JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
Blood lipids and the incidence of atrial fibrillation: the Multi-Ethnic Study of Atherosclerosis and the Framingham Heart Study.
J Am Heart Assoc
PUBLISHED: 10-09-2014
Show Abstract
Hide Abstract
Dyslipidemia is a major contributor to the development of atherosclerosis and coronary disease. Its role in the etiology of atrial fibrillation (AF) is uncertain.
Related JoVE Video
Twelve-single nucleotide polymorphism genetic risk score identifies individuals at increased risk for future atrial fibrillation and stroke.
Stroke
PUBLISHED: 08-14-2014
Show Abstract
Hide Abstract
Atrial fibrillation (AF) is prevalent and there is a clinical need for biomarkers to identify individuals at higher risk for AF. Fixed throughout a life course and assayable early in life, genetic biomarkers may meet this need. Here, we investigate whether multiple single nucleotide polymorphisms together as an AF genetic risk score (AF-GRS) can improve prediction of one's risk for AF.
Related JoVE Video
Genetic loci associated with atrial fibrillation: relation to left atrial structure in the Framingham Heart Study.
J Am Heart Assoc
PUBLISHED: 04-04-2014
Show Abstract
Hide Abstract
Atrial fibrillation (AF) results in significant morbidity and mortality. Genome-wide association studies (GWAS) have identified genetic variants associated with AF. Whether genetic variants associated with AF are also associated with atrial structure, an intermediate phenotype for AF, has had limited investigation. We sought to investigate associations between single nucleotide polymorphisms (SNPs) and atrial structure obtained by cardiovascular imaging in the Framingham Heart Study.
Related JoVE Video
Galectin 3 and incident atrial fibrillation in the community.
Am. Heart J.
PUBLISHED: 02-05-2014
Show Abstract
Hide Abstract
Galectin 3 (Gal-3) is a potential mediator of cardiac fibrosis, and Gal-3 concentrations predict incident heart failure. The same mechanisms that lead to cardiac fibrosis in heart failure may influence development of atrial fibrosis and atrial fibrillation (AF). We examined the association of Gal-3 and incident AF in the community.
Related JoVE Video
Whole blood gene expression and atrial fibrillation: the Framingham Heart Study.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Atrial fibrillation (AF) involves substantial electrophysiological, structural and contractile remodeling. We hypothesize that characterizing gene expression might uncover important pathways related to AF.
Related JoVE Video
Stroke prevention in atrial fibrillation in older adults: existing knowledge gaps and areas for innovation: a summary of an American Federation for Aging research seminar.
J Am Geriatr Soc
PUBLISHED: 09-19-2013
Show Abstract
Hide Abstract
Atrial fibrillation (AF) is a common and morbid cardiac arrhythmia that increases in prevalence with advancing age. The risk of ischemic stroke, a primary and disabling hazard of AF, also increases with advancing age. The aging of the population is anticipated to contribute to a rising burden of AF-related morbidity and economic costs, given the close association between the arrhythmia and aging. Recent biological, diagnostic, and therapeutic developments raise hope that AF-related stroke can be largely prevented, yet despite advances in stroke prevention for individuals with AF, numerous scientific and clinical knowledge gaps remain, particularly as these developments are applied to older adults. Given the public health importance of AF-related stroke in elderly adults, a group of clinician-investigators convened on April 5, 2012, to identify promising areas for investigation that may ultimately reduce stroke-related morbidity. This article summarizes the meeting discussion and emphasizes innovative topic areas that may ultimately facilitate the application of novel preventive, diagnostic, and therapeutic insights into the management of older adults with AF. The opinions of those that participated in the meeting limit this report, which may not represent all of the questions that other experts in this field might raise.
Related JoVE Video
Warfarin pharmacogenetics: a controlled dose-response study in healthy subjects.
