Conclusion: All DS patients, even in the absence of concomitant congenital heart disease should be followed up carefully by electrocardiography, looking for increased PWd and QTc-d to detect predisposed cases to arrhythmia.

Myocardial repolarization is affected in patients with ascending aortic aneurysm

ObjectiveAscending aortic aneurysm (AAA) is one of the major causes of ventricular diastolic dysfunction. Diastolic dysfunction can induce ventricular repolarization dispersion. Nevertheless, myocardial repolarization dispersion is not yet to be fully evaluated in patients with AAA. We aimed to evaluate ventricular repolarization using QT and Tp-Te interval and corrected (c) Tp-Te/QT ratio in patients with AAA. MethodsOne hundred-four patients with AAA without coronary artery disease (CAD) served as the aneurysm group and 82 patients having a normal aortic diameter as the control group. All patients underwent transthoracic echocardiography (TTE) for measurements of LV diastolic function and underwent electrocardiography (ECG) to calculate RR, QT, Tp-Te intervals and QT dispersion. Bazett's formula was used to calculate QTc and cTp-Te intervals. cTp-Te/QT ratio was also calculated. ResultsThe groups were similar according to basal characteristics. We found left ventricular diastolic properties were impaired and QT dispersion, QTc interval, and both of Tp-Te and cTp-Te intervals were significantly prolonged in the aneurysm group than the control group. There were also significant correlations between TTE and ECG parameters. On multivariate linear regression analysis, indexed ascending aortic dimension (AAoD), LA diameter and E/e′ ratio were independent predictors of ventricular repolarization dispersion in AAA patients. ConclusionsOur study results showed that patients with AAA may have an increased risk for ventricular arrhythmogenesis because of deteriorated the left ventricular diastolic function.

Evaluation of P Wave Dispersion, QT Dispersion and P Wave Amplitude in Patients with Obstructive Sleep Apnea Syndrome

Evaluation of P Wave Dispersion, QT Dispersion and P Wave Amplitude in Patients with Obstructive Sleep Apnea Syndrome

Evaluation of ventricular repolarization features with Tp-e, Tp-e/QTc, JTc and JTd during electroconvulsive therapy

ObjectiveThe purpose of this study was to investigate the influence of electrical stimulation transmitted through the body during electroconvulsive therapy on traditional and relatively new ventricular repolarization parameters (Rate corrected QT interval (QTc), QT dispersion (QTd), rate corrected JT interval (JTc), JT dispersion (JTd), T-peak to T-end interval (Tp-e) and Tp-e/QTc ratio) under propofol anaesthesia. MethodsTwenty-two patients (aged 18–50 years) who were each scheduled for ECT for major depression, bipolar disorder or schizophrenia enrolled to the study. Electrocardiography (ECG) recordings were obtained before anaesthesia and within 3–5 min after electrical stimulus of ECT for measurements. QTc, QTd, JTc, JTd, Tp-e and Tp-e/QTc were measured as repolarization indices. ResultsThe study included twenty-two patients, 9(40.9%) females and 13(59.1%) males, and the mean age accounted for 33.57 ± 9.95 years. The comparison of the measured parameters before and after ECT, which were not statistically different, were as follows: QTc (416.52 ± 46.64 vs 430.00 ± 34.00msn; p = 0.18), JTc (308.09 ± 25.09 vs 315.47 ± 26.89msn; p = 0.30), QTd (22.27 ± 11.51 vs 20.45 ± 9.9msn; p = 0.52) and JTd (22.72 ± 11.2 vs 17.72 ± 10.20msn; p = 0.06). Also, no significant difference was detected at the following parameters Tp-e (80.0 ± 13.45 vs 78.63 ± 15.21msn; p = 0.65) and Tp-e/QTc ratio (0.19 ± 0.03 vs 0.18 ± 0.07; p = 0.08). On the other hand, HR showed a significant increase after ECT at 88.13 ± 13.74 vs 93.0 ± 15.2 bpm; p = 0.03. ConclusionQTc, QTd, JTc, JTd, Tp-e interval and Tp-e/QTc ratio, which are thought to be potential repolarisation markers for ventricular arrhythmias, did not demonstrate significant change within 3–5 min of electrical stimulation during ECT.

The effect of transcatheter aortic valve implantation on Tp-e interval, Tp-e/QT and Tp-e/QTc ratios, and Tp-e dispersion in patients with severe aortic stenosis.

