Ventricular Repolarization In Patients Research Articles

Drug-induced increase in dispersion of ventricular repolarization in patients with heart failure with preserved ejection fraction

BackgroundHeart failure (HF) with preserved ejection fraction (HFpEF) is associated with enhanced response to drug-induced QT interval lengthening. We determined the influence of HFpEF on drug-induced lengthening of dispersion of repolarization, a measure of proarrhythmic risk. MethodsWe administered intravenous ibutilide 0.003 mg/kg to 10 patients with HFpEF and 10 age- and sex-matched controls without HF. Twelve‑lead electrocardiograms were obtained prior to ibutilide and serially for 8 h post-ibutilide. Tpeak-Tend, a measure of dispersion of ventricular repolarization, and heart rate-corrected J-Tpeak (J-Tpeakc), representing early repolarization, were measured by an investigator blinded to study groups. ResultsBaseline (pre-ibutilide) Tpeak-Tend and J-Tpeakc were not significantly different in the HFpEF and control groups. Maximum Tpeak-Tend was longer in the HFpEF group than in the control group (85 ± 10 vs 73 ± 8 ms, p = 0.01). Additionally, % change from baseline in Tpeak-Tend was greater in the HFpEF group [median (IQR) 17 (11) vs 8 (3)%, p = 0.003]. The area under the effect curve from 0 to 8 hours following ibutilide (including the 10-minute infusion) (AUEC0-8.17) for Tpeak-Tend was also larger in the HFpEF group (600 ± 42 vs. 543 ± 49 ms•hr, p = 0.03). Maximum J-Tpeakc, % change from baseline in J-Tpeakc and AUEC0-8.17 for J-Tpeakc in the two groups were not significantly different. ConclusionHFpEF is associated with enhanced response to drug-induced increases in dispersion of repolarization.

Evaluating the effect of Roxadustat on ventricular repolarization in patients undergoing peritoneal dialysis

BackgroundRoxadustat is a novel oral medication used to treat anemia in CKD patients. Several studies have shown that Roxadustat can alleviate anemia in CKD patients by increasing hemoglobin levels and regulating iron metabolism. We aimed to evaluate the effect of Roxadustat on ventricular repolarization in PD patients. This study may provide a new integrated approach to the assessment and treatment of CKD.MethodsThe present prospective cohort study enrolled 65 CKD patients who were treated with Roxadustat and 31 CKD patients who received conventional therapy between January 2021 and June 2022. All patients were examined for ECG in the absence of clinical symptoms and compared the ECG indicators. Demographic and clinical data of all patients were collected. All data used SPSS 18.0 for statistical analyses.ResultsThe T peak-to-end (Tpe) of PD patients in the Roxadustat group was remarkably slower than that of patients in the conventional group. Additionally, the Tpe/QT ratio in the conventional group was significantly elevated than that in the Roxadustat group. The results of logistic regression analysis showed that Tpe (95%CI 1.191 ~ 2.141, P = 0.002) and Roxadustat treatment (95%CI 1.357 ~ 42.121, P = 0.021) were the risk factors of PD patients with high Tp-e/QT ratio.ConclusionIn summary, we found that Roxadustat could improve ventricular repolarization in peritoneal dialysis patients, which indicated a potential cardiovascular protective effect of Roxadustat. This study might provide a new integrated approach to the assessment and treatment of CKD.

Effect of dapagliflozin on ventricular repolarization in patients with heart failure with reduced ejection fraction.

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 10mg/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 ± 52.6ms vs. 415.4 ± 35.1ms; p = 0.047, 437.1 ± 37.3ms vs. 425.6 ± 22.7ms; p = 0.019, 54.1 ± 11.8ms vs. 47.6 ± 14.7ms; p = 0.003, 56.0 ± 11.2ms vs. 49.4 ± 12.3ms; p = 0.004, 98.0 ± 15.6ms vs. 85.5 ± 20.9ms; 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 1year 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.

