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