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Clinical Cardiology Sep 2023Screening elite athletes for conditions associated with sudden cardiac death is recommended by numerous international guidelines. Current athlete electrocardiogram... (Review)
Review
Screening elite athletes for conditions associated with sudden cardiac death is recommended by numerous international guidelines. Current athlete electrocardiogram interpretation criteria recommend the Bazett formula (QTcB) for correcting QT interval. However, other formulae may perform better at lower and higher heart rates (HR). This review aimed to examine the literature on various QT correction methods in athletes and young people aged 14-35 years and determine the most accurate method of calculating QTc in this population. A systematic review of MEDLINE, EMBASE, Scopus, and SportDiscus was performed. Papers comparing at least two different methods of QT interval correction in athletes or young people were included. Quality and risk of bias were assessed using a standardized tool. The search strategy identified 545 papers, of which 10 met the criteria and were included. Nine of these studies concluded that QTcB was least reliable for removing the effect of HR and was inaccurate at both high (>90 beats per min [BPM]) and low (<60 BPM) HRs. No studies supported the use of QTcB in athletes and young people. Alternative QT correction algorithms such as Fridericia (QTcF) produce more accurate correction of QT interval at HRs seen in athletes and young people. QTcB is less accurate at lower and higher HRs. QTcF has been shown to be more accurate in these HR ranges and may be preferred to QTcB for QTc calculation in athletes and young people. However, accurate QTc reference values for discrete HRs using alternative algorithms are not well established and require further research.
Topics: Humans; Adolescent; Long QT Syndrome; Heart Rate; Death, Sudden, Cardiac; Athletes; Algorithms; Electrocardiography
PubMed: 37470093
DOI: 10.1002/clc.24093 -
Journal of Alzheimer's Disease : JAD 2021Markers of altered cardiac function might predict cognitive decline and dementia.
BACKGROUND
Markers of altered cardiac function might predict cognitive decline and dementia.
OBJECTIVE
This systematic review aims to review the literature that examines the associations of various electrocardiogram (ECG) markers with cognitive decline and dementia in middle-aged and elderly populations.
METHODS
We searched PubMed, Embase, and Web of Science through 1 July 2020 for literature and conducted a systematic literature review. We included studies examining the associations of ECG markers (e.g., left ventricular hypertrophy [LVH], spatial QRS-T angle, and QT prolongation) with cognitive function and dementia in adult populations regardless of study setting and design, but excluded studies examining atrial fibrillation and heart rate variability.
RESULTS
Fourteen community-based cross-sectional and longitudinal studies were identified. ECG markers were investigated in association with dementia in four prospective studies, and with cognitive decline in ten prospective studies. ECG-assessed LVH was associated with dementia in one study while five heterogeneous prospective studies yielded inconsistent associations with cognitive decline. Regarding ventricular repolarization markers, spatial QRS-T angle was associated with cognitive decline in one study while another study found no association between QT prolongation and cognitive decline. High resting heart rate was associated with both dementia and cognitive decline in one study but not associated with dementia in another study. P-wave abnormality was significantly associated with incident dementia and cognitive decline in one prospective study.
CONCLUSION
Some ECG markers were associated with incident dementia and cognitive decline. However, limited number of heterogeneous studies did not allow us to make firm conclusions. Further studies are needed.
Topics: Cognitive Dysfunction; Dementia; Electrocardiography; Heart Rate; Humans; Hypertrophy, Left Ventricular; Long QT Syndrome
PubMed: 34657883
DOI: 10.3233/JAD-210606 -
Frontiers in Cardiovascular Medicine 2022Mutations in the gene-encoding for the major Ca channel of the heart-may exhibit a variety of clinical manifestations. These include typical or atypical Timothy...
Geno- and phenotypic characteristics and clinical outcomes of gene mutation associated Timothy syndrome, "cardiac only" Timothy syndrome and isolated long QT syndrome 8: A systematic review.
BACKGROUND
Mutations in the gene-encoding for the major Ca channel of the heart-may exhibit a variety of clinical manifestations. These include typical or atypical Timothy syndromes (TS) which are associated with multiple organ manifestations, and cardiac involvement in form of malignant arrhythmias, QTc prolongation, or AV block. "Cardiac only" Timothy syndrome (COTS) shows no extracardiac manifestation, whereas some gene mutations are associated with QTc prolongation alone (isolated long QT syndrome 8, LQT8).
METHODS
A systematic search of the literature reporting cases of gene mutation associated syndromes, including TS, COTS and isolated LQT8 major databases published from 2004 through 2019 was performed. Detailed patient-level phenotypic and genotypic characteristics, as well as long-term outcome measures were collected and compared between pre-specified patient groups, defined both on phenotype and genotype.
