Atrial Fibrillation
t
• 1874 Alfred Vulpian- ‘Fremissement fibrillaire’• 1876 Carl Nothnagel- ‘Delerium Cordis’
1906- Einthoven- 1st EKG of afib1909- Rothberger,Winterberg& Lewis- correlation between
EKG and pulse
• Atrial Fibrillation-Atrial Fibrillation-
– Absent Absent ‘P’‘P’ waves waves
– Irregular atrial activity- ‘F’ wavesIrregular atrial activity- ‘F’ waves
• Variable- amplitude, duration and Variable- amplitude, duration and morphologymorphology
– Resultant irregular ventricular responseResultant irregular ventricular response– Impostures- atrial flutter and MATImpostures- atrial flutter and MAT
Classification
• First detected- single documented episode
• Recurrent- 2 or more episodes
• Paroxysmal- Spontaneous conversion (usually <7 days)
• Persistent- episodes are sustained (often >7 days)
• Permanent/Chronic- persistent (typically > 1year)
Etiologies
• Valvular Heart Disease- esp. Mitral• Non valvular and Secondary causes
– Cardiomyopathies (IDCM/NIDCM)– Hypertension– Post-CABG/Post operative state– Toxin- Thyrotoxicosis, ETOH– Pulmonary embolus/COPD– Hypoxia/Acidemia– Sinus Node dysfunction– Congenital Heart disease- WPW, ASD
• Lone Atrial Fibrillation– <12% without identifiable cause– Age <60
Conditions Allied with AF
Copyright restrictions may apply.
Go, A. S. et al. JAMA 2001;285:2370-2375.
Prevalence of Diagnosed Atrial Fibrillation Stratified by Age and Sex
In General- <1% of Population < 60 yrs >6-8% of Population >80 yrs
Copyright restrictions may apply.
Go, A. S. et al. JAMA 2001;285:2370-2375.
Projected Number of Adults With Atrial Fibrillation in the United States Between 1995 and 2050
Concerns
• Thromboembolism
• Mortality
• Cardiomyopathy and CHF
• As well as– Known Knowns– Known Unknowns– Unknown Unknowns
Copyright ©2001 American Heart Association
Fuster, V. et al. Circulation 2001;104:2118-2150
Relative risk of stroke and mortality in patients with AF compared with patients without AF
Risk of CV ~5% per year with risk factorsAnnual CVA risk 23.5% for those aged 80 to 89 years
Copyright ©2005 American Heart Association
Verma, A. et al. Circulation 2005;112:1214-1222
Kaplan-Meier curves describing survival in 46 984 post-coronary bypass surgery patients at the
Cleveland Clinic from 1972 to 2000
AF and CVA Risk Factors• CHADS2
– Hypertension- even a history thereof =1– Diabetes =1– Congestive heart failure =1– Age >75 years– Prior TIA/CVA = 2
• Others– Prior MI– Echo data- LV dysfunction (EF<35-40%) , Left atrial
enlargement– Some argue age >60 or 65
BF Gage et al. JAMA 2001 285: 2864-2870.Krahn AD et al. Am J Med. 1995;98:476-84 .Atrial Fibrillations Investigators. Arch Intern Med. 1998;158:1316-20.
Risk for CVA: CHADS2
Score CVA risk/Yr
0 1.9%
1 2.8%
2 4.0%
3 5.9%
4 8.5%
5 12.5%
6 18.2%BF Gage et al. JAMA 2001 285: 2864-2870.
AF and Cardiomyopathy
• Rawles (Br Heart J 1990;63:157-61)-↓C.O. with HR>90• Tachycardia-induced Cardiomyopathy- may
occur with heart rates ≥ 105-110 BPM over 10-14 days– Reversible with proper rate control– Symptoms vary between patients
• Rate Control– AFFIRM
• Resting HR ≤ 80 BPM• 24 Hour Holter- Avg HR ≤ 100 BPM and no HR > 110% MTHR• HR ≤ 110 BPM during 6 minute walk test
Shinbane et al. J Am Coll Cardiol 1997;29:709-15.NHLBI AFFIRM investigators Am J. Cardiol 1997;79:1198-1202
AF in CHF: Prognostic Implications
V-HeFT no effect of AF
on mortality
Middlekauf Carson Dries Mahoney Crijns Mathew0
10
20
30
40
50
60
p=NSp=NS
Mo
rta
lity
(p
erc
en
t) Sinus Rhythm AF
…but SOLVD found RR 1.34, p=0.002 (Cox) Framingham HR for death 1.6 in males; 2.7 females (Cox)
V HeFT found no effect of AF on survival
Prevalence of AF and CHF
• 80% in “dropsy”– Mackenzie J. The
Oxford medicine,
1920:387-492.
