Download Atrial FIbrillation - familypracticeresidency.org

David W Kabel MD, FACC
September 4, 2013
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2.7 million Americans have atrial fibrillation
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Numbers are expected to rise in the future
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Aging population
More chronic cardiac conditions
Better detection through long term monitoring
 Event monitors, pacemakers, implantable monitors
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Costs continue to rise
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Annual cost is $7-10 billion per year and rising
Admissions for AF are up 66% in past 20 years
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Overall prevalence-1%
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<65 3-5%
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<80 10%+
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1.5 times higher in men
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2 times higher in caucasians
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Cardiac risk factors
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Non-cardiac risk factors
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Hypertension
ASHD and PVD
CHF
Cardiac surgery (25-30% postop)
Family history of AF
Diabetes and metabolic syndrome
Obstructive sleep apnea
Obesity
Psychological stress
COPD
Hyperthyroidism
Tall stature
Inflammatory conditions (elevated CRP)
Modifiable risk factors
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Smoking
ETOH >3 drinks per day
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AF in absence of underlying risk factors
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12-20% of all AF patients
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45% of AF in younger patients
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Presence and nature of symptoms
Clinical type
Onset of first attack or date of discovery
Frequency, duration, precipitating factors, and
mode of termination
Response to any medications previously given
Presence of underlying heart disease or other
reversible conditions (hyperthyroidism, etc)
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Confirm presence of AF
LVH
P wave morphology
Pre-excitation
Previous MI
Left or Right BBB
Other atrial arrhythmias
Measure PR, QRS, and QT intervals in
conjunction with anti-arrhythmic therapy
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Valvular disease
LA and RA atrial size
LV size and function
LVH
Right sided pressures (pulmonary hypertension)
LA thrombus(low sensitivity)
Pericardial disease
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Chest X-ray
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Cardiomegaly
Pulmonary disease
Blood work
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Thyroid functions
BMP
Hepatic profile
CRP?
CBC
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May be indicated in some circumstances
Stress testing
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Holter monitor, event monitor
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Looking for LAA thrombus
To guide cardioversion
EP studies
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If diagnosis is in question
To assess rate control
TEE
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If AF is exercise induced
To assess rate control
Wide complex tachycardia
Pulmonary vein isolation
AV node ablation and pacemaker
Sleep study-especially if episodes are mostly nocturnal
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Rate control
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Restoration of sinus rhythm (rhythm control)
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Most important initial strategy
Prevention of CHF (tachycardia induced
cardiomyopathy)
May be initial strategy in some patients
Prevention of thromboembolism(TE)
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Class I
Symptoms or signs of ischemia, hypotension, angina or
heart failure
 Pre-excitation syndrome with extreme tachycardia and
hypotension
 Symptoms are unacceptable to the patient
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Class IIa
Part of long term management strategy
 Patient preference in cases of infrequent episodes of AF
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Class III
Relatively short intervals between episodes of AF
 Presence of digitalis toxicity or hypokalemia
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Class I
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Duration >48 hrs or unknown-Oral anticoagulation
(OAC) for 3 weeks before and 4 weeks after DCC
Duration >48 hrs and hemodynamically unstable-IV
heparin followed by OAC for 4 weeks. Role of
LMWH is uncertain
Duration <48 hrs-DCC without prior OAC, followed
byOAC post-procedure depending upon TE risk
Class IIa
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Duration <48 hrs-OAC prior dependent upon risk
TEE guided-Proceed if no LAA thrombus-OAC for 4
weeks post DCC. Limited date on LMWH
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AV node ablation with pacemaker
Indicated in persistent or permanent AF when ventricular
rate cannot be controlled medically or patient is intolerant
to rate control medications
 Cryoablation of AV node
 Patient becomes pacemaker dependent
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Pulmonary vein isolation-cryoablation
Right sided approach across atrial septum to LA.
4 pulmonary veins are identified and cryoablation occurs
in circular pattern around pulmonary vein orifices
 Rare complication of PV stenosis leading to PHT
 Initial success rate of 80-90%
 Repeat PVI common
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Surgical Maze Procedure
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Series of incisions inside the left atrium to redirect
and organize electrical impulses -done on
cardiopulmonary bypass
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Usually done in conjunction with mitral valve
surgery or other cardiac surgeries
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May be done as stand alone procedure in intractable
cases who are highly symptomatic
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Risk Stratification is key to decision making
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Must weigh risk of bleeding into the calculation
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Newer anticoagulants appear “non-inferior” to
warfarin for prevention of TE
“Non-valvular” AF means absence of rheumatic
mitral valve disease of mechanical prosthesis
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Estimates are that only 50-60% of AF patients at
risk for TE are on OAC
Reasons cited include risk of bleeding and risk
of falls.
Patients at highest risk of bleeding and falls are
also at highest risk of TE
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182,000 patients through national registry
Compared risk of ischemic stroke without
OAC vs risk of intracranial hemorrhage while
taking OAC
Used CHADS-VASC and HAS-BLED scoring
systems
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Anticoagulation and Risk Factors in AF Cohort
Kaiser Permanente of Northern California
database
13,559 adults with AF followed a mean of 6
years
Followed patients taking and not taking OAC
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Benefits of OAC far outweigh risks in high risk
populations, even when intracranial hemorrhage
is weighted a higher risk
More weight can be assigned to age
Vascular disease and ischemic heart disease do
not appear to increase TE risk in AF
Renal disease and proteinuria are risk factors for
TE
ATRIA score may be better at predicting both
low risk patients and those at highest risk of
severe stroke than CHADS2 and CHADS-VASC
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The incidence of AF is rising exponentially due to
an aging population and improved prognosis in
patients with cardiovascular disease
AF is multifactoral
Prevention of AF depends upon aggressive
management of risk factors such as hypertension
Strategies of rate vs rhythm control depend upon
individual patient characteristics
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There are several anti-arrhythmic drugs
available, all of which have issues of
effectiveness and side effects which limit their
usefulness
Non-pharmacologic therapies are gaining in
popularity and becoming more effective
AF is associated with high medical costs in
both inpatient and outpatient settings
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A large number of AF patients are at low risk
for TE and should be treated with ASA or
nothing
OAC is under-utilized in the group of patients
at highest risk for ischemic stroke, namely the
elderly
Risk for falls is not a contraindication to OAC