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ISSN: 1747-0862
Journal of Molecular and Genetic Medicine
The International Open Access
Journal of Molecular and Genetic Medicine
Special Issue Title:
Molecular & Cellular Aspects in Obesity
and Diabetes
Handling Editor
Masayoshi Yamaguchi
Emory University School of Medicine, USA
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Digital Object Identier: http://dx.doi.org/10.4172/1747-0862.S1-006
Research Article Open Access
Mozos, J Mol Genet Med 2014, S1
http://dx.doi.org/10.4172/1747-0862.S1-006
Review Article Open Access
Molecular and Genetic Medicine
J Mol Genet Med ISSN: 1747-0862 JMGM, an open access journal Molecular & Cellular Aspects in Obesity and Diabetes
*Corresponding author: Ioana Mozos, M.D., Ph.D., Associate Professor,
Department of Functional Sciences, “Victor Babes” University of Medicine
and Pharmacy, T. Vladimirescu Str. 14, 300173, Timisoara, Romania, Tel:
+40745610004; E-mail: ioanamozos@yahoo.de
Received November 20, 2013; Accepted December 26, 2013; Published January
01, 2014
Citation: Mozos I (2014) Arrhythmia Risk and Obesity. J Mol Genet Med S1: 006.
doi: 10.4172/1747-0862.S1-006
Copyright: © 2014 Mozos I. This is an open-access article distributed under the
terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original author and
source are credited
Arrhythmia Risk and Obesity
Ioana Mozos*
Department of Functional Sciences, “Victor Babes” University of Medicine and Pharmacy, Timisoara, Romania
Keywords: Obesity; Cardiac arrhythmias; Atrial brillation;
Ventricular arrhythmia; QT interval; Late ventricular potentials;
Sudden cardiac death; Electrocardiography; Pathophysiology; Body
mass index; Obstructive sleep apnea; Inammation; Oxidative stress
Introduction
Overweight and obesity are dened, according to the World Health
Organization as abnormal or excessive fat accumulation. A person with
a body mass index (BMI) between 25 and 29,9 kg/m² is considered
overweight, and with a BMI of 30 kg/m² or more obese [1]. Obesity
has reached epidemic proportions, its prevalence continues to increase
worldwide and cardiovascular disease dominates the mortality and
morbidity in obese patients [2,3]. e most rapidly growing segment
of the obese population is the severely obese, with a BMI of 40 kg/m²
or more [4].
Obesity is a cardiovascular risk factor and is signicantly associated
with hypertension, coronary heart disease, cardiac arrhythmias, heart
failure, diabetes mellitus and dyslipidemia [2,5,6]. In obese and
overweight individuals, the cardiac structure and function change
as a consequence of an increased in total plasma and blood volume,
with subsequent increase in le ventricular lling and cardiac
output, causing le ventricular hypertrophy, le atrium and right
ventricular hypertrophy, and the peripheral resistance is decreased
[5,7-9]. Cardiomyopathy of obesity includes increased ventricular
mass and chamber size, hypoplastic coronary arteries and severe
coronary atherosclerosis [10]. e increased abdominal mass impairs
the function of the diaphragm, reducing oxygen supply and enabling
arrhythmia and sudden cardiac death [11]. Hypoxia can cause
pulmonary vasoconstriction, pulmonary hypertension and right heart
failure [11]. Despite higher prevalence of cardiovascular pathology
with excessive fat, a survival advantage has been also described in obese
patients with heart failure, hypertension, myocardial infarction or
peripheral arterial disease: “the obesity paradox” [3,9].
ere are multiple mechanisms linking obesity to cardiovascular
pathology, including the cardiometabolic consequences of obesity,
accelerated atherosclerosis, altered release of adipokines and chemical
mediators, promoting a proinammatory and prothrombotic state,
neurohormonal activation with increased sympathetic tone, endothelial
dysfunction, increased arterial stiness, le ventricular hypertrophy,
hemodynamic alterations, altered cardiomyocyte electrical properties,
obesity-related cardiomyopathy, inltration of fat into the myocardium
and coronary artery calcication [5,6,8,9,12,13].
Obesity increases the risk of arrhythmias. e most commonly noted
arrhythmias include sinus arrhythmia, premature atrial and ventricular
contractions, atrial brillation, ventricular and supraventricular
tachycardia [5]. Cardiac arrhythmias may be precipitated in obese by
several factors, including: hypoxia, hypercapnia, electrolyte imbalances
due to diuretic therapy, coronary heart disease, increased circulating
catecholamines, obstructive sleep apnea, le ventricular hypertrophy,
and fatty inltration of the conduction system [2].
e present review focuses on the mechanisms linking overweight
and obesity with cardiac arrhythmias and provides a brief review of the
latest studies in this area.
Atrial Arrhythmias and Obesity
Premature atrial contractions
Premature atrial contractions (PAC) are independent predictors of
Abstract
Obesity is a known cardiovascular risk factor and it increases the risk of cardiac arrhythmias and sudden cardiac
death. The most commonly reported arrhythmias are atrial brillation and ventricular tachycardia.
The present review focuses on the mechanisms linking overweight and obesity with cardiac arrhythmias and
provides a brief review of the latest studies in this area.
Obesity is one of the very few identied modiable risk factors for the occurrence and progression of atrial
brillation, and the mechanisms linking atrial brillation and obesity include: structural and electrophysiological atrial
remodeling, metabolic factors, sympatho-vagal imbalance, clinical links (obstructive sleep apnea, cardiovascular
comorbidities) and inammation.
The main mechanisms leading to ventricular arrhythmia and sudden cardiac death in obese individuals include
cardiomyopathy, metabolic factors, sympathetic hyperinnervation, obesity-induced electrophysiological remodeling,
coronary heart disease as common comorbidity and radical weight reduction strategies.
Electrocardiographic monitoring, including P wave and QT interval duration, are extremely important in obese
patients. Weight control may be an effective strategy for reducing the burden of cardiac arrhythmias and sudden
cardiac death.
Citation: Mozos I (2014) Arrhythmia Risk and Obesity. J Mol Genet Med S1: 006. doi: 10.4172/1747-0862.S1-006
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atrial brillation and stroke, and were associated with several factors,
including age, height, history of cardiovascular disease, natriuretic
peptide levels, but not body mass index [14]. e metabolic syndrome,
a cluster of atherosclerotic risk factors, including central obesity, was
associated with an increased number of extrasystoles, supraventricular
tachyarrhythmias, sinus node arrest and atrial brillation [15-17].
Signicant correlations were found between arrhythmias and the
number of components of the metabolic syndrome, demonstrating a
cause-eect relationship [15].
Sinus arrhythmias
Sinus arrhythmias are frequent in obese patients, especially sinus
bradycardia [18]. Prolonged sinus pauses were revealed by 24-hour
ECG monitoring in a patient with Prader-Willi syndrome, requiring
pacemaker insertion [19]. e Prader-Willi syndrome is a rare genetic
syndrome, resulting from an abnormality in chromosome 15, and is
characterized by severe childhood obesity, short stature, behavioral
disturbances, intellectual disability, and severe hyperphagia [19].
e patients are at increased risk of sudden death, and elevated
inammatory markers, premature atherosclerosis, increased systolic
blood pressure and abnormal microcirculatory responses, could have
an important contribution [19,20].
Atrial brillation
Atrial brillation is the most common sustained arrhythmia in
clinical practice, and is associated with an increased risk of ischemic
stroke, heart failure, systemic embolism, cognitive dysfunction,
dementia, diminished quality of life and exercise capacity, and death
[16,21-27]. e classic risk factors for atrial brillation include
hypertension, valvular disease, cardiomyopathy, male sex, aging, thyroid
disease and diabetes mellitus [22,28,29]. e increasing incidence of
atrial brillation is due to advancing age of the population, a better
survival of individuals with structural heart disease and the current
obesity epidemics [12,25]. Aging increases the risk of developing atrial
brillation through age-dependent structural and electrophysiological
characteristics [22,30]. e majority of patients with atrial brillation
suer from a cardiovascular disorder (substrate related), which may
have an additive eect on the perpetuation of the arrhythmia [22,26],
but there are some patients with “lone” atrial brillation, without
an underlying cardiovascular disorder [28]. Patients with lone atrial
brillation have normal life expectancy, a low risk of stroke, and rarely
progress to persistent or permanent atrial brillation [28].
Several studies demonstrated the link between obesity and atrial
brillation [31,32], but earlier reports did not support this association
[33,34].
Wanahita et al. [31] found a risk of developing atrial brillation up
to 50% in overweight and obese. e mechanisms linking obesity and
atrial brillation are complex, including atrial remodeling, increased
activity in the conduction system of the heart, electrophysiological
remodeling of the le atrium, neurohormonal activation, an
increased sympathetic activity, elevated plasma volume, increasing
le ventricular diastolic lling pressure, metabolic factors (insulin
resistance, dyslipidemia, free fatty acids, reactive oxygen species),
mechanical eects (raised intrathoracic pressures and obstructive sleep
apnea), increased arterial stiness, genetic predisposition and gene-
environment interactions [6,8,16,21,25,27,29,34-37] (Figure 1).
