scholarly journals Mechanisms, Risk Factors, and Management of Acquired Long QT Syndrome: A Comprehensive Review

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Eleftherios M. Kallergis ◽  
Christos A. Goudis ◽  
Emmanuel N. Simantirakis ◽  
George E. Kochiadakis ◽  
Panos E. Vardas
Keyword(s):  
Risk Factors ◽  
Long Qt Syndrome ◽  
Polymorphic Ventricular Tachycardia ◽  
Qtc Interval ◽  
Environmental Stressor ◽  
Long Qt ◽  
Acquired Long Qt Syndrome ◽  
Number Of Patients ◽  
Long Term Treatment ◽  
Qt Syndrome

Long QT syndrome is characterized by prolongation of the corrected QT (QTc) interval on the surface electrocardiogram and is associated with precipitation of torsade de pointes (TdP), a polymorphic ventricular tachycardia that may cause sudden death. Acquired long QT syndrome describes pathologic excessive prolongation of the QT interval, upon exposure to an environmental stressor, with reversion back to normal following removal of the stressor. The most common environmental stressor in acquired long QT syndrome is drug therapy. Acquired long QT syndrome is an important issue for clinicians and a significant public health problem concerning the large number of drugs with this adverse effect with a potentially fatal outcome, the large number of patients exposed to these drugs, and our inability to predict the risk for a given individual. In this paper, we focus on mechanisms underlying QT prolongation, risk factors for torsades de pointes and describe the short- and long-term treatment of acquired long QT syndrome.

scholarly journals Paediatric/young versus adult patients with long QT syndrome or catecholaminergic polymorphic ventricular tachycardia

2021 ◽  
Author(s):  
Sharen Lee ◽  
Jiandong Zhou ◽  
Kamalan Jeevaratnam ◽  
Wing Tak Wong ◽  
Ian Chi Kei Wong ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Long Qt Syndrome ◽  
Primary Outcome ◽  
Public Hospitals ◽  
Adult Patients ◽  
Polymorphic Ventricular Tachycardia ◽  
Qtc Interval ◽  
Long Qt ◽  
Old Patients ◽  
Qt Syndrome

AbstractIntroductionLong QT syndrome (LQTS) and catecholaminergic ventricular tachycardia (CPVT) are less prevalent cardiac ion channelopathies than Brugada syndrome in Asia. The present study compared paediatric/young and adult patients with these conditions.MethodsThis was a territory-wide retrospective cohort study of consecutive patients diagnosed with LQTS and CPVT attending public hospitals in Hong Kong. The primary outcome was spontaneous ventricular tachycardia/ventricular fibrillation (VT/VF).ResultsA total of 142 LQTS (mean onset age= 27±23 years old) and 16 CPVT (mean presentation age=11±4 years old) patients were included. For LQTS, arrhythmias other than VT/VF (HR=4.67, 95% confidence interval=[1.53-14.3], p=0.007), initial VT/VF (HR=3.25 [1.29-8.16], p=0.012) and Schwartz score (HR=1.90 [1.11-3.26], p=0.020) were predictive of the primary outcome for the overall cohort, whilst arrhythmias other than VT/VF (HR=5.41 [1.36-21.4], p=0.016) and Schwartz score (HR=4.67 [1.48-14.7], p=0.009) were predictive for the adult subgroup (>25 years old; n=58). All CPVT patients presented before the age of 25 but no significant predictors of VT/VF were identified. A random survival forest model identified initial VT/VF, Schwartz score, initial QTc interval, family history of LQTS, initially asymptomatic, and arrhythmias other than VT/VF as the most important variables for risk prediction in LQTS, and initial VT/VF/sudden cardiac death, palpitations, QTc, initially symptomatic and heart rate in CPVT.ConclusionClinical and ECG presentation vary between the pediatric/young and adult LQTS population. All CPVT patients presented before the age of 25. Machine learning models achieved more accurate VT/VF prediction.

scholarly journals Phase 2 Early Afterdepolarization as a Trigger of Polymorphic Ventricular Tachycardia in Acquired Long-QT Syndrome