0441 Positive airway pressure therapy associated changes in ventricular repolarization in patients with heart failure

Abstract Introduction Obstructive sleep apnea (OSA) is associated with prolonged ventricular repolarization at baseline that further increases during sleep when an apnea/hypopnea event occurs. Aggressive treatment of OSA with positive airway pressure therapy (PAP) may further prolong ventricular repolarization during apnea/hypopnea events particularly in patients with heart failure (HF). The goal of this study was to evaluate how ventricular repolarization changes during apnea/hypopnea events in patients with heart failure with reduced (HFrEF) and preserved (HFpEF) ejection fraction and in those patients without HF. Methods Thirty patients with OSA in each of the following groups were randomly selected from a dataset of 2,817 patients: HFrEF, HFpEF and no HF failure. Overnight polysomographies (PSG) for these patients were reviewed and beat-to beat measurements during apnea/hypopnea events were obtained at baseline (without PAP) and on the highest PAP setting attempted. Fridericia’s heart rate corrections were used to calculate QTc. QT variability was measured as the standard deviation of QT intervals (SDQT). Results The electrocardiogram was analyzable for n=11 with HFrEF (age 71± 17 years , 91% male) , n=28 with HFpEF (age 71± 12 years , 43% male) and n=30 without HF (age 57± 12 years , 50% male). In those with HFrEF, the mean (SD) QTc increased from 442(12)ms to 452(13)ms and SDQT increased from 9(2) to 13 (2) from baseline to the highest level of PAP attempted. In those with HFpEF, the mean (SD) QTc decreased from 448 (8) to 436 (8) ms and SDQT increased from 10 (1) to 11 (1) from baseline to the highest level of PAP attempted. In those without HF, the mean (SD) QTc increased from 429(37) to 439(56) and SDQT was stable from 8(6) to 8(8) from baseline (no PAP) to the highest level of PAP attempted. There were significant differences noted between the groups in changes in QTc (p=0.002) and SDQT (p=0.048) on PAP when compared to baseline. Conclusion Patients with HFrEF had increases in both QTc and SDQT with PAP at high pressures placing them at greater risk for ventricular arrhythmias. Support (if any) AASM Foundation (203-JF-18), NIH (HL126140, 2L30HL154400-023), University of Arizona (5299903; 5833261; 4258021)

Delayed ventricular conduction alters ventricular repolarization in patients with heart failure: an electrocardiographic imaging study

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): Personal grant from the Dutch Heart Foundation. Background In the normal human heart, the polarity of the T-wave is concordant with the QRS complex. This phenomenon is often explained by longer repolarization of earlier activated regions. Patients with delayed ventricular conduction often have discordant T-waves, but the link to regional repolarization is unknown. Aim To compare epicardial repolarization-activation (RT-AT) relations in patients with heart failure and reduced ejection fraction (HFrEF) with those having a structural normal heart. Methods 14 patients with HFrEF and delayed ventricular conduction and 11 patients no history of structural heart disease and a normal surface ECG (nQRS) were analyzed using electrocardiographic imaging (ECGI). HFrEF patients were subcategorized as left bundle branch block (LBBB, n=6) or non-specified intraventricular conduction disturbance (IVCD, n=8). Noninvasive ECGI was used to assess epicardial activation (ATs) and repolarization times (RTs). RT-AT relationships were evaluated for 24 epicardial segments using linear regression analysis. Interventricular repolarization dispersion (inter-RTD) was defined as the difference between average left-ventricular (LV) and right-ventricular RT, while total epicardial repolarization dispersion (total-RTD) was defined as the standard deviation of all epicardial RTs. The maximum of the local RT gradients (RTG) was defined as their 95th percentile. RT parameters were described as median±IQR and Kruskal Wallis tests were used to evaluate the differences between the groups. Results An HFrEF patient’s representative 24-segment AT and RT bullseyes with a positive RT-AT relation (~depolarize last, repolarize last) is provided in Figure1A. A positive RT-AT slope was present in the majority of HFrEF patients (1.14±0.17 for LBBB and 1.16±0.55 for IVCD), whereas the nQRS group (-0.25±2.16) demonstrated an overall slightly negative slope with high variability (Figure 1B and 1C). Individual (thin lines) and group-averaged (thick lines) RT-AT slopes normalized for the earliest AT and earliest RT (in case of a positive RT-AT slope) or latest RT (in case of a negative slope) are visualized in Figure 1C. Both inter-RTD (41±25 for LBBB, 32±13 ms for IVCD, and 8±20 ms for nQRS) as well as total-RTD (34±9for LBBB, 34±12 ms for IVCD, and 24±8 ms for nQRS) was significantly higher in the LBBB and IVCD group compared to the nQRS group, whereas RTG did not differ between the groups (Figure 1B). RT-AT slopes, inter-RTD, total-RTD, and RTG did not significant differ between the LBBB and IVCD subgroup. Conclusion This ECGI study shows that in patients with HFrEF, later activated regions also have a later completion of repolarization, regardless of conduction delay, whereas a variable RT-AT relation is present in subjects with structural normal hearts. HFrEF additionally initiates a higher degree of interventricular and total repolarization dispersion.

