5. The ANS as AF trigger
Modifiable AF risk factors promote ANS dysfunction
6.
7. Incidence and prevalence Increasing
Increase in Aging Population
Increase in Obesity
Increased Survival in AF patients
Multi factorial
Increased Detection
20. Definitions
Term Definitions
AF A SVT with uncoordinated atrial activation and ineffective atrial contraction
Clinical AF
Subclinical AF
Atrial high-rate episodes
AF burden
First detected AF
Paroxysmal AF
Persistent AF
Long-standing persistent AF
Permanent AF
21. Risk Stratification and Population Screening
CHARGE-AF (Co- horts for Heart and Aging Research in
Genomic Epidemiology model for atrial fibrillation
Total points 0-8. For the C2HEST
score, the C statistic was 0.749, with
95% CI of 0.729–0.769.10 The incident
rate of AF increased significantly with
higher C2HEST scores.
22.
23.
24. AF Complicating ACS or Percutaneous Coronary Intervention (PCI)
Chronic Coronary Disease (CCD)
AF is a chaotic, rapid (300-500 bpm), and irregular atrial
Rhythm
AF is the result of either electrophysiological abnormalities
that underlie impulse generation and/or structural
abnormalities of cellular connections that typically facilitate
rapid and uniform impulse conduction
AF often is initiated from electrical activity originating from
ectopic action potentials most commonly generated in the
pulmonary veins (PVs) of the left atrium (LA), or in
response to reentrant activity promoted by heterogeneous
conduction due to interstitial fibrosis
PV
features that increase vulnerability for initiating ectopy
include a higher resting membrane potential, stretchactivated
channels,2 and pattern of cross myofiber
orientation
Downregulation of connexin results in
decreased gap junctions, leading to slow heterogeneous
atrial conduction velocity and repolarization, promoting
regional functional conduction block that can support
reentry. Connexin remodeling can be due to genetic or
acquired factors, such as inflammatory state, older age,
or sleep-disordered breathing (SDB
Calcium mishandling from remodeling increases calcium
load in the sarcoplasmic reticulum
Remodeling in sarcoplasmic reticulum
calcium ATPase underlies sequestration of intracellular
Calcium
milieu for delayed
afterdepolarizations, the most likely trigger for AF initiation.
Action potential
alternans related to Ca2+ mishandling can be noted
to precede AF onset and increases with age.
The atria of patients with AF tend to have both shorter
effective refractory periods and slower conduction, which
enhances dispersion of repolarization and favor reentry
PAC burden is
associated with development of AF.2 Larger LA volume
increased NT-proBNP levels, and impaired LA emptying
are associated with increased PAC burden
Atrial cardiomyopathy has been identified as “any complex
of structural, architectural, contractile or electrophysiological
changes affecting the atria with the
potential to produce clinically relevant manifestations.”
Prothrombotic changes are often evident in
the LA, including increased endocardial expression of von
Willebrand factor, vascular cell adhesion molecule-1 and
monocyte chemoattractant protein-1 changes, which may
increase risk of thrombus formation and stroke
A suitable substrate for AF has a wavelength
(wavelength ¼ refractory period conduction velocity)
that is shorter than the dimensions of the tissue, with
heterogenous conduction velocity and/or repolarization
duration. Thus, an individual with large, fibrotic, and/or
fatty atria is more likely to have persistent AF than one
with a normal-sized atria with little interstitial fibrosis or
adipose infiltration
Sympathetic efferent stimulation releases noradrenaline,
stimulating G-coupled b-adrenergic receptors, enhancing
L-type calcium channels, and increasing inward current
(automaticity/early afterdepolarization). Delayed afterdepolarization
occurs via calcium overload and
ryanodine-2 receptor dysfunction
Parasympathetic
stimulation shortens atrial effective refractory period by
increasing IKACh (acetyl-choline receptor mediated inward
rectifying potassium channel) activity. Atrial effective
refractory period heterogeneity follows the pattern of
autonomic innervation. Sympathetic and parasympathetic
activity, alone or combined, can trigger AF.
ANS maintains AF
Atrial fibrillation (AF) is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the globally .The increasing burden is multifactorial; causes include the aging of the population, rising tide of obesity, increasing detection, and increasing survival with AF and other forms of cardiovascular disease
The estimated global prevalence was 50 million in 2020 with majority underdiagnosed
SDI was made up of the geometric mean of 3 common indicators: the lag distributed income per capita, mean educational achievement for those aged $15 y, and total fertility rate <25 y. SDI ranged from 0 to 1, where 0 represents the theoretical minimum level of development, whereas 1 represents the theoretical maximum level of development
AF is associated with a 1.5- to 2-fold increased risk of death; studies suggest that the mortality risk may be higher in women than in men.6 In meta-analyses, AF is also associated with increased risk of multiple adverse outcomes, including a 2.4-fold risk of stroke, 1.5-fold risk
of cognitive impairment or dementia,1.5-fold risk of myocardial infarction 2-fold risk of sudden cardiac death, 5-fold risk of heart failure (HF), 1.6-fold risk of chronic kidney disease (CKD), and 1.3-fold risk of peripheral artery disease (PAD). In Medicare beneficiaries, the most frequent outcome in the 5 years after AF diag- nosis was death (19.5% at 1 year; 48.8% at 5 years)11; the next most common diagnosis was HF (13.7%), followed by new-onset stroke (7.1%), gastrointestinal hemorrhage (5.7%), and MI (3.9%
Other atrial arrhythmias are often encountered in patients with AF