Circulation ◽  
2001 ◽  
Vol 103 (23) ◽  
pp. 2851-2856 ◽  
Author(s):  
Gan-Xin Yan ◽  
Ying Wu ◽  
Tengxian Liu ◽  
Jixin Wang ◽  
Roger A. Marinchak ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Long Qt Syndrome ◽  
Polymorphic Ventricular Tachycardia ◽  
Phase 2 ◽  
Long Qt ◽  
Acquired Long Qt Syndrome ◽  
Early Afterdepolarization ◽  
Qt Syndrome

scholarly journals Acquired Long QT Syndrome and Torsade de Pointes Associated with HIV Infection

2010 ◽  
Vol 2010 ◽  
pp. 1-2 ◽  
Author(s):  
Alexander Shimabukuro-Vornhagen ◽  
Jan Rybniker ◽  
Shahram Zoghi ◽  
Gerd Faetkenheuer ◽  
Guido Michels ◽  
...  
Keyword(s):  
Long Qt Syndrome ◽  
Infected Patient ◽  
Torsade De Pointes ◽  
Torsades De Pointes ◽  
Hiv Positive ◽  
Qtc Interval ◽  
Fatal Complication ◽  
Long Qt ◽  
Acquired Long Qt Syndrome ◽  
Qt Syndrome

Here, we report the case of an HIV infected patient that was treated for pneumonia with a macrolid antibiotic. The patient experienced a prolongation of the already pathologic QTc interval resulting in repeated torsades de pointes necessitating CPR and implantation of an AICD. This case exemplifies that torsades de pointes due to acquired long QT syndrome is a serious and potentially fatal complication in HIV-positive patients.

Should We be Worried About QTc Prolongation Using Citalopram? A Review

2016 ◽  
Vol 30 (3) ◽  
pp. 353-358 ◽  
Author(s):  
Lauren M. J. Hutton ◽  
Andrew J. Cave ◽  
Renée St-Jean ◽  
Hoan Linh Banh
Keyword(s):  
Risk Factors ◽  
Long Qt Syndrome ◽  
Causal Link ◽  
Clinical Impact ◽  
Patient Specific ◽  
Qtc Interval ◽  
Qtc Prolongation ◽  
Long Qt ◽  
Specific Risk ◽  
Qt Syndrome

Purpose: Summarize available information regarding clinical impact of citalopram on the QTc interval. Methods: A literature search was conducted in Pubmed, EMBASE, and Cochrane databases using the MeSH term “long QT syndrome” and key word “citalopram” on July 11, 2014. Results: Thirty-one studies were evaluated with 4 included in this review. Studies were excluded if they reported acute overdoses of citalopram or did not report on patient-specific risk factors for long QT syndrome (eg, hypokalemia, bradycardia, and increased age). The majority of the available data is derived from case reports. A number of confounders complicate the determination of a causal link between QTc prolongation and citalopram. Of the 4 studies included for review, none identified significant QTc prolongation in patients taking citalopram 20 to 60 mg daily without the patients having one or more patient-specific risk factors for prolonged QTc. Conclusion: There is insufficient evidence to establish a causal link between citalopram 20 to 60 mg orally daily and increased risk of TdP. Further research is required to determine the clinical impact and association between citalopram 20 to 60 mg daily and QTc prolongation.

Acquired Long QT Syndrome: Frequency, Onset, and Risk Factors in Intensive Care Patients

2012 ◽  
Vol 32 (5) ◽  
pp. 32-41 ◽  
Author(s):  
Teri M. Kozik ◽  
Shu-Fen Wung
Keyword(s):  
Risk Factors ◽  
Intensive Care ◽  
Long Qt Syndrome ◽  
Retrospective Chart Review ◽  
Torsades De Pointes ◽  
Long Qt ◽  
Intensive Care Patients ◽  
Acquired Long Qt Syndrome ◽  
Qt Intervals ◽  
Qt Syndrome