PECULIARITIES OF HEART RHYTHM DISORDERS AND VENTRICULAR REPOLARIZATION STATUS IN PATIENTS WITH MYOCARDIAL INFARCTION WITHOUT ELEVATION OF SEGMENT ST DEPENDING ON THE INDICATORS OF STRUCTURAL REMODELING OF THE LEFT VENTRICLE

SUMMARY. Despite advances in the treatment of acute myocardial infarction in most developed countries, this pathology remains the leading cause of morbidity and mortality. The search for opportunities to predict the development of complications, study of remodeling processes and their impact on the development of electrical instability of the myocardium is currently considered as a promising area of non-invasive diagnosis of myocardial infarction. The aim – to establish the features of cardiac arrhythmias and the condition of ventricular repolarization in patients with NSTEMI depending on the indicators of structural remodeling of the left ventricle. Material and Methods. We conducted a comprehensive study of 200 patients with NSTEMI aged 38 to 80 years. All patients were examined according to the current protocol of diagnosis and treatment of patients with acute coronary syndrome without ST-segment elevation and daily Holter ECG monitoring was performed for 3–5 days after hospitalization. Results. An increase in the left ventricular myocardial mass index and a change in the geometric model are associated with an increase in the probability of developing myocardial electrical instability, in particular extrasystoles of any topic and paroxysmal tachycardia. At the same time, changes in structural remodeling indicators did not reveal correlations with ventricular repolarization disorders in the early NSTEMI period. Conclusions. Evaluation of the indicators of structural remodeling of the ventricular myocardium in the early period of NSTEMI allows to predict the risk of electrical instability of the myocardium and to carry out appropriate preventive measures.

PECULIARITIES OF HEART RHYTHM DISORDERS AND VENTRICULAR REPOLARIZATION STATUS IN PATIENTS WITH MYOCARDIAL INFARCTION WITHOUT ST SEGMENT ELEVATION DEPENDING ON THE INDICATORS OF STRUCTURAL REMODELING OF THE LEFT VENTRICLE

Resume. Despite advances in the treatment of acute myocardial infarction in most developed countries, this pathology remains the leading cause of morbidity and mortality. The search for opportunities to predict the development of complications, study of remodeling processes and their impact on the development of electrical instability of the myocardium is currently considered as a promising area of ​​non-invasive diagnosis of myocardial infarction. Aim. To establish the features of cardiac arrhythmias and the condition of ventricular repolarization in patients with NSTEMI depending on the indicators of structural remodeling of the left ventricle. Materials and methods. We conducted a comprehensive study of 200 patients with NSTEMI aged 38 to 80 years. All patients were examined according to the current protocol of diagnosis and treatment of patients with acute coronary syndrome without ST-segment elevation and daily Holter ECG monitoring was performed for 3-5 days after hospitalization. Results. An increase in the left ventricular myocardial mass index and a change in the geometric model are associated with an increase in the probability of developing myocardial electrical instability, in particular extrasystoles of any topic and paroxysmal tachycardia. At the same time, changes in structural remodeling indicators did not reveal correlations with ventricular repolarization disorders in the early NSTEMI period. Conclusions. Evaluation of the indicators of structural remodeling of the ventricular myocardium in the early period of NSTEMI allows to predict the risk of electrical instability of the myocardium and to carry out appropriate preventive measures.

