Transcript June 20 2011 - Siegel - AF Afl

Atrial fibrillation and flutter:
Practical Management Tips
Internal Medicine Residency
Program Noon Conference 2011
Learning Goals
A brief discussion of supraventricular
tachycardia (SVT)
 Review of AF and AFl physiology and
EKG differentiation
 Management of atrial fibrillation (AF)
 Management of atrial flutter (AFl)

Management of fib/flutter
Anticoagulation
 Cardioversion
 Rate control
 Rhythm control
 Ablation
 Cardiothoracic surgery

But, first, a brief diversion
Definition of supraventricular
tachycardia (SVT)
 Differentiating among types of SVT
 Differentiating AF from AFl

Supraventricular tachycardia





Abbreviated SVT
“Supra” means “above”
Supraventricular tachycardia comes from
above the ventricles
DO NOT CONFUSE with NSVT (non-sustained
ventricular tachycardia)
(Essentially) all narrow-complex tachycardia
has a supraventricular origin
SVT possible sites of origin

Sinus node
 Atria
 Atrioventricular node
 His bundle

Or some combination of the above
Supraventricular tachycardia







Sinus tachycardia
Multifocal atrial tachcyardia
Paroxysmal atrial tachycardia
AV nodal reentrant tachycardia (AVNRT)
Atrioventricular reentrant tachycardia (AVRT)
Atrial fibrillation
Atrial flutter
Rare types of SVT



Inappropriate sinus tachycardia (previously called
SNRT or SANRT)
Junctional ectopic tachycardia (JET) and paroxysmal
junctional reciprocating tachycardia (PJRT) -- mostly
seen in infants and children
Nonparoxysmal junctional tachycardia (NPJT) -- seen
in acute right coronary artery occlusion and digitalis
toxicity
Supraventricular tachycardia




A nonspecific term that technically refers to seven
separate diagnoses
When clinicians use the term “SVT,” they mean that it
is a narrow-complex tachycardia, and they cannot
specify which one
Do not use the term “SVT” if you have an actual
diagnosis
Do use “SVT” when the patient has “supraventricular
tachycardia, not otherwise specified”
Supraventricular tachycardia







Sinus tachycardia
Multifocal atrial tachcyardia
Paroxysmal atrial tachycardia
AV nodal reentrant tachycardia (AVNRT)
AV reentrant tachycardia (AVRT)
Atrial fibrillation
Atrial flutter
When in doubt, use a vagal
maneuver

Adenosine 6mg IV push
-We don’t use enough adenosine!
-But must be done with proper monitoring

Valsalva maneuver
-Safe; usually ineffective

Carotid sinus massage
-In properly selected populations, complications
are rare
Carotid Sinus Massage
Contraindications
Carotid bruit
 Prior stroke or transient ischemic attack,
unless imaging has shown no significant
carotid disease
 Myocardial infarction in the previous six
months
 History of serious cardiac arrhythmias
(VT, VF)

Vagal maneuvers

Diagnostic
-Usually you can learn which SVT it was by
doing a vagal maneuver

Therapeutic
-Vagal maneuvers can terminate AVRT and
AVNRT
Differentiating AF from AFl

AFl is a macroreentrant atrial rhythm with
a reentry circuit that involves a large area
of atrial myocardium

AF is caused by multiple wandering
wavelets, a hodgepodge of
microreentrant circuits, often located in
the pulmonary veins
Atrial flutter
Atrial flutter
P waves exhibit a “sawtooth” pattern
referred to as flutter waves or “F” waves
 Atrial rate is typically 250-350 beats per
minute (bpm)

Atrial flutter, continued
Classically, atrial rate is 300 bpm with
2:1 AV conduction, leading to a heart
rate of 150 bpm
 But focus on the atrial pattern when
diagnosing SVT--try to ignore the QRS
complexes, just looking at the P (or F)
waves at first