Background Acquired long QT syndrome is a reversible condition that can lead to torsades de pointes and sudden cardiac death. Objective To determine the frequency, onset, frequency of medications, and risk factors for the syndrome in intensive care patients. Methods In a retrospective chart review of 88 subjects, hourly corrected QT intervals calculated by using the Bazett formula were collected. Acquired long QT syndrome was defined as a corrected QT of 500 milliseconds or longer or an increase in corrected QT of 60 milliseconds or greater from baseline level. Risk factors and medications administered were collected from patients’ medical records. Results The syndrome occurred in 46 patients (52%); mean time of onset was 7.4 hours (SD, 9.4) from time of admission. Among the 88 patients, 52 (59%) received a known QTc-prolonging medication. Among the 46 with the syndrome, 23 (50%) received a known QT-prolonging medication. No other risk factor studied was significantly predictive of the syndrome. Conclusions Acquired long QT syndrome occurs in patients not treated with a known QT-prolonging medication, indicating the importance of frequent QT monitoring of all intensive care patients.

Abstract 223: A Case for Hypoxia and Long QT Syndrome in Sudden Infant Death Syndrome

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Marianne Neary ◽  
Timothy J Mohun ◽  
Ross A Breckenridge
Keyword(s):  
Risk Factors ◽  
Heart Rate ◽  
Sudden Death ◽  
Long Qt Syndrome ◽  
Sudden Infant Death ◽  
Sudden Infant ◽  
Qtc Interval ◽  
Long Qt ◽  
Qt Syndrome ◽  
Ecg Morphology

INTRODUCTION: Long QT syndrome is considered an important factor in the pathogenesis of Sudden Infant Death Syndrome (SIDS). Prolonged QTc intervals (c=corrected for heart rate) in SIDS are sometimes caused by mutations in genes encoding ion channels. Other causes remain largely idiopathic. HYPOTHESIS: Risk factors for SIDS, including maternal bed sharing, head covering and high altitude, are associated with a reduced oxygen environment. Our studies investigate a link between hypoxia and long QT syndrome in the neonate. METHODS: We characterised, for the first time, changes in the murine neonatal electrocardiogram (ECG) at: 0, 1, 3, 6, 12, 24 hours (n=12) and 2, 6 and 10 days (n=25) after birth. We investigated whether birth into hypoxia 10% O2 (n=16) and genetically elevating cardiac hypoxic signalling in neonatal mice alters the course of changes in ECG morphology (n=14). We analysed the ECG for heart rate and parameters associated with dysrrhythmia and sudden death, including the QTc interval. RESULTS: In the hours and days following birth, we observed a steady increase in heart rate (p<0.0001) and decrease in QTc interval (p<0.05). When neonates were raised in hypoxia for 24 hours, the trends in heart rate (p<0.001) and QTc interval (p<0.0001) were abolished and risk of neonatal death was 52% (17 out of 33) over 24 hours. In transgenic neonatal mice with elevated cardiac hypoxic signalling, we observed a significant bradycardia (p<0.0001) and elongated QTc interval (p<0.0001) compared to controls at ten days after birth, with death occurring pre-weaning. >CONCLUSIONS: Following birth there are significant changes in ECG morphology, including an increase in heart rate and decrease in QTc interval. Hypoxia diminishes these changes resulting in bradycardia and elongated QTc intervals. We hypothesise that the increase in ambient oxygen concentration after birth drives the maturation of cardiac electrical conduction, failure of which predisposes to dysrhythmia and sudden death. This is consistent with known risk factors of SIDS and provides a link between neonatal hypoxia and ECG repolarisation abnormalities.

Abstract 12257: Calmodulin Interacting Genes as a Novel Candidate for Pathogenesis of Long-QT Syndrome

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Takeshi Aiba ◽  
Daichi Shigemizu ◽  
Hidewaki Nakagawa ◽  
Kouichi Ozaki ◽  
Fuyuki Miya ◽  
...  
Keyword(s):  
Long Qt Syndrome ◽  
De Novo ◽  
Association Studies ◽  
Polymorphic Ventricular Tachycardia ◽  
Compound Heterozygous ◽  
Qtc Interval ◽  
Cardiac Events ◽  
Long Qt ◽  
Network Analyses ◽  
Qt Syndrome