RESULTS
A total of 59 TS, 6 COTS, and 20 isolated LQT8 index cases were identified. Apart of syndactyly or baldness, there were no major differences regarding clinical manifestations or outcome measures between TS subtypes, either defining TS subtypes on the genotype or based on the phenotype. Both subtypes were characterized by an extreme degree of QTc prolongation (median ≥600 ms) which were reflected in high major adverse cardiac event rate. On the other hand, there were marked differences between TS, COTS, and isolated LQT8. Timothy syndrome was characterized by a much earlier disease onset, much more pronounced QTc prolongation and much higher mortality rate than COTS or isolated LQT8. Similar differences were observed comparing exon 8/8A vs. non-exon 8/8A mutation carriers. TS showed a high degree of genetic homogeneity, as the p.Gly406Arg mutation either in exon 8 or exon 8A alone was responsible for 70% of the cases.
CONCLUSIONS
Clinical phenotypes associated with mutations in the gene show important clinical differences. Timothy syndrome is associated with the most severe clinical phenotype and with the highest risk of morbidity and mortality. However, distinguishing TS subtypes, in any form, are not supported by our data.
SYSTEMATIC REVIEW REGISTRATION
[https://www.crd.york.ac.uk/prospero/], identifier [CRD42020184737].
PubMed: 36523353
DOI: 10.3389/fcvm.2022.1021009 -
Cureus Aug 2022Torsades de Pointes (TdP) is a rare form of tachyarrhythmia which can potentially be fatal due to its tendency to degenerate into ventricular fibrillation. It is... (Review)
Review
Torsades de Pointes (TdP) is a rare form of tachyarrhythmia which can potentially be fatal due to its tendency to degenerate into ventricular fibrillation. It is described as a polymorphic ventricular tachycardia characterized by twisting of the QRS complexes around the electrocardiogram (ECG) baseline in patients with a prolonged QT interval. Prolonged QT interval is known as long QT syndrome. Torsades de Poccurs most commonly in patients with an extended QT interval duration, and even though monitoring an ECG can assist in its prevention, there is no defined duration of a QT interval that can lead to an increased risk of Torsades de Pointes. So, it is hard to determine what QT interval constitutes enough risk for Torsades de Pointes to require intervention. The QT interval duration also depends on other factors, namely heart rate (HR) and other factors such as drugs, congenital diseases, and a combination of both. In this study, we considered various causes of QT prolongation but mainly focused on congenital diseases, drugs, or perioperative risk of QT prolongation and the correlation with the risk of impending TdP. By following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and researching studies on various databases, namely PubMed, Science Direct, Medline, and CiNii we were able to find various systematic reviews and articles showing the association between prolonged QT interval and its degeneration into TdP. This review encourages further research into this topic to understand the implications of QT prolongation and how it can help save the lives of patients with known long QT syndrome, or those on QT prolonging drugs with simple ECG monitoring and treatment for the respective cause.
PubMed: 36110477
DOI: 10.7759/cureus.27833 -
Journal of Pharmacy Practice Feb 2024Drug-drug interactions (DDIs) are considered an emerging threat to the patients if undetected. DDIs can prolong QT interval, leading to fatal ventricular arrhythmia.... (Meta-Analysis)
Meta-Analysis Review
Drug-drug interactions (DDIs) are considered an emerging threat to the patients if undetected. DDIs can prolong QT interval, leading to fatal ventricular arrhythmia. Antipsychotics and antidepressants prescribed commonly to psychiatric patients have the propensity to prolong QT interval and can precipitate Torsades de pointes (TdP). This review aimed to summarize the prevalence of QT interval prolonging DDIs in psychiatric patients. This meta-analysis was carried out following the MOOSE (Meta-analysis of Observational Studies in Epidemiology) statement. Databases like Pubmed/MEDLINE, Google Scholar and Research gate were scanned for English language papers. Indexed terms from Medical Subject (MeSH) and other search terms for "QT prolongation", "Drug interactions", and "Psychiatry" were used to identify the articles. All published articles available until the day of the collection were considered. Outcome measures were analyzed with meta package in R language. A total of 5 studies were eligible for inclusion. From the included studies, QT-prolonging DDIs were found in 14806 patients out of 30122 patients. The prevalence of QT-prolonging DDIs in psychiatric patients was found to be 42% (95% confidence interval: 21%, 66%). The factors associated with potential drug-drug interactions were related to patient characteristics such as polypharmacy, age and comorbid disease. This review concluded that psychiatric patients were prescribed the drugs/drug combinations which can prolong QT interval and can cause adverse effects on the cardiovascular system. Hence, it is important to implement precautionary safety interventions, be vigilant and prevent QT prolongation and adverse cardiac effects in clinical practice.
