ATRIAL FIBRILLATION 2016

By Dr. Ravikanth Moka
JR/Post Graduate in General Medicine
K.V.G.M.C.H.
Sullia, D.K.

Atrial fibrillation
 Atrial fibrillation(AF or A fib), is a
supraventricular arrhythmia characterised
electrocardiographically by low-amplitude
baseline oscillations(fibrillatory or ‘f’ waves)
and an irregularly irregular ventricular rhythm.
 The ‘f’ waves have a rate of 300-600 bpm
and are variable in amplitude, shape and
timing.
 The ventricular rate during Afib typically is
100-160 bpm

Definition
 Atrial fibrillation(AF or A fib), is a
supraventricular arrhythmia characterised
electrocardiographically by low-amplitude
baseline oscillations(fibrillatory or ‘f’ waves)
and an irregularly irregular ventricular rhythm.
 Atrial fibrillation Vs Atrial flutter??
Irregularly irregular R-R intervals
Absent ‘p’ waves
Fibrillatory or ‘f’ waves
Atrial fibrillation

Incidence
 Most common sustained cardiac arrhythmia
 Incidence and prevalence increases with
age
 The incidence
 <0.5% below 50Yrs
 2% in age 60-69
 4.6% in age 70-79
 8.8% in age 80-89
 Men > Women
 Whites > Blacks

Pathophysiology
1. Atrial structural abnormalities
 Disturbance of normal atrial architecture
 Atrial ischemia
 Extra cardiac factors
 Autonomic system
2.Electrophysiological mechanisms
 Multiple wavelet theory
 Automatic focus theory
3. Other pathophysiological mechanisms

Causes & risk factor a/w Afib
 Mnemonic “PIRATES”:
 Pulmonary embolus, Pulmonary disease, Post-
operative, Pericarditis
 Ischemic heart disease, Idiopathic (“lone atrial
fibrillation”),Intravenous central line (in right atrium)
 Rheumatic valvular disease (specifically mitral stenosis
or mitral regurgitation)
 Anemia, Alcohol (“holiday heart”), Advanced age,
Autonomic tone (vagally mediated Atrial fibrillation)
 Thyroid disease (hyperthyroidism)
 Elevated blood pressure (hypertension), Electrocution
 Sleep apnea, Sepsis.

Causes & risk factor a/w Afib
 Hypertension with LVH, IHD, MVD,
Cardiomyopathies, Constrictive pericarditis,
Cardiac tumours, Pulmonary hypertension
and Diabetes.
 Obesity and Obstructive sleep apnea.
 Temporary causes: Alcohol, Open heart or
thoracic surgery, Myocardial infarction,
Pericarditis, Myocarditis and Pulmonary
embolism.
 Reversible causes: Hyperthyroidism

Terminology Features
1. Paroxysmal AF Spontaneous termination <7 days
2. Persistent AF Not self-terminating lasting >7 days
3. Long standing AF Persistent AF for >1 year
4. Permanent AF Long standing AF refractory to
cardioversion
5. Lone AF Occurs in age group <60 years with
no H/o HTN/Heart disease
6. Nonvalvular AF Absence of rheumatic mitral
stenosis, a mechanical or
bioprosthetic heart valve, or mitral
valve repair
Classification

1. Vagotonic AF
2. Adrenergic AF
Classification
Paroxysmal AF:

Clinical features
 Hallmark of AF on physical examination:
Irregularly irregular pulse.
 Short R-R intervals lead to low LV diastolic filling,
low stroke volume and absence of peripheral
pulses which results in “pulse deficit.”
 Other findings: Irregular jugular venous pulsations
and variable intensity of first heart sound.