Atrial flutter (with 4:1 response)
Atrial flutter (with 2:1 response)
Atrial flutter (variable response)
Atrial flutter (and more)
Atrial fibrillation
Rapid and irregular atrial activity at a
rate of 350-600 impulses per minute
 Usually irregularly irregular ventricular
response
 There are no P waves
 Sometimes the F waves are so fine, the
surface EKG cannot detect them

Atrial fibrillation
Atrial fibrillation
Atrial fibrillation terms
Paroxysmal
 Persistent
 Permanent
 “Lone”

Atrial fibrillation terms, cont.
Paroxysmal
-episodes terminate spontaneously in less
than seven days
 Persistent
-fails to terminate within seven days

Atrial fibrillation terms, cont.
Permanent
-AF lasts for more than one year, and
-Cardioversion has not been attempted or
has failed
 “Lone”
-patients less than 60 years of age
without structural heart disease

Atrial fibrillation terms, cont.
This classification applies only when no
clear reversible cause of AF.
 If AF is clearly due to heart surgery,
pericarditis, myocardial infarction,
hyperthyroidism, pulmonary embolism,
or other reversible causes, avoid this
classification system

Management of fib/flutter
Anticoagulation
 Cardioversion
 Rate control
 Rhythm control
 Ablation
 Cardiothoracic surgery

Anticoagulation (AC)
Recommendations are essentially the
same for AF and AFl
 First, assess if the patient is high risk for
cardioembolic stroke
 Most patients with high risk should be
on AC if they ever were seen in AF or
AFl

High risk for cardioembolic
stroke
Rheumatic mitral stenosis
2
-Mitral valve area less than 2.0 cm
 Prosthetic heart valves
 Hyperthyroid (?)
-2006 ACC/AHA/ESC guidelines
recommend INR 2-3 in all patients until
euthyroid; ACCP does not comment on
this

CHADS2 score
For use in patients without the high risk
factors on the previous slide
 There are other risk models, including
the CHADS2-VASc score

CHADS2 score
When can you stop AC?
If AF was due to a completely reversed
reversible cause, maybe you can stop
 For AFl, you can never stop
 After ablation you still can’t stop
 If you had HF, and your EF returns to
normal, you still can’t stop
 Paroxysmal has same risk as others

When to stop AC
Pretty much you have to develop a
contraindication to anticoagulation
before you stop it
 Fall risk is a relative contraindication; it’s
rare that someone is falling so
frequently that it rises to the level of
contraindication

When to stop AC
Really, paroxysmal AF has same stroke
risk as other AF
 Caution when diagnosing AF! If you
misdiagnosed NSR with PAC’s or
multifocal atrial tachycardia as AF, you
can doom someone to lifelong AC

When to bridge with heparin
If patient has any evidence of
hypercoagulable state
 If patient has prosthetic heart valves


Otherwise, risk of intracranial bleeding
and HIT outweighs benefit of reduced
stroke risk and warfarin skin necrosis
Risk of stroke per day off AC
Less than 4 events per 100 personyears prevented
 One day is 4/100/365=0.0011% per day
stroke risk reduction

Efficacy and safety of anticoagulant treatment in acute
cardioembolic stroke: a meta-analysis of randomized
controlled trials. Paciaroni M, Agnelli G, Micheli S,
Caso VS. Stroke. 2007;38(2):423.
What about asa+clopidogrel?
Active-A continued—bleeding
Take-home point
Warfarin>ASA+clopidogrel>ASA
 This applies to stroke prevention
 And to bleeding risk


Every AF patient who is off warfarin
should be on aspirin unless there is a
contraindication to ASA therapy
Clopidogrel + Warfarin = Bleed
ASA+warfarin and ASA+clopidogrel
are relatively safe in most situations
where both are indicated
 Warfarin+clopidogrel has a relative risk
of bleeding >3 times greater than
warfarin alone
 ASA+warfarin+clopidogrel has less
rigorous data; evidence suggests >5
times greater than asa+clopidogrel alone

Dabigatran and Apixaban
Oral anticoagulant medications that do
not require monitoring
 Dabigatran approved for AC in AF/AFl in
USA; NYS Medicaid and NBHN do not
pay for it. Medicare part D does pay
 Apixaban likely similar; not yet approved

You’re the night intern
78 W with HTN, DM, COPD, and history
of paroxysmal AF
 Nurse pages you to say that HR is now
172 beats per minute after albuterol
 You ask, “what’s the blood pressure?”
 The nurse says she will check. You go
to the bedside.

