Lecture 8 - Afib Flashcards
Atrial Fibrillation info
Supraventricular tachyarrhythmia
Uncoordinated atrial activation**
irregularly, irregular pulse
ineffective atrial contraction
Atrial flutter info
Supraventricular tachyarrhythmia
Regular atrial activation***
Variable rapid pulse
where does AFib come from?
Atrial Structure abnormalities
Atrial Electrical abnormalities
A-Fib risk factors
Hypertension Obesity Sleep apnea Hyperthyroidism Alcohol + Drugs
Anything changing structure of heart
Non-cardiac Etiology for A-Fib
Genetic/Family history Social - Drinking, smoking Endocrine Surgery (post-op) Exercise Medications idiopathic = "lone AFib"
Meds that can increase AFib
Theophylline Adenosine Digoxin Bisphosphonates NSAIDs
Acute A-Fib
< 48hrs
Paroxysmal A-Fib
< 7 days
Persistent A-Fib
> 7 days
Long-standing persistent A-Fib
> 1 year
5 Step approach to treatment of AF?
- is pt stable or unstable?
- How long have they been in AF
- Does the pt need rate control
- Does the pt need rhythm control
- Do we need anticoag
Ventricular rate control strategy shown to…
impact quality of life
reduce morbidity
decrease complications
rate control mostly for people who are stable
Heart rate targets for Ventricular rate control?
Resting < 80 bpm
Moderate exercise < 110 bpm
Using Beta-Blockers in Ventricular Rate control
- rapidly controls HR at rest and during exercise
- ** Avoid use in acute decompensated HF **
- Titration necessary o avoid bradycardia
Using Beta-Blockers in Ventricular Rate control (Acute, IV)
Metoprolol
Propranolol
Esmolol
Using Beta-Blockers in Ventricular Rate control (Chronic, PO)
Atenolol Metoprolol Timolol Pindolol Nadolol Labetalol Bisoprolol Carvedilol
Non-DHP CCB for Ventricular Rate control
Controls HR at rest and during exercise
** Avoid in acute decompensated HF or HFrEF (LVEF < 40%)
Non-DHP CCB for Ventricular Rate control drugs
Diltiazem
Verapamil
IV or PO for acute
Digoxin for Ventricular Rate control MOA
Vagotonic actions result in Ca current inhibition in AV node
Activation of acetylcholine-mediated potassium currents in atrium
*Lengthens refractoriness, decreases impulse conduction
Digoxin for Ventricular Rate control Considerations
Not 1st line, commonly used tho
Reduces HR during rest, ineffective during activity
Can be used in combo with BB or CCB
Maybe useful in HFrEF
Digoxin for Ventricular Rate control Therapeutic Drug Monitoring
Goal: 0.8-2 ng/ml
Conc >1.2 associated with inc mortality
Amiodarone for Ventricular Rate control MOA
Sympatholytic and CB properties slow AV node conduction
Prolongs repolarization, lengthens refractoriness, inhibits automaticity
Amiodarone for Ventricular Rate control useful in…
refractory or with CI to other agents
OK in acute decompensated HF
Less effective than non-DHP CCB
similar efficacy to digoxin for use in persistent AF
Amiodarone for Ventricular Rate control drawbacks
reg high dose load regimen to accelerate onset of action
toxicities and drug interactions limit use
Which drugs should not be used with Wolff-Parkinson White Syndrome
BB
Non-DHP CCB
Digoxin
Amiodarone
If rate control necessary, with an accessory pathway treat with….
Cardioversion or ablation
If rate control necessary, with a preserved EF, treat with…
Start with BB or non-DHP CCB
use combo BB+non-DHP CCB + amiodarone for further rate control
Consider cardioversion or ablation if those don’t work
If rate control necessary, with a reduced EF w/o decomposition, treat with…
Start with BB or digoxin
use combo BB + digoxin + amiodarone for further rate control
Consider cardioversion or ablation if those don’t work
If rate control necessary, with a reduced EF w/ decomposition, treat with…
digoxin or amiodarone
use combo digoxin and amiodarone for further rate control
Consider cardioversion or ablation if those don’t work
Indications for Rhythm Control
- Hemodynamic Instability
- First episode of AF
- Failure of rate control
- Younger pts ( < 65yr old)
- Pts early in their natural history
- Patient preference
Rate vs Rhythm control
If rhythm selected, rate control also necessary to prevent recurrence of AF
- Rate control simpler + lower cost, but structural/electrical remodeling continues
- Rhythm control is associated with more SE
Rhythm Control Pharmacologic treatment
Type I and Type III antiarrhythmics
Rhythm Control Electrical option
Cardioversion + Ablation
Antiarrhythmics are not recommended for routine use after….
cardioversion in pts with their first presentations of AF
Class 1 Antiarrhythmics
Quinidine (A)
Disopyramide
Procainamide
Flecainide (C)
Propafenone
Propafenone info
Has B-blocking properties
Propafenone & Flecainide info
Class 1 rec
Most effective if AF < 7 days
“Pill-in-pocket” therapy
Cautions of Class 1C (Flecainide & Propafenone)
Avoid in pts with CV disease
Multiple DI
may increase risk of embolism
Dofetilide & Ibutilide info
Class 1 rec
OK in pt with CV disease
Ibutilide is IV only
Class 3 Antiarrhythmics
Dofetilide
Ibutilide
Sotalol
Amiodarone
Dofetilide & Ibutilide Cautions
QTc prolongation
Dose adjustment in renal impairment
Sotalol Cautions
Avoid in HF
Renal elim
Needs a lot of monitoring
Amiodarone Cautions
DI
SE
Long 1/2 life
Rhythm Control W/ CV disease acute
Dofetilide
Ibutilide
Amiodarone
DCC
Rhythm control W/o CV disease acute
Dofetilide flecainide Propafenone Ibutilide Amiodarone DCC
Big issue with Dronedarone?
CI in pt with HF or recent decomposition
Rhythm control Maintenance, No Structural Heart Disease
Dofetilides Dronedarone Flecainide Propafenones Sotalol
Amiodarone = last option
Rhythm control Maintenance, CAD
Dofetilide
Dronedarone
Sotalol
Amiodarone = last option
Rhythm control, Maintenance HF
Amiodarone or Dofetilides