Complications
 Stroke
 Heart failure

Stroke with A Fib
Stroke risk:
Without AF
< 60 yrs : 0.5%
> 80 yrs : 3 yrs
With AF
< 60 yrs : 3%
> 80 yrs : 30%

Stroke with A Fib
Blood stasis
Abnormal
blood
constituents
Left atrium
thrombus
To carotid artery
Anatomical
and structural
defects

Diagnostic evaluation
 Clinical history and Physical examination
 ECG
 Holter monitoring
 Stress test
 ECHO
 Chest radiograph
 Blood tests

ECG
‘p’ waves are absent and R-R interval is variable.
Absent ‘p’ waves are replaced by small irregular oscillations,
called ‘f’ waves(f waves 350-600 beats /min).
ventricular response is grossly irregular at 100-160 beats /min.
Rate : No. of R waves x 10 ( 6 sec strip)

DDX
 Atrial fibrillation Vs Atrial flutter/ MAT/ AVNRT/
NSR with multiple PAC’S ??

Definition A Fib
Atrial
Flutter
MAT
AVNRT
NSR with
Multiple
PAC’S
Atrial flutter

Approach to A Fib
 Type of Afib
 Complete history
 Symptoms
 ?Structural heart disease
 Exclude CAD
 Identify correctable Secondary/Reversible
causes
 Develop a treatment strategy

Strategies for treating Atrialfibrillation
 Rhythm control (including cardioversion)
OR
 Rate control
PLUS
 Thromboembolic risk prevention:
based on CHA2DS2-VAS2C score

Acute management
 For hemodynamically unstable patients:
 Sedate if possible and perform an immediate cardioversion.
 If refractory to cardioversion, use IV amiodarone, ibutilide, or
procainamide.
 For hemodynamically stable patients:
 Initiate anticoagulation and rate control.
 If first occurrence, consider cardioversion after adequate
anticoagulation (4 weeks) or no clot seen on TEE and therapeutic
anticoagulation initiated.
 With recurrence, consider referral to an electrophysiologist.
 Consider admission if history suggests a precipitating event (e.g.,
acute MI, PE, HF, etc.).
 Rule out secondary causes based on history.
 Perform complete evaluation.

Rhythm and rate control approaches
 Rhythm control
 Cardioversion (electrical or pharmacological)
 Pharmacological agents (Class IC and III
antiarrhythmics)
 Surgery (maze procedure, ablation)
 Device implantation (pacemaker)
 Rate control
 Pharmacological agents (AV node blockers)
 Surgery with device implantation (ablation plus
pacemaker insertion)

Rate control medications
 -Metoprolol / Esmolol: IV or Oral
 -Diltiazem: IV or Oral
 -Verapamil: Oral Only
 -Digoxin: Patients with hypotension
 -Amiodarone: Also for rhythm control

Rhythm control
Synchronized DC cardioversion
 -Emergencies/Hemodynamic instability
 -Greater efficacy than medications
Pharmacologic cardioversion
 -If AF < 7days –dofetilide, flecainide, ibutilide,
propaferone or amiodarone
 -If AF > 7 day –dofetilide or amiodarone

Rate control as preferred therapy
 Age > 65, less symptomatic,
hypertension
 Recurrent afib
 Previous antiarrhythmic drug failure
 Unlikely to maintain sinus rhythm
(enlarged LA)

Dosage for Rate Control of
AF Beta blockers

Rhythm control as preferred therapy
 ? First episode afib
 Reversible cause (alcohol)
 Symptomatic patient despite rate control
 Patient unable to take anticoagulant (falls,
bleeding, noncompliance)
 CHF precipitated or worsened by afib
 ? Young afib patient (to avoid chronic
electrical and anatomic remodeling that
occurs with afib)

Thrombo-embolic Risk and Treatment
Risk Based Antithrombotic Therapy
 CHA2DS2-VASc score recommended to
assess stroke risk (Class I)

How do we determine stroke risk ?
 0 points – low risk (1.2-3.0 strokes per 100
patient years)
 1-2 points – moderate risk (2.8-4.0 strokes
per 100 patient years)
 > 3 points – high risk (5.9-18.2 strokes per
100 patient years)

Contd…
 With prior stroke, TIA, or CHA2DS2-VASc
score ≥2, oral anticoagulants recommended.
Options include:
 Warfarin
 Dabigatran, rivaroxaban, or apixaban (Class I)
 With nonvalvular AF and CHA2DS2-VASc
score of 0, it is reasonable to omit
antithrombotic therapy (Class IIa)