You’re the night intern
HR=172 irregular, BP is 72/48
 Pt. is pale, diaphoretic, lethargic but
responds to questions
 You confirm with EKG that the rhythm is
atrial fibrillation
 Put patient in Trendelenberg position to
optimize cerebral perfusion, then you…

Single best answer: Next step
A) DC cardioversion without sedation
 B) Ativan 2mg IV over 30 seconds, then
direct current (DC) cardioversion
 C) Amiodarone 150mg IV over 15 min.
 D) Diltiazem 10mg IV over 2 minutes
 E) Adenosine 6mg IV push

Single best answer: Next step
A) DC cardioversion without sedation
 B) Ativan 2mg IV over 30 seconds, then
direct current (DC) cardioversion
 C) Amiodarone 150mg IV over 15 min.
 D) Diltiazem 10mg IV over 2 minutes
 E) Adenosine 6mg IV push

Management of fib/flutter
Anticoagulation
 Cardioversion
 Rate control
 Rhythm control
 Ablation
 Cardiothoracic surgery

Indications for cardioversion
Hemodynamically unstable patient with
any (non-sinus) tachycardia with RVR
 Cardiovert first; page cardiology second
 When people are awake, sedate before
cardioversion
 (You learned this in ACLS)

Cardioversion when
hemodynamically stable
Has never been shown to improve
prognosis or reduce embolic risk,
despite rigorous evaluation of this
question in AFFIRM and RACE
 Still, “every patient deserves a trial of
sinus rhythm”

Cardioversion when
hemodynamically stable
AFl is hard to rate control and easy to
cardiovert
 Heart failure (HF) may improve with
restoration of atrial “kick” from
cardioversion
 Particularly important in severe diastolic
HF, also beneficial in systolic HF

Cardioversion complication:
Cardioembolism
Mostly in patients who are not
anticogulated at time of cardioversion
 Reduce risk by anticoagulating
beforehand for 3-4 weeks
 If not on A/C for ~4 weeks prior, do TEE
-If no thrombus on transesophageal
echocardiogram, give heparin bolus,
then cardiovert

Cardioversion complication:
Cardioembolism
Continue anticoagulation for at least 4
weeks after cardioversion
 If stroke risk is low enough, change
from warfarin to ASA (+/- clopidogrel)
 What if someone in paroxysmal AF selfcardioverts in front of you? Do they
need 4 weeks of warfarin? If they selfcardiovert at home, will anyone know?

Cardioversion complications
ST-T changes, CK, troponin
 Myocardial stunning
 Transient hypotension
 Pulmonary edema
 Skin burns/Self-injury
 Ventricular fibrillation (not if SYNC on)
-Much more common in digitalis toxicity

DC Cardioversion, fine points
Usually should be done with one pad on
front and one on patient’s back
 Optimal current level to use in first
shock is not known; lower in AFl
 Biphasic is more successful than
monophasic in terminating arrhythmias
 Turn on the SYNC function

DC Cardioversion, fine points
If first attempt fails, try increasing the
current to 200 joules
 Then try changing the pad position
 Then try pretreatment with
antiarrhythmic drugs
-might require long-term drug treatment
 Still, about 1/3 of DC cardioversion
efforts will fail

Chemical cardioversion
Usually with ibutilide
 Restricted to Cardiology use
 Lower cardioversion success rate than
electrical, but more comfortable (no
sedation needed)
 Caution in long QT
 Amiodarone IV is not cardioversion

Cardioversion take-home
When hemodynamically unstable,
cardiovert immediately (with sedation if
awake patient)
 Consider doing with AC and TEE in
other scenarios, especially newly
diagnosed AF/AFl, AFl difficult to rate
control, and HF—needs cardiology
supervision

