Atrial fibrillation Flashcards
In more stable patients, the decision of whether to convert the rhythm depends on a number of factors, including what?
- risk of thromboembolism
- need for anticoagulation
- and odds of recurrent AF
AF has several clinical implications, most important of which are what?
cardiomyopathy
and thromboembolism.
Describe : Algorithm for management of atrial fibrillation
Management differs depending on whether
the patient is hemodynamically stable or unstable. How?
- Hemodynamically stable: rate control and/or rhythm control, with or without anticoagulation.
- Hemodynamically unstable: immediate electrical cardioversion to restore sinus rhythm. This approach assumes that the instability is rhythm related. In most patients, however, the instability is caused by other disease processes (myocardial infarction, gastrointestinal bleed, pulmonary embolism, sepsis, etc), with AF representing merely a potentially distracting side effect.
Should unstable patients receive rate-crontrolling agents?
No
Should patients with Wolff-Parking-White receive rate-controlling aents ?
No
Name therapies for RATE CONTROL of AF? (4)
- Calcium channel blocker (Verapamil, diltiazem) : Very effective
- BB (metoprolol, propanolol) : Very effective
- Digoxin : Secondary role in the ED due to slow onset and long half-life
- Amiodarone (oral or IV) : Less effective than the pure rate control agents listed previously.
Describe use of anticoagulants in AF
- to avoid thrombogenesis
- 48-Hour Rule. AF of less than 48 hours’ duration does not generally require acute anticoagulation; however, several recent studies suggest that even those with AF for less than 48 hours have highly variable risk for early thrombotic complications.
- Newer recommendations are for patients with a CHA,DS,-VASc score of greater than 2 in men or greater than 3 in women to receive acute anticoagulation prior to cardioversion, which then is continued in the outpatient setting
Describe : CHA2D2S-VASC
Describe suggested anticoagulation in AF according to CHA2DS2-VASC score
- 0 : low stroke risk = No therapy is recommended other than aspirin
- 1: intermediate stroke risk = DOAC or warfarin° is better than aspirin (Reasonable to omit therapy in women)
- 2 or greater: high stroke risk = DOC or warfarin
Patients with valvular AF due to moderate to
severe mitral stenosis or mechanical valves
have high stroke risk = Warfarin
Describe : ANTICOAGULATION APPROACHES FOR CARDIOVERSION
Name the two main approaches for pre-cardioversion anticoagulation in AF (2)
- Conventional approach
- Alternative approach
Describe conventional approach for pre-cardioversion anticoagulation in AF (2)
- Direct oral anticoagulant (DOAC) or warfarin for at least 3 weeks prior to cardioversion, with an international normalized ratio (INR) goal of 2-3.
- This option has the advantage of standing the “test of time” but delays cardioversion.
Describe alternative approach for pre-cardioversion anticoagulation in AF (3)
- Transesophageal echocardiogram (TEE) and, if no clot is seen, administering a DOC or heparin/enoxaparin and proceeding immediately to cardioversion.
- This approach is quicker and more useful in individuals with high bleeding risk and in patients with persistent symptoms.
- However, it requires a TEE, which carries a higher risk of complications.
In both approaches, anticoagulation therapy must be continued for at least ___ post-cardioversion to prevent new clot formation during the “atrial stunning window.
4 weeks
Name methods of cardioversion (2)
- (1) direct current (DC) cardioversion
- (2) pharmacologic cardioversion
Name and describe : DRUGS FOR PHARMACOLOGIC CARDIOVERSION
Describe : Ablation (3)
- recommended for a select patient population with symptomatic AF and mild or no left atrial enlargement
- in whom a rihythm control strategy has been chosen but who have failed treatment with one or more antiarrhythmic drugs.
- Given the shortcomings of chronic antiarrhythmic therapy in terms of side effects and recidivism rates, electrophysiologic interventions are likely to become more widespread.
The most validated and clinically useful risk stratification models for determining stroke and bleeding risk are what? (2)
the CHA,DS,-VASc and HAS-BLED scores
Describe : Anticoagulation (3)
- Anticoagulation therapy consists of DOACs or warfarin, with an INR goal of 2 to 3.
- In general, DOACs are now the preferred method of anticoagulation in non-valvular AF
- with the exception of AF related to mechanical heart valves and moderate to severe mitral stenosis, for which warfarin is still required.
Compare DOACs and warfarin (4)
- When compared to warfarin, DOCs reduce the rate of ischemic and hemorrhagic strokes, major bleeding, and overall mortality.
- Furthermore, DOACs do not require INR monitoring
- are less susceptible to diet and drug interactions
- and do not have warfarin’s narrow therapeutic window.
Some drawbacks to DOACs include what? (2)
- higher cost
- the need for adjustment in patients with renal failure.
Describe : HAS-BLED SCORE: FOR ASSESSMENT OF RISK OF MAJOR BLEEDING AND SUGGESTED THERAPY
Describe : Antiplatelet Therapy (2)
- consists of aspirin 75 to 325 mg daily, clopidogrel 75 mg daily, or both together.
- Aspirin has only a limited ability to reduce stroke risk, estimated to be about one-third that of warfarin.
