scholarly journals QT interval dynamicity during exercise test in adolescent athletes

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
L Balykova ◽  
L.M Makarov ◽  
V.N Komolyatova ◽  
N.V Shchekina ◽  
S.A Ivyanskij ◽  
...  
Keyword(s):  
Exercise Test ◽  
Qt Interval ◽  
Initial Level ◽  
Peak Load ◽  
Qtc Interval ◽  
Myocardial Remodeling ◽  
Young Athletes ◽  
Early Recovery ◽  
Rate Dependent ◽  
Repolarization Dynamics

Abstract   In search of predictors of the life-threatening arrhythmias, the objective of this research was to study repolarization dynamics and reveal the signs of myocardial electrical instability in young athletes during exercise test (ET). Methods 124 young athletes including 78 boys 11–16 years old and 50 healthy untrained boys were enrolled into the study. All the children underwent ET with ECG recording and manually evaluated durations of QT interval and its derivatives –QTc interval, calculated by Basett and Fridericia formulas (QTc, FQTc), QTc and FQTc interval dispersion. Rate-dependent QT interval parameters (“QT dynamics”) were measured using of linear regression formula for determining slope, intercept, and correlation (r) between QT and RR intervals (Zareba W, Bayes de Luna A, 2005). Results Initially and on low and moderate loading (25–100 Wt) the athletes had lower heart rate (HR) than in untrained, and quicker (3 min) restoration to initial level (<450 ms) during recovery. The athletes had higher absolute QT interval duration at rest due to bradycardia and myocardial hypertrophy. Beginning step II QTc and FQTc intervals and their dispersions shortening up to minimal in both athlete and untrained groups. Maximal QTc interval in athletes as well as in untrained was recorded at stage I (25 Wt) and did not exceed 460 ms in boys and 470 ms in girls versus 450 and 440 ms, respectively. Maximal QTc prolongation (δQTc) during ET (QTcmax − QTcmin) in athletes did not exceed 80 ms. A shorter FQTc duration compared to QTc was noted. More efficient rate-dependent QT interval reduction (“QT/RR hyperadaptation”) was noted in athletes at peak load: the upper limits of normal QTc, FQTc and dQTc were 400, 330 and 14 ms, respectively. These parameters increasing along with other (echocardiographic and biochemical) signs may serve as myocardial remodeling markers. Decreased (“flat”) slope QT/RR and lower level of QT/RR correlation (“hypoadaptation of QT to RR”) were recorded in athletes at rest and at the initial stages of load, probably due to a higher vagal tone. At the peak load increase both in slope (“steep slope”) and correlation QT/RR (“QT/RR hyper-adaptation”) was noted. Absence of this phenomenon was observed in athletes with cardiac remodeling. Conclusions Repolarization dynamics during ET test was similar in athletes and untrained children. Maximal QTc interval in athletes during ET was higher than in untrained and QTc shortening at peak load was more efficient. Complete restoration of HR and QTc intervals to the initial level in athletes occurred at an early recovery period (3 min). Absence of such dynamics gave evidence of myocardial remodeling. Funding Acknowledgement Type of funding source: None

scholarly journals Abnormal repolarization dynamics revealed in exercise test in long QT syndrome mutation carriers with normal resting QT interval

EP Europace ◽  
2010 ◽  
Vol 12 (9) ◽  
pp. 1296-1301 ◽  
Author(s):  
A.-M. Hekkala ◽  
M. Viitasalo ◽  
H. Vaananen ◽  
H. Swan ◽  
L. Toivonen
Keyword(s):  
Long Qt Syndrome ◽  
Exercise Test ◽  
Qt Interval ◽  
Long Qt ◽  
Mutation Carriers ◽  
Qt Syndrome ◽  
Repolarization Dynamics

Changes of QT interval in the acute phase after pulmonary vein isolation for paroxysmal atrial fibrillation