Increased le atrial pressure may increase atrial ectopy, triggering
atrial brillation [36]. Atrial remodeling is characterized by changes in
ion channel function, calcium homeostasis, and atrial structure, such
as cellular hypertrophy, activation of broblasts and subsequent tissue
brosis, enabling the occurrence of “triggers” for atrial brillation and
the formation of a “substrate” for atrial brillation that promotes its
perpetuation [30]. Increased le atrial pressure and volume, shortened
eective refractory period in the le atrium and pulmonary vein may
facilitate atrial brillation in obese patients [38]. Prolonged BMI
– mediated le atrial stretch was associated with the development
of brosis [34]. ere are several clinical links between obesity and
atrial brillation, including hypertension, macro- and microvascular
ischemia, impaired coronary perfusion and obstructive sleep apnea
[27]. A high fat diet, even in the absence of obesity, increases the
sympathetic activity, enabling arrhythmic events [39].
Tsang et al. [34] found obesity as a risk factor for progression of
paroxysmal to permanent atrial fibrillation, depending on the left
atrial size.
Watanabe et al. [16] demonstrated an increased risk for the
development of atrial brillation in patients with metabolic syndrome.
Most of the components of the metabolic syndrome were related to
the development of atrial brillation. Inammation, oxidative and
mechanical stress and enlargement of the atrium, loss of muscle mass,
brosis and spatial remodeling of gap junctions have been proposed as
factors linking the components of the metabolic syndrome and atrial
brillation [16,40-42].
Nicolaou et al. [21] reported a greater risk for progression of
atrial brillation in obese elderly women due to the enlarged atrium.
e combination aging-obesity increases sympathetic activity and
angiotensin II production, which increased blood pressure and aects
le atrial remodeling and the onset of atrial brillation, through the
association with le ventricular hypertrophy and subclinical diastolic
dysfunction, which aects the size and function of both atria and
ventricles [21,27,43-45].
Abed and Wittert [35] mentioned atrial electro-structural
dysfunction enabled by obesity-related risk factors, such as
hypertension, vascular disease, obstructive sleep apnea, insulin
resistance and pericardial fat. Atrial brillation risk was associated not
only with pericardial, but also with systemic and regional epicardial
adiposity [27]. e eect of epicardial fat was independent of BMI and
other known risk factors for atrial brillation [46].
Li et al. [26] reported an increased risk of atrial brillation in
patients with myocardial infarction, le ventricular hypertrophy,
obesity and alcohol consumption in a Chinese population, but a lower
prevalence compared to European studies.
Atrial brillation is the most common arrhythmia in women, as
well. Obesity was associated with atrial brillation in postmenopausal
Figure 1: Pathophysiological links between obesity and atrial brillation.
Citation: Mozos I (2014) Arrhythmia Risk and Obesity. J Mol Genet Med S1: 006. doi: 10.4172/1747-0862.S1-006
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women [47], among fertile young women [25,29], in pregnant
women with a history of atrial brillation, and in female health care
professionals without cardiovascular history [48]. Karasoy et al. [29]
reported a strong relationship between obesity and new-onset atrial
brillation, especially lone atrial brillation, in young, fertile women.
Hemodynamic changes associated with pregnancy and delivery
and electrophysiological phenomena may play an important role in
developing lone atrial brillation [28,29].
Early life factors may be involved in the pathogenesis of atrial
brillation and obesity among individuals with a low birth weight
[49,50]. A signicant part of the association between birth weight and
atrial brillation is mediated through height and cumulative exposure
to elevated body mass, and lower birth weight protects the atria against
brillation in adults [50]. Genetic or environmental intrauterine factors
may “program” adult body mass, le atrial size and subsequent atrial
brillation risk [50]. Genome studies on patients with atrial brillation
emphasized the importance of genes related to atrial brillation,
especially PITX2, on chromosome 4q25, for the development of the le
atrium, and ZFHX3, in growth regulation of several tissues [50].
Obesity was associated with an increased atrial brillation
risk in community- and population-based cohort studies, and in
cardiothoracic surgery cohorts, independent of type of cardiac surgery
[27,51]. Body mass index was included, as an atrial brillation risk
factor, in multiple risk scores, including the Framingham Heart Study
10-year AF risk calculator [27].
e Atrial brillation Follow-up Investigation of Rhythm
Management Study (AFFIRM) demonstrated better outcomes (lower
all-cause and cardiovascular mortality) in obese patients with atrial
brillation than in lean, concluding that an obesity paradox exists for
outcomes in obese patients with atrial brillation [52].
P wave indices, derived from the surface ECG, include P-wave
duration, morphology and amplitude, may assess atrial electric
function, progressively altered by obesity [27,53]. P wave dispersion,
the dierence between maximum and minimum P wave duration,
an electrocardiographic marker for the prediction of atrial
brillation, was increased in obese women [53]. e most important
electrocardiographic markers of atrial remodeling and prolongation of
atrial conduction time are: an increased maximum P wave duration
in the standard, 12-lead electrocardiogram and long signal-averaged P
wave duration [54].
Adipose tissue itself may be directly involved in the pathogenesis
of cardiovascular disease, considering that obesity has been associated
with generalized enlargement of fat depots, involved in the production
of pro-inammatory cytokines and reactive oxygen species and
uncontrolled release of fatty acids [8,55]. Cardiac adiposity is
characterized by an increase in intramyocardial triglyceride content
and an enlargement of the fat tissue surrounding the heart and vessels,
which can lead to myocardial damage [55]. Fatty acid inltration and
overload promotes fatty acid oxidation, accumulation of triglycerides
and metabolites which can impair calcium signaling, beta-oxydation
and glucose utilization, damage mitochondrial function with increased
production of reactive species, proapoptotic and inammatory
molecules [55]. Fatty inltration or “fatty metamorphosis” can induce
abnormal automaticity from degenerated myocardial cells [56].
Several biomarkers have been identied as a link between obesity
and atrial brillation, including inammatory markers, adipocytokines,
pericardial and epicardial fat, and atrial tissue [27,57,58]. Obesity is an
established inammatory condition [59], and adipocytes enable local
inammation through adipocytokines and proinammatory cytokines
[60]. Inammation, measured by plasma levels of high sensitivity
C reactive protein, brinogen and soluble intracellular adhesion
molecule-1, was signicantly associated with the risk of incident atrial
brillation in healthy, middle-aged women, free of cardiovascular
disease [58]. Various other inammatory markers have been associated
with atrial brillation, including tumor necrosis factor alpha, interleukin
2, 6 and 8 [24]. Inammatory inltrates, myocyte necrosis, and brosis
have been found in atrial biopsies of patients with atrial brillation
[61,62]. Chronic inammation may induce electrophysiological and
structural changes in the atrial myocardium predisposing patients with
triggering atrial foci to atrial brillation [63]. Proposed mechanisms
linking inammation and atrial brillation include endothelial
dysfunction, production of tissue factor from monocytes, increased
platelet activation, and increased expression of brinogen [24]. It is
still not clear if inammatory markers elevation is a consequence or a
cause of atrial brillation [23,58]. Probably preexisting inammation
initiates the arrhythmia that subsequently propagates an inammatory
response, enabling persistence of atrial brillation [23]. C-reactive
protein has been shown to decrease cardiac contractility [64]. On the
other hand, it was suggested that inammation is not a major mediator
of the atrial brillation risk associated with obesity [48].
Adiponectin is one of the adipocytokines secreted by the adipose
tissue, both a biomarker and a possibly mediator of cardiovascular
disease, with antiatherogenic, antidiabetic and antiinammatory
properties, able to inuence the extent of atrial and le ventricular
remodeling, which can increase cardiac contractility and action potential
duration by inhibiting delayed rectier potassium currents [59,60,65].
Higher adiponectin levels were detected in patients with chronic atrial
brillation than in paroxysmal atrial brillation, correlated with a
collagen type I degradation marker, demonstrating that adiponectin
is a useful marker of atrial remodeling [65]. Activation of broblasts
and subsequent brosis contribute to atrial structural remodeling and
heterogeneity of the cardiac conduction tissue [56,60,65].
Epicardial fat tissue modulates atrial electrophysiological
and contractive properties, through inammatory cytokines,
adipocytokines and adipocyte-cardiomyocyte interactions, and heart
failure epicardial fat has a greater arrhythmogenic eect on the le
atrium, prolonging action potential duration [66]. Epicardial adipose
tissue was also suggested to be involved in the maintenance of atrial
brillation [67]. e right atrium is more resistant to hypoxia/
reoxygenation than the le atrium, due to higher heat shock proteins
[68]. Several experiments showed that epicardial adipocytes modulate
atrial cardiac ionic currents with decrease of delayed rectier inward
and outward currents and increase of late sodium currents and L-type
calcium currents [69].