 With CHA2DS2-VASc score ≥2 and end-stage
CKD (CrCl <15 mL/min) or on hemodialysis, it
is reasonable to prescribe warfarin for oral
anticoagulation (Class IIa)
 With nonvalvular AF and a CHA2DS2-VASc
score of 1, no antithrombotic therapy or
treatment with oral anticoagulant or aspirin
may be considered (Class IIb)
 After coronary revascularization in patients
with CHA2DS2-VASc score ≥2, it may be
reasonable to use clopidogrel concurrently
with oral anticoagulants but without aspirin
(Class IIb)

Management
 Acute management
 Long term management

Bleeding Risk Accessment
• Assessment of bleeding risk should be
part of the clinical assessment of AF
patients prior to starting anticoagulation
• Antithrombotic benefits and potential
bleeding risks of long-term coagulation
should be explained and discussed with
the patient
• Aim for a target INR of between 2.0 and
3.0
• HAS-BLED Score

Bleeding Risk Accessment(HAS-BLED Score)
Points
 Hypertension (> 160 mm Hg systolic) 1
 Abnormal renal or hepatic function 1-2
 Stroke 1
 Bleeding history or anemia 1
 Labile INR (TTR < 60%) 1
 Elderly (age > 75 years) 1
 Drugs (antiplatelet, NSAID) or alcohol 1-2
 High risk (> 4%/year)>4
 Moderate risk(2-4%/year)2-3
 Low risk(< 2%.year)0-1

Novel oral anticoagulants
Dabigatran
 Oral direct thrombin inhibitor
 Twice daily dosing
 Renal clearance
Rivaroxaban
 Direct factor Xainhibitor
 Once daily (maintenance), twice daily (loading)
 Renal clearance
Apixaban
 Twice daily dosing
 Hepatic clearance
Edoxaban
 Once daily dosing
 Hepatic clearance

Prevention of Thromboembolism
 With AF or atrial flutter for ≥48 h, or unknown duration,
anticoagulate with warfarin for at least 3 wk before and 4
wk after cardioversion (Class I)
 With AF or atrial flutter for >48 h or unknown duration,
requiring immediate cardioversion, anticoagulate as soon
as possible and continue for at least 4 wk (Class I)
 With AF or atrial flutter <48 h and high stroke risk, IV
heparin or LMWH, or factor Xa or direct thrombin inhibitor,
is recommended before or immediately after
cardioversion, followed by long-term anticoagulation
(Class I)
 With AF or atrial flutter <48 h and low thromboembolic
risk, IV heparin, LMWH, a new oral anticoagulant, or no
antithrombotic may be considered for cardioversion
(Class IIb)

Rate Control guidelines(AHA)
 Control ventricular rate using a beta blocker or non-
DHP CCBs for paroxysmal, persistent, or permanent
AF (Class I)
 IV beta blocker or non-DHP CCBs is recommended
to slow ventricular heart rate in the acute setting in
patients without pre-excitation. In hemodynamically
unstable patients, electrical cardioversion is
indicated (Class I)
 A heart rate control (resting heart rate <80 bpm)
strategy is reasonable for symptomatic management
of AF (Class IIa)
 IV amiodarone can be useful for rate control in
critically ill patients without pre-excitation (Class IIb)

Rate Control guidelines(AHA)
 AV nodal ablation with permanent ventricular pacing
is reasonable when pharmacological therapy is
inadequate and rhythm control is not achievable
(Class IIa)
 A lenient rate-control strategy (resting heart rate
<110 bpm) may be reasonable when patients
remain asymptomatic and LV systolic function is
preserved (Class IIb)
 Non-DHP CCBs should not be used in
decompensated HF (Class III)
 With pre-excitation and AF, digoxin, Non-DHP
CCBs , or amiodarone should not be administered
(Class III)

