Atrial fibrillation and flutter: Practical Management Tips

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


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


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”


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)

AF diagram

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 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


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


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

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-Mitral valve area less than 2.0 cm2

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 person-years 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

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 self-cardioverts in front of you? Do they need 4 weeks of warfarin? If they self-cardiovert 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

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

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

AF diagram

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

AF diagram

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

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

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Atrial fibrillation and flutter: Practical Management Tips

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