In this study, we aimed to investigate the effect of transcatheter aortic valve implantation using two types of bioprosthetic valves on novel ventricular repolarization markers including Tp-e, Tp-e/QT and Tpe/QTc ratios, and Tp-ed. A total of 61 patients (17 males, 44 females; mean age 78.6±6.5 years; range 55 to 89 years) who underwent transcatheter aortic valve implantation with either a Medtronic CoreValve (n=40) or an Edwards SAPIEN XT valve (n=21) were retrospectively analyzed. The electrocardiographic parameters and left ventricular mass index were calculated prior to the procedure, on postoperative Day 1, and at three months after the procedure. The Tp-e interval, Tp-e/QT and Tp-e/QTc ratios, Tp-ed, and left ventricular mass index significantly reduced at three months of the procedure, compared to baseline values (p<0.01, for all). Similar findings were observed for QT, QTc, and QT dispersion (p<0.01, for all). These changes were independent from the types of bioprosthetic valves used. Before the procedure, the left ventricular mass index was positively correlated with the Tp-e (r=0.350, p=0.007), Tp-e/QT (r=0.314, p=0.015) and Tp-e/QTc ratios (r=0.285, p=0.029). In the multivariate analysis, Tp-e interval was found to be independently associated with the left ventricular mass index (b=0.350, p=0.007). In the present study, the Tp-e interval, Tp-e/QT and Tp-e/QTc ratios, Tp-ed, and left ventricular mass index significantly reduced at three months after transcatheter aortic valve implantation indicating reverse left ventricular remodeling. The effects of two types of bioprosthetic valves on ventricular repolarization markers and left ventricular mass index were similar.

A Comparison Study of QT Dispersion in Early and Delayed Thrombolytic Therapy in Acute ST Elevation Myocardial Infarction

A Comparison Study of QT Dispersion in Early and Delayed Thrombolytic Therapy in Acute ST Elevation Myocardial Infarction

The effects of supraphysiological oestrogen levels on ventricular repolarisation parameters.

The frequency of arrhythmic death developing without a structural cardiac disease is higher in women. Also, female sex is an independent risk factor regarding development of torsades de pointes. Several studies have been conducted on the physiological and therapeutic effects of sex hormones on the cardiac conduction system. In this study we aim to examine the effect of hormonal changes, especially supraphysiological E2 level changes occurring during in vitro fertilisation treatment, on ventricular repolarisation parameters. The study included female patients aged between 23 and 39 years, who were administered controlled ovarian hyperstimulation treatment. Patients' electrocardiograms and blood samples were obtained and analysed before and after the ovarian hyperstimulation treatment. Mean QTc intervals before ovarian hyperstimulation were 411.9 ± 23.7 ms. Measurements during oestradiol peak were calculated as 420.7 ± 23.3 ms, and the QTc interval increase was significant (p = 0.007). Corrected QT dispersion averages were not significant before or after hyperstimulation (53 ± 17 ms vs. 54.5 ± 18.2 ms, respectively, p > 0.05). Tp-e, J-T peak, and PR dispersion changes were not significant after the ovarian hyperstimulation therapy. Supraphysiological oestradiol levels that occur during controlled ovarian hyperstimulation cause prolongation of QTc intervals, but not to a pathological level. Although this prolongation is not significant in healthy individuals, it might increase ventricular arrhythmia risk in patients with congenital long QT syndrome and in patients taking medication that prolongs QT.

Effect of primary percutaneous coronary intervention on ventricular repolarization through evaluation of QT dispersion in patient with acute myocardial infarction

Background: Cardiovascular disease is the most common cause of death around the world. QT dispersion is one of the parameters that used for evaluation of ventricular arrhythmia. Primary PCI increases probability of coronary artery and reperfusion of the ventricular arrhythmia. The aim of this study was to determine effect of primary percutaneous coronary intervention (PCI) on ventricular repolarization through evaluation of QT dispersion in patient with acute myocardial infarction. Methods: In this pre-post test study, 77 patients with acute ST with elevated myocardial infarction under primary PCI were investigated. The ECG and ST dispersion before PCI and 24 hours after PCI were determined and then the amount of QTd was calculated. The repeated measurement ANOVA was used to compare QTd of pre- PCI treatment and QTd in 24 hours after PCI. Data analysis was performed using statistical software SPSS ver.17. Results: From 77 participants, 60 were male and 17 were female. 43 (55.8%) had a MI position in ANT, PRE, and EXT, 33 (42.9%) had in the INF, and only one person (1.3%) had a MI position in LAT. The results showed that mean QT dispersion in ECG, 24h after primary PCI, for most of measured variables was deceased compare to before primary PCI, but the difference was not significant. Conclusions: The amount of QTd 24 hours after PCI decreased but its decline was not significant. With regards to lack of convenience data, more researches are recommended in this field.

