Download Atrial Fibrillation

Atrial Fibrillation
2008
Zoll Firm Lecture Series
Joyce Meng, M.D.
Eli V. Gelfand, M.D, F.A.C.C.
Atrial fibrillation is associated with a wide
variety of clinical situations:
►
►
►
►
►
►
2008
Hypertension
CAD
CHF
Advanced age
Valvular heart disease
(especially MS)
Post-operative (especially
after cardiac surgery)
Physiologic stress (infection,
SIRS…etc).
► Pulmonary embolism
► Chronic lung disease
► Hyperthyroidism
► WPW
► “lone atrial fibrillation”
►
Zoll Firm Lecture Series
Joyce Meng, M.D.
Eli V. Gelfand, M.D, F.A.C.C.
Atrial fibrillation nonmenclature
►
Lone atrial fibrillation
 Patients with a-fib without clinical or echocardiographic evidence of
heart disease.
►
New onset atrial fibrillation
 First recognized episode
►
Recurrent atrial fibrillation
 More than 1 episode has occured
►
Paroxysmal atrial fibrillation
 Recurrent atrial fibrilation that has returned to sinus rhythm
►
2008
Permanent atrial fibrillation
Zoll Firm Lecture Series
Joyce Meng, M.D.
Eli V. Gelfand, M.D, F.A.C.C.
Morbidity of atrial fibrillation
► Symptoms associated with fast ventricular rate, lost of
AV synchrony, and loss of RR-regularity
► Embolic event/Stroke
► “conversion pauses”
 Patient with atrial fibrillation often have sick sinus syndrome
and experiences a prolonged pause when they convert back
to sinus rhythm which can lead to syncope.
2008
Zoll Firm Lecture Series
Joyce Meng, M.D.
Eli V. Gelfand, M.D, F.A.C.C.
Symptoms
►
When the ventricular rate is very fast,
 does not have enough time to fill- lower output
 congestion backs to the lungs
►
►
►
Loss of AV-synchrony leads to loss of “atrial kick”
Symptoms often includes palpitations, dypsnea, fatigue,
dizziness, chest discomfort.
Worst in patient with a thick, non-compliant ventricle
 Needs time to fill
 Needs the atrial kick to fill
 Includes pt with AS, HOCM, massive LVH…etc.
2008
Zoll Firm Lecture Series
Joyce Meng, M.D.
Eli V. Gelfand, M.D, F.A.C.C.
Treatment
►
If the patient is unstable, needs to cardiovert immediately
 Understand that there is a risk of stroke in patient who are not
therapeutically anticoagulated.
►
Otherwise, it is not clear whether rhythm control or rate
control is better.
 5 clinical trials randomized patients to a strategy of rate control vs
rhythm control (AFFIRM, RACE, PIAF, STAF, and HOT-CAFÉ).
 AFFIRM and RACE were the largest of the 5 trials.
 All found no major difference in the primary end-point between
the two strategies.
 The primary reason to attempt rhythm control for patients who are
highly symptomatic with atrial fibrillation and/or who cannot be
well rate controlled.
2008
Zoll Firm Lecture Series
Joyce Meng, M.D.
Eli V. Gelfand, M.D, F.A.C.C.
“Rhythm control”- Cardioversion
 For a-fib>48 or of unknown duration, cardioversion should be delayed
until pts have been therapeutically anticoagulated for 4 weeks or if
TEE shows no thrombus
 Electricaleffective (70-90%), pre-treatment with antiarrhythmic agents may increase
likelihood of success.
► often requires sedation (pt preferably fasted), can be complicated by pulmonary
edema due to transient stunning
►
 Pharmacologic
Not as effective (40-70%)
► Dofetilide, flecainide, ibutilide, propafeone > amiodarone if <7 days duration;
dofetilide> amiodarone + ibutilide if >7 days duration.
► Can be proarrythmic- some agents can induce torsades
►
 Many people thinks that most patients deserves one trial of
cardioversion if the a-fib is diagnosed for the 1st time.
2008
Zoll Firm Lecture Series
Joyce Meng, M.D.
Eli V. Gelfand, M.D, F.A.C.C.
“Rhythm control”- maintanance of sinus
rhythm
Class Ia (quinidine, disopyramide, procainamide), class Ic
(flecainide, propafenone), and class III (amiodarone, sotalol,
dofetilide), class I associated with increase mortality.
► Amiodarone is the most effective agent and can be used in the
setting of LV dysfunction, CAD, LVH…etc. However, it has a lot of
side effects (pulmonary, thyroid…etc).
► Sotalol less effective but safe in pts with CAD.
► Dofetilide safe in patients with heart failure but can induce
torsades and require an in-patient load.
► In patients without structural heart disease, class Ic agents such
as flecainide and propafenone are a reasonable choice.
►
2008
Zoll Firm Lecture Series
Joyce Meng, M.D.
Eli V. Gelfand, M.D, F.A.C.C.
Rate control
►
►
►
►
►
2008
Urgent treatment in very symptomatic but not overtly unstable patients often
requires IV medication. Long term maintenance is with oral medication.
B-blocker, non-dihydropyridine Ca channel blockers (verapamil, diltiazem),
digoxin, and to some degree amiodarone are effective.
In general, beta blockers are more effective during exercise compared to at
rest. Digoxin is more effective at rest compared to exercise. Ca channel
blockers maybe effective in both situations
Co-existing conditions often dictate use- i.e. pts with systolic heart failure
gets beta blockers, pts with low BP gets digoxin…etc.
Needs to assess response to treatment at rest and with exertion using
Holters, exercise test…etc.
Zoll Firm Lecture Series
Joyce Meng, M.D.
Eli V. Gelfand, M.D, F.A.C.C.
Thromboembolic risk/Anticoagulation
C- congestive heart failure (1), H- hypertension (1), A- age >=75 (1), D- diabetis mellitus (1), S- previous
history of Stroke (2)
►
 Event per 100 person/years
CHADS2
Warfarin
no warfarin
NNT
0
0.25
0.49
417
1
0.72
1.52
125
2
1.27
2.5
81
3
2.2
5.27
33
4
2.35
6.02
27
5/6
4.6
6.88
44
Patients with CHADS score >1 needs to be anticoagulated with coumadin.
However, they don’t need to be bridged with heparin for surgery unless
they have rheumatic mitral stenosis.
2008
Zoll Firm Lecture Series
Joyce Meng, M.D.
Eli V. Gelfand, M.D, F.A.C.C.
Catheter ablation
►
►
►
►
2008
Most of the focus of initiation of atrial fibrillation occurs around
the pulmonary veins.
Radiofrequency catheter ablation techniques to “electrically
isolate” the pulmonary veins is effective in reducing future
episodes of atrial fibrillation with an efficacy of approximately
50-70% in one year.
Probably most effective in patients with structurally normal
hearts, paroxysmal atrial fibrillation who has a shorter duration
of symptoms
The procedures can be complicated by cardiac tamponde,
pulmnary vein stenosis…etc.
Zoll Firm Lecture Series
Joyce Meng, M.D.
Eli V. Gelfand, M.D, F.A.C.C.
Suggested algorithm for management of
atrial fibrillation
2008
Zoll Firm Lecture Series
Joyce Meng, M.D.
Eli V. Gelfand, M.D, F.A.C.C.