Long QT syndrome type 1 and 2 patients respond differently to arrhythmic triggers: The TriQarr in vivo study

Marstrand, Peter; Almatlouh, Kasim; Kanters, Jørgen K.; Graff, Claus; Christensen, Alex Hørby; Bundgaard, Henning; Theilade, Juliane

doi:10.1016/j.hrthm.2020.08.017

Cited by 9 publications

(11 citation statements)

References 18 publications

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“…96 Principally, auditory stimuli have been related with triggered cardiac events in LQT2 patients. 64,66 Sex has also been identified as an important independent contributor to cardiac event risks in LQT2, as adolescent and adult women were shown to have higher risk for cardiac events than the corresponding men in this population. 59,[61][62][63] Furthermore, reports show that women with LQTS have a reduced risk for cardiac events during pregnancy, but an increased risk during the 9-month postpartum period, especially among women with LQT2.…”

Section: Clinical Aspects and Arrhythmic Triggersmentioning

confidence: 99%

Section: Molecular Underpinning Of Lqtsmentioning

confidence: 99%

“…The authors of the study mentioned that although bradycardia is a well-established risk factor for arrhythmias in LQTS patients, further studies are needed to fully understand the association with swimming-associated events. 66 Furthermore, genotype-phenotype studies in LQT1 syndrome indicated that LQT1 patients with mutations located in the transmembrane portion of the ion channel are at the highest risk of congenital LQTS-related cardiac events and have greater sensitivity to sympathetic stimulation compared with patients with COOH terminal mutations. 67,68 In addition, the degree of ion channel dysfunction caused by the mutations is an important independent risk factor influencing the clinical course of this disorder.…”

Section: Pip 2 Regulation Of Kcnq1/kcne1 Channelmentioning

confidence: 99%

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Long QT syndrome – Bench to bedside

Ponce-Balbuena

Deschênes

2021

Heart Rhythm O2

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Long QT syndrome (LQTS) is a cardiovascular disorder characterized by an abnormality in cardiac repolarization leading to a prolonged QT interval and T-wave irregularities on the surface electrocardiogram. It is commonly associated with syncope, seizures, susceptibility to torsades de pointes, and risk for sudden death. LQTS is a rare genetic disorder and a major preventable cause of sudden cardiac death in the young. The availability of therapy for this lethal disease emphasizes the importance of early and accurate diagnosis. Additionally, understanding of the molecular mechanisms underlying LQTS could help to optimize genotype-specific treatments to prevent deaths in LQTS patients. In this review, we briefly summarize current knowledge regarding molecular underpinning of LQTS, in particular focusing on LQT1, LQT2, and LQT3, and discuss novel strategies to study ion channel dysfunction and drug-specific therapies in LQT1, LQT2, and LQT3 syndromes.

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Section: Clinical Aspects and Arrhythmic Triggersmentioning

confidence: 99%

Section: Molecular Underpinning Of Lqtsmentioning

confidence: 99%

Section: Pip 2 Regulation Of Kcnq1/kcne1 Channelmentioning

confidence: 99%

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Long QT syndrome – Bench to bedside

Ponce-Balbuena

Deschênes

2021

Heart Rhythm O2

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“…Одним из самых значимых факторов является сдвиг необходимых для нормального сокращения миокарда потока Са 2+ (кальция), Na + (натрия), К + (калия) через мембрану клетки. Скопление молекул, ставшее фрагментированным, вызывает нарушение образования сердечного импульса, генерируя его сверхнормальное или недостаточное проведение, формирует основу для возникновения аритмогенного эффекта [16].…”

Section: общий патогенез формирования аритмийunclassified

Genetic polymorphisms associated with the development of arrhythmic type of cardiovascular events

et al. 2022

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The review analyzes the global agenda on mutational status of genes associated with adverse cardiovascular events of arrhythmic type. Whole exome sequencing will identify a risk group for the likelihood of early or delayed cardiovascular events of arrhythmic type, especially among patients receiving anticancer therapy with cardiotoxic drugs. The dedicated up-to-date panel of genetic polymorphisms will provide an opportunity to optimize management of patients, based on not only clinical, paraclinical and anamnestic data.

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“…Patients with LQTS in active beta-blocker treatment and with a variant in KCNQ1 or KCNH2 (LQTS1 or LQTS2) were prospectively included at the Herlev-Gentofte Hospital, Copenhagen University Hospital, as part of the TriQarr project, which explored the mechanism of QT prolongation. 7 When arriving at our clinic, patients took their usual beta blocker. One hour after intake, electrocardiograms were recorded after a minimum of 5 min of rest and during change from supine position to standing-'brisk standing'.…”

Section: Clinical Inclusionmentioning

confidence: 99%

Effect of moderate potassium-elevating treatment in long QT syndrome: the TriQarr Potassium Study

et al. 2021

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BackgroundIn long QT syndrome (LQTS), beta blockers prevent arrhythmias. As a supplement, means to increase potassium has been suggested. We set to investigate the effect of moderate potassium elevation on cardiac repolarisation.MethodsPatients with LQTS with a disease-causing KCNQ1 or KCNH2 variant were included. In addition to usual beta-blocker treatment, patients were prescribed (1) 50 mg spironolactone (low dose) or (2) 100 mg spironolactone and 3 g potassium chloride per day (high dose+). Electrocardiographic measures were obtained at baseline and after 7 days of treatment.ResultsTwenty patients were enrolled (10 low dose and 10 high dose+). One patient was excluded due to severe influenza-like symptoms, and 5 of 19 patients completing the study had mild side effects. Plasma potassium in low dose did not increase in response to treatment (4.26±0.22 to 4.05±0.19 mmol/L, p=0.07). Also, no change was observed in resting QTcF (QT interval corrected using Fridericia's formula) before versus after treatment (478±7 vs 479±7 ms, p=0.9). In high dose+, potassium increased significantly from 4.08±0.29 to 4.48±0.54 mmol/L (p=0.001). However, no difference in QTcF was observed comparing before (472±8 ms) versus after (469±8 ms) (p=0.66) high dose+ treatment. No patients developed hyperkalaemia.ConclusionIn patients with LQTS, high dose+ treatment increased plasma potassium by 0.4 mmol/L without cases of hyperkalaemia. However, the potassium increase did not shorten the QT interval and several patients had side effects. Considering the QT interval as a proxy for arrhythmic risk, our data do not support that potassium-elevating treatment has a role as antiarrhythmic prophylaxis in patients with LQTS with normal-range potassium levels.Trial registration numberNCT03291145.

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Long QT syndrome type 1 and 2 patients respond differently to arrhythmic triggers: The TriQarr in vivo study

Cited by 9 publications

References 18 publications

Long QT syndrome – Bench to bedside

Long QT syndrome – Bench to bedside

Genetic polymorphisms associated with the development of arrhythmic type of cardiovascular events

Effect of moderate potassium-elevating treatment in long QT syndrome: the TriQarr Potassium Study

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