Effects of permanent cardiac pacing on ventricular repolarization when compared to cardioneuroablation

IntroductionThe impact of cardioneuroablation (CNA) on ventricular repolarization by using corrected QT interval (QTc) measurements has been recently demonstrated. The effects of cardiac pacing (CP) on ventricular repolarization have not been studied in patients with vasovagal syncope (VVS). We sought to compare ventricular repolarization effects of CNA (group 1) with CP (group 2) in patients with VVS. MethodsWe enrolled 69 patients with age 38 ± 13 years (53.6% male), n = 47 in group 1 and n = 22 in group 2. Clinical diagnosis of cardioinhibitory type was supported by cardiac monitoring or tilt testing. QTc was calculated at baseline (time-1), at 24 h after ablation (time-2), and at 9–12 months (time-3) in the follow-up. ResultsIn the group 1, from time-1 to time-2, a significant shortening in QTcFredericia (from 403 ± 27 to 382 ± 27 ms, p < 0.0001), QTcFramingham (from 402 ± 27 to 384 ± 27 ms, p < 0.0001), and QTcHodges (from 405 ± 26 to 388 ± 24 ms, p < 0.0001) was observed which remained lower than baseline in time-3 (373 ± 29, 376 ± 27, and 378 ± 27 ms, respectively). Although the difference between measurements in time-1 and time-2 was not statistically significant for QTcBazett, a significant shortening was detected between time-1 and time-3 (from 408 ± 30 to 394 ± 33, p = 0.005). In the group 2, there was no time-based changes on QTc measurements. In the linear mixed model analysis, the longitudinal reduction tendency in the QTcFredericia and QTcFramingham was more pronounced in group 1. ConclusionsOur results demonstrate that CNA reduces QTc levels through neuromodulation effect whereas CP has no effect on ventricular repolarization in patients with VVS.

Abstract 13929: Methadone Lengthens Both Early and Late Ventricular Repolarization in Patients Undergoing Maintenance Therapy in an Urban Narcotic Treatment Center

Introduction: Methadone, a racemic mixture of S - and R -enantiomers, prolongs the QT interval and causes torsades de pointes. Methadone has been shown to lengthen late ventricular repolarization, represented by the T peak-Tend interval, which is modulated primarily by I Kr and I Ks . However, it is unknown whether methadone prolongs early ventricular repolarization, represented by the heart rate-corrected J-T peak (J-T peak c) interval, which is regulated primarily by L-type calcium and late sodium currents. In addition, the relationship between stereospecific serum methadone and metabolite concentrations and effects on J-T peak c and T peak -T end intervals are unknown. Hypothesis: 1) Methadone lengthens both J-T peak c and T peak -T end , and 2) Methadone effects on J-T peak c and T peak -T end correlate with serum S - and R -methadone and S - and R -metabolite [ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP)] concentrations. Methods: Patients (n=81) on steady state maintenance methadone therapy at an urban narcotic treatment center who had undergone a pre-methadone 12-lead ECG within the previous 6 months were identified and asked to return for a followup ECG during steady-state methadone therapy. In a subset (n=41), blood was obtained to determine serum S - and R -methadone and S - and R -EDDP concentrations. Results: Compared to baseline, methadone lengthened mean ± SD J-T peak c (225 ± 26 vs 232 ± 28 ms, p=0.02) as well as T peak - T end (80 ±14 vs 90 ± 16 ms, p&lt;0.00001). Serum concentrations of S -methadone correlated with J-T peak c [R 2 = 0.41 (95% CI 0.11-0.65), p=0.007]. Serum R -methadone concentrations also correlated with J-T peak c [R 2 = 0.47 (0.17-0.68), p=0.002]. In addition, serum concentrations of S - and R -EDDP correlated with J-T peak c [R 2 = 0.39 (0.09-0.63), p=0.01] and [R 2 = 0.38 (0.07-0.62), p=0.02], respectively. There were no significant correlations between serum S - and R -methadone or S- and R-EDDP concentrations with T peak - T end intervals. Conclusions: Methadone lengthens both early and late ventricular repolarization, suggesting that methadone’s ion channel effects may extend beyond inhibition of I Kr . Serum S - and R -methadone and S -and R -EDDP concentrations are associated with effects on J-T peak c intervals.