Management of fib/flutter
Anticoagulation
 Cardioversion
 Rate control
 Rhythm control
 Ablation
 Cardiothoracic surgery

Rate control
Keep the patient in the arrhythmia
 Simply slows down the rate
 Beta blockers (β-B)
 Calcium Channel Blockers (CCB)
 Digoxin
 Must continue anticoagulation

Rhythm control
Goal is to keep patient in sinus rhythm
 First anticoagulate
 Then load rhythm control medication
 Then cardiovert (possibly with TEE)
 Monitor for antiarrhythmic side effects


Can you stop AC in rhythm control?
Rhythm control: choice of agent
Amiodarone and dronedarone
-Side effects and safety monitoring are an
entire Up-to-Date article
 Sotalol and dofetilide
-Less side effect burden but less effective
in maintaining sinus rhythm, requires
hospitalization for QT monitoring during
initiation, CKD is contraindication, needs
cardiology approval at JMC

AFFIRM trial
Compared morbidity and mortality in
patients randomly assigned to rate or
rhythm control strategy
 In the rhythm control strategy, patients
were allowed to stop A/C if serial Holter
studies showed no AF

Wyse DG, Waldo AL, DiMarco JP, Domanski MJ, Rosenberg Y,
Schron EB, Kellen JC, Greene HL, Mickel MC, Dalquist JE, Corley
SD. A comparison of rate control and rhythm control in patients with
atrial fibrillation. N Engl J Med. 2002 Dec 5;347(23):1825-33.
AFFIRM, continued
The question was: Which is better, rate
control or rhythm control?
 The answer was: Anticoagulation.

In both treatment arms, anyone with a
subtherapeutic INR for any reason had
higher stroke risk
 Serial Holter did not predict stroke risk
 Rhythm control had more side effects

Management of fib/flutter
Anticoagulation
 Cardioversion
 Rate control
 Rhythm control
 Ablation
 Cardiothoracic surgery

Atrial flutter ablation
Takes about 30 minutes
 Success rate >80%
 Technically straightforward
 Main complication is AF after


Should probably be offered to anyone
who ever had AFl and has a good
prognosis, unless they also had AF
Atrial flutter
Atrial fibrillation ablation
Also called pulmonary vein isolation
 Can last more than six hours
 Requires atrial septal puncture and
heparinization

Atrial fibrillation ablation
Main post-procedural complication is a
special type of atrial tachycardia
 No evidence that it’s safe to stop
anticoagulation afterward
 Often requires repeat ablation
procedure to maintain sinus rhythm

Ablate and pace
Insert a biventricular pacemaker
 Ablate the AV node (on purpose)
 Very high procedural success rate
 But leaves the patient lifelong
pacemaker dependent
 Most useful in heart failure, particularly
tachycardia-induced cardiomyopathy
 Also in pacemaker-dependent patients

Management of fib/flutter
Anticoagulation
 Cardioversion
 Rate control
 Rhythm control
 Ablation
 Cardiothoracic surgery

Surgical options
MAZE procedure
-Routinely done during mitral valve
surgeries; often done other times
 LA appendage ligation
 Percutaneous left atrial appendage
occlusion (PLAATO) and others

MAZE
PLAATO
PLAATO

Very cool; effectiveness studies of this
and competing devices are underway
Learning Goals
A brief discussion of supraventricular
tachycardia (SVT)
 Review of AF and AFl physiology and
EKG differentiation
 Management of atrial fibrillation (AF)
 Management of atrial flutter (AFl)

Conclusion





Anticoagulation, when indicated, is the most
important treatment in most patients with
AF/AFl; mostly warfarin/dabigatran
Stronger AC has less stroke but more bleed
Cardiovert your hemodynamically unstable
patients right away
Rate control for most patients
Call cardiology for cardioversion, rhythm
control, ablation, or surgery if appropriate
Thank you

Insert humorous cartoon or scenic
image on this slide