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Chikata ◽  
T Kato ◽  
K Ududa ◽  
S Fujita ◽  
K Otowa ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Pulmonary Vein ◽  
Female Patient ◽  
Pulmonary Vein Isolation ◽  
Acute Phase ◽  
Paroxysmal Atrial Fibrillation ◽  
Qt Interval ◽  
Qt Prolongation ◽  
Qtc Interval ◽  
The Impact

Abstract Introduction Pulmonary vein isolation (PVI) affects ganglionated plexi (GP) around the atrium, leading to a modification of the intrinsic cardiac autonomic system (ANS). In animal models, GP ablation has a potential risk of QT prolongation and ventricular arrhythmias. However, the impact of PVI on QT intervals in humans remains unclear. Purpose This study aims to evaluate the Impact of PVI on QT interval in patients with paroxysmal atrial fibrillation. Methods We analyzed consecutive 117 PAF patients for their first PVI procedures. 12-lead ECG was evaluated at baseline, 4 hr, day 1, 1 month, and 3 months after ablation. Only patients with sinus rhythm on 12-lead ECG at each evaluation point without antiarrhythmic drugs were included. Results Heart rate significantly increased at 4 hr, day 1, and 1 month. Raw QT interval prolonged at 4 hr (417.1±41.6 ms, P<0.001) but shortened at day 1 (376.4±34.1 ms, P<0.001), 1 month (382.2±31.5 ms, P<0.001), and 3 months (385.1±32.8 ms, P<0.001) compared to baseline (391.6±31.4 ms). Bazett- and Fridericia- corrected QTc intervals significantly prolonged at 4hr (Bazett: 430.8±27.9 ms, P<0.001; Fridericia: 425.8±27.4 ms, P<0.001), day1 (Bazett: 434.8±22.3 ms, P<0.001; Fridericia: 414.1±23.7 ms, P<0.001), 1M (Bazett: 434.8±22.3 ms, P<0.001; Fridericia: 408.2±21.0 ms, P<0.05), and 3M (Bazett: 420.1±21.8 ms, P<0.001; Fridericia: 407.8±21.1 ms, P<0.05) compared to baseline (Bazett: 404.9±25.2 ms; Fridericia: 400.0±22.6 ms). On the other hand, Framingham- and Hodges- corrected QTc interval significantly prolonged only at 4hr (Framingham: 424.1±26.6 ms, P<0.001; Hodges: 426.8±28.4 ms, P<0.001) and at day1 (Framingham: 412.3±29.3 ms, P<0.01; Hodges: 410.6±40.2 ms, P<0.05) compared to baseline (Framingham: 399.2±22.7 ms; Hodges: 400.7±22.8 ms). At 4 hr after ablation, raw QT and QTc of all formulas significantly prolonged than baseline. Raw QT and QTc prolongation at 4hr after ablation were more frequently observed in female patients. Multiple regression analysis revealed that female patient is a significant predictor of raw QT and QTc interval prolongation of all formulas 4hr after PVI. Conclusions Raw QT and QTc prolonged after PVI, especially in the acute phase. Female patient is a risk factor for QT prolongation in the acute phase after PVI. Funding Acknowledgement Type of funding source: None

scholarly journals Antipsychotics in routine treatment are minor contributors to QT prolongation compared to genetics and age

2021 ◽  
pp. 026988112110034
Author(s):  
Leif Hommers ◽  
Maike Scherf-Clavel ◽  
Roberta Stempel ◽  
Julian Roth ◽  
Matthias Falter ◽  
...  
Keyword(s):  
Qt Interval ◽  
Multivariate Regression Analysis ◽  
Cardiac Repolarization ◽  
Qtc Interval ◽  
Serum Concentrations ◽  
Drug Induced ◽  
Individual Level ◽  
Main Determinants ◽  
The Individual ◽  
Polygenic Variation