Vasc Med
PUBLISHED: 09-12-2013
Show Abstract
Hide Abstract
The aim of this study was to determine how genetic variants contribute to warfarin dosing variability when non-genetic factors are controlled. Thirty healthy subjects were subjected to a warfarin dosing algorithm with daily international normalized ratio (INR) measurements to INR ? 2.0, then off warfarin to INR ? 1.2. The primary outcome was the cumulative dose required to achieve INR ? 2.0 for 2 consecutive days. CYP2C9 (p=0.004) and VKORC1 (p=0.02) variant carriers required lower cumulative doses, and CYP4F2 carriers required higher doses (p=0.04). Subjects with variants in both CYP2C9 and VKORC1 required fewer days to reach INR ? 2.0 than wild-type subjects or those with variants in CYP2C9 or VKORC1 (p=0.01). Genetic contribution to dose variability (~62%) was greater than previously reported, suggesting that uncontrolled clinical variables influence the effect of these variants. In conclusion, genotype-guided warfarin-dosing algorithms may rely more on genetic variables in healthier individuals than in patients with clinical confounders.
Related JoVE Video
Atrial fibrillation patterns and risks of subsequent stroke, heart failure, or death in the community.
J Am Heart Assoc
PUBLISHED: 09-05-2013
Show Abstract
Hide Abstract
Atrial fibrillation (AF) patterns and their relations with long-term prognosis are uncertain, partly because pattern definitions are challenging to implement in longitudinal data sets. We developed a novel AF classification algorithm and examined AF patterns and outcomes in the community.
Related JoVE Video
Related JoVE Video
Genetic etiology and evaluation of sudden cardiac death.
Curr Cardiol Rep
PUBLISHED: 07-02-2013
Show Abstract
Hide Abstract
A wide range of inherited syndromes can result in ventricular arrhythmias and sudden cardiac death (SCD). The natural histories of inherited arrhythmia syndromes are highly variable and current risk stratification techniques are limited. Thus, the management of these conditions can be difficult and often involves a combination of risk assessment, lifestyle modification, cardiac interventions, counselling, and family screening. Recent advances in high throughput sequencing have enabled routine testing in patients with a high clinical index of suspicion for an inherited arrhythmia condition, and cascade screening in relatives of mutation carriers. Given the complexity in screening and data interpretation that has been introduced by recent genomic advances, individuals with inherited arrhythmia syndromes are encouraged to seek care at specialized centers with cardiovascular genetics expertise. In this review, we discuss the etiologies of SCD syndromes and discuss strategies for the evaluation of patients at risk for SCD with a focus on the role of genetic testing and family screening.
Related JoVE Video
Risk assessment for incident heart failure in individuals with atrial fibrillation.
Eur. J. Heart Fail.
PUBLISHED: 04-17-2013
Show Abstract
Hide Abstract
Atrial fibrillation (AF) is a strong risk factor for heart failure (HF); HF onset in patients with AF is associated with increased morbidity and mortality. Risk factors that predict HF in individuals with AF in the community are not well established.
Related JoVE Video
Reciprocal relations between physical disability, subjective health, and atrial fibrillation: the Framingham Heart Study.
Am. Heart J.
PUBLISHED: 02-28-2013
Show Abstract
Hide Abstract
Atrial fibrillation (AF)-related symptoms and physical performance are relied upon to guide therapeutic management of patients with AF. We sought to understand whether AF predisposes to or is a result of physical disability and poor subjective health in the community.
Related JoVE Video
Copy number variation and warfarin dosing: evaluation of CYP2C9, VKORC1, CYP4F2, GGCX and CALU.
Pharmacogenomics
PUBLISHED: 12-21-2011
Show Abstract
Hide Abstract
To determine if copy number variants contribute to warfarin dose requirements, we investigated CYP2C9, VKORC1, CYP4F2, GGCX and CALU for deletions and duplications in a multiethnic patient population treated with therapeutic doses of warfarin.
Related JoVE Video
Related JoVE Video
White blood cell count and risk of incident atrial fibrillation (from the Framingham Heart Study).
Am. J. Cardiol.
