atrial fibrilation
DESCRIPTION
atrial fibrillation, classification, pathophysiologyTRANSCRIPT
http://cardiologysearch.blogspot.in/
Atrial fibrillationAtrial fibrillation (Classification, Mechanism & (Classification, Mechanism &
Management)Management)
http://cardiologysearch.blogspot.in/
Introduction…Introduction… AF is characterised by wavelets propagating in different AF is characterised by wavelets propagating in different
directions causing disorganized atrial depolarization directions causing disorganized atrial depolarization without effective atrial contractionwithout effective atrial contraction
Electrical activity of atrium can be detected in ECG as Electrical activity of atrium can be detected in ECG as small irregular baseline undulations of variable small irregular baseline undulations of variable amplitude & morphology (f waves) at rate of 350 to 600amplitude & morphology (f waves) at rate of 350 to 600
Ventricular response is irregularly irregular, & in Ventricular response is irregularly irregular, & in untreated patients with normal AV conduction, is untreated patients with normal AV conduction, is usually between 100 to 160usually between 100 to 160
WPWsyndrome ventricular rate may be rapid >300 due WPWsyndrome ventricular rate may be rapid >300 due to conduction over accessory pathway( short antegrade to conduction over accessory pathway( short antegrade refractory periods) refractory periods)
http://cardiologysearch.blogspot.in/
Introduction…Introduction…
ventricular rate during AF is altered ventricular rate during AF is altered due todue to
Autonomic toneAutonomic toneProperty of AV nodeProperty of AV nodeEffect of drugs on AV conductionEffect of drugs on AV conduction
http://cardiologysearch.blogspot.in/
Atrial fibrillation is the most common arrhythmia & Atrial fibrillation is the most common arrhythmia & the incidence & prevalence increases with the agethe incidence & prevalence increases with the age
The incidenceThe incidence <0.5% below 50Yrs<0.5% below 50Yrs 2% in age 60-692% in age 60-69 4.6% in age 70-794.6% in age 70-79 8.8% in age 80-898.8% in age 80-89
Men were 1.5 times more likely to develop AF than Men were 1.5 times more likely to develop AF than womenwomen
Whites were more likely to develop AF than blacksWhites were more likely to develop AF than blacks
IntroductionIntroduction
http://cardiologysearch.blogspot.in/
Framingham heart studyFramingham heart study ---cardiac ---cardiac factor predicting AFfactor predicting AF
• CHFCHF• RHDRHD• HTHT• StrokeStroke• Left atrial enlargementLeft atrial enlargement• Increased LV wall thicknessIncreased LV wall thickness• Decreased LV fractional shorteningDecreased LV fractional shortening
http://cardiologysearch.blogspot.in/
Relative risk of stroke - 6 fold in non Relative risk of stroke - 6 fold in non rheumatic AFrheumatic AF
Relative risk of stroke - 17 fold in Relative risk of stroke - 17 fold in rheumatic AFrheumatic AF
Annual risk of stroke in pt aged 50-Annual risk of stroke in pt aged 50-59:1.5%59:1.5%
Annual risk of stroke in aged 80-Annual risk of stroke in aged 80-89:23.5%89:23.5%
http://cardiologysearch.blogspot.in/
Underlying causes of AFUnderlying causes of AF
CVS CVS Rheumatic heart diseaseRheumatic heart disease ASDASD Cardiac surgeryCardiac surgery CardiomyopathyCardiomyopathy HypertrophicHypertrophic IdiopathicIdiopathic InfiltrativeInfiltrative HypertensionHypertension CAD (Acute & chronic)CAD (Acute & chronic) MVPSMVPS Non rheumatic mitral or Non rheumatic mitral or
tricuspid valve diseasetricuspid valve disease PericarditisPericarditis Tacycardia-bradycardia Tacycardia-bradycardia
syndromesyndrome
TumorsTumors WPW syndromeWPW syndrome SystemicSystemic Alcohol (holiday heart Alcohol (holiday heart
syndrome)syndrome) CVACVA COPDCOPD DefibrillationDefibrillation EffortEffort ElectrocutionElectrocution Electrolyte abnormalitiesElectrolyte abnormalities FeverFever HypothermiaHypothermia
http://cardiologysearch.blogspot.in/
PneumoniaPneumonia Pulmonary embolismPulmonary embolism Sudden emotionSudden emotion ThyrotoxicosisThyrotoxicosis TraumaTrauma RareRare Acute hypovolemiaAcute hypovolemia
CongenitalCongenital Multiple sclerosisMultiple sclerosis Muscular dystrophyMuscular dystrophy PheochromocytomaPheochromocytoma Right atrial cold Right atrial cold
injectionsinjections SwallowingSwallowing Tyramine foodsTyramine foods
Underlying causes of AF…Underlying causes of AF…
http://cardiologysearch.blogspot.in/
Classification of Atrial fibrillationClassification of Atrial fibrillation
http://cardiologysearch.blogspot.in/
Classification of Atrial Classification of Atrial fibrillationfibrillation
First detected AFFirst detected AF -usually <48hr -usually <48hr in AF during diagnosisin AF during diagnosis
Paraoxysmal AFParaoxysmal AF - last < 7days - last < 7days (most<24hrs) self-terminating (most<24hrs) self-terminating episodesepisodes
Persistent AFPersistent AF - last >7days - last >7days requires electrical or pharmacologic requires electrical or pharmacologic cardioversioncardioversion
Permanent AFPermanent AF - sustained >1yr & - sustained >1yr & failed cardioversion failed cardioversion
http://cardiologysearch.blogspot.in/
It was first thought that irregular contractions of the atria It was first thought that irregular contractions of the atria are caused by either single or multiple fociare caused by either single or multiple foci
In 1924, In 1924, GarryGarry had suggested reentry to be the mechanism had suggested reentry to be the mechanism behind the AFbehind the AF