Background: Drug-induced prolongation of cardiac repolarization limits the treatment with many psychotropic drugs. Recently, the contribution of polygenic variation to the individual duration of the QT interval was identified. Aims: To explore the interaction between antipsychotic drugs and the individual polygenic influence on the QT interval. Methods: Retrospective analysis of clinical and genotype data of 804 psychiatric inpatients diagnosed with a psychotic disorder. The individual polygenic influence on the QT interval was calculated according to the method of Arking et al. Results: Linear regression modelling showed a significant association of the individual polygenic QT interval score (ßstd = 0.176, p < 0.001) and age (ßstd = 0.139, p < 0.001) with the QTc interval corrected according to Fridericia’s formula. Sex showed a nominal trend towards significance (ßstd = 0.064, p = 0.064). No association was observed for the number of QT prolonging drugs according to AZCERT taken. Subsample analysis ( n = 588) showed a significant association of potassium serum concentrations with the QTc interval (ßstd = −0.104, p = 0.010). Haloperidol serum concentrations were associated with the QTc interval only in single medication analysis ( n = 26, ßstd = 0.101, p = 0.004), but not in multivariate regression analysis. No association was observed for aripiprazole, clozapine, quetiapine and perazine, while olanzapine and the sum of risperidone and its metabolite showed a negative association. Conclusions: Individual genetic factors and age are main determinants of the QT interval. Antipsychotic drug serum concentrations within the therapeutic range contribute to QTc prolongation on an individual level.

scholarly journals Prevalence and Risk Factors of Prolonged QTc Interval among Chinese Patients with Type 2 Diabetes

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Xiang Li ◽  
Hui Ren ◽  
Zhang-rong Xu ◽  
Yan-jun Liu ◽  
Xiao-pin Yang ◽  
...  
Keyword(s):  
Risk Factors ◽  
Blood Pressure ◽  
Type 2 Diabetes ◽  
Waist Circumference ◽  
Qt Interval ◽  
Postprandial Glucose ◽  
Chinese Patients ◽  
Qtc Interval ◽  
Fasting Insulin

Objectives. The aim of this study was to evaluate the prevalence and the risk factors of prolonged QTc interval among Chinese patients with type 2 diabetes.Methods. The retrospective study included 3156 outpatients from the Diabetes Centre, the 306th Hospital of PLA, during the period from September 2003 to June 2010. QT interval was measured manually in the 12-lead conventional electrocardiogram. The QT interval corrected for heart rate (QTc) was calculated using Bazett’s formula. Additional demographic and laboratory data were also collected. Potential risk factors of prolonged QTc interval were assessed using multivariable regression.Results.The prevalence of prolonged QTc interval among Chinese patients with type 2 diabetes was 30.1%. Height (OR 0.156, 95% CI 0.032~0.748), waist circumference (OR 1.025, 95% CI 1.010~1.040), diastolic blood pressure (OR 1.016, 95% CI 1.007~1.026), postprandial glucose (OR 1.040, 95% CI 1.022~1.059), fasting insulin (OR 1.014, 95% CI 1.003~1.025), and presence of microalbuminuria (OR 1.266, 95% CI 1.033~1.551) were significant risk factors.Conclusions. The prevalence of prolonged QTc interval among Chinese patients with type 2 diabetes is high. Risk factors for prolongation of QTc interval were low height, high waist circumference, increasing diastolic blood pressure levels, high postprandial glucose levels, high fasting insulin levels, and presence of microalbuminuria.

Optimizing QT Interval Measurement for the Preparticipation Screening of Young Athletes

2016 ◽  
Vol 48 (9) ◽  
pp. 1745-1750 ◽  
Author(s):  
DAVID PICKHAM ◽  
DAVID HSU ◽  
MUHAMMAD SOOFI ◽  
JANA M. GOLDBERG ◽  
DIVAKAR SAINI ◽  
...  
Keyword(s):  
Qt Interval ◽  
Young Athletes ◽  
Interval Measurement ◽  
Preparticipation Screening

scholarly journals Absence of relevant QT interval prolongation in not critically ill COVID-19 patients

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Juan Jiménez-Jáimez ◽  
Rosa Macías-Ruiz ◽  
Francisco Bermúdez-Jiménez ◽  
Ricardo Rubini-Costa ◽  
Jessica Ramírez-Taboada ◽  
...  
Keyword(s):  
Critically Ill ◽  
Qt Interval ◽  
Treatment Initiation ◽  
Qtc Interval ◽  
Risk Markers ◽  
Interval Prolongation ◽  
Qt Interval Prolongation ◽  
Qtc Interval Prolongation ◽  
Ambulatory Patients ◽  
Reported Data