Restoration of Sinus Rhythm
guidelines(AHA)
Principles of Cardioversion:
 CV may be achieved by means of a drug or an electrical shock.
 Direct-current CV is more effective than pharmacological CV.
 The more recent the onset of AF, the more effective is
pharmacological CV.
 The primary disadvantage of electrical CV is that it requires
sedation or anesthesia.
 The primary disadvantage of pharmacological CV is the risk of
ventricular proarrhythmia.
 The risk of thromboembolism or stroke does not differ between
pharmacological and electrical CV.
 Significant sinus bradycardia after CV can occur in patients on high-
dose AV nodal blocking drugs.
 Antiarrhythmic drug therapy may be administrated prior to CV to
facilitate long-term success and maintenance of normal sinus
rhythm.

guidelines(AHA)
Direct Current Cardioversion:
 Shocks should be delivered synchronous to the R-wave.
 The use of a biphasic defibrillator should be considered with
150-200 joules as the initial energy setting.
 When a rapid ventricular response does not respond
promptly to pharmacological measures for AF patients with
ongoing myocardial ischemia, symptomatic hypotension,
angina, or HF, immediate CV is recommended.
 In case of early relapse of AF after CV, repeated direct-
current CV attempts may be made following administration of
antiarrhythmic medication.
 Electrical CV is contraindicated in patients with digitalis
toxicity or hypokalemia.

guidelines(AHA)
Pharmacological Cardioversion:
 IV ibutilide is an effective drug available to convert AF.
Due to its risk of torsades de pointes, ibutilide should be
avoided in patients with severe systolic dysfunction or a
prolonged QTc (>480 ms).
 More effective for conversion of atrial flutter than of AF;
more effective in cases of more recent onset.
 Can also be used to facilitate electrical CV when it is
unsuccessful, or when there is an immediate recurrence
of AF after initially successful CV.
 Consider IV magnesium (2 grams) prior to giving
ibutilide to reduce risk of torsades de pointes.
 ECG monitoring must be performed for 4 hours after
administration.

guidelines(AHA)
Pharmacological Cardioversion:
 Flecainide and Propafenone
 Both flecainide and propafenone have been studied for
their use as a “pill-in-the pocket” approach to
cardioverting AF.
 Generally, a beta blocker or a calcium channel blocker
should be taken an hour prior to taking the
antiarrhythmic drug when trying to convert AF to SR. For
a person >70 Kg, 300 mg of flecainide or 600 mg of
propafenone should be administered. For <70 Kg, the
dose for flecainide and propafenone is 200 mg and 450
mg, respectively. After administration of the drug, heart
rhythm must be monitored for at least 4-8 hours.

Maintenance of Sinus Rhythm
guidelines(AHA)
Principles of Antiarrhythmic Drug Therapy(AAD):
 Pharmacological therapy to maintain SR is indicated in
patients who have troublesome symptoms related to
paroxysmal AF or recurrent AF after CV who can
tolerate antiarrhythmic drugs (AADs) and have a good
chance of remaining in SR.
 AAD choice is based on side effect profiles and the
presence or absence of structural heart disease, HF,
and hypertension (see flow diagram).
 Drug choice should be individualized and must account
for underlying renal and hepatic function.
 Goals of drug therapy are to decrease the frequency
and duration of episodes, and to improve symptoms.

Maintenance of Sinus Rhythm
guidelines(AHA)
Principles of Antiarrhythmic Drug Therapy:
 AF recurrence while taking an AAD is not indicative of
treatment failure and does not necessitate a change in
antiarrhythmic therapy.
 An AAD should be abandoned when it does not result in
symptomatic improvement or causes adverse effects.
 Ensure normal electrolyte status and appropriate
anticoagulation prior to starting AAD therapy.
 Initiate AV nodal blockade prior to use of an AAD (e.g.
flecainide) that does not provide substantial AV node
blockade.
 Initiate therapy at low dose and titrate up as needed and
after evaluating drug effects on ECG parameters.