In 1960, In 1960, MoeMoe suggested the suggested the ““multiple wavelet multiple wavelet hypothesishypothesis” ”
AF is characterized by fragmentation of a wavefront into AF is characterized by fragmentation of a wavefront into multiple, independent daughter wavelets that move multiple, independent daughter wavelets that move randomly throughout the atrium, giving rise to new wavelets randomly throughout the atrium, giving rise to new wavelets that collide with each other & mutually annihilate, or that that collide with each other & mutually annihilate, or that give rise to new wavelets in a perpetual activity that give rise to new wavelets in a perpetual activity that resembles Brownian motionresembles Brownian motion
MechanismsMechanisms
http://cardiologysearch.blogspot.in/
Stability of AF is a function of several Stability of AF is a function of several factorsfactors
Non-uniform distribution of refractory periodsNon-uniform distribution of refractory periods
Specially large tissue areaSpecially large tissue area
Either a relatively brief refractory period or a Either a relatively brief refractory period or a relatively slow conduction velocity of the relatively slow conduction velocity of the impulse, or bothimpulse, or both
Average no. of the waveletsAverage no. of the wavelets
Allessie et al,Allessie et al, estimated the critical no. of estimated the critical no. of wavelets to sustain AF was approximately 4 - 6 wavelets to sustain AF was approximately 4 - 6
MechanismsMechanisms
http://cardiologysearch.blogspot.in/
MechanismsMechanisms
http://cardiologysearch.blogspot.in/
MechanismsMechanisms
Trigger factor - self-terminating AFTrigger factor - self-terminating AFPerpetuating factor - AF does not Perpetuating factor - AF does not
terminate spontaneouslyterminate spontaneouslyParaoxysmal AF - 95% of Triggering Paraoxysmal AF - 95% of Triggering
foci are mapped in pulmonary veinfoci are mapped in pulmonary veinOther foci - within SVC ,coronary Other foci - within SVC ,coronary
sinussinus
http://cardiologysearch.blogspot.in/Anatomic distribution of Anatomic distribution of
focal trigger in focal trigger in Paraoxysmal AFParaoxysmal AF
http://cardiologysearch.blogspot.in/
Waldo et alWaldo et al divided AF into 4 types according divided AF into 4 types according atrial electrogramatrial electrogram
• Type – IType – I --- ECG showed discrete complexes of --- ECG showed discrete complexes of variable morphology separated by a clear variable morphology separated by a clear isoelectric baselineisoelectric baseline
• Type – IIType – II --- ECG characterized by discrete atrial --- ECG characterized by discrete atrial complexes with variable cycle lengths and complexes with variable cycle lengths and morphology, the baseline is not isoelectric morphology, the baseline is not isoelectric
• Type – IIIType – III --- ECGs were highly fragmented, --- ECGs were highly fragmented, showing no discrete complexes or isoelectric showing no discrete complexes or isoelectric intervalsintervals
• Type – IVType – IV --- Fibrillation was characterized by --- Fibrillation was characterized by alterations between type III & other typesalterations between type III & other types
MechanismsMechanisms
http://cardiologysearch.blogspot.in/
““f” wavesf” waves They do not represent total atrial activity but depict They do not represent total atrial activity but depict
only the larger vectors generated by the multiple only the larger vectors generated by the multiple wavelets of depolarization that occur at any given timewavelets of depolarization that occur at any given time
Why ventricular response is irregularly irregular?Why ventricular response is irregularly irregular? Large no. of atrial impulses that penetrate the AV node, Large no. of atrial impulses that penetrate the AV node,
makes it partially refractory to subsequent impulsesmakes it partially refractory to subsequent impulses
These effect of non conducted atrial impulses to These effect of non conducted atrial impulses to influence the response of subsequent atrial impulse is influence the response of subsequent atrial impulse is called as called as “concealed conduction”“concealed conduction”
MechanismsMechanisms
http://cardiologysearch.blogspot.in/
Electrical remodellingElectrical remodelling It means long term changes in refractory periods It means long term changes in refractory periods
resulting from prolonged changes in atrial rateresulting from prolonged changes in atrial rate EPS EPS --- --- ↓ERP,↓↓ERP,↓Action potential, Action potential, ↓↓ amplitude of AP amplitude of AP
plateauplateau MechanismsMechanisms --- Structural , cellular or ion channels It --- Structural , cellular or ion channels It
encompasses diverse structural changes in the encompasses diverse structural changes in the myocardium -interstitial fibrosismyocardium -interstitial fibrosis
Alteration in quantity or properties of ion channel Alteration in quantity or properties of ion channel proteins in sarcolemmaproteins in sarcolemma
Microscopic changes in cell size , content & extra Microscopic changes in cell size , content & extra cellular matrix leads to irreversible macroscopic changescellular matrix leads to irreversible macroscopic changes
MechanismsMechanisms
http://cardiologysearch.blogspot.in/
Maladoptations of atrial refractionaries – cause of Maladoptations of atrial refractionaries – cause of chronic AFchronic AF
Atrial remodellingAtrial remodelling Caused by atrial ischemia & stretch leads to AF due Caused by atrial ischemia & stretch leads to AF due
to to ↑ ↑ automaticity & reentry automaticity & reentry
