Atrial fibrillation

Question 1

In more stable patients, the decision of whether to convert the rhythm depends on a number of factors, including what?

Answer 1

• risk of thromboembolism
• need for anticoagulation
• and odds of recurrent AF

Question 2

AF has several clinical implications, most important of which are what?

Answer 2

cardiomyopathy
and thromboembolism.

Question 3

Describe : Algorithm for management of atrial fibrillation

Answer 3

Question 4

Management differs depending on whether
the patient is hemodynamically stable or unstable. How?

Answer 4

• 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.

Question 5

Should unstable patients receive rate-crontrolling agents?

Answer 5

No

Question 6

Should patients with Wolff-Parking-White receive rate-controlling aents ?

Answer 6

No

Question 7

Name therapies for RATE CONTROL of AF? (4)

Answer 7

• 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.

Question 8

Describe use of anticoagulants in AF

Answer 8

• 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

Question 9

Describe : CHA2D2S-VASC

Answer 9

Question 10

Describe suggested anticoagulation in AF according to CHA2DS2-VASC score

Answer 10

• 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

Question 11

Describe : ANTICOAGULATION APPROACHES FOR CARDIOVERSION

Answer 11

Question 12

Name the two main approaches for pre-cardioversion anticoagulation in AF (2)

Answer 12

• Conventional approach
• Alternative approach

Question 13

Describe conventional approach for pre-cardioversion anticoagulation in AF (2)

Answer 13

• 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.

Question 14

Describe alternative approach for pre-cardioversion anticoagulation in AF (3)

Answer 14

• 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.

Question 15

In both approaches, anticoagulation therapy must be continued for at least ___ post-cardioversion to prevent new clot formation during the “atrial stunning window.

Answer 15

4 weeks

Question 16

Name methods of cardioversion (2)

Answer 16

• (1) direct current (DC) cardioversion
• (2) pharmacologic cardioversion

Question 17

Name and describe : DRUGS FOR PHARMACOLOGIC CARDIOVERSION

Answer 17

Question 18

Describe : Ablation (3)

Answer 18

• 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.

Question 19

The most validated and clinically useful risk stratification models for determining stroke and bleeding risk are what? (2)

Answer 19

the CHA,DS,-VASc and HAS-BLED scores

Question 20

Describe : Anticoagulation (3)

Answer 20

• 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.

Question 21

Compare DOACs and warfarin (4)

Answer 21

• 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.

Question 22

Some drawbacks to DOACs include what? (2)

Answer 22

• higher cost
• the need for adjustment in patients with renal failure.

Question 23

Describe : HAS-BLED SCORE: FOR ASSESSMENT OF RISK OF MAJOR BLEEDING AND SUGGESTED THERAPY

Answer 23

Question 24

Describe : Antiplatelet Therapy (2)

Answer 24

• 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.