PUBLISHED: 06-22-2011
Show Abstract
Hide Abstract
Several studies have reported that inflammatory markers are associated with atrial fibrillation (AF). The white blood cell (WBC) count is a widely available and broadly used marker of systemic inflammation. We sought to investigate the association between an increased WBC count and incident AF and whether this association is mediated by smoking, myocardial infarction, and heart failure. We examined the participants in the Framingham Heart Study original cohort. Cox proportional hazard regression analysis was used to examine the relation between the WBC count and incident AF during a 5-year follow-up period. We adjusted for standard AF risk factors, smoking, previous myocardial infarction, and interim myocardial infarction and heart failure before the incident AF. Our sample consisted of 936 participants (mean age 76 ± 6 years and 61% women). The median WBC count was 6.4 × 10(9)/L (25th to 75th percentile 5.6 × 10(9)/L to 7.8 × 10(9)/L). During a median 5-year follow-up period, 82 participants (9%) developed new-onset AF. After adjusting for standard risk factors for AF, an increased WBC count was significantly associated with incident AF, with a hazard ratio per SD (0.26 × 10(9)/L) increase of 2.22 (95% confidence interval 1.10 to 4.48; p = 0.03). We found no substantive differences adjusting for smoking, previous myocardial infarction, interim myocardial infarction, or heart failure. In conclusion, in our community-based sample, an increased WBC count was associated with incident AF during 5 years of follow-up. Our findings provide additional evidence for the relation between systemic inflammation and AF.
Related JoVE Video
Plasma resistin, adiponectin, and risk of incident atrial fibrillation: the Framingham Offspring Study.
Am. Heart J.
PUBLISHED: 05-03-2011
Show Abstract
Hide Abstract
We sought to investigate whether higher concentrations of resistin and lower concentrations of adiponectin relate to incident atrial fibrillation (AF) and whether this association is mediated by AF risk factors and inflammation. Resistin and adiponectin are adipokines that have been associated with multiple known risk factors for AF including diabetes, obesity, inflammation, and heart failure.
Related JoVE Video
Insulin resistance and atrial fibrillation (from the Framingham Heart Study).
Am. J. Cardiol.
PUBLISHED: 04-21-2011
Show Abstract
Hide Abstract
Diabetes mellitus and obesity are increasing in prevalence and are associated with an elevated risk of atrial fibrillation (AF). Given the aging of the United States population, AF is projected to concomitantly increase in prevalence in the upcoming decades. Both diabetes and obesity are associated with insulin resistance. Whether insulin resistance is an intermediate step for the development of AF is uncertain. We hypothesized that insulin resistance is associated with an increased risk of incident AF. We examined the association of insulin resistance with incident AF using multivariate Cox proportional hazards regression analysis adjusting for the established AF risk factors (i.e., age, gender, systolic blood pressure, hypertension treatment, PR interval, significant heart murmur, heart failure, and body mass index). Of the 3,023 eligible participants (55% women; mean age 59 years) representing 4,583 person-examinations (Framingham Offspring fifth and seventh examination cycles), 279 participants developed AF (9.3%) within ?10 years of follow-up. With multivariate modeling, insulin resistance was not significantly associated with incident AF (hazard ratio comparing top quartile to other 3 quartiles of homeostatic model assessment index 1.18, 95% confidence interval 0.84 to 1.65, p = 0.34). In a community-based cohort with ?10 years of follow-up, no significant association was observed between insulin resistance and incident AF.
Related JoVE Video
Vitamin D status is not related to development of atrial fibrillation in the community.
Am. Heart J.
PUBLISHED: 03-24-2011
Show Abstract
Hide Abstract
Atrial fibrillation (AF) is common and is an important cause of cardiovascular morbidity and mortality. Vitamin D is an emerging risk factor in cardiovascular disease, and vitamin D status is modifiable. Thus, we sought to investigate whether vitamin D status predisposed to the development of AF in a community-based sample.
Related JoVE Video
A novel clinical prediction rule for 30-day mortality following balloon aortic valuloplasty: the CRRAC the AV score.