After AF has continued for a long time, atria are not After AF has continued for a long time, atria are not only electrically remodelled, but atrial contractile only electrically remodelled, but atrial contractile function is also disturbedfunction is also disturbed
Recovery of atrial transport function may depend upon Recovery of atrial transport function may depend upon duration of AFduration of AF
After sinus rhythm is restored, it may take several After sinus rhythm is restored, it may take several weeks before atrial contractility fully returnsweeks before atrial contractility fully returns
MechanismsMechanisms
http://cardiologysearch.blogspot.in/
Modulating factorsModulating factors The onset & persistence of AF may be modulated by The onset & persistence of AF may be modulated by
autonomic nervous systemautonomic nervous system
Coumel etCoumel et al distinguished vagal & adrenergic AF al distinguished vagal & adrenergic AF (distinction is not clear)(distinction is not clear)
Vagally mediated AFVagally mediated AF Occurs more frequently in men than in womenOccurs more frequently in men than in women
Usually younger age group (30 – 50 years)Usually younger age group (30 – 50 years)
MechanismsMechanisms
http://cardiologysearch.blogspot.in/
Predominantly occurs in the absence of structural heart Predominantly occurs in the absence of structural heart diseasedisease
Rarely progresses to permanent AFRarely progresses to permanent AF
Attacks occur at night, end of the morningAttacks occur at night, end of the morning
Neither emotional stress nor exertion trigger the arrhythmia Neither emotional stress nor exertion trigger the arrhythmia
Rest, postprandial state, & alcohol are other precipitating Rest, postprandial state, & alcohol are other precipitating factorsfactors
Mechanism may relate to vagally induced shortening of the Mechanism may relate to vagally induced shortening of the atrial refractory periodatrial refractory period
MechanismsMechanisms
http://cardiologysearch.blogspot.in/
Adrenergic AFAdrenergic AF More frequently associated with structural heart More frequently associated with structural heart
disease (IHD)disease (IHD)
Occurs during the day time, & it is precipitated by Occurs during the day time, & it is precipitated by stress, exercise, tea, coffee or alcoholstress, exercise, tea, coffee or alcohol
The underlying mechanism is unknownThe underlying mechanism is unknown
MechanismsMechanisms
http://cardiologysearch.blogspot.in/
Hemodynamic effectHemodynamic effect
Loss of atrial contractionLoss of atrial contractionRapid ventricular rate - Rapid ventricular rate - ↓duration of ↓duration of
diastole & ventricular fillingdiastole & ventricular filling irregular ventricular rhythm - irregular ventricular rhythm - ↓ CO & ↓ CO &
coronary blood flowcoronary blood flowLoss of AV synchrony - Loss of AV synchrony - ↓LVEDP - ↓SV↓LVEDP - ↓SVAF causes hypotension or pulmonary AF causes hypotension or pulmonary
oedema in the setting of restrictive oedema in the setting of restrictive physiologyphysiology
http://cardiologysearch.blogspot.in/Antiarrhythmic therapy of atrial Antiarrhythmic therapy of atrial
fibrillationfibrillation Three antiarrhythmic strategiesThree antiarrhythmic strategies Acute pharmacologic terminationAcute pharmacologic termination Prevention of recurrence after cardioversionPrevention of recurrence after cardioversion Control of ventricular rate Control of ventricular rate Acute conversion of paroxysmal AFAcute conversion of paroxysmal AF Pharmacologic cardioversionPharmacologic cardioversion Most effective if initiated within 7 days after onset of AFMost effective if initiated within 7 days after onset of AF Restoration of sinus rhythm can be achieved in 70% of Restoration of sinus rhythm can be achieved in 70% of
the patientsthe patients First choiceFirst choice: Propafenone & flecainide (po & iv), : Propafenone & flecainide (po & iv),
ibutilide, dofetilideibutilide, dofetilide Second choiceSecond choice: Amaiodarone (high dose, iv +oral) & : Amaiodarone (high dose, iv +oral) &
Qunidine (po)Qunidine (po)
http://cardiologysearch.blogspot.in/Antiarrhythmic to maintain sinus rhythm Antiarrhythmic to maintain sinus rhythm in AFin AF
http://cardiologysearch.blogspot.in/
Class IC drugsClass IC drugs – Restore sinus rhythm with in a – Restore sinus rhythm with in a short period of time ( 1 hour) – conversion rate up to short period of time ( 1 hour) – conversion rate up to 90% (PAFIT-3)90% (PAFIT-3)
IbutilideIbutilide It acts twice more effectively for conversion of atrial It acts twice more effectively for conversion of atrial
flutter than atrial fibrillation (63% v 31%)flutter than atrial fibrillation (63% v 31%)
Efficacy decreased significantly with AF of >7 daysEfficacy decreased significantly with AF of >7 days
Studies, enrolled patients with mild to moderate Studies, enrolled patients with mild to moderate underlying disease, so these results may not be underlying disease, so these results may not be generalizable to patients with markedly depressed LVFgeneralizable to patients with markedly depressed LVF
Antiarrhythmic therapy of atrial Antiarrhythmic therapy of atrial fibrillationfibrillation
http://cardiologysearch.blogspot.in/
Dofetilide Dofetilide DIAMOND-CHFDIAMOND-CHF Study of 1518 patients with symptomatic heart failure Study of 1518 patients with symptomatic heart failure
(EF <35%)(EF <35%)
Therapy with 1000mic.g was associated with a greater Therapy with 1000mic.g was associated with a greater rate of conversion to sinus rhythm (44% v14%)rate of conversion to sinus rhythm (44% v14%)
