the internists approach to atrial fibrillation: a simple strategy for a complex problem peter...

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;155:469-473.

U.S. population

Population withatrial fibrillation

Age, yr

<5 5-9

10-14

15-19

20-24

25-29

30-34

35-39

40-44

45-49

50-54

55-59

60-64

65-69

70-74

75-79

80-84

85-89

90-94

>95

U.S. populationx 1000

Population with AFx 1000

30,000

20,000

10,000

0

500

400

300

200

100

0

Atrial fibrillation accounts for 1/3 of all patient discharges with arrhythmia as principal diagnosis.

2%VFData 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

Disease3% 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 RateAssess 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):1833-42

92

64

0102030405060708090

100

24 hrs

IV amiodaroneIV Placebo

Conversion (%)

P=0.0017

< 24 hrs duration

Minimally symptomatic with rate control Observe for another 24 hrs (may be

paroxysmal) Anticoagulate if indicated

< 48hrs but > 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;328:750-755.

A Left Atrium B 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 - 252 PAF2 - 141 RACE - 522 STAF - 200 AFFIRM - 4060 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 FibrillationAbsence of identifiable cardiovascular, pulmonary, or associated systemic disease

Approximately 0.8 - 2.0% of patients with atrial fibrillation (Framingham Study)1

In one series of patients undergoing electrical cardioversion, 10% had lone AF.2

1 1 Brand FN. JAMA. 1985;254(24):3449-3453.

2 Van Gelder IC. Am J Cardiol. 1991;68:41-46.

Predictors of Thromboembolic Risk in Atrial Fibrillation

Previous Stroke or TIA - 2.5

History of HTN - 1.6

CHF - 1.4

Advanced Age >65 yrs (cont. per decade) - 1.4

DM - 1.7

CAD - 1.5Atrial Fibrillation Investigators. Arch Intern Med. 1994;154:1449-1457.

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