Long-term prognostic significance of dispersion of ventricular repolarization in patients with cardiac sarcoidosis

Abstract Background Although the presence of cardiac involvement is recognised as a determinant of worse clinical outcomes in sarcoidosis patients, the determinants of adverse outcomes in patients with cardiac sarcoidosis (CS) have not been well understood. T-peak to T-end interval (TpTe) on the surface electrocardiogram (ECG) was proposed as a marker of dispersion of ventricular repolarisation. Prolonged TpTe to QT interval ratio (TpTe/QT) represents a period of potential vulnerability to reentrant ventricular arrhythmias. Notably, prolonged TpTe/QT has been associated with increased risk of mortality in hypertrophic cardiomyopathy, congenital long-QT syndrome, and Brugada syndrome. However, its prognostic implication in patients with CS is unclear. Purpose We sought to investigate whether TpTe/QT was associated with long-term clinical outcomes in patients with CS. Methods A total of 108 consecutive CS patients between August 1986 and March 2019 in two academic hospitals who had ECG data before initiation of immunosuppressive therapy were examined. We excluded patients who received pacemaker (n=15) or cardiac resynchronization therapy (n=3) at the time of ECG. Ultimately, 90 CS patients were included in this study. All standard 12-lead ECGs were recorded at 25 mm/s with an amplification of 10 mm/mV. TpTe was measured from the peak of T wave to the end of T wave which defined as the intersection of the tangent to the down slope of the T wave and the isoelectric line. Lead V5 was selected for the analyses. If V5 is not suitable for analyses, V4 was selected. The primary outcome was the composite of advanced atrioventricular block (AVB), ventricular tachycardia or ventricular fibrillation (VT/VF), heart failure hospitalisation and all-cause death. Results During a median follow-up period of 4.70 (interquartile range [IQR] 2.06–7.23) years, adverse events occurred in 21 patients (23.3%), including 2 advanced AVB, 12 VT/VF, 4 heart failure hospitalisation and 3 all-cause death. Events group had higher TpTe/QT compared to no events group (0.231 [IQR 0.193–0.261] vs. 0.282 [IQR 0.263–0.304] P&amp;lt;0.001). Kaplan-Meier analyses revealed that the primary outcome, especially VT/VF or sudden cardiac death more frequently occurred in patients with higher TpTe/QT (≥0.242, the median) compared to those with lower TpTe/QT (Figure 1). Multivariable Cox regression analysis showed that higher TpTe/QT was independently associated with increased subsequent risk of adverse events (hazard ratio 1.09, 95% confidence interval [CI] 1.02–1.17, P=0.014) even after adjustment for age, sex and left ventricular ejection fraction. Furthermore, the optimal cut-off value of TpTe/QT for the discriminatory of primary outcome was 0.257, and c-index was 0.77 (95% CI 0.64–0.89). Conclusions Higher TpTe/QT was associated with worse long-term clinical outcomes in patients with CS. Our findings indicate the importance of assessing TpTe/QT for risk stratification in patients with CS. Figure 1 Funding Acknowledgement Type of funding source: None

Effect of thyrotropin suppressive therapy on heart rate variability and QT dispersion in patients with differentiated thyroid cancer

