Torsades de pointes complicating complete heart block with QT interval prolongation

2016 ◽  
Vol 71 (5) ◽  
pp. 627-627
Author(s):  
Ivan Stankovic ◽  
Biljana Putnikovic ◽  
Aleksandar N. Neskovic
2007 ◽  
Vol 292 (4) ◽  
pp. H1782-H1788 ◽  
Author(s):  
Fumiaki Suto ◽  
Wei Zhu ◽  
Alice Chan ◽  
Gil J. Gross

Bradycardic ventricular electrical remodeling predisposes to lethal tachyarrhythmias. We investigated the early temporal sequence and reversibility of electrical remodeling in a rabbit complete heart block model subjected to bradycardic ventricular pacing for either 2 or 8 days, with a third group of animals undergoing 8 days of bradycardic pacing followed by 8 days of physiological-rate pacing. At specified time points after complete heart block induction and pacing initiation, steady-state QT interval measurements and variability as well as dynamic QT interval adaptation to abrupt heart rate acceleration were assessed in the absence and presence of isoproterenol. Rapidly ( IKr) and slowly ( IKs) activating delayed rectifier repolarizing K+ tail current densities were evaluated using whole cell patch clamp in isolated right ventricular myocytes. Steady-state QT interval prolongation at both 2 and 8 days was associated with moderate IKr reduction. IKs downregulation was apparent by day 2 but more profound at day 8. Dynamic QT interval adaptation was impaired under baseline conditions at day 8 but only during isoproterenol administration at day 2. Both in vivo and cellular manifestations of remodeling reverted toward control values after 8 days of physiological-rate pacing. In conclusion, in this bradycardic model, IKs downregulation 1) proceeds more gradually but more extensively than that of IKr and 2) is most prominently associated with impaired dynamic QT interval adaptation to heart rate acceleration. Isoproterenol blunts the dynamic QT interval response in animals with partially downregulated IKs, consistent with stress-related phenomena in known IKs-impaired states. Relative early sparing of IKs could explain the delay in the onset of lethal tachyarrhythmia predisposition in bradycardic electrical remodeling. Reversibility of remodeling supports the potential utility of preventive pacing intervention soon after bradycardia onset.


2000 ◽  
Vol 43 (5) ◽  
pp. 1049 ◽  
Author(s):  
Rolando Cimaz ◽  
Marco Stramba-Badiale ◽  
Antonio Brucato ◽  
Luca Catelli ◽  
Paola Panzeri ◽  
...  

Author(s):  
Amy D Morris ◽  
Jennifer Chen ◽  
Elaine Lau ◽  
Jennifer Poh

<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>


2005 ◽  
Vol 28 (5) ◽  
pp. 472-473 ◽  
Author(s):  
STAVROS P. KOUNAS ◽  
KONSTANTINOS P. LETSAS ◽  
ANTONIOS SIDERIS ◽  
MICHALIS EFRAIMIDIS ◽  
FOTIOS KARDARAS

2002 ◽  
Vol 18 (2) ◽  
pp. 57-62 ◽  
Author(s):  
Gregory D. Sides

Prolongation of the QT interval on the surface 12-lead electrocardiogram is widely accepted as a biomarker for the potential of a drug to produce torsades de pointes and/or sudden death. Detection of drug-induced prolongation of the QT interval in animals and man is frequently confounded by extrinsic and intrinsic factors that limit the ability to detect a true drug effect. In particular drugs that increase heart rate show an apparent increase in QT interval that confounds assessment of a true drug effect on cardiac ventricular repolarization. The basis for the use of the QT interval as a biomarker will be examined.


2020 ◽  
Vol 11 ◽  
pp. 204209862094241 ◽  
Author(s):  
Katie Malone ◽  
Jules C. Hancox

Background: Acetylcholinesterase inhibitors (AChEis) including donepezil, galantamine and rivastigmine are used to treat Alzheimer’s disease (AD). This study aimed to evaluate evidence from the case report literature for an association between these agents and risk of QT interval prolongation and Torsades de Pointes (TdP) arrhythmia. Methods: Published literature was mined with predetermined MeSH terms for each of donepezil, galantamine and rivastigmine, to identify cases of QT interval prolongation and TdP. Case reports were analysed using causality scales and a QT interval nomogram. Results: A total of 13 case reports were found (10 for donepezil, 2 for galantamine and 1 for rivastigmine) with rate corrected QT interval (QTc) prolongation. Five cases with donepezil exhibited TdP. TdP was not reported in the cases with galantamine and rivastigmine. The use of a QT heart rate nomogram highlighted risk with donepezil compared with the other two drugs and the application of the Naranjo causality scale suggested probable or possible causation for all donepezil cases. All patients had at least two other risk factors for TdP, including modifiable risk factors such as electrolyte disturbances, bradycardia, co-administration of QT prolonging drugs. A number of recent cases involved recent changes in medication. Conclusion: Our evaluation of the case report literature suggests that there is evidence for a causal association between donepezil and QTc/TdP risk. Attention to risk factors for QTc prolongation/TdP should be exercised when prescribing donepezil and modifiable risk factors corrected. Owing to the low number of cases with galantamine and rivastigmine, further work is needed to establish whether these drugs may be more suitable than donepezil for patients with other risk factors for TdP.