Future research should focus on the relation between atrial
brillation and adiposity phenotypes, gene-environment interactions,
obesity years, childhood obesity, increased risk due to comorbidities,
weight loss, atrial remodeling and reverse remodeling, mechanisms
of resolution of atrial brillation and new biomarkers [23,27].
Electrocardiographic monitoring is extremely important in obese
patients, considering that a substantial proportion of atrial brillation
episodes are asymptomatic.
Ventricular Arrhythmias and Obesity
Patients with morbid obesity have high rates of sudden cardiac
death (SCD), before the development of heart disease [70-72]. SCD
is more common in obese persons than in lean individuals, although
Citation: Mozos I (2014) Arrhythmia Risk and Obesity. J Mol Genet Med S1: 006. doi: 10.4172/1747-0862.S1-006
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progression to heart failure may be the most common cause of death
in patients with obesity-associated cardiomyopathy [6,12,13]. Obesity
was an important comorbidity in SCD patients with structurally normal
hearts [73]. e main mechanisms leading to arrhythmia and SCD in
obese include cardiomyopathy, with myocyte hypertrophy, abnormal
cardiomyocyte lipid deposits, lipotoxicity of the myocardium induced
by free fatty acids, cardiac brosis and mononuclear cell inltration,
and obesity-induced electrophysiological remodeling, myocardial
infarction, le ventricular hypertrophy, impaired connexins,
sympathetic hyperinnervation and parasympathetic withdrawal [13,72-
77] (Figure 2). Fatty inltration separates the myocardial bundles and
disrupts their parallel orientation, impairing ventricular activation and
resulting in heterogeneous repolarization [72].
Obesity is a known risk factor for coronary heart disease and
myocardial infarction, due to the association with other cardiovascular
risk factors [78-80]. Ischemia/reperfusion injury enabled scar
expansion and inadequate brosis in obese rats and mice [74-76].
Feeding rats a high calorie diet resulted not only in increased body
weight, visceral fat content, plasma insulin, nonesteried free fatty
acids and triglycerides, but also in cardiac hypertrophy [75]. Myocyte
hypertrophy may lead to le ventricular hypertrophy in “healthy”
obese rats aer high-fat diet [7]. e fatty acid milieu causes structural
and functional changes in the heart of obese [7].
Hearts of female rats fed a high-fat diet were associated with
arrhythmias and an impaired reparative brotic response following
an ischemic insult, due to sympathetic hyperinnervation and impaired
gap junction proteins, despite a nonsignicant increase in body weight,
a normal plasma lipid prole [76].
Increased intracellular lipid content can impair repolarization due
to a decrease in potassium channel protein levels, causing ventricular
tachycardia and sudden cardiac death [13]. Adipocytokines from
epicardial fat signicantly decrease delayed rectier outward currents in
cardiomyocytes, prolonging action potential duration and facilitating
triggered activity with early aer depolarizations [81].
Obese patients have an increased frequency of premature
ventricular contractions compared to healthy controls, unrelated to
hypertension or concentric ventricular hypertrophy [13,82].
Besides changes in P wave and PR interval, several other
electrocardiographic changes may occur in obese individuals,
including an increased heart rate, prolonged QT interval and QRS
complex duration, increased QT dispersion, modied QRS voltage,
STT abnormalities, multiple electrocardiographic criteria for le
ventricular hypertrophy, attening of the T waves and leward shis
of the P wave, QRS and T wave axes [4,18,83-85]. Many of these ECG
abnormalities are reversible with substantial weight loss [84].
Obese individuals have a faster heart rate and reduced heart rate
variability due to abnormalities in sympatho-vagal balance, factors
associated with an increased risk of myocardial infarction and sudden
cardiac death [3,12].
erapy of ventricular arrhythmias in obese patients includes
ICD and pacemaker implantation, chronic optimal medical therapy,
programmed weight reduction [85]. Food-, plant- and drug-based
therapies for weight loss have, lately, gained great attention [86].
Several ventricular arrhythmias and SCD were reported due to weight
loss pills in young women [86-88]. Sibutramine, an oral anorexiant,
prolongs the QT interval and causes a reversible cardiomyopathy,
ventricular brillation and cardiac arrest, and was withdrawn from
the market worldwide [89,90]. Potassium loss due to diuretics can
prolong the QT interval and cause serious arrhythmias [90]. Clinicians
prescribing weight loss pills should consider the cardiovascular prole
and monitor their patients for ECG abnormalities.
e QT Interval and QT Dispersion in Obese
Weight gain delays cardiac repolarization, and several studies
reported prolonged QT intervals in obese patients, including persons
with uncomplicated obesity and abdominal fat deposition [13,52,91-
96]. Other studies, conducted in patients with uncomplicated obesity,
reported no eect of weight gain on cardiac repolarization [97].
e dierences between the outcomes of the studies may be due to
heterogeneity of study populations, dierent QT interval measurement
techniques and measurement errors [52].
Prolonged heart rate corrected QT interval (QTc) correlated with
body mass index, waist circumference, waist-to-hip ratio, and obese
patients with glucose intolerance and hyperinsulinemia are more likely
to have a prolonged QT interval [93,94,96,98]. e correlation between
QTc and waist circumference was stronger than the one between
QTc and body mass index, indicating that abdominal obesity is a
more important predictor of cardiac risk than BMI in obese patients
[96]. e prolonged QT interval was associated with an increased
sympathetic and decreased parasympathetic tone in obese patients
[6]. Insulin resistance and decreased serum HDL cholesterol were
risk factors for QTc prolongation in obese children [99]. Patients
with uncomplicated metabolic syndrome had a greater dispersion of
ventricular repolarization time and increased maximal and minimal
QTc [100].
e QTc interval correlated with free fatty acid level in normal
subjects and obese women, and fatty inltration can increase
dispersions of action potential duration, increasing the possibility
of reentry circuits [81,93,101]. Corbi et al. [93] found a signicant
relationship between QTc intervals, waist-to-hip ratio, plasma free
fatty acids, epinephrine and norepinephrine concentrations, suggesting
autonomic nervous system dysfunction as a possible mechanism of
the prolonged QTc intervals in visceral obesity. Elevated plasma free
fatty acid level has a stimulatory eect on the sympathetic nervous
system [102]. QT dispersion in nonapneic simple snoring, overweight
adults was signicantly increased [95]. An increased QT dispersion in
obese women was associated with le ventricular hypertrophy and late
ventricular potentials [103].
QT interval prolongation in obese patients is related to the
functional and structural changes in the heart, metabolic factors
Figure 2: Pathophysiological links between obesity and sudden cardiac death.
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including hyperinsulinemia, glucose intolerance, free fatty acids,
decreased HDL cholesterol, autonomic dysfunction, fatty inltration
and comorbidities [52,93,99,101].
Body mass index did not aect overall QT duration, but QT
dispersion was signicantly higher in normal-weight coronary patients
than in obese [98]. On the other hand, intraventricular conduction was
aected in obese patients with an old myocardial infarction [11].
Reduction of body weight in obese women resulted in signicant
shortening of the QTc interval and QT dispersion, correlated with
reduction in plasma free fatty acid concentration [93] and regression
of le ventricular hypertrophy [104]. Shortening of the QT interval
and cardiac parasympathetic activity increase, may reduce the risk of
potentially fatal arrhythmias and sudden death [93]. Sleeve gastrectomy
in morbidly obese patients was associated with QT interval shortening
3 months aer surgery [105].
QT prolongation, cardiac arrhythmias and sudden deaths have been
reported among dieters using very low energy diets, recommending
regular inpatient electrocardiographic monitoring for obese patients
on therapeutic starvation [106].
Late Ventricular Potentials in Obese
Late ventricular potentials are high frequency, low amplitude
signals, appearing in the terminal part of the QRS complex, obtained
using signal averaged ECG [77]. According to an international
convention, late ventricular potentials are present, if 2 of the following
criteria are positive: SAECG-QRS duration >120 ms, low amplitude
signal: LAS40 (duration of the terminal part of the QRS complex with
an amplitude below 40 μV>38 ms, and the root mean square signal
amplitude of the last 40 ms of the signal <20 μV (RMS40) [107].
Several studies reported late ventricular potentials in obese
patients [72,92,108]. e presence of late ventricular potentials in
obese individuals could be secondary to changes in obesity-associated
cardiomyopathy, including brosis, fat and mononuclear cell
inltration and myocyte hypertrophy [12,109].
Late ventricular potentials are aected by body size and le
ventricular mass [108]. Masui et al. [108] reported no correlation
between QRS duration and root mean square voltage with body
weight and body mass index, sum of skin folds or le ventricular mass.
Positive linear correlations were found between low amplitude signals
and weight, body mass index, sum of skin folds [108]. Subadipose
tissue may prolong low amplitude signals by attenuation of the QRS
complex, suggesting that low amplitude signals are inappropriate for
the denition of positive late ventricular potentials in obese persons
[108].