The effects of thyrotropin (TSH) suppressive therapy on autonomic regulation and ventricular repolarization in patients with differentiated thyroid cancer (DTC) have not been elucidated. The aim of present study was to evaluate variation in heart rate variability (HRV) and QT dispersion after TSH suppressive therapy in patients with DTC.Cases, defined as 271 patients with DTC within 1 year of exogenous levothyroxine, and all patients underwent a full history, physical examination, including standard 12 lead electrocardiogram (ECG), and 24 h ambulatory ECG monitoring (Holter) with normal free thyroxine (FT4) and free triiodothyronine (FT3) with levothyroxine. To evaluate effects of TSH suppressive therapy on HRV and QT dispersion, patients were divided into three groups according to different levels of TSH: TSH < 0.1 mIU/L group and 0.1 ≤ TSH < 0.5 mIU/L group were as TSH suppression groups, and 0.5 ≤ TSH < 2.0 mIU/L group was as TSH replacement group.Comparing with 0.5 ≤ TSH < 2.0 mIU/L group, significant changes in both time and frequency domain of HRV and QT dispersion were observed in TSH < 0.1 mIU/L group (P < .001: SDNN, SDANN, HF, LF/HF, QTd, and QTcd; P < .05: rMSSD) and 0.1 ≤ TSH < 0.5 mIU/L group (P < .001: SDNN, HF, LF/HF, QTd, and QTcd), and especially were more pronounced in TSH < 0.1 mIU/L group. Moreover, we found that TSH level was proportional to SDNN (β = 15.829, P < .001), but inversely proportional to LF/HF (β = −0.671, P < .001), QTd (β = −16.674, P < .001) and QTcd (β = −18.314, P < .001) in DTC patients with exogenous levothyroxine.Compared with euthyroid state, patients with suppressed serum TSH have increased sympathetic activity in the presence of diminished vagal tone, ultimately showed sympathovagal imbalance and with an increased inhomogeneity of ventricular recovery times. These findings revealed that TSH suppression therapy had a significant impact on cardiovascular system and had certain guiding role in the treatment and management of patients with DTC.

Atrial septal defect patients with greater shunts show susceptibility for ventricular arrhythmias

Objective: Ventricular arrhythmia episodes are not infrequent in patients with atrial septal defect (ASD). Disturbance in cardiac volume and pressures may lead to enlargement and fibrosis in heart. An interatrial volume displacement through septal defect, briefly interatrial shunt, is the major reason for this complication. Prolongation of the interval between the peak and end of the T wave (Tpeak to Tend, Tp-e) on the 12-lead electrocardiogram (ECG), is utilized as a marker of ventricular arrhythmogenesis during last years. The aim of this study was to assess if there is an impact of shunt ratio on ventricular repolarization in patients with ASD by using Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio. Methods: Patient records of Samsun Training and Research Hospital were retrospectively analyzed. Electrocardiograms of 133 patients, who were diagnosed as ASD between January 2016 and December 2019 were obtained and scanned. ECG intervals were measured. Shunt ratios, right ventricle diameters and volumes were also acquired. Patients were grouped into two by their calculated shunt ratio, ratio of ≥2.0 is accepted as a high shunt group and &amp;lt;2.0 as a low shunt group. Results: Both groups’ baseline characteristics were similar. Right ventricular dimensions and systolic pulmonary artery pressure were higher in high shunt group. Furthermore, ASD patients with higher shunt ratio had significantly higher ECG measurements than controls, Tp-e: 103.0 (22.1) vs 76.2 (10.2); Tp-e/QT: 0.25 (0.03) vs 0.21 (0.02); Tp-e/QTc: 0.22 (0.03) vs, 0.17 (0.02); for all p&amp;lt;0.001). Of all ECG parameters; Tp-e (r=0.631, p&amp;lt;0.001), Tp-e/QT (r=0.531, p&amp;lt;0.001) and Tp-e/QTc (r=0.614, p&amp;lt;0.001) had moderate correlation with shunt ratio. Conclusion: T wave peak-to-end interval is a measure of transmural dispersion of repolarization and accepted as a surrogate for increased ventricular arrhythmogenesis risk. Our findings show that ASD patients whose shunt ratio are ≥2.0 show increased risk for arrhythmias. Key words: atrial septal defect, electrocardiogram, ventricular arrhythmia, risk, ventricular repolarization

Ventricular Repolarization in Patients With Premature Ovarian Insufficiency (QT-IOP)

Ventricular Repolarization in Patients With Premature Ovarian Insufficiency (QT-IOP)

Abnormalities in electrocardiographic ventricular repolarization in patients with dengue virus infection.