2012 ◽  
Vol 117 (2) ◽  
pp. 321-328 ◽  
Author(s):  
Peter Nagele ◽  
Swatilika Pal ◽  
Frank Brown ◽  
Jane Blood ◽  
J. Philipp Miller ◽  
...  

Background Abnormal cardiac repolarization, indicated by a prolongation of the QT interval, increases the risk for torsades de pointes, a potentially life-threatening arrhythmia. Many perioperatively administered drugs and conditions prolong the QT interval. Despite several reports of perioperative torsades de pointes, systematic evidence regarding perioperative QT interval prolongation is limited. Methods Serial postoperative 12-lead electrocardiograms were obtained from 469 adult patients undergoing major noncardiac surgery under general anesthesia. Heart rate corrected QT-interval duration (Fridericia formula) was the primary outcome. All perioperatively administered drugs were recorded. Emphasis was placed on absolute QTc prolongation greater than 500 ms and relative increases of 30 and 60 ms. Results At the end of surgery, 80% of the patients (345 of 429) experienced a significant QTc interval prolongation (ΔQTc 23 ± 26 ms (mean and SD), 95% CI 20-25 ms, P less than 0.001). Approximately 51% (219 of 429) had a QTc greater than 440 ms, and 4% (16 of 429) a QTc greater than 500 ms. In 39% (166 of 429), the ΔQTc was greater than 30 ms, in 8% (34 of 429) &gt;60 ms, and in greater than 0.5% (2 of 429) &gt;100 ms. No changes in ΔQTc occurred at subsequent time points. One patient developed torsades de pointes with a ΔQTc: 29 ms (0.4% incidence rate). Several drugs had a large effect on ΔQTc: isoflurane, methadone, ketorolac, cefoxitin, zosyn, unasyn, epinephrine, ephedrine, and calcium. Postoperative body temperature had a weak negative correlation with ΔQTc (r = -0.15, P = 0.02); serum magnesium, potassium, and calcium concentrations were not correlated. Conclusion Postoperative QT-interval prolongation is common. Several perioperatively administered drugs are associated with a substantial QT-interval prolongation. The exact cause and its clinical relevance are, however, unclear. Nevertheless, an association between postoperative QT prolongation and risk for torsades de pointes is likely.


2021 ◽  
Vol 76 (2) ◽  
pp. 169-176
Author(s):  
Oleg O. Kirilochev

Background; Events associated with a risk of death are the most serious complications of pharmacotherapy; One of these complications is prolongation of the QT interval leading to Torsades de Pointes, a life-threatening condition that can result in asystole and sudden death. Factors contributing to the development of the long QT syndrome include heredity, structural abnormalities of the heart, electrolyte disorders, female gender, advanced age, use of drugs with certain electrophysiological properties, and drug-drug interactions. Consideration of all these factors can help achieve the most accurate and objective assessment of the risk of these rhythm disturbances. Aims to assess the risk of prolongation of the QT interval and the development of Torsades de Pointes in psychiatric inpatients. Methods. The study enrolled 500 patients who received medical care in a psychiatric inpatient setting. The risk of QT interval prolongation and development of Torsades de Pointes was assessed using the MedSafety Scan medical decision support system. Results. Of the 500 patients treated in the psychiatric inpatient setting, 224 had a risk of QT interval prolongation and developing Torsades de Pointes; the incidence was highest in the group of elderly patients. The mean risk score was 7.59 3.29 in general, 6.02 3.14 in patients aged under 65 years, and 9.16 2.62 in subjects over 65 years of age. An analysis of the frequencies of risk factors for prolongation of the QT interval and Torsades de Pointes revealed that patients aged over 65 years most commonly had atrial fibrillation, chronic heart failure, heart valve disorders, hypertension, and a history of myocardial infarction. Patients under 65 years of age more commonly received medicinal products prolonging the QT interval and drug combinations that can lead to potential drug-drug interactions of relevant clinical significance. Conclusion. The obtained results indicate the importance of assessing the risk of QT interval prolongation and development of Torsades de Pointes in psychiatric inpatients as an affordable preventive tool that can increase the safety of drug therapy.


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