Catheter Cardiovasc Interv
PUBLISHED: 03-16-2011
Show Abstract
Hide Abstract
We seek to identify predictors of 30-day mortality after balloon aortic valvuloplasty (BAV).
Related JoVE Video
P wave duration and risk of longitudinal atrial fibrillation in persons ? 60 years old (from the Framingham Heart Study).
Am. J. Cardiol.
PUBLISHED: 01-20-2011
Show Abstract
Hide Abstract
Long-term risk prediction is a priority for the prevention of atrial fibrillation (AF). P wave indices are electrocardiographic measurements describing atrial conduction. The role of P wave indices in the prospective determination of AF and mortality risk has had limited assessment. We quantified by digital caliper the P wave indices of maximum duration and dispersion in 1,550 Framingham Heart Study participants ? 60 years old (58% women) from single-channel electrocardiograms recorded from 1968 through 1971. We examined the association of selected P wave indices and long-term outcomes using Cox proportional hazards regression incorporating age, gender, body mass index, systolic blood pressure, treatment for hypertension, significant murmur, heart failure, and PR interval. Over a median follow-up of 15.8 years (range 0 to 38.7), 359 participants developed AF and 1,525 died. Multivariable-adjusted hazard ratios (HRs) per SD increase in maximum P wave duration were 1.15 (95% confidence interval [CI] 0.90 to 1.47, p = 0.27) for AF and 1.02 (95% CI 0.96 to 1.08, p = 0.18) for mortality. The upper 5% of P wave maximum duration had a multivariable-adjusted HR of 2.51 (95% CI 1.13 to 5.57, p = 0.024) for AF and an HR of 1.11 (95% CI 0.87 to 1.40, p = 0.20) for mortality. We found no significant associations between P wave dispersion with incidence of AF or mortality. In conclusion, maximum P wave duration at the upper fifth percentile was associated with long-term AF risk in an elderly community-based cohort. P wave duration is an electrocardiographic endophenotype for AF.
Related JoVE Video
Genome-wide association studies of the PR interval in African Americans.
PLoS Genet.
PUBLISHED: 01-11-2011
Show Abstract
Hide Abstract
The PR interval on the electrocardiogram reflects atrial and atrioventricular nodal conduction time. The PR interval is heritable, provides important information about arrhythmia risk, and has been suggested to differ among human races. Genome-wide association (GWA) studies have identified common genetic determinants of the PR interval in individuals of European and Asian ancestry, but there is a general paucity of GWA studies in individuals of African ancestry. We performed GWA studies in African American individuals from four cohorts (n?=?6,247) to identify genetic variants associated with PR interval duration. Genotyping was performed using the Affymetrix 6.0 microarray. Imputation was performed for 2.8 million single nucleotide polymorphisms (SNPs) using combined YRI and CEU HapMap phase II panels. We observed a strong signal (rs3922844) within the gene encoding the cardiac sodium channel (SCN5A) with genome-wide significant association (p<2.5 x 10??) in two of the four cohorts and in the meta-analysis. The signal explained 2% of PR interval variability in African Americans (beta ?=?5.1 msec per minor allele, 95% CI ?=?4.1-6.1, p?=?3 x 10?²³). This SNP was also associated with PR interval (beta?=?2.4 msec per minor allele, 95% CI?=?1.8-3.0, p?=?3 x 10?¹?) in individuals of European ancestry (n?=?14,042), but with a smaller effect size (p for heterogeneity <0.001) and variability explained (0.5%). Further meta-analysis of the four cohorts identified genome-wide significant associations with SNPs in SCN10A (rs6798015), MEIS1 (rs10865355), and TBX5 (rs7312625) that were highly correlated with SNPs identified in European and Asian GWA studies. African ancestry was associated with increased PR duration (13.3 msec, p?=?0.009) in one but not the other three cohorts. Our findings demonstrate the relevance of common variants to African Americans at four loci previously associated with PR interval in European and Asian samples and identify an association signal at one of these loci that is more strongly associated with PR interval in African Americans than in Europeans.