Lalani et al. [72] considered pericardial adipose tissue, brosis and
myocyte hypertrophy to be related with the increased frequency of late
ventricular potentials in obese individuals, and body mass index as an
independent predictor of abnormal signal averaged ECG results.
Body mass index correlated with SAECG-QRS duration and LAS40
in patients with an old myocardial infarction, suggesting a body mass
index dependent sudden cardiac death risk [110].
Cardiac Conduction System Involvement in Obese
Frank et al reported unfrequent conduction abnormalities in obese
patients [18]. Involvement of the conduction system in sudden death
of obese young people has been explored by Bharati et al, reporting
an hypertrophied and enlarged heart, focal mononuclear cells in and
around the sinoatrial node, marked fat throughout the conduction
system, brosis of the atrioventricular bundle and le bundle branch,
a brous atrioventricular node and focal brosis of the ventricular
septum [111]. e mild to moderately obese patients demonstrated a
higher degree of brosis compared to the markedly obese, showing a
higher amount of fat [111].
Obstructive Sleep Apnea and Arrhythmias in Obese
Patients
Obstructive sleep apnea (OSA) is dened by recurrent episodes of
upper airway collapse during sleep, impairing ventilation and resulting
in subsequent hypoxia, hypercapnia, sleep arousals and loud snoring
[53,112]. Overnight polysomnography is the gold standard test to
diagnose and stratify sleep apnea, but patients may be screened for OSA
with a simple tool, as well, such as Berlin questionnaire [113]. Central
obesity is a common nding and major risk factor for obstructive sleep
apnea and increased adipose tissue predisposes to airway narrowing
[6,112]. e major risk factors for OSA are, besides obesity, age, male
gender and alterations in craniofacial structure [114].
OSA is a risk factor for excessive daytime sleepiness, road
trac accidents, cardiovascular morbidity (hypertension, stroke,
metabolic syndrome) and mortality [112]. Both tachyarrhythmia and
bradyarrhythmia are possible causes of cardiovascular morbidity in
patients with OSA [114]. OSA is also independently associated with
type 2 diabetes mellitus, insulin resistance, diabetic microvascular
complications, dyslipidemia and bronchial asthma [115].
Increased mortality in patients with OSA, particularly at night,
emphasizes the importance of identifying the mechanisms of
myocardial electrical instability [115]. e main mechanisms linking
OSA with cardiac arrhythmias are: increased intrathoracic pressure,
autonomic imbalance (repetitive oscillations between sympathetic
and parasympathetic predominance), systemic and pulmonary
hypertension, structural and electrical atrial and ventricular remodeling,
inammation, diastolic dysfunction, endothelial dysfunction,
atherogenesis and myocardial ischemia, night-time hypoxemia
and acidosis [22,27,28,53,114-117]. Repetitive inspiration against
collapsed upper airways generates important shis in intrathoracic
pressure, transmitted to the atria and contributing to atrial remodeling
(enlargement and brosis) [53]. Hypoxemia may cause pulmonary
vasoconstriction and pulmonary hypertension and stimulates the
sympathetic nervous system via reex mechanisms [28,118]. e
combination of repetitive uctuations in heart rate, blood pressure
and intrathoracic pressure during sleep with increased sympathetic
tone, leads to increased le and right ventricular wall stress, le and
right ventricular hypertrophy and systolic and diastolic heart failure
[118]. Several observations point toward a long-lasting sympathetic
hyperactivity, aected by comorbidities [119].
All kinds of arrhythmias have been observed in patients with OSA,
ranging from asymptomatic sinus bradycardia to fatal ventricular
arrhythmias and asystole [112,114]. A paroxysm of atrial brillation
may lead to central sleep apnea, due to an acute decrease in le
ventricular lling, with an increase in pulmonary wedge pressure and
consequent stimulation of pulmonary vagal receptors [28]. Both OSA
and central sleep apnea modulate the autonomic nervous system at
night through central respiratory-cardiac coupling in the brainstem,
chemoreexes, baroreexes, and reexes related to lung ination
and arousals [120]. e repetitive oscillations between sympathetic
and parasympathetic predominance enable the development of
cardiac arrhythmias: bradyarrhythmias when parasympathetic
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tone predominates, and atrial and ventricular arrhythmias when
sympathetic tone predominates [118].
Studies on the prevalence of bradyarrhythmias in patients with
OSA have yielded conicting results [118]. Many studies reported
sleep-related bradyarrhythmias or asystole in patients with OSA, not
related to a diseased sinus node or atrio-ventricular conduction system
[112,121]. Uninhibited paroxysmal parasympathetic discharges lead to
marked paroxysmal bradycardia [113]. Bradyarrhythmias during sleep
are associated with OSA severity, and concomitant chronic obstructive
pulmonary disease or beta 2-therapy may play a role in development
of tachyarrhythmias [117]. Other studies reported no increase in
bradyarrhythmias rates [122,123].
Atrial remodeling related to OSA may cause atrial arrhythmias,
including interatrial block, atrial brillation and utter. It has been
reported that OSA may increase le atrial size independently of obesity,
hypertension and diastolic dysfunction [118]. OSA was found as an
independent risk factor for atrial brillation [113]. e association
between atrial brillation prevalence and OSA is related to the severity
of hypoxemia [124], chronically increased sympathetic activity due to
hypoxemia and hypercapnia, surges in adrenergic and vagal tone, atrial
remodeling, and a higher prevalence of traditional risk factors [113,118].
Nocturnal hypoxemia may cause mitochondrial dysfunction, resulting
in repetitive oxidative stress and increased production of inammatory
cytokines, leading to endothelial dysfunction, insulin resistance,
hypercoagulability and adverse myocardial remodeling [113]. e
increased sympathetic tone and intrathoracic pressure may lower atrial
eective refractory period due to activation of acetylcholine-dependent
potassium channels, enabling pulmonary vein discharges and atrial
dilation [113]. e high prevalence of atrial brillation explains the
increased risk of stroke and heart failure in patients with OSA [112].
OSA not only promotes initiation of atrial brillation, but also
may contribute to its progression, and makes management of atrial
brillation more dicult [113,125]. OSA was associated with higher
rates of early and overall recurrence aer catheter ablation of atrial
brillation and it predicts atrial brillation recurrence aer pulmonary
vein isolation [113,125-127]. A signicantly higher incidence of atrial
brillation recurrences following cardioversion and ablation was found
in patients with untreated compared to treated OSA, suggesting that
OSA may trigger atrial brillation [128]. Serum markers of oxidative
stress and free radical production predict atrial brillation recurrences
aer atrial brillation ablation [113]. It is important for physicians to
monitor atrial brillation patients for OSA and monitor those with
OSA for atrial brillation [125].
A signicant association between OSA and ventricular arrhythmias
has been also demonstrated, due to myocardial ischemia, the
procoagulant, proinammatory and heightened adrenergic state, heart
remodeling, systolic and diastolic heart failure, arterial desaturation
and arousal [118,129]. Ventricular ectopy and nonsustained ventricular
tachycardia were recorded during sleep, but the prognosis of
nonsustained ventricular tachycardia is debatable in the absence
of heart disease [130]. A high prevalence of OSA was also found in
implantable cardioverter-debrillator recipients [53]. Namtvedt et
al. [117] reported an increased prevalence of ventricular premature
complexes in middle-aged patients with mild or moderate OSA. A high
prevalence of sleep-disordered breathing (60%) was found in patients
with ventricular arrhythmias and normal le ventricular function,
demonstrating a strong association in patients without heart failure
[129]. Repetitive intermittent hypoxemia and hypercapnia due to
OSA, act through chemoreceptors, increase sympathetic activity and
induce ventricular arrhythmias [129]. Only few studies investigated the
association between OSA and sudden cardiac death. Habitual snorers
and patients with OSA had a higher risk of sudden cardiac death in the
early morning [131,132].
Obstructive sleep apnea is increasing in the pediatric population,
as well, and is more common among overweight and obese boys [114].
QT dispersion was signicantly increased only in obese children
with OSA [114]. QT dispersion increases also in adult patients with
moderate-to-severe OSA, and a positive correlation was found between
QT dispersion and the severity of OSA [133].
Patients who presented advanced atrioventricular block had more
severe OSA than those without arrhythmias [134].
OSA is a common but underestimated disorder, linked to
cardiovascular morbidity and mortality. Unfortunately, OSA is largely
undiagnosed, due to the insucient awareness of the disorder among
physicians and there should be heightened suspicion of OSA in patients
with atrial brillation [112,113]. e deleterious cardiovascular eects
of OSA may be reversible with early therapy [114], and patients could
benet of weight normalization, ECG monitoring, continuous positive
airway pressure ventilation (CPAP) and avoidance of factors known
to increase upper airway obstruction, such as alcohol consumption
(alcohol reduces the muscle tone of the upper airways and prologs
apnea) and use of sedatives [112,117]. CPAP may improve oxidative
stress and reduce the structural and electrical remodeling of the atria
due to OSA, resulting in a lower atrial brillation recurrence rate
[113,127]. On the other hand, CPAP reduces preload, which may
further compromise diastolic lling of the ventricles, already impaired
to the loss of atrial pump in atrial brillation [113]. More attention
should be given to patients with more severe OSA or concomitant
comorbidities [117].