Background: Approximately 30% of long-QT syndrome (LQTS) cases remains genetically elusive. Here, we investigated usefulness of the whole exon sequencing (WES) by next-generation sequencing for identification of novel pathogenic candidates which directly or indirectly interact with proteins encoded by known LQTS genes. Methods: Of 1815 Japanese LQTS cohort patients, WES was performed in 59 LQTS patients and 61 unaffected individuals from 35 families and 138 unrelated LQTS cases, all were screened major LQTS genes such as KCNQ1, KCNH2, SCN5A, KCNE1, KCNE2 and KCNJ2. After WES, the genes known as inherited arrhythmias were screened by the Human Gene Mutation Database, and the Sanger sequencing was also referred for validation of the mutations and common variants were excluded by the public (1000G, ESP6500 and dbSNP) and Riken database. Results: Total 92 candidate mutations including 11 de novo, 5 recessive (2 homozygous and 3 compound heterozygous) and 73 dominant mutations in 88 genes were identified in 23 of the 35 families. Protein-protein interaction network analyses revealed ten new pathogenic candidates (WDR26, RYR2, UBR5, UBR4, KIF21B, CIT, SIRT6, PIK3CG, PI4KA and RIMS1) that directly or indirectly interact with proteins encoded by known LQTS genes. Furthermore, gene based association studies identified an additional novel candidate; SLC2A5. Taken together, mutations in these new candidates or known LQTS genes were identified in 13 of the 35(37%) genotype-unknown LQTS families. Moreover, 5 of the 11 newly identified candidates directly interact with calmodulin (CaM). Subsequent variant analysis in the independent set of 138 cases identified 16 variants in the 11 genes, of which, 14 (87.5%) were in the CaM-interacting genes and 8 of them were in RYR2. Many of the patients with RyR2 mutation had similar exercise-induced cardiac events (3 syncope, 2 VF) as LQTS patients, while the QTc interval was shorter in patients with RyR2 mutation than those with genotype-negative LQTS (441±32 vs. 487±47ms; p=0.01). Conclusions: These findings suggest that CaM interacting genes have an important role on the pathogenesis of LQTS. In particular, RYR2 mutations may cause an overlap syndrome between catecholaminergic polymorphic ventricular tachycardia and LQTS.

scholarly journals An unusual cause of polymorphic ventricular tachycardia: Acquired long QT syndrome from atypical variant of stress-induced cardiomyopathy

2020 ◽  
Vol 8 ◽  
pp. 2050313X2094430 ◽  
Author(s):  
Mashael Alfarih ◽  
James C Moon ◽  
Marianna Fontana ◽  
Dan Knight ◽  
Gabriella Captur
Keyword(s):  
Ventricular Tachycardia ◽  
Long Qt Syndrome ◽  
Systolic Function ◽  
Invasive Coronary Angiography ◽  
Polymorphic Ventricular Tachycardia ◽  
Supraglottic Airway ◽  
Long Qt ◽  
Acquired Long Qt Syndrome ◽  
Qt Syndrome ◽  
Atypical Variant

A 55-year-old woman with a recent history of surgically and radioiodine treated thyroid cancer experienced a run of polymorphic ventricular tachycardia with hemodynamic perturbation during anaesthetic induction with propofol, fentanyl and rocuronium for elective surgical excision of right hip metastasis. Electrocardiography showed new T-wave inversion and QT prolongation that subsequently resolved. Cardiac enzymes were elevated but invasive coronary angiography showed unobstructed epicardial coronary arteries. Cardiovascular magnetic resonance showed not only normal biventricular size and systolic function but also a striking pattern of patchy myocardial oedema involving the basal-to-mid anterior, septal and inferior walls and some associated hypertrophy in the anteroseptum (representing focal myocardial swelling from the oedema) but no focal or diffuse myocardial fibrosis. All these abnormalities resolved on subsequent convalescent imaging. A diagnosis of multifactorial acquired long QT syndrome secondary to atypical variant stress-induced cardiomyopathy was made with the likely provoking factors in this case having been the female sex, understandable pre-operative anxiety, anaesthetic drugs, supraglottic airway placement and thyroid dysfunction. An implantable loop recorder during follow-up detected no further significant arrhythmias and she remains well and asymptomatic to date on a low dose of beta-blocker.

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