Related JoVE Video
Primary prevention of sudden cardiac death in silent cardiac sarcoidosis: role of programmed ventricular stimulation.
Circ Arrhythm Electrophysiol
PUBLISHED: 12-30-2010
Show Abstract
Hide Abstract
Cardiac involvement in sarcoidosis is often silent and may lead to sudden death. This study was designed to assess the value of programmed electric stimulation of the ventricle (PES) for risk stratification in patients with sarcoidosis and evidence of preclinical cardiac involvement on imaging studies.
Related JoVE Video
Monogenic atrial fibrillation as pathophysiological paradigms.
Cardiovasc. Res.
PUBLISHED: 11-30-2010
Show Abstract
Hide Abstract
Atrial fibrillation (AF) is the most common cardiac rhythm abnormality and represents a major burden, both to patients and to health-care systems. In recent years, increasing evidence from population-based studies has demonstrated that AF is a heritable condition. Although familial forms of AF have been recognized for many years, they represent a rare subtype of the arrhythmia. However, despite their limited prevalence, the identification of mutations in monogenic AF kindreds has provided valuable insights into the molecular pathways underlying the arrhythmia and a framework for investigating AF encountered in the general population. In contrast to these rare families, the typical forms of AF occurring in the community are likely to be multigenic and have significant environmental influences. Recently, genome-wide association studies have uncovered common sequence variants that confer increased susceptibility to the arrhythmia. In the future, the elucidation of the genetic substrate underlying both familial and more typical forms of AF will hopefully lead to the development of novel diagnostic tools as well as more targeted rhythm control strategies. In this article, we will focus on monogenic forms of AF and also provide an overview of case-control association studies for AF.
Related JoVE Video
European ancestry as a risk factor for atrial fibrillation in African Americans.
Circulation
PUBLISHED: 11-25-2010
Show Abstract
Hide Abstract
Despite a higher burden of standard atrial fibrillation (AF) risk factors, African Americans have a lower risk of AF than whites. It is unknown whether the higher risk is due to genetic or environmental factors. Because African Americans have varying degrees of European ancestry, we sought to test the hypothesis that European ancestry is an independent risk factor for AF.
Related JoVE Video
Dietary factors and incident atrial fibrillation: the Framingham Heart Study.
Am. J. Clin. Nutr.
PUBLISHED: 11-24-2010
Show Abstract
Hide Abstract
There have been conflicting reported associations between dietary factors and incident atrial fibrillation (AF).
Related JoVE Video
Association between familial atrial fibrillation and risk of new-onset atrial fibrillation.
JAMA
PUBLISHED: 11-13-2010
Show Abstract
Hide Abstract
Although the heritability of atrial fibrillation (AF) is established, the contribution of familial AF to predicting new-onset AF remains unknown.
Related JoVE Video
A common connexin-40 gene promoter variant affects connexin-40 expression in human atria and is associated with atrial fibrillation.
Circ Arrhythm Electrophysiol
PUBLISHED: 11-13-2010
Show Abstract
Hide Abstract
A common single-nucleotide polymorphism (SNP) in the promoter of the Connexin-40 (Cx40) gene GJA5 was suggested to affect Cx40 promoter activity and the risk of atrial fibrillation (AF), but the role of other common Cx40 polymorphisms is unknown.
Related JoVE Video
P-wave indices: derivation of reference values from the Framingham Heart Study.
Ann Noninvasive Electrocardiol
PUBLISHED: 10-16-2010
Show Abstract
Hide Abstract
P-wave indices, an electrocardiographic phenotype reflecting atrial electrophysiology and morphology, may be altered in multiple disease states or by cardiovascular risk factors. Reference values for P-wave indices, providing cut points for their classification and interpretation, have not yet been established and are essential toward facilitating clinical application and comparison between studies.
Related JoVE Video
Challenges in the classification of atrial fibrillation.