Oxidative Stress and Arrhythmogenesis
Obese subjects exhibit increased systemic oxidative stress, enhanced
by abdominal adiposity and associated with adiponectin deciency
[135]. Recent clinical and experimental evidence demonstrated the
involvement of oxidative stress in cardiac electrical and structural
remodeling [23,136,137]. Reactive oxygen species may impair Na,
K and Ca channels, Na-Ca exchanger activity, may be implicated in
gap junction remodeling, decrease the action potential amplitude and
duration, and increase the incidence of cardiac arrhythmias in animal
models [136-140].
Oxidative stress results in decreased hERG protein levels,
accelerated activation and deactivation of hERG, and increase in current
amplitude of hERG and hKv1.5, allowing a greater amount of K ions
to ow through these channels in the phase 3 of the action potential,
downregulation of Ito (responsible for the rapid repolarization phase),
and increases the channel opening probability of Ik1 (inward rectifying
channel) [136,137].
An abundance of oxidative markers was found in atrial tissues from
patients with persistent atrial brillation, although plasma markers of
oxidative stress did not correlate with developing atrial brillation [23].
Not only L-type calcium channels and sodium channels are sensitive
to the redox state, but also cardiac creatine kinase, explaining the link
between inammation and the structural remodeling of the atrium [23].
General and mitochondrial anti-oxidants may be promising
therapeutic strategies of arrhythmias in obese patients [137].
Citation: Mozos I (2014) Arrhythmia Risk and Obesity. J Mol Genet Med S1: 006. doi: 10.4172/1747-0862.S1-006
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Conclusions
e present review illustrates the signicant association of excess
body weight with an increased arrhythmia risk, and the mechanisms
explaining the high prevalence of atrial and ventricular arrhythmias in
overweight and obese patients, with implications for prevention and
therapy of atrial brillation and sudden cardiac death. Atrial brillation
is very common in obese patients with cardiovascular disorders. Obesity
impairs ventricular depolarization and repolarization, prolongs the QT
interval and is frequently associated with ventricular arrhythmias, even
before the development of heart disease.
Obstructive sleep apnea is common in obese patients and it is
linked to atrial and ventricular arrhythmias due to structural and
electrical cardiac remodeling, an increased sympathetic tone, systemic
and pulmonary hypertension, intermittent hypoxia and inammation,
activation of humoral, metabolic and thrombotic factors.
Obesity is one of the very few identied modiable risk factors
for arrhythmias, and the development of a risk score, incorporating
clinical, biochemical, ECG and genetic obesity markers would be useful
in assessing arrhythmia risk. Considering the multiple factors linking
obesity and cardiac arrhythmias, may provide a more comprehensive
picture of arrhythmia risk, enabling preventive and therapeutic
measures. Future research should focus on the genetic component
enabling the association obesity-cardiac arrhythmias, changes in the
molecular components of the ion channels and repolarization reserve,
nontraditional obesity biomarkers predicting arrhythmia risk, without
neglecting the use of other known ECG markers.
Weight control may be a reasonable strategy for reducing the
burden of cardiac arrhythmia, but electrocardiographic monitoring is
recommended for obese patients during weight reduction programs.
Prevention and treatment of obesity and detection and control of
obstructive sleep apnea could represent cornerstones for the prevention
of cardiac arrhythmias. Standard 12-lead ECG can play an important
role in obese patients in predicting atrial brillation (P wave duration
and dispersion) and ventricular arrhythmia risk (QT interval duration
and dispersion). ECG is the gold standard for diagnosis of arrhythmias,
considering that most of the patients are asymptomatic.
References
1. [Noauthors listed] (2000) Obesity: preventing and managing the global
epidemic. Report of a WHO consultation. World Health Organ Tech Rep Ser
894: i-xii, 1-253.
2. Adams JP, Murphy PG (2000) Obesity in anesthesia and intensive care. Br J
Anaest 85: 95-108.
3. Lavie CJ, Milani RV, Ventura HO (2009) Obesity and cardiovascular disease:
risk factor, paradox, and impact of weight loss. J Am Coll Cardiol 53: 1925-
1932.
4. Poirier P, Eckel RH (2008) Cardiovascular consequences of obesity. Drug
Discovery Today: Therapeutic strategies 5: 45-51.
5. Wilborn C, Beckham J, Campbell B, Harvey T, Galbreath M, et al. (2005)
Obesity: prevalence, theories, medical consequences, management, and
research directions. J Int Soc Sports Nutr 2: 4-31.
6. Diaz-Melean CM, Somers VK, Rodriguez-Escudero JP, Singh P, Sochor O, et
al. (2013) Mechanisms of adverse cardiometabolic consequences of obesity.
Curr Atheroscler Rep 15: 364.
7. Jeckel KM, Miller KE, Chicco AJ, Chapman PL, Mulligan CM, et al. (2011) The
role of dietary fatty acids in predicting myocardial structure in fat-fed rats. Lipids
Health Dis 10: 92.
8. Chrostowska M, Szyndler A, Hoffmann M, Narkiewicz K (2013) Impact of
obesity on cardiovascular health. Best Pract Res Clin Endocrinol Metab 27:
147-156.
9. Guglin M, Baxi K, Schabath M (2013) Anatomy of the obesity paradox in heart
failure. Heart Fail Rev.
10. Alexander JK (1985) The cardiomyopathy of obesity. Prog Cardiovasc Dis 27:
325-334.
11. Mozos I (2005) Chronic myocardial infarction. Inuence of obesity on dispersion
parameters. Timisoara Medical Journal 55: 272-275.
12. López-Jiménez F, Cortés-Bergoderi M (2011) Update: systemic diseases and
the cardiovascular system (i): obesity and the heart. Rev Esp Cardiol 64: 140-149.
13. Huang H, Amin V, Gurin M, Wan E, Thorp E, et al. (2013) Diet-induced
obesity causes long QT and reduces transcription of voltage-gated potassium
channels. J Mol Cell Cardiol 59: 151-158.
14. Conen D, Adam M, Roche F, Barthelemy JC, Felber Dietrich D, et al. (2012)
Premature atrial contractions in the general population: frequency and risk
factors. Circulation 126: 2302-2308.
15. Provotorov VM, GlukhovskiĬ ML (2009) [Rhythm and conductivity disorders in
patients at the initial stages of metabolic syndrome]. Klin Med (Mosk) 87: 26-28.
16. Watanabe H, Tanabe N, Watanabe T, Darbar D, Roden DM, et al. (2008)
Metabolic syndrome and risk of development of atrial brillation: the Niigata
preventive medicine study. Circulation 117: 1255-1260.
17. Alberti KGMM, Eckel RH, Grundy SM, Zimmet PZ, Cleeman JI, et al. (2009)
Harmonizing the Metabolic Syndrome: A Joint Interim Statement of the
International Diabetes Federation Task Force on Epidemiology and Prevention;
National Heart, Lung and Blood Institute; American Heart Association; World
Heart Federation; International Atherosclerosis Society; and International
Association for the Study of Obesity. Circulation 120: 1640-1645.
18. Frank S, Colliver JA, Frank A (1986) The electrocardiogram in obesity: statistical
analysis of 1,029 patients. J Am Coll Cardiol 7: 295-299.
19. Patel S, Harmer JA, Loughnan G, Skilton MR, Steinbeck K, et al. (2007)
Characteristics of cardiac and vascular structure and function in Prader-Willi
syndrome. Clin Endocrinol (Oxf) 66: 771-777.
20. Lamb AS, Johnson WM (1987) Premature coronary artery atherosclerosis in a
patient with Prader-Willi syndrome. Am J Med Genet 28: 873-880.
21. Nicolaou VN, Papadakis JE, Dermitzakis G, Dermitzaki SI, Tsakiris AK (2009)
Effect of obesity on atrial size in older women with non-valvular paroxysmal
atrial brillation. Aging Clin Exp Res 21: 344-348.
22. European Heart Rhythm Association; European Association for Cardio-Thoracic
Surgery, Camm AJ, Kirchhof P, Lip GY, Schotten U, et al. (2010) Guidelines for
the management of atrial brillation: the Task Force for the Management of
Atrial brillation of the European Society of Cardiology (ESC). Eur Heart J 31:
2369-2429.
23. Endoh Y, Endoh I, Geczy C, Nakagomi A, Kusama Y, et al. (2011) Inammation
and atrial brillation. J Arrhythmia 27:106-115.