AbstractSARS-CoV-2 is a rapidly evolving pandemic causing great morbimortality. Medical therapy with hydroxicloroquine, azitromycin and protease inhibitors is being empirically used, with reported data of QTc interval prolongation. Our aim is to assess QT interval behaviour in a not critically ill and not monitored cohort of patients. We evaluated admitted and ambulatory patients with COVID-19 patients with 12 lead electrocardiogram at 48 h after treatment initiation. Other clinical and analytical variables were collected. Statistical analysis was performed to assess the magnitude of the QT interval prolongation under treatment and to identify clinical, analytical and electrocardiographic risk markers of QT prolongation independent predictors. We included 219 patients (mean age of 63.6 ± 17.4 years, 48.9% were women and 16.4% were outpatients. The median baseline QTc was 416 ms (IQR 404–433), and after treatment QTc was prolonged to 423 ms (405–438) (P < 0.001), with an average increase of 1.8%. Most of the patients presented a normal QTc under treatment, with only 31 cases (14.1%) showing a QTc interval > 460 ms, and just one case with QTc > 500 ms. Advanced age, longer QTc basal at the basal ECG and lower potassium levels were independent predictors of QTc interval prolongation. Ambulatory and not critically ill patients with COVID-19 treated with hydroxychloroquine, azithromycin and/or antiretrovirals develop a significant, but not relevant, QT interval prolongation.

scholarly journals Domperidone-Associated QT Interval Prolongation in Non-oncologic Pediatric Patients: A Review of the Literature

2016 ◽  
Vol 69 (3) ◽  
Author(s):  
Amy D Morris ◽  
Jennifer Chen ◽  
Elaine Lau ◽  
Jennifer Poh
Keyword(s):  
Qt Interval ◽  
Cardiac Death ◽  
Pediatric Patients ◽  
Heart Diseases ◽  
Torsades De Pointes ◽  
Qtc Interval ◽  
Interval Prolongation ◽  
Medical Subject Headings ◽  
Qt Interval Prolongation ◽  
Mort Subite