SAFIRE-DSAFIRE-D Study of 325 patients with persistent AF &/or atrial flutterStudy of 325 patients with persistent AF &/or atrial flutter
Cardioversion rates were 6.1%,9.8% & 29.9% for 125, Cardioversion rates were 6.1%,9.8% & 29.9% for 125, 250 & 500mic.g bid compared with 1.2% of conversion 250 & 500mic.g bid compared with 1.2% of conversion with placebowith placebo
Antiarrhythmic therapy of atrial Antiarrhythmic therapy of atrial fibrillationfibrillation
http://cardiologysearch.blogspot.in/
AmiodaroneAmiodarone Produce sinus rhythm in 80% within 24hours (late Produce sinus rhythm in 80% within 24hours (late
conversion)conversion) AdvantagesAdvantages It lowers ventricular rate before conversion (IC drugs It lowers ventricular rate before conversion (IC drugs
increase the rate)increase the rate) Recommended in hemodynamically compromised Recommended in hemodynamically compromised
patients since it is less negatively inotropicpatients since it is less negatively inotropic Prefered in pts with LVF, LVH, IHDPrefered in pts with LVF, LVH, IHD IV amiodarone is moderately effective in converting AF IV amiodarone is moderately effective in converting AF
compared with placebo (63% v 44%), with maximum compared with placebo (63% v 44%), with maximum effect at 24hours (74% v 55%) --- 12 meta-analysiseffect at 24hours (74% v 55%) --- 12 meta-analysis
Higher than usual dose & combination of IV & oral Higher than usual dose & combination of IV & oral administration may enhance the cardioversion rate administration may enhance the cardioversion rate
Antiarrhythmic therapy of atrial Antiarrhythmic therapy of atrial fibrillationfibrillation
http://cardiologysearch.blogspot.in/
QuinidineQuinidine Usually administered in conjunction with B-BlockerUsually administered in conjunction with B-Blocker
Cumulative dose of up to 1350mg has shown to Cumulative dose of up to 1350mg has shown to cardiovert 50-77% of patients with cardiovert 50-77% of patients with recent onset AFrecent onset AF
SotalolSotalol It is ineffective in acute conversionIt is ineffective in acute conversion
It is effective for the prevention of AFIt is effective for the prevention of AF
This discrepancy relates to its property to prolong the This discrepancy relates to its property to prolong the refractory period predominantly at lower atrial rates, refractory period predominantly at lower atrial rates, but not during rapid AF but not during rapid AF
Antiarrhythmic therapy of atrial Antiarrhythmic therapy of atrial fibrillationfibrillation
http://cardiologysearch.blogspot.in/
Availability of studies on the efficacy of procainamide & Availability of studies on the efficacy of procainamide & disopyramide is limited, precluding definite conclusions disopyramide is limited, precluding definite conclusions
Digitalis, B-Blockers, & CCBs are ineffective for acute Digitalis, B-Blockers, & CCBs are ineffective for acute conversion of AFconversion of AF
DAAF study (Digoxin in acute AF)DAAF study (Digoxin in acute AF) There was no difference in cardioversion rates at 16 There was no difference in cardioversion rates at 16
hours between IV digoxin & placebo (51% v 46%) hours between IV digoxin & placebo (51% v 46%)
Digoxin can Digoxin can facilitate AFfacilitate AF due to its cholinergic effects due to its cholinergic effects which may cause a non-uniform reduction in conduction which may cause a non-uniform reduction in conduction velocity & effective refractory periods of the atria, and to velocity & effective refractory periods of the atria, and to delay the reversal of remodellingdelay the reversal of remodelling after restoration of after restoration of sinus rhythmsinus rhythm
Antiarrhythmic therapy of atrial Antiarrhythmic therapy of atrial fibrillationfibrillation
http://cardiologysearch.blogspot.in/
Conversion of paroxysmal AF(<3days)Conversion of paroxysmal AF(<3days)
http://cardiologysearch.blogspot.in/
Prevention of paroxysmal AFPrevention of paroxysmal AF No need for prophylactic AADNo need for prophylactic AAD After first episode of AF which may self terminate or After first episode of AF which may self terminate or
require electrical or pharmacologic cardioversionrequire electrical or pharmacologic cardioversion
Patients with infrequent, self limiting & well tolerated Patients with infrequent, self limiting & well tolerated paroxysms of AFparoxysms of AF
Prophylactic AAD are recommended ifProphylactic AAD are recommended if Occurs frequently (1 episode per 3 months)Occurs frequently (1 episode per 3 months)
Associated with significant symptomsAssociated with significant symptoms
Antiarrhythmic therapy of atrial Antiarrhythmic therapy of atrial fibrillationfibrillation
http://cardiologysearch.blogspot.in/
Prophylactic AAD are recommended if…Prophylactic AAD are recommended if… Worsening of LV functionWorsening of LV function
In the presence of left atrial enlargement, LVD, In the presence of left atrial enlargement, LVD, underlying CVS pathology, long duration of AF, underlying CVS pathology, long duration of AF, advanced ageadvanced age
B-blockersB-blockers Effective in adrenergic dependent AF (class IA & IC are Effective in adrenergic dependent AF (class IA & IC are
ineffective) ineffective)
It prevents the recurrence of persistent AF after It prevents the recurrence of persistent AF after cardioversion cardioversion
Antiarrhythmic therapy of atrial Antiarrhythmic therapy of atrial fibrillationfibrillation
http://cardiologysearch.blogspot.in/