Nat Rev Cardiol
PUBLISHED: 06-22-2010
Show Abstract
Hide Abstract
The incidence and prevalence of atrial fibrillation (AF) are increasing worldwide. AF is of public health importance because it accounts for substantial morbidity, mortality, and health-care costs. AF may be transient initially, but many patients have progressive disease marked by increasing frequency and duration of episodes. Various classification schemes for AF have been proposed, although current guidelines are based on temporal rhythm-based patterns. We discuss existing schemes for the classification of AF, focusing on the advantages and limitations of the pattern-based scheme, in the context of new knowledge about AF pathophysiology, AF patterns, and clinical outcomes. Furthermore, we address gaps in knowledge that present opportunities to re-examine the current pattern-based classification of AF. A future classification scheme should ideally combine elements such as the risk of stroke, an assessment of symptoms, and the degree of impairment of the atrial substrate.
Related JoVE Video
Evaluation of non-synonymous NPPA single nucleotide polymorphisms in atrial fibrillation.
Europace
PUBLISHED: 06-12-2010
Show Abstract
Hide Abstract
Atrial fibrillation (AF), the most common sustained cardiac arrhythmia, is an important cause of morbidity and mortality. A genetic mutation in the NPPA gene, which encodes the atrial natriuretic peptide, has been identified as the putative causative factor in a family with an autosomal dominant pattern of inheritance for AF. Two common single nucleotide polymorphisms (SNPs) in NPPA, rs5063 and rs5065, result in amino acid changes of the primary peptide and have been previously implicated in conditions associated with AF, including stroke and hypertension. Recently, the rs5063 SNP has been reported to confer an increased risk of AF development in a Chinese population. We sought to examine the associations of both rs5063 and rs5065 with AF in two separate North American cohorts of European ancestry.
Related JoVE Video
Genetics of atrial fibrillation.
Heart Fail Clin
PUBLISHED: 03-30-2010
Show Abstract
Hide Abstract
Recent studies of atrial fibrillation (AF) have identified mutations in a series of ion channels; however, these mutations appear to be relatively rare causes of AF. A genome-wide association study has identified novel variants on chromosome 4 associated with AF, although the mechanism of action for these variants remains unknown. Ultimately, a greater understanding of the genetics of AF should yield insights into novel pathways, therapeutic targets, and diagnostic testing for this common arrhythmia.
Related JoVE Video
Atrial fibrillation in congestive heart failure.
Heart Fail Clin
PUBLISHED: 03-30-2010
Show Abstract
Hide Abstract
Atrial fibrillation and congestive heart failure are morbid conditions that have common risk factors and frequently coexist. Each condition predisposes to the other, and the concomitant presence of the two identifies individuals at increased risk for mortality. Recent data have emerged that help elucidate the complex genetic and nongenetic pathophysiological mechanisms that contribute to the development of atrial fibrillation in individuals with congestive heart failure. Clinical trial results offer insights into the noninvasive prevention and management of these conditions, although newer technologies, such as catheter ablation for atrial fibrillation, have yet to be studied extensively in patients with congestive heart failure.
Related JoVE Video
Effectiveness of cardiac resynchronization therapy in mild congestive heart failure: systematic review and meta-analysis of randomized trials.
Eur. J. Heart Fail.
PUBLISHED: 03-26-2010
Show Abstract
Hide Abstract
Cardiac resynchronization therapy (CRT) improves echocardiographic parameters, symptoms, hospitalizations, and mortality in patients with New York Heart Association (NYHA) Class III or IV symptoms with left ventricular systolic dysfunction, sinus rhythm, and a prolonged QRS duration. The effectiveness of CRT in patients with mild heart failure symptoms has not been systematically reviewed.
Related JoVE Video
Genome-wide association studies in cardiac electrophysiology: recent discoveries and implications for clinical practice.
