The Internists Approach to Atrial Fibrillation: A Simple Strategy for a Complex Problem Peter Holzberger, MD 12/4/03

Focus Immediate Treatment Anticoagulation Maintenance Issues

Background Atrial fibrillation is the most common sustained arrhythmia Affects 2 million Americans 6% over the age of 65 experience it Responsible for 15% strokes Benjamin E: Epidemiology of Atrial Fibrillation. In Falk RH, Podrida PJ, eds:Atrial Fibrillation: Mechanisms and Management. 2nd Ed, Lippincott-Raven Press, New York 1997, pp.1-22.

Atrial Fibrillation Demographics by Age Adapted from Feinberg WM. Arch Intern Med. 1995;155: U.S. population Population with atrial fibrillation Age, yr < >95 U.S. population x 1000 Population with AF x ,000 20,000 10,

Atrial fibrillation accounts for 1/3 of all patient discharges with arrhythmia as principal diagnosis. 2%VF Data source: Baily D. J Am Coll Cardiol. 1992;19(3):41A. 34% Atrial Fibrillation 18% Unspecified 6% PSVT 6% PVCs 4% Atrial Flutter 9% SSS 8% Conduction Disease 3% SCD 10% VT

Symptoms Inappropriate heart rate response Tachymyopathy Irregular rate Loss of atrial systolic function Thromboembolism

Guidelines

Immediate Treatment Cardiovert Hemodynamic collapse Control the Rate Assess symptoms

Immediate Treatment Significant symptoms Restore NSR +/- Antiarrhthymics Minimal symptoms Strongly Consider rate control

Immediate Treatment History,Physical,Labs Underlying heart disease,thyroid,alcohol ECG LVH, WPW, MI CX Pneumonia Echocardiogram Blown ticker ETT/Holter Rate assessment

Immediate Treatment Categorize the atrial fibrillation Follow the flowchart When faced with the antiarrhythmic option consider getting a referral almost never needed in the acute decision process exception: IV Amiodarone

Guidelines: Definitions

Case: 1 40 yr old male Seen in ED with new onset palpitations Started 2 hrs ago Otherwise healthy but nervous ECG: atrial fib 160 Rx’d with beta blocker: HR 85 Feels much better

Categorize 1: Is it Paroxysmal? 2: Is it Persistent? 3: Is it Permanent?

What Next? 1: DC Cardioversion +/- TEE 2: IV Amiodarone 3: IV Ibutilide 4: Come back in 24 hrs and reevaluate

Placebo Cotter et al,.Eur Heart J Dec 1999; 20(24): Conversion (%) P=0.0017

< 24 hrs duration Minimally symptomatic with rate control Observe for another 24 hrs (may be paroxysmal) Anticoagulate if indicated

24hrs Cardiovert if NSR is desirable Most patients with new onset atrial fibrillation regardless of age Rate control and anticoagulation if appropriate Hx or recurrent paroxysmal with minimal sx’s usually in the elderly

Case: 2 50 yr old female hasn’t felt well for 3 days Otherwise healthy ECG atrial fib rate 140 Rx’d beta blocker: HR 105 Still feels terrible

What next? 1: DC Cardioversion +/- TEE 2: IV Amiodarone 3: IV Ibutilide 4: Come back in 24 hrs and reevaluate

Manning WJ. N Engl J Med. 1993;328: A Left AtriumB Left Atrial Appendage Clot

> 48 hrs TEE cardioversion followed by anticoagulation if symptom intolerant Rate control and anticoagulation for 1 month before attempted cardioversion if NSR is desired Long term rate control and anticoagulation

Guidelines: Newly Discovered AF

Guidelines: Recurrent Paroxysmal

Case: 3 83 yr old noted to be in atrial fibrillation on routine office visit - asymptomatic Otherwise healthy except for HTN Wonders what all the fuss is about Evaluation for underlying causes is negative

What next? 1: If it ain’t broke don’t fix it 2: Anticoagulate, rate control and cardiovert 1 month later 3: Anticoagulate and rate control 4: Rate control

Case: 4 38 yr old with atrial fib noted on routine physical asymptomatic Otherwise healthy Evaluation unremarkable

What next? 1: If it ain’t broke don’t fix it 2: Anticoagulate, rate control and cardiovert 1 month later 3: Anticoagulate and rate control 4: Rate control

Guidelines: Recurrent Persistent

Rate Control : A New Paradigm 5 Randomized trails of Rhythm vs. Rate PIAF PAF RACE STAF AFFIRM patients 3.5 yrs

AFFIRM

Stroke AFFIRM 77 (5.5%) rate control and 80 (7.1%) rhythm control 1% per year Majority associated with no Coumadin or INR <2 RACE 14 (5.5%) rate control and 21 (7.9%) rhythm control 6 strokes after stopping Coumadin (5 in sinus) 23 with INR <2

Anticoagulation: The Gold Standard 5 large prospective randomized trials All comparing warfarin to placebo while utilizing rate control. All with the same highly significant result Embolic risk decreases to 1.4% (68% reduction)

Warfarin

Who Gets Warfarin?

Everyone with Atrial Fibrillation Except: “Lone” Atrial Fibrillation Absence of identifiable cardiovascular, pulmonary, or associated systemic disease Approximately % of patients with atrial fibrillation (Framingham Study) 1 In one series of patients undergoing electrical cardioversion, 10% had lone AF Brand FN. JAMA. 1985;254(24): Van Gelder IC. Am J Cardiol. 1991;68:41-46.

Predictors of Thromboembolic Risk in Atrial Fibrillation Previous Stroke or TIA History of HTN CHF Advanced Age >65 yrs (cont. per decade) DM CAD Atrial Fibrillation Investigators. Arch Intern Med. 1994;154:

Exception for 325 mg ASA Age <75 yrs No risk factors Normal echo

How to treat the symptomatic Referral: Antiarrhthymics Ablation AV Junction Pulmonary Veins Surgery MAZE

Maintenance Issues Rate Control Annual Holter with mean HR below 100 Anticoagulation Monthly INR when stabilized Antiarrhythmic Rx Periodic ECG, drug level -if possible, LFT and kidney function

Atrial Fibrillation: Surgery Hold anticoagulation 4 days prior to surgery Start back on day of surgery Exceptions High risk embolization-bridge with heparin Embolization within 3 months Mechanical mitral valve

Case: 5 70 yr old male with HTN develops atrial fib post op day 2 following emergency cholycystectomy Rate is adequately controlled No acute issues No prior history of atrial fib

What Next? 1: DC Cardioversion 2: IV Amiodarone 3: Anticoagulate for 1 month then cardiovert 4: Long term rate control and anticoagulation

Post-Operative Atrial Fibrillation Pre-op beta blocker in high risk patient Old, history of atrial fibrillation Rate control acutely Conversion Antiarrhythmic with conversion for 1 month If symptomatic otherwise avoid antiarrhythmic

Atrial Fibrillation: Pregnancy Anticoagulate as indicated Heparin 1st Trimester Coumadin 2nd and 3rd Control rate with beta, calcium or beta blocker or digoxin Convert with antiarrhythmic if stable, cardioversion if unstable

Atrial Fibrillation: Miscellaneous Hyperthyroidism Rate control Anticoagulate as needed. Wait till euthyroid to convert MI Cardiovert if hemodynamic IV amiodarone, digitalis if poor LV function for rate control Beta blockers Heparin

Summary Control the rate Decide whether NOT to anticoagulate Consider referral for antiarrhythmic or non pharmacological treatment