• Clinical Trial data 15-30% AF, higher with worse NYHA
– Ehrlich, Nattel, and Hohnloser, JCE 2002 13: 399-405
AF and CHF- in sum• AF and CHF appear to co-promote • While treatment of LV dysfunction
prevents AF, converse not clear (except in poorly rate-controlled subjects)
• Clinical trial data highly desirable– AF-CHF – Randomized study of non-pharmacologic treatment in
subjects with LV dysfunction
Circulation. 2008;118:S_827
Prevention of CHF by treatment of AF
• Ablate and pace– Uncontrolled studies show improvements in
LV function– Controlled study- improved dyspnea and
exercise tolerance but not LV function • Circulation 1998;98:953-960• Mayo experience- does not alter prognosis
– NEJM 344:1043-1051
• Bi-V might be better– Eur Heart Journal 2002 23: 1780-1787
Can We fix it?
• Management Strategies– Rate Control
• Pharmacologic• Non-Pharmacologic
– Rhythm Control• Anti-arrhythmics• Surgical ‘correction’• Percutaneous ‘correction’
– Prevention
Rate vs. Rhythm
Fuster et al. JACC.2006;48(4):e149-246
-No significant difference in mortality-Anticogulation is essential regardless of strategy
Fuster, V. et al. Circulation 2001;104:2118-2150
Pharmacological management of patients with newly discovered AF
Assess for underlying disease:EchocardiogramIschemic Heart diesaseEndocrine diseaseOSA
CVA Risk Stratify
Rate Control Strategy
• AV nodal blocking Agents– Beta-receptor antagonists– Non-dihydropyridine Calcium channel
blockers– Digoxin-indirect via vagal effects
• Ablate and Pace
Rate control strategery
Farshi et al. JACC 1999; 33(2): 304-310
Dig-βb
Mayo Ablate and pace experience
NEJM 344:1043-1051
Rhythm Control Simplified
Fuster et al. JACC.2006;48:854-906
Fuster, V. et al. Circulation 2001;104:2118-2150
Arrhythmia-free survival after electrical cardioversion in patients with persistent atrial
fibrillation
DCC- >87% successful in most patientsOnly 25-35% of patients will be in sinus rhythm at one year
Kastor, J.A. Arrhythmias, Second Edition W.B. Saunders Co.. 2000: pp79-81
Anti-arrhythmics
Fuster et al. JACC.2006;48(4):e149-246
Dronedarone
-Contraindicated in Class IV CHF
Roy, D. et al. N Engl J Med 2000;342:913-920
Percentage of Patients Remaining Free of Recurrence of Atrial Fibrillation
18% of the patients receiving amiodarone and 11% of patients receiving sotalol or propafenone had to discontinue therapy because of adverse effects
RACE II
Surgical Modification
• Cox-Maze• Several
Modifications• Variable results
– ? Data
• Still considered the ‘Gold Standard’
Dr. Cox?
Evolution of percutaneous AF ablation
• 1994 John Swartz first reports endocardial maze procedure
• 1998 Haissaguerre isolates pulmonary vein “culprit”
• 1999-2003 more PVs, more foci
• 2003 Pappone anatomic approach
• 2004 Morady Need to isolate 4/4 veins
• 2004 Pappone ablate vagal efferent
Marine, Prog Card Disease 2005
Pulmonary Vein Isolation
Alternative approach
Success rates for ablation outside the PV
“success rates 2-3 times that of antiarrhythmic medications” Verma Circ 2005
Complication in Modern Series
JACC 2009;53:1798-803
-45 K procedures, 32.5 K patients, 162 centers-Between 1995 and 2006-0.98 in 1000 mortality
Cost in Medicare Dollars
-50% unsuccessful
Theory: Prevention
Paroxysmal AF
Persistent AF
yearsHypertensionSleep apnea
RAAS activationFibrosisDiastolic Dysfunction
Altered substrate
Altered electrophysiology
Permanent AF
Non-Antiarrhythmic Agents for Afib prevention
Summary
• Highly prevalent condition with significant associated morbidity and mortality– Driven mostly by thromboembolic events
• Decision to pursue rhythm control based on patient symptoms
• Rhythm control– Anti-arrhythmics still 1st line– Ablative or surgical therapy- case by case