Dengue virus infection (DENV) is an arboviral disease that affects millions of people in many countries throughout the world every year. The disease is caused by the bite of a mosquito (Aedes aegypti and / or Aedes albopictus). The symptoms/signs observed in this arboviral disease are unspecific, and the blood count usually shows leukopenia and thrombocytopenia. Although ECG changes may be observed in DENV, little is known about parameters of ventricular repolarization in patients with this condition. Accordingly, the aim of this study was to evaluate the QTc and QT interval dispersion to detect ventricular repolarization changes in patients with DENV. Ninety-three consecutive patients seen during DENV epidemics in a small town with non-complicated DENV were included; 93 normal individuals served as controls. Clinical data, blood count and the 12-lead ECG were obtained from each individual. The QTc duration was higher in patients with DENV in comparison to controls. Furthermore, 5% of DENV patients had abnormal lengthening of the QTc interval. No difference regarding QT interval dispersion was observed between DENV patients and controls. No DENV patient had increased lengthening of the QT interval dispersion. Myocardial repolarization changes do occur in patients with DENV. Having into account the potential impact of these changes on patients' outcome, and because 12-lead ECG is not routinely recommended in the setting of DENV in our country, we recommend that a 12-lead ECG be taken from each patient with this condition during DENV epidemics.

Evaluation of Ventricular Repolarization in Patients with Erectile Dysfunction

Evaluation of Ventricular Repolarization in Patients with Erectile Dysfunction

P1946Longitudinal changes in ventricular repolarization in patients with CRT and its relation to ventricular tachyarrhythmias

P1946Longitudinal changes in ventricular repolarization in patients with CRT and its relation to ventricular tachyarrhythmias

Among patients with left bundle branch block, T-wave peak to T-wave end time is prolonged in the presence of acute coronary occlusion

BackgroundAssessing the effect of myocardial ischemia on ventricular repolarization in the setting of left bundle branch block (LBBB) poses a challenge due to secondary prolongation of the QT interval inherent in LBBB. The T-wave peak to T-wave end (TpTe) interval has been noted to prolong during myocardial ischemia and correct after reperfusion in patients with normal conduction. Here we compare the TpTe intervals of patients with LBBB both with and without complete acute coronary occlusion (ACO). MethodsRetrospectively, emergency department patients with LBBB and symptoms of myocardial ischemia were identified both with angiographically-proven ACO and with No-ACO. The longest QT, JT, and TpTe intervals were analyzed. ResultsThe ACO and No-ACO groups consisted of 33 and 129 patients, respectively. The mean TpTe was longer in ACO (103.6ms [95%CI 98.5–108.7]) compared to No-ACO patients (88.6ms [95%CI 85.3–91.9]) (P<0.0001) and this held true after correction for heart rate. In ACO versus No-ACO, the TpTe also more frequently exceeded prolongation cutoffs of 85ms (30 [90%] versus 69 [54%]) and 100ms (25 [76%] versus 42 [33%]) (P<0.0001 for all). The mean QT, JT, QTc, and JTc intervals were not significantly different between the groups for either the Bazett's or Rautaharju's correction formulas. ConclusionsIn patients with LBBB on the ECG, the TpTe is longer and more frequently prolonged in patients with ACO compared to patients without ACO. Future studies of ventricular repolarization in patients with LBBB should include analyses of the TpTe interval.

Ventricular Repolarization in Patients with Decompensated Liver Cirrhosis and its Relation to the in-Hospital Outcome: Electrocardiographic Study

Background: Prolonged ventricular repolarization has been documented in patients with chronic liver disease. The objective of this study was to study the electrocardiographic QTc interval in patients with decompensated liver disease and its relation to the in-hospital outcome. Methods: We retrospectively studied 75 patients with hepatic encephalopathy. The QTc interval was measured in a 12-lead electrocardiogram obtained on admission. Results: Patients were divided into two groups according to their clinical outcome during hospitalization. The first group included 53 (70.7%) patients who survived, and the second group included 22 (29.3%) patients who died. QTc interval was significantly prolonged in died patients than patients who survived (p<0.001). There was insignificant difference between two groups regarding age, sex, smoking status, hypertension, diabetes mellitus and basal laboratory findings except for serum creatinine level (p = 0.006) and MELD score (p = 0.033). Conclusions: In patients with hepatic encephalopathy, QTc interval was significantly higher in patients who died than in patients who survived, however, in multivariate logistic regression analysis, QTc interval, was not predictors of survival.