AF complicating ACS
 Urgent cardioversion of new-onset AF in the setting of ACS is
recommended for patients with hemodynamic compromise,
ongoing ischemia, or inadequate rate control (Class I)
 IV beta blockers are recommended to slow RVR with ACS and no
HF, hemodynamic instability, or bronchospasm (Class I)
 With ACS and AF with CHA2DS2-VASc score ≥2, anticoagulation
with warfarin is recommended unless contraindicated (Class I)
 Amiodarone or digoxin may be considered to slow RVR with ACS
and AF and severe LV dysfunction and HF or hemodynamic
instability (Class IIb)
 Non-DHP CCBs might be considered to slow RVR with ACS and
AF only in the absence of significant HF or hemodynamic
instability (Class IIb)

Hyperthyroidism
 Beta blockers are recommended to
control ventricular rate with AF
complicating thyrotoxicosis unless
contraindicated (Class I)
 When beta blockers cannot be used, a
Non-DHP CCBs is recommended to
control ventricular rate (Class I)

Pulmonary diseases
 Non-DHP CCBs is recommended to
control ventricular rate with AF and
COPD (Class I)
 Cardioversion should be attempted for
patients with pulmonary disease who
become hemodynamically unstable with
new-onset AF (Class I)

WPW and pre-excitation syndromes
 Cardioversion is recommended for patients with
AF, WPW syndrome who are hemodynamically
compromised (Class I)
 IV procainamide or ibutilide to restore sinus
rhythm or slow ventricular rate is (Class I)
recommended for patients with pre-excited AF
who are not hemodynamically compromised
(Class I)
 IV amiodarone, adenosine, digoxin, or non-DHP
CCBs in patients with WPW syndrome who
have pre-excited AF is potentially harmful
(Class III)

AF during pregnancy
 Digoxin, a beta blocker, or a nondihydropyridine
calcium channel antagonists are recommended
for rate control.
 Direct cardioversion if there is hemodynamic
instability
 Except in patients with low risk profile, either
aspirin or an anticoagulant is recommended for
prevention of thromboembolic complications.
 Unfractionated or LMWH in 1st & last trimester,
oral anticoagulant in 2nd trimester for high risk
group.
 Quinidine or procainamide for pharmacologic
cardioversion in stable patients.

Heart failure
 A beta blocker or non-DHP CCB is
recommended for persistent or permanent AF in
patients with HFpEF (Class I)
 In the absence of preexcitation, an IV beta
blocker (or a non-DHP CCB with HFpEF) is
recommended to slow ventricular response to
AF in the acute setting, with caution in patients
with overt congestion, hypotension, or HFrEF
(Class I)
 In the absence of pre-excitation, IV digoxin or
amiodarone is recommended to control heart
rate acutely (Class I)
 Digoxin is effective to control resting heart rate
with HFrEF (Class I)

Heart failure
 IV amiodarone can be useful to control heart rate with
AF when other measures are unsuccessful or
contraindicated (Class IIa)
 In patients with chronic HF who remain symptomatic
from AF despite a rate-control strategy, it is reasonable
to use a rhythm-control strategy (Class IIa)
 Amiodarone may be considered when resting and
exercise heart rate cannot be controlled with a beta
blocker (or a non-DHP CCB with HFpEF) or digoxin,
alone or in combination (Class IIb)
 For rate control, IV non-DHP CCB, IV beta blockers, and
dronedarone should not be given with decompensated
HF (Class III)

How Can Atrial Fibrillation Be
Prevented?
 Following a healthy lifestyle and taking steps
to lower your risk for heart disease may help
you prevent atrial fibrillation (AF). These
steps include:
 Following a heart healthy diet that's low in
saturated fat, trans fat, and cholesterol. A
healthy diet includes a variety of whole
grains, fruits, and vegetables daily.
 Not smoking.
 Being physically active.
 Maintaining a healthy weight.

 If already having heart disease or other AF
risk factors, regular checkup and followup. In
addition to adopting the healthy habits
above:
 Advise DASH eating plan to help lower blood
pressure.
 Keep cholesterol and triglycerides at healthy
levels with dietary changes and medicines (if
prescribed).
 Limit or avoid alcohol.
 Control of blood sugar level if diabetic.
 Medical care and medicines as prescribed.

Summary
 Most common cardiac arrhythmia
 High prevalence
 Stroke and Heart failure – Risk
 Treatable disease with early and proper
interventions.

.
THANK YOU FOR
YOUR PATIENCE
ravikanth.moka@gmail.com
References:
Braunwald’s
American Heart Association guidelines

ATRIAL FIBRILLATION 2016

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