24. Guo Y, Lip GY, Apostolakis S (2012) Inammation in atrial brillation. J Am Coll
Cardiol 60: 2263-2270.
25. Conen D (2013) Obesity and atrial brillation: the evidence is gaining weight.
Europace 15: 771-772.
26. Li Y, Wu YF, Chen KP, Li X, Zhang X, et al. (2013) Prevalence of atrial brillation
in China and its risk factors. Biomed Environ Sci 26: 709-716.
27. Magnani JW, Hylek EM, Apovian CM (2013) Obesity begets atrial brillation: a
contemporary summary. Circulation 128: 401-405.
28. Schoonderwoerd BA, Smit MD, Pen L, Van Gelder IC (2008) New risk factors
for atrial brillation: causes of 'not-so-lone atrial brillation'. Europace 10: 668-
673.
29. Karasoy D, Bo Jensen T, Hansen ML, Schmiegelow M, Lamberts M, et al.
(2013) Obesity is a risk factor for atrial brillation among fertile young women:
a nationwide cohort study. Europace 15: 781-786.
30. Schotten U, Verheule S, Kirchhof P, Goette A (2011) Pathophysiological
mechanisms of atrial brillation: a translational appraisal. Physiol Rev 91: 265-
325.
31. Wanahita N, Messerli FH, Bangalore S, Gami AS, Somers VK, et al. (2008)
Atrial brillation and obesity--results of a meta-analysis. Am Heart J 155: 310-
315.
Citation: Mozos I (2014) Arrhythmia Risk and Obesity. J Mol Genet Med S1: 006. doi: 10.4172/1747-0862.S1-006
Page 8 of 10
J Mol Genet Med ISSN: 1747-0862 JMGM, an open access journal Molecular & Cellular Aspects in Obesity and Diabetes
32. Menezes AR, Lavie CJ, DiNicolantonio JJ, O'Keefe J, Morin DP, et al. (2013)
Atrial brillation in the 21st century: a current understanding of risk factors and
primary prevention strategies. Mayo Clin Proc 88: 394-409.
33. Psaty BM, Manolio TA, Kuller LH, Kronmal RA, Cushman M, et al. (1997)
Incidence of and risk factors for atrial brillation in older adults. Circulation 96:
2455-2461.
34. Tsang TS, Barnes ME, Miyasaka Y, Cha SS, Bailey KR, et al. (2008) Obesity
as a risk factor for the progression of paroxysmal to permanent atrial brillation:
a longitudinal cohort study of 21 years. Eur Heart J 29: 2227-2233.
35. Abed HS, Wittert GA (2013) Obesity and atrial brillation. Obes Rev 14: 929-
938.
36. Gersh BJ, Tsang TS, Barnes M, Seward JB (2005) The changing epidemiology
and natural history of nonvalvular atrial brillation: the role of novel risk factors.
Eur Heart J Suppl 7: C5-C11.
37. Wang TJ, Parise H, Levy D, D'Agostino RB Sr, Wolf PA, et al. (2004) Obesity
and the risk of new-onset atrial brillation. JAMA 292: 2471-2477.
38. Munger TM, Dong YX, Masaki M, Oh JK, Mankad SV, et al. (2012)
Electrophysiological and hemodynamic characteristics associated with obesity
in patients with atrial brillation. J Am Coll Cardiol 60: 851-860.
39. McCully BH, Hasan W, Streiff CT, Houle JC, Woodward WR, et al. (2013)
Sympathetic cardiac hyperinnervation and atrial autonomic imbalance in diet-
induced obesity promote cardiac arrhythmias. Am J Physiol Heart Circ Physiol
305: H1530-1537.
40. Aimé-Sempé C, Folliguet T, Rücker-Martin C, Krajewska M, Krajewska S, et al.
(1999) Myocardial cell death in brillating and dilated human right atria. J Am
Coll Cardiol 34: 1577-1586.
41. Polontchouk L, Haeiger JA, Ebelt B, Schaefer T, Stuhlmann D, et al. (2001)
Effects of chronic atrial brillation on gap junction distribution in human and rat
atria. J Am Coll Cardiol 38: 883-891.
42. Allessie M, Ausma J, Schotten U (2002) Electrical, contractile and structural
remodeling during atrial brillation. Cardiovasc Res 54: 230-246.
43. Lavie CJ, Amodeo C, Ventura HO, Messerli FH (1987) Left atrial abnormalities
indicating diastolic ventricular dysfunction in cardiopathy of obesity. Chest 92:
1042-1046.
44. Vaziri SM, Larson MG, Lauer MS, Benjamin EJ, Levy D (1995) Inuence of
blood pressure on left atrial size. The Framingham Heart Study. Hypertension
25: 1155-1160.
45. Wong CY, O'Moore-Sullivan T, Leano R, Byrne N, Beller E, et al. (2004)
Alterations of left ventricular myocardial characteristics associated with obesity.
Circulation 110: 3081-3087.
46. Al Chekakie MO, Welles CC, Metoyer R, Ibrahim A, Shapira AR, et al. (2010)
Pericardial fat is independently associated with human atrial brillation. J Am
Coll Cardiol 56: 784-788.
47. Perez MV, Wang PJ, Larson JC, Soliman EZ, Limacher M, et al. (2013) Risk
factors for atrial brillation and their population burden in postmenopausal
women: the Women's Health Initiative Observational Study. Heart 99: 1173-
1178.
48. Tedrow UB, Conen D, Ridker PM, Cook NR, Koplan BA, et al. (2010) The long-
and short-term impact of elevated body mass index on the risk of new atrial
brillation the WHS (women's health study). J Am Coll Cardiol 55: 2319-2327.
49. Curhan GC, Chertow GM, Willett WC, Spiegelman D, Colditz GA, et al. (1996)
Birth weight and adult hypertension and obesity in women. Circulation 94:
1310-1315.
50. Conen D, Tedrow UB, Cook NR, Buring JE, Albert CM (2010) Birth weight is
a signicant risk factor for incident atrial brillation. Circulation 122: 764-770.
51. Hernandez AV, Kaw R, Pasupuleti V, Bina P, Ioannidis JP, et al. (2013)
Association between obesity and postoperative atrial brillation in patients
undergoing cardiac operations: a systematic review and meta-analysis. Ann
Thorac Surg 96: 1104-1116.
52. Badheka AO, Rathod A, Kizilbash MA, Garg N, Mohamad T, et al. (2010)
Inuence of obesity on outcomes in atrial brillation: yet another obesity
paradox. Am J Med 123: 646-651.
53. Seyfeli E, Duru M, Kuvandik G, Kaya H, Yalcin F (2006) Effect of obesity on
P-wave dispersion and QT dispersion in women. Int J Obes (Lond) 30: 957-
961.
54. Baranchuk A (2012) Sleep apnea, cardiac arrhythmias, and conduction
disorders. J Electrocardiol 45: 508-512.
55. Guzzardi MA, Iozzo P (2011) Fatty heart, cardiac damage, and inammation.
Rev Diabet Stud 8: 403-417.
56. Lin YK, Chen YC, Chang SL, Lin YJ, Chen JH, et al. (2013) Heart failure
epicardial fat increases atrial arrhythmogenesis. Int J Cardiol 167: 1979-1983.
57. Chang LC, Huang KC, Wu YW, Kao HL, Chen CL, et al. (2009) The clinical
implications of blood adiponectin in cardiometabolic disorders. J Formos Med
Assoc 108: 353-366.
58. Conen D, Ridker PM, Everett BM, Tedrow UB, Rose L, et al. (2010) A
multimarker approach to assess the inuence of inammation on the incidence
of atrial brillation in women. Eur Heart J 31: 1730-1736.
59. Musaad S, Haynes EN (2007) Biomarkers of obesity and subsequent
cardiovascular events. Epidemiol Rev 29: 98-114.
60. Lin YK, Chen YJ (2013) Adipocitokines modulate ionic currents – A key to
lipotoxicity potentiated cardiac arrhythmia. J Arrhythmia 29: 247-248.
61. Frustaci A, Chimenti C, Bellocci F, Morgante E, Russo MA, et al. (1997)
Histological substrate of atrial biopsies in patients with lone atrial brillation.
Circulation 96: 1180-1184.
62. Nakamura Y, Nakamura K, Fukushima-Kusano K, Ohta K, Matsubara H, et al.
(2003) Tissue factor expression in atrial endothelia associated with nonvalvular
atrial brillation: possible involvement in intracardiac thrombogenesis. Thromb
Res 111: 137-142.
63. Aviles RJ, Martin DO, Apperson-Hansen C, Houghtaling PL, Rautaharju P, et
al. (2003) Inammation as a risk factor for atrial brillation. Circulation 108:
3006-3010.
64. Mano Y, Anzai T, Kaneko H, Nagatomo Y, Nagai T, et al. (2011) Overexpression
of human C-reactive protein exacerbates left ventricular remodeling in diabetic
cardiomyopathy. Circ J 75: 1717-1727.