Heart Rhythm
PUBLISHED: 03-17-2010
Show Abstract
Hide Abstract
Genome-wide association studies have been increasingly used to study the genetics of complex human diseases. Within the field of cardiac electrophysiology, this technique has been applied to conditions such as atrial fibrillation, and several electrocardiographic parameters including the QT interval. While these studies have identified multiple genomic regions associated with each trait, questions remain, including the best way to explore the pathophysiology of each association and the potential for clinical utility. This review will summarize recent genome-wide association study results within cardiac electrophysiology and discuss their broader implications in basic science and clinical medicine.
Related JoVE Video
Common variants in KCNN3 are associated with lone atrial fibrillation.
Nat. Genet.
PUBLISHED: 01-22-2010
Show Abstract
Hide Abstract
Atrial fibrillation (AF) is the most common sustained arrhythmia. Previous studies have identified several genetic loci associated with typical AF. We sought to identify common genetic variants underlying lone AF. This condition affects a subset of individuals without overt heart disease and with an increased heritability of AF. We report a meta-analysis of genome-wide association studies conducted using 1,335 individuals with lone AF (cases) and 12,844 unaffected individuals (referents). Cases were obtained from the German AF Network, Heart and Vascular Health Study, the Atherosclerosis Risk in Communities Study, the Cleveland Clinic and Massachusetts General Hospital. We identified an association on chromosome 1q21 to lone AF (rs13376333, adjusted odds ratio = 1.56; P = 6.3 x 10(-12)), and we replicated this association in two independent cohorts with lone AF (overall combined odds ratio = 1.52, 95% CI 1.40-1.64; P = 1.83 x 10(-21)). rs13376333 is intronic to KCNN3, which encodes a potassium channel protein involved in atrial repolarization.
Related JoVE Video
Lack of replication in polymorphisms reported to be associated with atrial fibrillation.
Heart Rhythm
PUBLISHED: 01-21-2010
Show Abstract
Hide Abstract
Atrial fibrillation (AF) is the most common sustained arrhythmia and has a substantial heritable component. Numerous associations between single nucleotide polymorphisms (SNPs) and AF have been described, but few have been replicated.
Related JoVE Video
Genome-wide association study of PR interval.
Nat. Genet.
PUBLISHED: 01-10-2010
Show Abstract
Hide Abstract
The electrocardiographic PR interval (or PQ interval) reflects atrial and atrioventricular nodal conduction, disturbances of which increase risk of atrial fibrillation. We report a meta-analysis of genome-wide association studies for PR interval from seven population-based European studies in the CHARGE Consortium: AGES, ARIC, CHS, FHS, KORA, Rotterdam Study, and SardiNIA (N = 28,517). We identified nine loci associated with PR interval at P < 5 x 10(-8). At the 3p22.2 locus, we observed two independent associations in voltage-gated sodium channel genes, SCN10A and SCN5A. Six of the loci were near cardiac developmental genes, including CAV1-CAV2, NKX2-5 (CSX1), SOX5, WNT11, MEIS1, and TBX5-TBX3, providing pathophysiologically interesting candidate genes. Five of the loci, SCN5A, SCN10A, NKX2-5, CAV1-CAV2, and SOX5, were also associated with atrial fibrillation (N = 5,741 cases, P < 0.0056). This suggests a role for common variation in ion channel and developmental genes in atrial and atrioventricular conduction as well as in susceptibility to atrial fibrillation.
Related JoVE Video
CYP2C9*8 is prevalent among African-Americans: implications for pharmacogenetic dosing.
Pharmacogenomics
PUBLISHED: 08-12-2009
Show Abstract
Hide Abstract
Although the frequencies of pharmacogenetic variants differ among racial groups, most pharmacogenetic algorithms for genotype-guided warfarin dosing only include two CYP2C9 alleles (*2 and *3) and a single VKORC1 allele (g.-1639G>A or g.1173C>T) commonly found among Caucasians. Therefore, this study sought to identify other CYP2C9 and VKORC1 alleles important in warfarin dose variability and to determine their frequencies in different racial and ethnic groups.