Control of ventricular rate during paroxysmal AFControl of ventricular rate during paroxysmal AF Digitalis, B-blockers, CCBs are useful Digitalis, B-blockers, CCBs are useful
Addition of rate controlling drugs is necessary with class IA Addition of rate controlling drugs is necessary with class IA & IC drugs (not needed with amiodarone or sotalol)& IC drugs (not needed with amiodarone or sotalol)
Control of ventricular rate Control of ventricular rate in the setting of SSSin the setting of SSS may be may be impossible without implanting pacemakerimpossible without implanting pacemaker
In WPW syndromeIn WPW syndrome complicated by AF – acute rate control complicated by AF – acute rate control & conversion to SR may be achieved by & conversion to SR may be achieved by procainamide or procainamide or flecainideflecainide
Antiarrhythmic therapy of atrial Antiarrhythmic therapy of atrial fibrillationfibrillation
http://cardiologysearch.blogspot.in/
http://cardiologysearch.blogspot.in/
Antithrombotic therapyAntithrombotic therapy Whether AF is persistent or intermittent --- Whether AF is persistent or intermittent ---
Predisposes to strokePredisposes to stroke Non valvular AFNon valvular AF Most common cardiac disease associated with Most common cardiac disease associated with
cerebral embolism cerebral embolism The risk of stroke is 5-7 times greater when The risk of stroke is 5-7 times greater when
compared to control groupcompared to control group Risk factors that predicts strokeRisk factors that predicts stroke Previous stroke or TIAPrevious stroke or TIA Diabetes mellitus Diabetes mellitus Systemic hypertensionSystemic hypertension Increasing ageIncreasing age CADCAD CHFCHF
http://cardiologysearch.blogspot.in/
LV dysfunction & left atrial size > 2.5cm/sq.m --- LV dysfunction & left atrial size > 2.5cm/sq.m --- associated with thromboembolismassociated with thromboembolism
Age - 60-65, normal echo, no risk factors --- Age - 60-65, normal echo, no risk factors --- Extremely low risk for stroke (1% per year)Extremely low risk for stroke (1% per year)
Results from 5 large anticoagulation Results from 5 large anticoagulation trails trails
Annual rate of stroke in control group --- 4.5%Annual rate of stroke in control group --- 4.5%
Annual rate of stroke in warfarin-treated group --- Annual rate of stroke in warfarin-treated group --- 1.4% (68% risk reduction)1.4% (68% risk reduction)
Aspirin 325mg/d produced a risk reduction of 44%Aspirin 325mg/d produced a risk reduction of 44%
Antithrombotic therapyAntithrombotic therapy
http://cardiologysearch.blogspot.in/
Annual rate of major hemorrhageAnnual rate of major hemorrhage Control group --- 1%Control group --- 1%
Aspirin group --- 1%Aspirin group --- 1%
Warfarin group --- 1.3%Warfarin group --- 1.3%
No difference was noted in stroke risk, when patients No difference was noted in stroke risk, when patients with paroxysmal (intermittent) AF were compared with paroxysmal (intermittent) AF were compared with chronic AFwith chronic AF
Anticoagulation was 50% more effective than aspirin Anticoagulation was 50% more effective than aspirin in preventing ischemic strokein preventing ischemic stroke
Antithrombotic therapyAntithrombotic therapy
http://cardiologysearch.blogspot.in/
Risk factors for strokeRisk factors for stroke Prior stroke or TIAPrior stroke or TIA Significant valvular heart diseaseSignificant valvular heart disease HypertensionHypertension Diabetes mellitusDiabetes mellitus Age >65 yearsAge >65 years Left atrial enlargementLeft atrial enlargement CADCAD Congestive heart failureCongestive heart failure
Antithrombotic therapyAntithrombotic therapy
http://cardiologysearch.blogspot.in/
Lone AFLone AF Age <60years, no risk factorsAge <60years, no risk factors ---No antithrombotic ---No antithrombotic
therapytherapy
Age - 60-75 years (risk-2%per year)Age - 60-75 years (risk-2%per year) ---Aspirin ---Aspirin
Age > 75 yearsAge > 75 years --- Anticoagulation (INR – 2.0) --- Anticoagulation (INR – 2.0)
Any patients with AF + Risk factors for strokeAny patients with AF + Risk factors for stroke --- --- Treated with warfarin anticoagulation (INR – 2 to 3)Treated with warfarin anticoagulation (INR – 2 to 3)
Patients with contraindication to anticoagulation (or) Patients with contraindication to anticoagulation (or) unreliable individualunreliable individual (or) (or) no risk factorsno risk factors --- Aspirin --- Aspirin
Antithrombotic therapyAntithrombotic therapy
http://cardiologysearch.blogspot.in/
Risk of embolism after cardioversionRisk of embolism after cardioversion Risk --- 0 -7%Risk --- 0 -7%
Risk is independent of mode of cardioversionRisk is independent of mode of cardioversion High risk patients areHigh risk patients are Prior embolism, Mechanical valve prosthesis, Mitral Prior embolism, Mechanical valve prosthesis, Mitral
stenosisstenosis
In AF (>2d)In AF (>2d) --- Warfarin for 3 weeks before cardioversion --- Warfarin for 3 weeks before cardioversion + 3-4 weeks after reversion to sinus rhythm+ 3-4 weeks after reversion to sinus rhythm
Alternate strategyAlternate strategy --- TEE (to exclude LA thrombus) + --- TEE (to exclude LA thrombus) + heparin before cardioversion + followed by warfarin for heparin before cardioversion + followed by warfarin for 4weeks4weeks
Antithrombotic therapyAntithrombotic therapy
http://cardiologysearch.blogspot.in/
Risk of embolism after cardioversion…Risk of embolism after cardioversion… For emergency cardioversion (TEE cannot be For emergency cardioversion (TEE cannot be
obtained)obtained) --- heparin before cardioversion + followed --- heparin before cardioversion + followed by warfarin for 4weeksby warfarin for 4weeks