Evaluation of ventricular repolarization features with novel electrocardiographic parameters (Tp-e, Tp-e/QT) in patients with psoriasis.

Objective:Psoriasis is a chronic inflammatory disorder, which affects around 1%–3% of the human population worldwide. Cardiovascular events are the leading cause of morbidity and mortality in patients with psoriasis. Some studies have reported that psoriasis is related to increased arrhythmias. 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 assess ventricular repolarization in patients with psoriasis using Tp-e interval and Tp-e/QT ratio.Methods:The study population consisted of 74 patients with psoriasis and 74 healthy volunteers. The diagnosis of psoriasis was based on a clinical or histopathological examination of all patients. QT interval, corrected QT (QTc), QT dispersion (QTd), Tp-e interval, corrected Tp-e, and Tp-e/QT ratio were measured from the 12-lead electrocardiogram. These parameters were compared between groups.Results:According to the electrocardiographic parameters, QT and QTc intervals and QTd were significantly higher in patients with psoriasis than in control subjects (p<0.001; p<0.001; p=0.014; respectively). The Tp-e interval, corrected Tp-e, and Tp-e/QT ratio were significantly higher in patients with psoriasis than in control subjects [93±13 milliseconds (ms) vs. 98±14 ms, p=0.040; 104±17 ms vs. 111±17 ms, p=0.008; 0.23±0.03 vs. 0.25±0.03, p<0.001; respectively]. Additionally, the CRP value was an independent predictor of an increased Tp-e/QT ratio (β=0.537, p< 0.001).Conclusion:Our study revealed that ventricular repolarization features were impaired in patients with psoriasis. Therefore, these patients should be more closely screened for ventricular arrhythmias.

Diffuse interstitial fibrosis assessed by cardiac magnetic resonance is associated with dispersion of ventricular repolarization in patients with hypertrophic cardiomyopathy

BackgroundHypertrophic cardiomyopathy (HCM) is characterized by myocyte hypertrophy, disarray, fibrosis, and increased risk for ventricular arrhythmias. Increased QT dispersion has been reported in patients with HCM, but the underlying mechanisms have not been completely elucidated. In this study, we examined the relationship between diffuse interstitial fibrosis, replacement fibrosis, QTc dispersion and ventricular arrhythmias in patients with HCM. We hypothesized that fibrosis would slow impulse propagation and increase dispersion of ventricular repolarization, resulting in increased QTc dispersion on surface electrocardiogram (ECG) and ventricular arrhythmias. MethodsECG and cardiac magnetic resonance (CMR) image analyses were performed retrospectively in 112 patients with a clinical diagnosis of HCM. Replacement fibrosis was assessed by measuring late gadolinium (Gd) enhancement (LGE), using a semi-automated threshold technique. Diffuse interstitial fibrosis was assessed by measuring T1 relaxation times after Gd administration, using the Look–Locker sequence. QTc dispersion was measured digitally in the septal/anterior (V1–V4), inferior (II, III, and aVF), and lateral (I, aVL, V5, and V6) lead groups on surface ECG. ResultsAll patients had evidence of asymmetric septal hypertrophy. LGE was evident in 70 (63%) patients; the median T1 relaxation time was 411±38ms. An inverse correlation was observed between T1 relaxation time and QTc dispersion in leads V1–V4 (p<0.001). Patients with HCM who developed sustained ventricular tachycardia had slightly higher probability of increased QTc dispersion in leads V1–V4 (odds ratio, 1.011 [1.004–1.0178, p=0.003). We found no correlation between presence and percentage of LGE and QTc dispersion. ConclusionDiffuse interstitial fibrosis is associated with increased dispersion of ventricular repolarization in leads, reflecting electrical activity in the hypertrophied septum. Interstitial fibrosis combined with ion channel/gap junction remodeling in the septum could lead to inhomogeneity of ventricular refractoriness, resulting in increased QTc dispersion in leads V1–V4.