65. Shimano M, Shibata R, Tsuji Y, Kamiya H, Uchikawa T, et al. (2008) Circulating
adiponectin levels in patients with atrial brillation. Circ J 72: 1120-1124.
66. Lin YK, Chen YJ, Chen SA (2010) Potential atrial arrhythmogenicity of
adipocytes: implications for the genesis of atrial brillation. Med Hypotheses
74: 1026-1029.
67. Nagashima K, Nakahara S, Okumura Y, Mano H, Sonoda K, et al. (2013)
Termination of atrial brillation by ablation of high-dominant frequency sites
adjacent to epicardial adipose tissue. J Arrhythm 29: 242-243.
68. Lin YK, Lai MS, Chen YC, Cheng CC, Huang JH, et al. (2012) Hypoxia and
reoxygenation modulate the arrhythmogenic activity of the pulmonary vein and
atrium. Clin Sci (Lond) 122: 121-132.
69. Lin YK, Chen YC, Chen JH, Chen SA, Chen YJ (2012) Adipocytes modulate
the electrophysiology of atrial myocytes: implications in obesity-induced atrial
brillation. Basic Res Cardiol 107: 293.
70. Duou J, Virmani R, Rabin I, Burke A, Farb A, et al. (1995) Sudden death as a
result of heart disease in morbid obesity. Am Heart J 130: 306-313.
71. Kannel WB, Plehn JF, Cupples LA (1988) Cardiac failure and sudden death in
the Framingham Study. Am Heart J 115: 869-875.
72. Lalani AP, Kanna B, John J, Ferrick KJ, Huber MS, et al. (2000) Abnormal
signal-averaged electrocardiogram (SAECG) in obesity. Obes Res 8: 20-28.
73. Chugh SS, Kelly KL, Titus JL (2000) Sudden cardiac death with apparently
normal heart. Circulation 102: 649-654.
74. Eisenstein EL, Shaw LK, Nelson CL, Anstrom KJ, Hakim Z, et al. (2002)
Obesity and long-term clinical and economic outcomes in coronary artery
disease patients. Obes Res 10: 83-91.
75. du Toit EF, Smith W, Muller C, Strijdom H, Stouthammer B, et al. (2008)
Myocardial susceptibility to ischemic-reperfusion injury in a prediabetic model
of dietary-induced obesity. Am J Physiol Heart Circ Physiol 294: H2336-2343.
76. Aubin MC, Cardin S, Comtois P, Clément R, Gosselin H, et al. (2010) A high-fat
diet increases risk of ventricular arrhythmia in female rats: enhanced arrhythmic
risk in the absence of obesity or hyperlipidemia. J Appl Physiol (1985) 108: 933-
940.
Citation: Mozos I (2014) Arrhythmia Risk and Obesity. J Mol Genet Med S1: 006. doi: 10.4172/1747-0862.S1-006
Page 9 of 10
J Mol Genet Med ISSN: 1747-0862 JMGM, an open access journal Molecular & Cellular Aspects in Obesity and Diabetes
77. Breijo-Marquez FR (2012) Cardiac Arrhythmias-New Considerations. InTech,
Rijeka, Croatia.
78. Mittendorfer B, Peterson LR (2008) Cardiovascular Consequences of Obesity
and Targets for Treatment. Drug Discov Today Ther Strateg 5: 53-61.
79. Bagi Z (2009) Mechanisms of coronary microvascular adaptation to obesity. Am
J Physiol Regul Integr Comp Physiol 297: R556-567.
80. Barbosa JA, Rodrigues AB, Mota CC, Barbosa MM, Simões e Silva AC (2011)
Cardiovascular dysfunction in obesity and new diagnostic imaging techniques:
the role of noninvasive image methods. Vasc Health Risk Manag 7: 287-295.
81. Lee KT, Tang PW, Tsai WC, Liu IH, Yen HW, et al. (2013) Differential effects of
central and peripheral fat tissues on the delayed rectier K(+) outward currents
in cardiac myocytes. Cardiology 125: 118-124.
82. Schunkert H (2002) Obesity and target organ damage: the heart. Int J Obes
Relat Metab Disord 26 Suppl 4: S15-20.
83. Alpert MA, Terry BE, Cohen MV, Fan TM, Painter JA, et al. (2000) The
electrocardiogram in morbid obesity. Am J Cardiol 85: 908-910, A10.
84. Fraley MA, Birchem JA, Senkottaiyan N, Alpert MA (2005) Obesity and the
electrocardiogram. Obes Rev 6: 275-281.
85. Zipes DP, Camm AJ, Borggrefe M, Buxton AE, Chaitman B, et al. (2006)
ACC/AHA/ESC 2006 Guidelines for management of patients with ventricular
arrhythmias and the prevention of sudden cardiac death – executive summary.
Eur Heart J 27: 2099-2140.
86. Ramirez AH, Schildcrout JS, Blakemore DL, Masys DR, Pulley JM, et al.
(2011) Modulators of normal electrocardiographic intervals identied in a large
electronic medical record. Heart Rhythm 8: 271-277.
87. Simşek H, Doğan A, Sahin M, Gümrükçüoğlu HA (2013) [A case of
idiopathic ventricular tachycardia in a 14-year-old obese patient due to golden
berry fruit extract pills for weight loss]. Turk Kardiyol Dern Ars 41: 429-432.
88. Pareek M, Pedersen RL, Leren TP, Jensen HK (2013) [Weight loss pills
purchased on the internet as the cause of ventricular brillation]. Ugeskr Laeger
175: 739-740.
89. Ernest D, Gershenzon A, Corallo CE, Nagappan R (2008) Sibutramine-
associated QT interval prolongation and cardiac arrest. Ann Pharmacother 42:
1514-1517.
90. Schamroth CL (2012) The perils of pharmacological treatment for obesity: a
case of sibutramine-associated cardiomyopathy and malignant arrhythmias.
Cardiovasc J Afr 23: e11-12.
91. Peiris AN, Thakur RK, Sothmann MS, Gustafson AB, Hennes MI, et al. (1991)
Relationship of regional fat distribution and obesity to electrocardiographic
parameters in healthy premenopausal women. South Med J 84: 961-965.
92. el-Gamal A, Gallagher D, Nawras A, Gandhi P, Gomez J, et al. (1995) Effects of
obesity on QT, RR, and QTc intervals. Am J Cardiol 75: 956-959.
93. Corbi GM, Carbone S, Ziccardi P, Giugliano G, Marfella R, et al. (2002) FFAs
and QT intervals in obese women with visceral adiposity: effects of sustained
weight loss over 1 year. J Clin Endocrinol Metab 87: 2080-2083.
94. Benoit SR, Mendelsohn AB, Nourjah P, Staffa JA, Graham DJ (2005) Risk
factors for prolonged QTc among US adults: Third National Health and Nutrition
Examination Survey. Eur J Cardiovasc Prev Rehabil 12: 363-368.
95. Ozmen N, Cebeci BS, Kardesoglu E, Cincik H, Cekin E, et al. (2006) QT
dispersion in non-apneic simple snoring patients and the effect of surgical
therapy on QT dispersion. Int J Cardiol 113: 82-85.
96. Arslan E, Yiğiner O, Yavaşoğlu I, Ozçelik F, Kardeşoğlu E, et al.
(2010) Effect of uncomplicated obesity on QT interval in young men. Pol Arch
Med Wewn 120: 209-213.
97. Girola A, Enrini R, Garbetta F, Tufano A, Caviezel F (2001) QT dispersion in
uncomplicated human obesity. Obes Res 9: 71-77.
98. Nomura A, Zareba W, Moss AJ (2000) Obesity does not inuence
electrocardiographic parameters in coronary patients. Am J Cardiol 85: 106-
108, A9.
99. Güven A, Özgen T, Güngör O, Aydın M, Baysal K (2010) Association
between the corrected QT interval and carotid artery intima-media thickness in
obese children. J Clin Res Pediatr Endocrinol 2: 21-27.
100. Soydinc S, Davutoglu V, Akcay M (2006) Uncomplicated metabolic syndrome
is associated with prolonged electrocardiographic QTc interval and QTc
dispersion. Ann Noninvasive Electrocardiol 11: 313-317.
101. Marfella R, De Angelis L, Nappo F, Manzella D, Siniscalchi M, et al. (2001)
Elevated plasma fatty acid concentrations prolong cardiac repolarization in
healthy subjects. Am J Clin Nutr 73: 27-30.
102. Grekin RJ, Vollmer AP, Sider RS (1995) Pressor effects of portal venous oleate
infusion. A proposed mechanism for obesity hypertension. Hypertension 26:
193-198.
103. Mizia-Stec K, Mandecki T, Zahorska-Markiewicz B, Szulc A, Jastrzebska-Maj
E, et al. (2000) [The QT interval dispersion and ventricular late potential in
obese women]. Pol Merkur Lekarski 8: 84-86.