Low risk patientsLow risk patients Age <65 years without risk factor for stroke in Age <65 years without risk factor for stroke in
nonvalvular AFnonvalvular AF
Anticoagulation may not be necessary before Anticoagulation may not be necessary before cardioversion but aspirin is indicatedcardioversion but aspirin is indicated
It is important to emphasize that suggestions must be It is important to emphasize that suggestions must be individualized for a given patientindividualized for a given patient
Absolute contraindication for anticoagulation - Absolute contraindication for anticoagulation - ICH,SDH,GI bleedICH,SDH,GI bleed
Antithrombotic therapyAntithrombotic therapy
http://cardiologysearch.blogspot.in/
Non – pharmacologic therapiesNon – pharmacologic therapies
Rhythm control strategiesRhythm control strategies Device therapyDevice therapy Single site pacingSingle site pacing --- High right atrial & septal --- High right atrial & septal In many patients with SSS, atrial pacmaker allows In many patients with SSS, atrial pacmaker allows
higher dose of AAD since sinus node dysfunction is higher dose of AAD since sinus node dysfunction is treatedtreated
In patients with paroxysmal AF, there is evidence for In patients with paroxysmal AF, there is evidence for intraatrial conduction delayintraatrial conduction delay
Atrial pacing may decrease the frequency of recurrent Atrial pacing may decrease the frequency of recurrent AF in patients who have SSSAF in patients who have SSS
http://cardiologysearch.blogspot.in/
Incidence of AF is lower in patients treated by Incidence of AF is lower in patients treated by atrial pacing than ventricular pacing atrial pacing than ventricular pacing (prospective studies)(prospective studies)
Multisite pacingMultisite pacing --- Biatrial synchronous & Dual --- Biatrial synchronous & Dual site atrial pacingsite atrial pacing
In addition to the high RA lead, another atrial In addition to the high RA lead, another atrial lead is placed just outside the CS ostium for lead is placed just outside the CS ostium for stability & LA synchronization stability & LA synchronization
These pacing cause resynchronization of atrial These pacing cause resynchronization of atrial depolarisation & helpful in patients with intra depolarisation & helpful in patients with intra atrial conduction delayatrial conduction delay
Non – pharmacologic therapiesNon – pharmacologic therapies
http://cardiologysearch.blogspot.in/
Usually performed in patients with recurrent, Usually performed in patients with recurrent, symptomatic & drug refractory AFsymptomatic & drug refractory AF
ECG showed biphasic ‘p’ wave in inferior leads ECG showed biphasic ‘p’ wave in inferior leads with abbreviation of ‘P’ wave durationwith abbreviation of ‘P’ wave duration
Implantable atrial defibrillatorImplantable atrial defibrillator
Automatic atrial defibrillatorAutomatic atrial defibrillator• It detect AF by means of implanted RA, CS & RV It detect AF by means of implanted RA, CS & RV
leadsleads
Non – pharmacologic therapiesNon – pharmacologic therapies
http://cardiologysearch.blogspot.in/
• It delivers ‘R’ wave synchronization shock of 6J It delivers ‘R’ wave synchronization shock of 6J after a minimal preceding R-R interval of 500 msafter a minimal preceding R-R interval of 500 ms
• Unfortunately this device in its current form is not Unfortunately this device in its current form is not in usein use
Atrial-ventricular defibrillator/pacemaker Atrial-ventricular defibrillator/pacemaker • It has dual chamber algorithm-based arrhythmia It has dual chamber algorithm-based arrhythmia
detectiondetection
• Pacing & defibrillation therapies for treatment of Pacing & defibrillation therapies for treatment of AF & atrial tachycardiasAF & atrial tachycardias
• Therapy for VT/VFTherapy for VT/VF
Non – pharmacologic therapiesNon – pharmacologic therapies
http://cardiologysearch.blogspot.in/
Ablation therapy --- surgicalAblation therapy --- surgical His bundle ablationHis bundle ablation (surgical ligation, mechanical, (surgical ligation, mechanical,
cryothermia) + Pace maker implantationcryothermia) + Pace maker implantation
Corridor surgeryCorridor surgery Creating an isolated strip of muscle to isolate the SA & Creating an isolated strip of muscle to isolate the SA &
AV nodes, thus driving ventricular rate via AV node-His AV nodes, thus driving ventricular rate via AV node-His bundle complexbundle complex
But, atrial areas outside of narrow RA corridor continued But, atrial areas outside of narrow RA corridor continued to fibrillate with persistent loss of atrial transport to fibrillate with persistent loss of atrial transport function & persistent risk of thromboembolismfunction & persistent risk of thromboembolism
Non – pharmacologic therapiesNon – pharmacologic therapies
http://cardiologysearch.blogspot.in/
http://cardiologysearch.blogspot.in/
Maze procedureMaze procedure The principle is compartmentalize both atria so The principle is compartmentalize both atria so
that AF cannot be maintainedthat AF cannot be maintained
Right & left atrial appendages were resected, Right & left atrial appendages were resected, pulmonary vein ostia are isolated, linear RA & pulmonary vein ostia are isolated, linear RA & LA lesions are connected to anatomic structures LA lesions are connected to anatomic structures to form an to form an “electrical maze” --- “Maze 3”“electrical maze” --- “Maze 3”