Topics: Humans; Prevalence; Long QT Syndrome; Risk Factors; Drug Interactions; Drug-Related Side Effects and Adverse Reactions; Psychiatry; Observational Studies as Topic
PubMed: 35968552
DOI: 10.1177/08971900221121371 -
Journal of Electrocardiology 2018Congenital long QT syndrome (LQTS) predisposes affected individuals to ventricular tachycardia/fibrillation (VF/VF), potentially resulting in sudden cardiac death. The... (Meta-Analysis)
Meta-Analysis
BACKGROUND AND OBJECTIVES
Congenital long QT syndrome (LQTS) predisposes affected individuals to ventricular tachycardia/fibrillation (VF/VF), potentially resulting in sudden cardiac death. The T-T interval and the T-T/QT ratio, electrocardiographic markers of dispersion of ventricular repolarization, were proposed for risk stratification but their predictive values in LQTS have been controversial. A systematic review and meta-analysis was conducted to examine the value of T-T intervals and T-T/QT ratios in predicting arrhythmic and mortality outcomes in congenital LQTS.
METHOD
PubMed and Embase databases were searched until 9th May 2017, identifying 199 studies.
RESULTS
Five studies on long QT syndrome were included in the final meta-analysis. T-T intervals were longer (mean difference [MD]: 13ms, standard error [SE]: 4ms, P=0.002; I=34%) in congenital LQTS patients with adverse events [syncope, ventricular arrhythmias or sudden cardiac death] compared to LQTS patients without such events. By contrast, T-T/QT ratios were not significantly different between the two groups (MD: 0.02, SE: 0.02, P=0.26; I=0%).
CONCLUSION
This meta-analysis showed that T-T interval is significant higher in individuals who are at elevated risk of adverse events in congenital LQTS, offering incremental value for risk stratification.
Topics: Electrocardiography; Humans; Long QT Syndrome; Risk Assessment; Risk Factors
PubMed: 29550106
DOI: 10.1016/j.jelectrocard.2018.03.001 -
Journal of Biochemical and Molecular... Apr 2022Cardiac channelopathies are a heterogeneous group of inherited cardiac diseases that are associated with mutations in the genes that encode the expression of cardiac ion... (Review)
Review
Cardiac channelopathies are a heterogeneous group of inherited cardiac diseases that are associated with mutations in the genes that encode the expression of cardiac ion channels. In view of this, it can be mentioned that the main hereditary arrhythmias in children and adolescents, caused by dysfunction of the ion channels, are Brugada Syndrome (BrS) and Long QT Syndrome (LQTS). However, few studies address the physiological effects of these conditions on children and adolescents. Thus, the aim of this study is to describe the mutation phenotype related to voltage-gated sodium channels in children and adolescents. A search was performed in the literature of PubMed, Scielo, and Google scholar. The search was limited to articles written in the last 5 years, so articles published between 2014 and 2019 were included. Among 2196 studies identified through a systematic literature review, 30 studies related to the theme were identified for a complete review and after applying exclusion criteria, 4 articles were included in the results of this study. As the most frequently observed channelopathy, BrS was also more identified in children and adolescents, characterized by episodes of syncope or sudden cardiac death. LQTS shows clinical manifestations with a mild phenotype and good prognosis, although it is necessary to monitor and correct serum electrolyte disturbances to prevent ventricular arrhythmias and, consequently, sudden death in patients with the pathology. The aim of this study is to find the general phenotypes related to genetic mutations of voltage-gated sodium channels, in a population aged from 7- to 14-year-old.
Topics: Adolescent; Brugada Syndrome; Humans; Ion Channels; Long QT Syndrome; Mutation; Phenotype; Sodium Channels
PubMed: 35187757
DOI: 10.1002/jbt.22993 -
European Journal of Clinical... Dec 2020To evaluate the toxicity of azithromycin in neonates, infants, and children. (Meta-Analysis)
Meta-Analysis
PURPOSE
To evaluate the toxicity of azithromycin in neonates, infants, and children.
METHODS
A systematic review was performed for relevant studies using Medline (Ovid), PubMed, Cochrane Central Register of Controlled Trials, EMBASE, CINAHL, and International Pharmaceutical Abstracts. We calculated the pooled incidence of adverse drug reactions (ADRs) associated with azithromycin based on prospective studies (RCTs and prospective cohort studies) and analyzed the risk difference (RD) of ADRs between azithromycin and placebo or other antibiotics using meta-analysis of RCTs.