Effect of coexisting hypertension, blood pressure control, and antihypertensive treatment on QT interval parameters in type 2 diabetics: A cross-sectional study

Objectives: To study the electrocardiogram (ECG) based QT parameters namely QTc (heart rate corrected QT), QTd (QT dispersion) in treated type 2 diabetics (T2D) and the effect of hypertension (HTN), blood pressure (BP) control, and antihypertensives used on the above parameters. Materials and Methods: We performed a cross-sectional study in a tertiary care hospital of Gujarat, India, on 199 T2D (67 males and 132 females). Standard 12-lead ECG was recorded to derive QTc (Bazett's formula), QTd, and ECG left ventricular hypertrophy (LVH). QTc >0.43 s in male and >0.45 s in female and QTd >80 msec were considered abnormal. Results: Hypertensives (n = 138) and normotensives (n = 61) were comparable for most confounders. Hypertensives had better profile of QTc and QTd than normotensives. T2D with controlled BP revealed slightly better, though insignificant; QTc, QTd than those with BP uncontrolled. QT parameters were not significantly correlated with age, heart rate, or BP. Qualitative differences exceeded quantitative difference in QTc and QTd evaluation. There was no significant effect of use or nonuse of preventive pharmacotherapy on QT parameters. Conclusion: Low-to-moderate prevailing cardiac repolarization abnormality in T2D with very low ECG LVH was unaffected by HTN as a disease, its control status, and treatment modalities suggesting primary preventive role of antihypertensive use without class difference.

Evaluation of the Tp-Te interval, Tp-Te/QTc ratio, and QT dispersion in patients with Turner syndrome.

Objective:To evaluate ventricular repolarization parameters using the interval from the peak to the end of the T wave (Tp–Te), together with QT and corrected QT (QTc) intervals, QT dispersion (QTd), and Tp-Te/QTc ratio in patients with Turner syndrome (pwTS) and to compare the results with those from healthy controls.Methods:In total, 38 patients previously diagnosed with Turner syndrome (TS) and 35 healthy girls (controls) were included in our cross-sectional study. Twelve-lead electrocardiography (ECG) and echocardiography after a 30-min rest were performed. The QT, QTc, QTd, Tp-Te interval, and Tp-Te/QTc ratio were determined.Results:No differences in age or sex were observed between the groups. QT intervals were similar in both groups [pwTS: 354.76±25.33 ms, controls (C): 353.29±17.51 ms, p=0.775]. pwTS had significantly longer QTc and QTd than controls (411.87±22.66 ms vs. 392.06±13.21 ms, p<0.001 and 40.31±2.02 ms vs. 37.54±1.83 ms, p<0.001, respectively). Similarly, the Tp-Te interval and Tp-Te/QTc ratio were significantly longer in pwTS than in controls (71.89±3.39 ms vs. 65.34±2.88 ms, p<0.001 and 0.17±0.01 vs. 0.16±0.01, p=0.01).Conclusion:As pwTS have longer QTc, QTd, Tp–Te interval, and Tp-Te/QTc ratio, an annual follow-up with ECG can provide awareness and even prevent sudden death in them. Also avoiding the use of drugs that makes repolarization anomaly and having knowledge about the side effects of these drugs are essential in pwTS.

Does pulmonary endarterectomy have arrhythmia prevention effect?

Background: The aim of the present study was therefore to evaluate the evolution of electrocardiography (ECG) markers indicator of morbidity and mortality after pulmonary endarterectomy (PEA). It may be a good predictor of mortality and morbidity in chronic thromboembolic pulmonary hypertension (CTEPH) with patients who underwent PEA. PEA may be reduced risk of arrhythmia in patients with CTEPH. However, this claim must to be supported with long-term results. Materials and Methods: We collected demographic, ECG, and echocardiographic parameters data (baseline and after the operation) in patients undergoing PEA for CTEPH at our institution from 2009 to 2013.We assessed 62 CTEPH patients who underwent PEA. Results: P wave amplitude in DII, PR interval, P and QT dispersion changed significantly at 3 months after surgery. The P dispersion (17.66 ± 6.2, P < 0.04) and QT dispersion (23.75 ± 11.37, P < 0.015) were longer in before operation than in after operation. Conclusions: In our study, we found in ECG analyses of CTEPH with patients who are undergoing PEA that P dispersion, QT dispersion were changed when compared with before operation. For this reason, we think that PEA reduces the risk of atrial fibrillation and malignant arrhythmia.

The effect of type 2 diabetes on electrocardiographic markers of significant cardiac events.