104. Mukerji R, Petruc M, Fresen JL, Terry BE, Govindarajan G, et al. (2012) Effect
of weight loss after bariatric surgery on left ventricular mass and ventricular
repolarization in normotensive morbidly obese patients. Am J Cardiol 110:
415-419.
105. Al-Salameh A, Allain J, Jacques A, Verhaeghe P, Desailloud R (2013)
Shortening of the QT Interval is Observed Soon after Sleeve Gastrectomy in
Morbidly Obese Patients. Obes Surg.
106. Pringle TH, Scobie IN, Murray RG, Kesson CM, Maccuish AC (1983)
Prolongation of the QT interval during therapeutic starvation: a substrate for
malignant arrhythmias. Int J Obes 7: 253-261.
107. Goldberger JJ, Cain ME, Hohnloser SH, Kadish AH, Knight BP, et al. (2008)
American Heart Association/American College of Cardiology Foundation/
Heart Rhythm Society scientic statement on noninvasive risk stratication
techniques for identifying patients at risk for sudden cardiac death: a
scientic statement from the American Heart Association Council on Clinical
Cardiology Committee on Electrocardiography and Arrhythmias and Council
on Epidemiology and Prevention. Circulation 118: 1497-1518.
108. Masui A, Tsuji H, Tamura K, Tarumi N, Sugiura T, et al. (1994) Effect of body
characteristics on the variables of signal-averaged electrocardiograms in
healthy subjects. Chest 105: 1357-1359.
109. Aijaz B, Ammar KA, Lopez-Jimenez F, Redeld MM, Jacobsen SJ, et al.
(2008) Abnormal cardiac structure and function in the metabolic syndrome: a
population-based study. Mayo Clin Proc 83: 1350-1357.
110. Strbak V (2007) Joint Meeting of the Slovak Physiological Society, the
Physiological Society and the Federation of European Physiological Societies.
Bratislava (Slovak Republic), September 11-14, 2007. Medimond International
Proceedings. Monduzzi Editore, Bologna, Italy.
111. Bharati S, Lev M (1995) Cardiac conduction system involvement in sudden
death of obese young people. Am Heart J 129: 273-281.
112. Grimm W, Becker HF (2006) Obesity, sleep apnea syndrome, and
rhythmogenic risk. Herz 31: 213-218.
113. Goyal SK, Sharma A (2013) Atrial brillation in obstructive sleep apnea. World
J Cardiol 5: 157-163.
114. Khositseth A, Nantarakchaikul P, Kuptanon T, Preutthipan A (2011) QT
dispersion in childhood obstructive sleep apnoea syndrome. Cardiol Young
21: 130-135.
115. Kales SN, Straubel M (2013) Obstructive Sleep Apnea in North American
Commercial Drivers. Ind Health.
116. Barreiro B, Garcia L, Lozano L, Almagro P, Quintana S, et al. (2013)
Obstructive sleep apnea and metabolic syndrome in spanish population. Open
Respir Med J 7: 71-76.
117. Namtvedt SK, Randby A, Einvik G, Hrubos-Strøm H, Somers VK, et al. (2011)
Cardiac arrhythmias in obstructive sleep apnea (from the Akershus Sleep
Apnea Project). Am J Cardiol 108: 1141-1146.
118. Chan KH, Wilcox I (2010) Obstructive sleep apnea: novel trigger and potential
therapeutic target for cardiac arrhythmias. Expert Rev Cardiovasc Ther 8: 981-
994.
119. Olmetti F, La Rovere MT, Robbi E, Taurino AE, Fanfulla F (2008) Nocturnal
cardiac arrhythmia in patients with obstructive sleep apnea. Sleep Med 9: 475-
480.
120. Leung RS (2009) Sleep-disordered breathing: autonomic mechanisms and
arrhythmias. Prog Cardiovasc Dis 51: 324-338.
121. Grimm W, Koehler U, Fus E, Hoffmann J, Menz V, et al. (2000) Outcome
Citation: Mozos I (2014) Arrhythmia Risk and Obesity. J Mol Genet Med S1: 006. doi: 10.4172/1747-0862.S1-006
Page 10 of 10
J Mol Genet Med ISSN: 1747-0862 JMGM, an open access journal Molecular & Cellular Aspects in Obesity and Diabetes
of patients with sleep apnea-associated severe bradyarrhythmias after
continuous positive airway pressure therapy. Am J Cardiol 86: 688-692, A9.
122. Flemons WW, Remmers JE, Gillis AM (1993) Sleep apnea and cardiac
arrhythmias. Is there a relationship? Am Rev Respir Dis 148: 618-621.
123. Mehra R, Benjamin EJ, Shahar E, Gottlieb DJ, Nawabit R, et al. (2006)
Association of nocturnal arrhythmias with sleep-disordered breathing: The
Sleep Heart Health Study. Am J Respir Crit Care Med 173: 910-916.
124. Tanigawa T, Yamagishi K, Sakurai S, Muraki I, Noda H, et al. (2006) Arterial
oxygen desaturation during sleep and atrial brillation. Heart 92: 1854-1855.
125. Loomba RS, Arora R (2012) Obstructive sleep apnea and atrial brillation: a
call for increased awareness and effective management. Am J Ther 19: e21-
24.
126. Ng CY, Liu T, Shehata M, Stevens S, Chugh SS, et al. (2011) Meta-analysis
of obstructive sleep apnea as predictor of atrial brillation recurrence after
catheter ablation. Am J Cardiol 108: 47-51.
127. Naruse Y, Tada H, Satoh M, Yanagihara M, Tsuneoka H, et al. (2013)
Concomitant obstructive sleep apnea increases the recurrence of atrial
brillation following radiofrequency catheter ablation of atrial brillation: clinical
impact of continuous positive airway pressure therapy. Heart Rhythm 10: 331-
337.
128. Kanagala R, Murali NS, Friedman PA, Ammash NM, Gersh BJ, et al. (2003)
Obstructive sleep apnea and the recurrence of atrial brillation. Circulation
107: 2589-2594.
129. Koshino Y, Satoh M, Katayose Y, Yasuda K, Tanigawa T, et al. (2008)
Association of sleep-disordered breathing and ventricular arrhythmias in
patients without heart failure. Am J Cardiol 101: 882-886.
130. Katritsis DG, Zareba W, Camm AJ (2012) Nonsustained ventricular
tachycardia. J Am Coll Cardiol 60: 1993-2004.
131. Seppälä T, Partinen M, Penttilä A, Aspholm R, Tiainen E, et al. (1991) Sudden
death and sleeping history among Finnish men. J Intern Med 229: 23-28.
132. Gami AS, Howard DE, Olson EJ, Somers VK (2005) Day-night pattern of
sudden death in obstructive sleep apnea. N Engl J Med 352: 1206-1214.
133. Dursunoglu D, Dursunoglu N, Evrengül H, Ozkurt S, Kiliç M, et al. (2005) QT
interval dispersion in obstructive sleep apnoea syndrome patients without
hypertension. Eur Respir J 25: 677-681.
134. Becker HF, Koehler U, Stammnitz A, Peter JH (1998) Heart block in patients
with sleep apnoea. Thorax 53 Suppl 3: S29-32.
135. Sankhla M, Sharma TK, Mathur K, Rathor JS, Butolia V, et al. (2012)
Relationship of oxidative stress with obesity and its role in obesity induced
metabolic syndrome. Clin Lab 58: 385-392.
136. Drolet B, Simard C, Gailis L, Daleau P (2007) Ischemic, genetic and
pharmacological origins of cardiac arrhythmias: the contribution of the Quebec
Heart Institute. Can J Cardiol 23 Suppl B: 15B-22B.
137. Jeong EM, Liu M, Sturdy M, Gao G, Varghese ST, et al. (2012) Metabolic
stress, reactive oxygen species, and arrhythmia. J Mol Cell Cardiol 52: 454-
463.
138. Brown DA, Aon MA, Akar FG, Liu T, Sorarrain N, et al. (2008) Effects of
4'-chlorodiazepam on cellular excitation-contraction coupling and ischaemia-
reperfusion injury in rabbit heart. Cardiovasc Res 79: 141-149.
139. Wehrens XH, Lehnart SE, Marks AR (2005) Intracellular calcium release and
cardiac disease. Annu Rev Physiol 67: 69-98.
140. Venetucci LA, Trafford AW, O'Neill SC, Eisner DA (2008) The sarcoplasmic
reticulum and arrhythmogenic calcium release. Cardiovasc Res 77: 285-292.
Citation: Mozos I (2014) Arrhythmia Risk and Obesity. J Mol Genet Med S1:
006. doi: 10.4172/1747-0862.S1-006
This article was originally published in a special issue, Molecular & Cellular
Aspects in Obesity & Diabetes handled by Editor(s). Dr. Masayoshi
Yamaguchi, Emory University School of Medicine, USA
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