RESULTS
We included 133 studies with 4243 ADRs reported in 197,675 neonates, infants, and children who received azithromycin. The safety of azithromycin as MDA in pediatrics was poorly monitored. The main ADRs were diarrhea and vomiting. In prospective non-MDA studies, the most common toxicity was gastrointestinal ADRs (938/1967; 47.7%). The most serious toxicities were cardiac (prolonged QT or irregular heart beat) and idiopathic hypertrophic pyloric stenosis (IHPS). Compared with placebo, azithromycin did not show increased risk ADRs based on RCTs (risk difference - 0.17 to 0.07). The incidence of QT prolonged was higher in the medium-dosage group (10-30 mg/kg/day) than that of low-dosage group (≤ 10 mg/kg/day) (82.0% vs 1.2%).
CONCLUSION
The safety of azithromycin as MDA needs further evaluation. The most common ADRs are diarrhea and vomiting. The risk of the most serious uncommon ADRs (cardiac-prolonged QT and IHPS) is unknown.
Topics: Age of Onset; Anti-Bacterial Agents; Azithromycin; Child; Diarrhea; Humans; Incidence; Long QT Syndrome; Placebos; Prospective Studies; Pyloric Stenosis, Hypertrophic; Randomized Controlled Trials as Topic; Risk Assessment; Vomiting
PubMed: 32681202
DOI: 10.1007/s00228-020-02956-3 -
Psychosomatics 2015The aim of this systematic review is to identify case reports of citalopram use resulting in QTc prolongation, torsades de pointes, or both, in the medical literature. (Review)
Review
OBJECTIVES
The aim of this systematic review is to identify case reports of citalopram use resulting in QTc prolongation, torsades de pointes, or both, in the medical literature.
METHODS
A literature search was conducted of PubMed, MEDLINE, EMBASE, Scopus, and PsycINFO databases for case reports published in any language that reported the relationship between citalopram use and the development of QTc prolongation or torsades de pointes or both. In addition, bibliographic databases of published articles were searched for additional cases.
RESULTS
A total of 18 case reports of citalopram use resulting in QTc prolongation were identified. Of these, 10 cases were also associated with the development of torsades de pointes. A total of 14 cases occurred in women and 4 in men. There were 7 cases involving an overdose with citalopram. Of the 18 cases, 12 occurred in individuals who were aged <60 years and 6 were in individuals aged >60 years. In 8 of the 18 cases, the individuals were taking a dose between 20 and 60mg of citalopram in a day. Hypertension was the most common comorbid medical condition, as seen in 5 of the cases.
CONCLUSIONS
QTc prolongation or torsades de pointes are infrequently reported adverse effects associated with citalopram use.
Topics: Citalopram; Electrocardiography; Humans; Long QT Syndrome; Selective Serotonin Reuptake Inhibitors; Torsades de Pointes
PubMed: 25619672
DOI: 10.1016/j.psym.2014.09.002 -
Heart Rhythm Feb 2016Implantable cardioverter-defibrillators (ICDs) are implanted with the intention to prolong life in selected patients with inherited arrhythmia syndromes, but ICD... (Meta-Analysis)
Meta-Analysis Review
Implantable cardioverter-defibrillator harm in young patients with inherited arrhythmia syndromes: A systematic review and meta-analysis of inappropriate shocks and complications.
BACKGROUND
Implantable cardioverter-defibrillators (ICDs) are implanted with the intention to prolong life in selected patients with inherited arrhythmia syndromes, but ICD implantation is also associated with inappropriate shocks and complications.
OBJECTIVE
We aimed to quantify the rate of inappropriate shocks and other ICD-related complications to be able to weigh benefit and harm in these patients.
METHODS
We performed a systematic review and meta-analysis of inappropriate shock and/or other ICD-related complication rates, including ICD-related mortality, in patients with inherited arrhythmia syndromes, that is, arrhythmogenic right ventricular cardiomyopathy/dysplasia, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy, dilated cardiomyopathy due to a mutation in the lamin A/C gene, long QT syndrome, and short QT syndrome. We searched MEDLINE and EMBASE from inception to May 30, 2014.
RESULTS
Of 2471 unique citations, 63 studies comprising 4916 patients with inherited arrhythmia syndromes (mean age of 39 ± 15 years) were included. Inappropriate shocks occurred in 20% of patients (crude annual rate of 4.7% per year), with a significantly higher rate in studies published before 2008 (6.1% per year vs 4.1% per year). Moreover, 22% experienced ICD-related complications (4.4% per year) and there was a 0.5% ICD-related mortality (0.08% per year).
CONCLUSION
ICD implantation carries a significant risk of inappropriate shocks and inhospital and postdischarge complications in relatively young patients with inherited arrhythmia syndromes. These data can be used to better inform patients and physicians about the expected risk of adverse ICD events and thereby facilitate shared decision making.
Topics: Adult; Arrhythmias, Cardiac; Death, Sudden, Cardiac; Defibrillators, Implantable; Electric Countershock; Equipment Failure Analysis; Humans; Middle Aged; Risk Assessment
PubMed: 26385533
DOI: 10.1016/j.hrthm.2015.09.010