Related JoVE Video
Genetics of atrial fibrillation.
Cardiol Clin
PUBLISHED: 04-08-2009
Show Abstract
Hide Abstract
Recent studies of AF have identified mutations in a series of ion channels; however, these mutations appear to be relatively rare causes of AF. A genome-wide association study has identified novel variants on chromosome 4 associated with AF, although the mechanism of action for these variants remains unknown. Ultimately, a greater understanding of the genetics of AF should yield insights into novel pathways, therapeutic targets, and diagnostic testing for this common arrhythmia.
Related JoVE Video
Variants in ZFHX3 are associated with atrial fibrillation in individuals of European ancestry.
Nat. Genet.
PUBLISHED: 01-21-2009
Show Abstract
Hide Abstract
We conducted meta-analyses of genome-wide association studies for atrial fibrillation (AF) in participants from five community-based cohorts. Meta-analyses of 896 prevalent (15,768 referents) and 2,517 incident (21,337 referents) AF cases identified a new locus for AF (ZFHX3, rs2106261, risk ratio RR = 1.19; P = 2.3 x 10(-7)). We replicated this association in an independent cohort from the German AF Network (odds ratio = 1.44; P = 1.6 x 10(-11); combined RR = 1.25; combined P = 1.8 x 10(-15)).
Related JoVE Video
Personalized medicine and atrial fibrillation: will it ever happen?
BMC Med
Show Abstract
Hide Abstract
Atrial fibrillation (AF) is a common arrhythmia of substantial public health importance. Recent evidence demonstrates a heritable component underlying AF, and genetic discoveries have identified common variants associated with the arrhythmia. Ultimately one hopes that the consideration of genetic variation in clinical practice may enhance care and improve health outcomes. In this review we explore areas of potential clinical utility in AF management including those relating to pharmacogenetics and risk prediction.
Related JoVE Video
Low serum magnesium and the development of atrial fibrillation in the community: the Framingham Heart Study.
Circulation
Show Abstract
Hide Abstract
Low serum magnesium has been linked to increased risk of atrial fibrillation (AF) after cardiac surgery. It is unknown whether hypomagnesemia predisposes to AF in the community.
Related JoVE Video
Novel loci associated with PR interval in a genome-wide association study of 10 African American cohorts.
Circ Cardiovasc Genet
Show Abstract
Hide Abstract
The PR interval, as measured by the resting, standard 12-lead ECG, reflects the duration of atrial/atrioventricular nodal depolarization. Substantial evidence exists for a genetic contribution to PR, including genome-wide association studies that have identified common genetic variants at 9 loci influencing PR in populations of European and Asian descent. However, few studies have examined loci associated with PR in African Americans.
Related JoVE Video
Meta-analysis identifies six new susceptibility loci for atrial fibrillation.
Nat. Genet.
Show Abstract
Hide Abstract
Atrial fibrillation is a highly prevalent arrhythmia and a major risk factor for stroke, heart failure and death. We conducted a genome-wide association study (GWAS) in individuals of European ancestry, including 6,707 with and 52,426 without atrial fibrillation. Six new atrial fibrillation susceptibility loci were identified and replicated in an additional sample of individuals of European ancestry, including 5,381 subjects with and 10,030 subjects without atrial fibrillation (P < 5 × 10(-8)). Four of the loci identified in Europeans were further replicated in silico in a GWAS of Japanese individuals, including 843 individuals with and 3,350 individuals without atrial fibrillation. The identified loci implicate candidate genes that encode transcription factors related to cardiopulmonary development, cardiac-expressed ion channels and cell signaling molecules.
Related JoVE Video
Age of natural menopause and atrial fibrillation: the Framingham Heart Study.
Am. Heart J.
Show Abstract
Hide Abstract
Early menopausal age is associated with risk of cardiovascular events including myocardial infraction, stroke, and increased mortality. Relations between menopausal age and atrial fibrillation (AF) have not been investigated. We examined the association between menopausal age and AF.
Related JoVE Video

What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.