Appropriately placed atrial incisions not only Appropriately placed atrial incisions not only interrupt the conduction routes of reentrant interrupt the conduction routes of reentrant circuits, but they also direct the sinus impulse circuits, but they also direct the sinus impulse from SA to AV along a specified routefrom SA to AV along a specified route
Non – pharmacologic therapiesNon – pharmacologic therapies
http://cardiologysearch.blogspot.in/
Indication for maze procedureIndication for maze procedure
Symptomatic AFSymptomatic AFRefractory to AAD Refractory to AAD Recurrent systemic embolism despite Recurrent systemic embolism despite
anticoagulationanticoagulation
http://cardiologysearch.blogspot.in/
Maze procedureMaze procedure 90% pt cured of AF with operative mortality <190% pt cured of AF with operative mortality <1
<10% requires PPI due to sinus node <10% requires PPI due to sinus node dysfunctiondysfunction
Transient fluid retention due to Transient fluid retention due to ↓atrial ↓atrial natriuretic peptide must be treated with natriuretic peptide must be treated with diureticsdiuretics
The entire atrial myocardium was electrically The entire atrial myocardium was electrically activated & atrial transport function is activated & atrial transport function is preservedpreserved
http://cardiologysearch.blogspot.in/
Non – pharmacologic therapiesNon – pharmacologic therapies
http://cardiologysearch.blogspot.in/
Tans catheter ablation therapyTans catheter ablation therapy Linear atrial ablationLinear atrial ablation (Radiofrequency) (Radiofrequency) It is employed in LA & RA for substrate It is employed in LA & RA for substrate
compartmentalizationcompartmentalization
Trigger ablationTrigger ablation (Radiofrequency) (Radiofrequency) Focal pulmonary veinFocal pulmonary vein Pulmonary vein isolation - transseptal puncture Pulmonary vein isolation - transseptal puncture
followed by pulmonary venography to define anatomyfollowed by pulmonary venography to define anatomy
Adverse effect Adverse effect StrokeStroke Phrenic nerve injuryPhrenic nerve injury Pericardial effusion & tamponadePericardial effusion & tamponade Pulmonary vein stenosisPulmonary vein stenosis
Non – pharmacologic therapiesNon – pharmacologic therapies
http://cardiologysearch.blogspot.in/
Indication for ablationIndication for ablation
Symptomatic AF Symptomatic AF Refractory to AAD Refractory to AAD Without structural heart diseaseWithout structural heart disease
http://cardiologysearch.blogspot.in/
Rate control strategyRate control strategy Catheter AV junctional modificationCatheter AV junctional modification (radiofrequency) (radiofrequency) PrinciplePrinciple --- Posterior inputs of AV node have shorter ERP, --- Posterior inputs of AV node have shorter ERP,
their ablation slows the ventricular response during AFtheir ablation slows the ventricular response during AF
Patient who becomes symptomatic due rapid ventricular Patient who becomes symptomatic due rapid ventricular response will benefitresponse will benefit
Currently, AV node modification is usually reserved for Currently, AV node modification is usually reserved for patients who require non-pharmacologic control but are patients who require non-pharmacologic control but are opposed to pacemaker implantationopposed to pacemaker implantation
Non – pharmacologic therapiesNon – pharmacologic therapies
http://cardiologysearch.blogspot.in/
Catheter ablation (DC shock or radiofrequency) + Catheter ablation (DC shock or radiofrequency) + PacemakerPacemaker
It is performed in patients with unmanageable symptoms It is performed in patients with unmanageable symptoms related to rapid ventricular response related to rapid ventricular response
DC current ablation is highly dangerous --- produce electrical DC current ablation is highly dangerous --- produce electrical arcing & barotrauma ( cardiac perforation, tamponade, arcing & barotrauma ( cardiac perforation, tamponade, acute depression of LV, proarrhythmia & sudden deathacute depression of LV, proarrhythmia & sudden death
Radiofrequency ablation ---avoid complicationsRadiofrequency ablation ---avoid complications DisadvantagesDisadvantages Dependence on pacemakerDependence on pacemaker
Atria will continue to fibrillate --- need long term Atria will continue to fibrillate --- need long term anticoagulationanticoagulation
Non – pharmacologic therapiesNon – pharmacologic therapies
http://cardiologysearch.blogspot.in/
Choice of pace maker typeChoice of pace maker type --- determined by the current --- determined by the current phase of AFphase of AF
Chronic AF --- VVIR + AV nodal ablationChronic AF --- VVIR + AV nodal ablation
Paroxysmal AF ( usually in sinus rhythm between Paroxysmal AF ( usually in sinus rhythm between episodes) --- Dual-chamber pacemaker with mode episodes) --- Dual-chamber pacemaker with mode switchingswitching
Stroke prevention strategyStroke prevention strategy Percutaneous LA appendage transcatheter Percutaneous LA appendage transcatheter
occlusion (PLAATO)occlusion (PLAATO)
Involves insertion of an occlusion device by catheter into Involves insertion of an occlusion device by catheter into the LA appendage via trans septal puncturethe LA appendage via trans septal puncture
Non – pharmacologic therapiesNon – pharmacologic therapies
http://cardiologysearch.blogspot.in/A circular mapping catheter is in the ostium of the left A circular mapping catheter is in the ostium of the left lower PV and an ablation catheter with a large-tip lower PV and an ablation catheter with a large-tip
electrode is recording a PV potential from the nearby electrode is recording a PV potential from the nearby
strandstrand. .
