Everything you wanted to know about atrial fibrillation and flutter…and then some more!
Consult with electrophysiologist Randy Jones MD
Is there a limit to the number of cardioversions a patient can have in a year?
- No limit
- If a patient comes into the ED for frequent cardioversion, treatment strategy needs to be changed.
- Ablation, increased dose of medication or new medication
- Goal is have the patient be able to tolerate the condition. No matter the treatment, it should be considered a chronic condition like hypertension. It can be managend and controlled, but it is a lifelong companion
What is the clinical difference between a-fib and a- flutter?
- If it looks like a mix of fib and flutter, it’s probably just a-fib. Delete the term fib-flutter from your EKG lexicon.
- Classic/ typical flutter –EKG down going saw tooth pattern in II, III and AVF & up going in V1. An electric circuit going around the tricuspid valve counter-clockwise.
- Interrupting the circuit will terminate the rhythm. That’s why it doesn’t take so muchenergy to cardiovert.
- It is a defined track.
- If any point of the track is interrupted, the dysrhythmia ends. Compare to a-fib, which involves a larger area of atrium and thus takes more energy to convert
Why you should be nervous about sending an atrial flutter patient home
- Be aware if you slow the atrial rate you may raise the ventricular rate, by allowing the av node to conduct 1:1
- A concern in sending someone home with a flutter is that the rate may become very variable (i.e. while lying down they may be in a 4:1 conduction though while standing may go to 2:1.
- Ablation is an effective tx for a –flutter
- Recurrence rate almost 100% without ablation
Treatment of Atrial Fibrillation (outside of rate control)
- Chemical: Procainamide: 1 gm in 250cc D5w over 1 hour-discussed in previous episode-52% conversion
Pill in a Pocket
- American guidelines of tx of atrial fibrillation August 2006, endorsed the pill in pocket approach.
- Dosage is 200 mg of flecainide or 450 mg of propafenone (for people weighing 70 kg (155 lbs) or less) or 300 mg of flecainide or 600 mg of propafenone for people weighing more than 70 kg.
- First time should be done in the a monitored setting
- Candidates: younger, normal sized atrium, not in long term/chronic afib
- Desire to discontinue use of warfarin not a reason for ablation. Ablation does not decrease stroke risk. Pts will still need anticoagulation. Desired outcome from ablation is to improve symptoms and quality of life
- Warfarin treatment after an ablation procedure typically 2-3 months, though this can be looked at individually
- *IF a patient is high risk for thromboembolic event, will place pt on warfarin indefinitely, even if in NSR
How do you decide if a patient needs anticoagulation?
In the United States
Recent European guidelines use the CHADS-VASc score, which favors oral anticoagulants. Anyone over a score 2 oral anticoagulant, 1=ASA or oral anticoagulant and 0 was basically nonexistent
Dabigatran: Alternative to Warfarin
- Dabigatran (Pradaxa) is an anticoagulant from the class of the direct thrombin inhibitors. An alternative to warfarin, it does not require frequent blood tests for international normalized ratio (INR) monitoring while offering similar results in terms of efficacy.
- The U.S. Food and Drug Administration (FDA) approved dabigatran on October 19, 2010, for prevention of stroke in patients with non-valvular atrial fibrillation. Click here to read the RE-LY trial that compared Dagibatran and warfarin.
- No direct reversal agent, factor VII may be effective (in theory).
- Dosing 150mg BID
- Be aware -Although no way to monitor if anticoagulation is adequate, physicians may have to take the patients “word” on the fact that have been compliant with BID dosing.
Written Summary: Justin Arambasick MD Akron General Medical Center