<p><strong>ABSTRACT</strong></p><p><strong>Background: </strong>Domperidone is a prokinetic agent used to treat pediatric gastroesophageal reflux disease. Health Canada has issued warnings about an increased risk of domperidone-associated ventricular arrhythmias and sudden cardiac death. However, the supporting data referred only to adult patients; therefore, extrapolating the safety risks to pediatric patients is difficult.</p><p><strong>Objective: </strong>To summarize and evaluate the evidence for domperidone associated QT interval prolongation, ventricular arrhythmias, and sudden cardiac death to determine the safety of this drug for pediatric patients.</p><p><strong>Data Sources: </strong>Two databases (MEDLINE [1946 to August 2015] and Embase [1980 to August 2015]) were searched with the following Medical Subject Headings and keywords: “domperidone”, “arrhythmias, cardiac”, “death, sudden, cardiac”, “electrocardiography”, “heart diseases”, “long QT syndrome”, “tachycardia, ventricular”, “torsades de pointes”, and “ventricular fibrillation”. The search was limited to studies conducted in humans under 18 years of age and published in English.</p><p><strong>Study Selection and Data Extraction:</strong> Original research included in this review reported on the cardiac-related safety of domperidone in nononcologic patients under 18 years of age.</p><p><strong>Data Synthesis: </strong>Of the 5 studies meeting the inclusion criteria (<em>n </em>= 137 patients), one reported a statistically significant change in the corrected QT (QTc) interval, but the clinical significance was unclear. Most of the studies reported rare occurrences of pathological QTc intervals in a limited number of patients. However, confounding factors (e.g., abnormal electrolyte level or concurrent medications) were not consistently considered. Potential bias might have been alleviated by blinding of electrocardiogram (ECG) assessors; however, this was not consistently implemented. The designs of the included studies did not allow assessment of causality. The results should be interpreted with caution.</p><p><strong>Conclusions: </strong>Although the available evidence is limited, pathological QTc intervals were noted among a small number of infants, which supports the possibility of domperidone-associated risk of prolonged QTc interval. Because of the potential severity of QT interval prolongation, individual assessment and routine ECG monitoring should be implemented for patients receiving domperidone.</p><p><strong>RÉSUMÉ</strong></p><p><strong>Contexte : </strong>La dompéridone est un agent gastroprocinétique utilisé pour traiter le reflux gastro-oesophagien chez l’enfant. Santé Canada a publié des mises en garde à propos d’un risque accru d’arythmies ventriculaires et de mort subite cardiaque associées à la dompéridone. Or, comme les données probantes ne concernent que l’adulte, il est difficile de généraliser les risques pour la santé à l’enfant.</p><p><strong>Objectif : </strong>Résumer et analyser les données probantes portant sur l’allongement de l’intervalle QT, les arythmies ventriculaires et la mort subite cardiaque associés à la dompéridone afin de déterminer le degré d’innocuité du médicament chez l’enfant.</p><p><strong>Sources des données : </strong>Deux bases de données (MEDLINE [1946 à août 2015] et EMBASE [1980 à août 2015]) ont été interrogées en utilisant les mots clés et les Medical Subject Headings (MeSH) suivants : « domperidone »  dompéridone), « arrhythmias, cardiac » (arythmies cardiaques), « death, sudden, cardiac » (mort, subite, cardiaque),« electrocardiography » (électrocardiographie), « heart diseases » (cardiopathies), « long QT syndrome » (syndrome du QT long), « tachycardia, ventricular » (tachycardie, ventriculaire), « torsades de pointes » (torsades de pointes) et « ventricular fibrillation » (fibrillation ventriculaire). La recherche se limitait aux études publiées en anglais et effectuées chez l’humain de moins de 18 ans.</p><p><strong>Sélection des études et extraction des données : </strong>Les études retenues dans la présente revue abordaient l’innocuité cardiaque de la dompéridone chez les patients de moins de 18 ans qui ne sont pas atteints d’un cancer.</p><p><strong>Synthèse des données : </strong>Parmi les cinq études qui répondaient aux critères d’inclusion (<em>n </em>= 137 patients), une indiquait un changement statistiquement significatif dans l’intervalle QT corrigé (QTc), mais la signification clinique demeurait floue. La plupart des études signalaient de rares cas d’intervalles QTc pathologiques chez un nombre limité de patients. Cependant, des facteurs de confusion (déséquilibre électrolytique ou emploi concomitant de médicaments, par exemple) n’étaient pas systématiquement pris en compte. Il aurait été possible d’éviter de potentiels biais en tenant les lecteurs d’électrocardiogramme (ECG) dans l’ignorance du traitement, mais cette mesure n’était pas toujours mise en oeuvre. Les plans des études retenues ne permettaient pas d’évaluer la causalité. Il faut donc interpréter les résultats avec prudence.</p><p><strong>Conclusions : </strong>Bien qu’il n’y ait que peu de données probantes, des cas d’intervalles QTc pathologiques ont été relevés chez un petit nombre de nourrissons, ce qui vient appuyer le risque possible d’allongement de l’intervalle QTc associé à la dompéridone. À cause de la potentielle gravité de l’allongement de l’intervalle QT, une évaluation individuelle et une surveillance ECG systématique doit être mise en place pour les patients qui reçoivent de la dompéridone.</p>

What is the role of QTc prolongation assessment in new drugs development phase I oncology trials?