Background & Objectives:In diabetics, cardiac microvascular circulation disorder increases the risk of arrhythmia and sudden cardiac death. Tpeak-Tend (Tp-e) interval, Tp-e dispersion, and Tp-e/QT and Tp-e/QTc ratios measured by surface electrocardiogram (ECG) are new parameters used to evaluate ventricular arrhythmogenity. We aimed to compare QT dispersion (QTd), corrected QT dispersion (QTcd), P dispersion (Pd), Tp-e interval, Tp-e dispersion, and Tp-e/QT and Tp-e/QTc ratios in patients with type- 2 diabetes (T2D) with healthy population.Methods:Electrocardiographic parameters of a total of 100 patients diagnosed with T2D were retrospectively analyzed and compared with the ECG results of 100 healthy age-, sex-, and body weight and height-matched controls.Results:The Pd, QT interval, QTc interval, QTd, QTcd, Tp-e/QT, Tp-e/QT ratios were higher in the patients. A statistically significant correlation was found only between hemoglobin A1c and Tp-e dispersion, QTd, QTcd, Pd, Tp-e/QT and Tp-e/QTc parameters, in linear regression analysis. There was also a statistically significant positive correlation between the values of low-density lipoprotein, systolic blood pressure, and Tp-e dispersion.Conclusion:The risk of arrhythmia can be predicted by evaluating Tp-e interval, Tp-e dispersion, Tp-e/QT, and Tp-e/QTc ratio, suggesting heterogeneity of ventricular repolarization and P wave and Pd showing heterogeneity of atrial repolarization in diabetic patients.

Does attention deficit hyperactivity disorder have cardiac arrhythmia potential?

Objective: Attention deficit hyperactivity disorder (ADHD) is quite common in the general pediatric population. In this population, sympathomimetic drugs, which are at risk of arrhythmia, are frequently used. In this study, ECG characteristics of drug naive ADHD patients were compared control group. Methods: This study was performed 43 drug naive ADHD patients and 36 healthy children who admitted to the child and adolescent psychiatry outpatient clinic between November 2017 and January 2018. A standard 12-lead ECG of the patient and control group were evaluated. The ADHD and control group data were compared by calculating the minimum and maximum QT inter-val, corrected QT (QTc), QT dispersion (QTd), the peak and the end of the T wave (Tp-e) and Tp-e dispersion (Tp-ed) on 12-lead surface ECG. Tp-e interval was measured tangent method. The Bazett formula was used for QT correction. Results: The mean age of the patients with ADHD was 10.6±3.2 and 62.8% of them were male and similar to the control group. There was no significant difference between ADHD and control groups in terms of heart rate, min QT, max QT and min Tp-e values. QTc, QTd, max Tp-e and Tp-ed intervals were statistically higher ADHD patients than control group. Conclusion: QT dispersion and Tp–e is a measure of transmural dispersion of repolari-zation and related to cardiac arrhythmias. High QTd, QTc, max Tp-e and Tp-ed intervals in ADHD patients may indicate a potential cardiac arrhythmia. Physicians should make careful assessments of ADHD patients before pre-scribing sympathomimetic drugs.

Regional QT Interval Dispersion as an Early Predictor of Reperfusion in Patients with Acute Myocardial Infarction after Fibrinolytic Therapy.

BackgroundPatients with ST-elevation acute myocardial infarction attending primary care centers, treated with pharmaco-invasive strategy, are submitted to coronary angiography within 2-24 hours of fibrinolytic treatment. In this context, the knowledge about biomarkers of reperfusion, such as 50% ST-segment resolution is crucial.ObjectiveTo evaluate the performance of QT interval dispersion in addition to other classical criteria, as an early marker of reperfusion after thrombolytic therapy.MethodsObservational study including 104 patients treated with tenecteplase (TNK), referred for a tertiary hospital. Electrocardiographic analysis consisted of measurements of the QT interval and QT dispersion in the 12 leads or in the ST-segment elevation area prior to and 60 minutes after TNK administration. All patients underwent angiography, with determination of TIMI flow and Blush grade in the culprit artery. P-values < 0.05 were considered statistically significant.ResultsWe found an increase in regional dispersion of the QT interval, corrected for heart rate (regional QTcD) 60 minutes after thrombolysis (p = 0.06) in anterior wall infarction in patients with TIMI flow 3 and Blush grade 3 [T3B3(+)]. When regional QTcD was added to the electrocardiographic criteria for reperfusion (i.e., > 50% ST-segment resolution), the area under the curve increased to 0.87 [(0.78-0.96). 95% IC. p < 0.001] in patients with coronary flow of T3B3(+). In patients with ST-segment resolution >50% and regional QTcD > 13 ms, we found a 93% sensitivity and 71% specificity for reperfusion in T3B3(+), and 6% of patients with successful reperfusion were reclassified.ConclusionOur data suggest that regional QTcD is a promising non-invasive instrument for detection of reperfusion in the culprit artery 60 minutes after thrombolysis.