scholarly journals Novel ECG markers for ventricular repolarization: Is the QT interval obsolete?

Heart Rhythm ◽  
2011 ◽  
Vol 8 (7) ◽  
pp. 1044-1045 ◽  
Author(s):  
Babar Parvez ◽  
Dawood Darbar
Keyword(s):  
Qt Interval ◽  
Ventricular Repolarization

scholarly journals Recent Ventricular Repolarization Markers in Resistant Hypertension: Are They Different from the Traditional QT Interval?

2008 ◽  
Vol 21 (1) ◽  
pp. 47-53 ◽  
Author(s):  
G. F. Salles ◽  
C. R. L. Cardoso ◽  
S. M. Leocadio ◽  
E. S. Muxfeldt
Keyword(s):  
Resistant Hypertension ◽  
Qt Interval ◽  
Ventricular Repolarization

scholarly journals Indexes for ventricular repolarization abnormality: Re-evaluation of QT interval.

1992 ◽  
Vol 12 (3) ◽  
pp. 327-335
Author(s):  
Takahisa Maruyama ◽  
Tohru Ohe ◽  
Yoshiaki Okano ◽  
Takashi Kurita ◽  
Naohiko Aihara ◽  
...  
Keyword(s):  
Qt Interval ◽  
Ventricular Repolarization ◽  
Repolarization Abnormality

scholarly journals Abnormalities in electrocardiographic ventricular repolarization in patients with dengue virus infection

2019 ◽  
Vol 13 (08) ◽  
pp. 759-763 ◽  
Author(s):  
Rosemary Aparecida Furlan-Daniel ◽  
Luis Felipe Silveira Santos ◽  
Tufik José Magalhães Geleilete ◽  
Carolina Baraldi Araujo Restini ◽  
Reinaldo Bulgarelli Bestetti
Keyword(s):  
Virus Infection ◽  
Dengue Virus ◽  
Qt Interval ◽  
Blood Count ◽  
Ventricular Repolarization ◽  
Qtc Interval ◽  
Dengue Virus Infection ◽  
Qt Interval Dispersion ◽  
Arboviral Disease ◽  
Interval Dispersion

Introduction: 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. Methodology: 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. Results: 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. Conclusions: 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.

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

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
James E Tisdale ◽  
Elena Tomaselli Muensterman ◽  
Erika Titus-Lay ◽  
Heather Jaynes ◽  
Todd Walroth ◽  
...  
Keyword(s):  
Steady State ◽  
Qt Interval ◽  
Torsades De Pointes ◽  
Ventricular Repolarization ◽  
Treatment Center ◽  
Racemic Mixture ◽  
Serum Concentrations ◽  
Metabolite Concentrations ◽  
Channel Effects ◽  
The Relationship

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<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.

Abstract P230: Metabolically Healthy Obesity and QT interval. The Polish Norwegian Study

Circulation ◽  
2017 ◽  
Vol 135 (suppl_1) ◽  
Author(s):  
Georgeta Vaidean ◽  
Marta Manczuk ◽  
Jared W Magnani
Keyword(s):  
Qt Interval ◽  
Large Population ◽  
Ventricular Repolarization ◽  
Qtc Interval ◽  
Benign Condition ◽  
Metabolically Healthy Obese ◽  
Increased Risk ◽  
Healthy Obese ◽  
Metabolically Healthy ◽  
Age And Sex

Introduction: Obesity has been linked to increased risk of sudden cardiac death and ventricular arrhythmia. Whether the metabolically healthy obese phenotype is a benign condition, is debatable and few studies examined its ventricular repolarization profile. Purpose: To examine the association of metabolically healthy/unhealthy obesity phenotypes with prolonged corrected QT (QTc) interval in a large population-based study. Methods: Cross-sectional data from an ongoing cohort study in Poland. Data was collected using a standardized protocol. The QT intervals were obtained from digital standard 12-lead resting ECG and were corrected for heart rate by Bazett’s formula. Plasma lipids and glucose were measured in a fasting state. After excluding drugs known to affect the QT interval (antiarrhythmics, digoxin, antipsychotics), the analytic sample size was 11068 participants, ages 45 to 64 years. Based on the presence of obesity (BMI ge 30 kg/ m 2 ) and metabolic syndrome (per the AHA/NHLBI harmonized definition), we defined four phenotypes: metabolically healthy non-obese (MHNO), metabolically unhealthy nonobese (MUNO), metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO). Multivariable linear and logistic regression models were used for analyses. Results: The prevalence of the 4 phenotypes was: MHNO: 51.34%, MUNO: 18.07%, MHO: 10.07%, MUO: 20.52%. The prevalence of an increased QTc interval (greater than >430ms in men/450ms in women) was 14.28%, and the prevalence of a highly prolonged QTc interval (greater than 450ms in men/470ms in women) was 5.2%. The age- and sex-adjusted mean QTc across the 4 phenotypes was: MHNO: 417.05ms (416.39- 417.71; MUNO: 418.82 ms (417.71-419.92); MHO: 420.46 ms (418.99 -421.93); MUO: 422.45 ms (421.41-423.49). The age- and sex adjusted odds (OR, 95% CI) of an increased QTc interval (greater than 430/450ms in men/women) were increased in MUNO (1.11, 0.96-1.29), MHO (1.44, 1.20-1.72) and MUO (1.47, 1.28-1.69), compared to MHNO phenotype. These estimates were minimally attenuated after additional adjustment for prevalent CVD, LVH on ECG, smoking, alcohol intake, physical activity and education: MUNO (1.10, 0.94-1.28), MHO (1.45, 1.21-1.73) and MUO (1.44, 1.26-1.66). We did not detect effect modification by sex. We obtained similar results in subgroup analyses restricted to those without diabetes and after excluding those with third degree atrioventricular blocks or conduction abnormalities with QRS>120ms. Conclusion: Both metabolically healthy- and non-healthy obese phenotypes had a higher likelihood of an increased/borderline QTc interval compared to the MHNO phenotype. Our study furthered our understanding of ventricular repolarization as reflected in the QTc interval, in the setting of different obesity phenotypes.

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