http://cardiologysearch.blogspot.in/During radiofrequency ablation near Lasso-8 During radiofrequency ablation near Lasso-8 recording site, the sharp PVPs are seen in the recording site, the sharp PVPs are seen in the first two beats but are absent during the last first two beats but are absent during the last
two beatstwo beats
http://cardiologysearch.blogspot.in/
http://cardiologysearch.blogspot.in/
Thank youThank you
http://cardiologysearch.blogspot.in/
http://http://cardiologysearch.blogspot.in/cardiologysearch.blogspot.in/
http://cardiologysearch.blogspot.in/
Kindly send your suggestions to Kindly send your suggestions to improve this site improve this site
Visit us regularly for updatesVisit us regularly for updates
Send your articles/ ppt/pdf to Send your articles/ ppt/pdf to publish in this site . publish in this site .
http://http://cardiologysearch.blogspot.in/cardiologysearch.blogspot.in/
http://cardiologysearch.blogspot.in/
http://cardiologysearch.blogspot.in/
http://cardiologysearch.blogspot.in/
http://cardiologysearch.blogspot.in/
http://cardiologysearch.blogspot.in/
IntroductionIntroduction
Paroxysmal AFParoxysmal AF Short lasting < 1 hourShort lasting < 1 hour Long lasting >1; < 48 hours Long lasting >1; < 48 hours AF interspersed with periods of sinus rhythm & usually AF interspersed with periods of sinus rhythm & usually
terminates spontaneouslyterminates spontaneously Persistent AFPersistent AF Occur between 2days - weeksOccur between 2days - weeks Intervention is needed to restore the sinus rythumIntervention is needed to restore the sinus rythum Chronic or permanent AFChronic or permanent AF Persists for months to yearsPersists for months to years No spontaneous conversion No spontaneous conversion Interventions to restore sinus rythum are either Interventions to restore sinus rythum are either
ineffectual or not triedineffectual or not tried
http://cardiologysearch.blogspot.in/
http://cardiologysearch.blogspot.in/
Type – IType – I --- Activation consisted of single, broad --- Activation consisted of single, broad wavefronts propagating without conduction delay & either wavefronts propagating without conduction delay & either only short arcs of conduction block or small areas of slow only short arcs of conduction block or small areas of slow conduction that did not disrupt the main course of conduction that did not disrupt the main course of propagationpropagation
Type – IIType – II --- Activation consisted of either the presence of --- Activation consisted of either the presence of 2 wavelets or of single wave (with either considerable 2 wavelets or of single wave (with either considerable conduction block or slow conduction or both)conduction block or slow conduction or both)
Type – IIIType – III --- Activation was characterized by 3 or more --- Activation was characterized by 3 or more wavelets combined with areas of slow conduction & wavelets combined with areas of slow conduction & multiple arcs of conduction blockmultiple arcs of conduction block
As the fibrillation changed from type I to III, AFs frequency As the fibrillation changed from type I to III, AFs frequency & irregularity increased, creating a higher incidence of & irregularity increased, creating a higher incidence of continuous electrical activity & reentrycontinuous electrical activity & reentry
MechanismsMechanisms
http://cardiologysearch.blogspot.in/
Familial AF Familial AF • Genetic predisposition – is a hypothesisGenetic predisposition – is a hypothesis
• Defect linked to Defect linked to chromosome 10qchromosome 10q (21 of 49 members (21 of 49 members from 3 spanish families presented with AF)from 3 spanish families presented with AF)
• Missense mutation in the Missense mutation in the lamin A/C genelamin A/C gene (In DCM – (In DCM – associated with AF)associated with AF)
• Missense mutationMissense mutation Arg663His Arg663His ( In specific phenotype of ( In specific phenotype of HCM – associated with 47% of AF)HCM – associated with 47% of AF)
MechanismsMechanisms
http://cardiologysearch.blogspot.in/
Rate control in atrial fibrillationRate control in atrial fibrillation
http://cardiologysearch.blogspot.in/
Rate control in atrial fibrillationRate control in atrial fibrillation
http://cardiologysearch.blogspot.in/
http://cardiologysearch.blogspot.in/
Antiarrhythmic therapy of atrial Antiarrhythmic therapy of atrial fibrillationfibrillation
http://cardiologysearch.blogspot.in/
http://cardiologysearch.blogspot.in/
30%