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 2006-2006
Author(s):  
G. Curigliano ◽  
C. Cipolla ◽  
C. Sessa ◽  
C. Noberasco ◽  
T. De Pas ◽  
...  
Keyword(s):  
Phase I ◽  
Qt Interval ◽  
Phase I Study ◽  
Qt Prolongation ◽  
New Drugs ◽  
Accurate Information ◽  
Investigational Drug ◽  
Qtc Interval ◽  
Qtc Prolongation ◽  
Qt Interval Prolongation

2006 Background: QT interval prolongation associated with “torsades de pointes” (TdP) has been a common cause of withdrawal from the market for several promising drugs. We determined the degree of QT prolongation in patients treated within a phase I study with a thioxanthone derivative known to have arrhythmogenic potential. Methods: Clinical data and serial ECGs from 31 patients with advanced tumors who received 86 courses of investigational drug were prospectively reviewed. The drug has been administered intravenously over 24 hours every 3 weeks. Patients have been on a 24 hour Holter monitor until 24 hours after infusion was complete. Three baseline ECGs were done and compared to those every 6 hours during therapy and once 6 hours after the infusion was complete. ECGs were read at a central lab according to a standard protocol. All QT measurements were then corrected for heart rate (QTc) using Bazett’s formula (QTc = QT interval divided by the square root of the R-R interval). Results: Overall,843 ECG tracings were obtained, all evaluable for analysis. No basal ECG showed significant abnormalities. Prolonged QT intervals developed in 2 patients without clinical symptoms (1 patient had intervals 500 milliseconds).In both cases it was associated with the maximum concentration of the drug. Compared with baseline, the QTc interval was prolonged by 30 to 60 milliseconds in 20% of total tracings, and by more than 60 milliseconds in 2% of ECGs. In patients receiving multiple courses, QTc intervals returned to pretreatment levels before the second course. Conclusions: The assessment of QTc prolongation was a major effort in this study but produced an accurate information about such event. In phase I study such an effort is justified when arrhythmogenicity is suspected. The timing of collection of ECGs should be guided by the available preclinical information about the pharmacokinetic profile of the drug. Nevertheless uncertainty remains regarding the specific relationship between the degree of QT prolongation and the risk of life-threatening arrhythmias. The decision to use the drug ultimately has to be based on an estimation of the perceived risk relative to expected benefits for patients. No significant financial relationships to disclose.

Risk factors for prolonged QTc among US adults: Third National Health and Nutrition Examination Survey

2005 ◽  
Vol 12 (4) ◽  
pp. 363-368 ◽  
Author(s):  
Stephen R. Benoit ◽  
Aaron B. Mendelsohn ◽  
Parivash Nourjah ◽  
Judy A. Staffa ◽  
David J. Graham
Keyword(s):  
Risk Factors ◽  
Myocardial Infarction ◽  
National Health ◽  
Thyroid Disease ◽  
Qt Interval ◽  
Qtc Interval ◽  
Nutrition Examination Survey ◽  
Health And Nutrition ◽  
Qt Interval Prolongation ◽  
Medical Histories

Background QT interval prolongation can lead to torsades de pointes, a potentially fatal arrhythmia. Although research exists on the relationship between QT prolongation and clinical outcome, few studies have described risk factors for prolonged QT interval in the general population. Methods The Third National Health and Nutrition Examination Survey (NHANES III) collected electrocardiogram interval data on 8561 subjects over 40 years of age and projected results to the US population. QT was corrected for heart rate using Fridericia's formula. Logistic regression analyses were performed to identify factors independently associated with prolonged QTc interval, defined as being in the upper 5% of the population QTc interval distribution. Analyses were conducted separately for women and men as a result of differences in the QT distribution between the sexes and also because of potential effect modification. Analytical variables included age, race/ethnicity, electrolyte measurements, body mass index, the recent use of QT-prolonging drugs and past medical histories of stroke, thyroid disease, hypertension, diabetes and myocardial infarction. Results Age, female sex, hypocalcemia (men), hypokalemia (women), and a history of thyroid disease and myocardial infarction (men) were associated with a prolonged QTc interval. In addition, taking QT-prolonging medications in the past month was associated with more than a twofold increase in the odds of prolonged QTc interval in both men and women. Conclusions Healthcare practitioners should be aware that a prolonged QTc interval is a potential indicator of cardiovascular risk, and should exercise caution in prescribing potentially QT-prolonging medications to certain patients.

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