Master the board step 3

Cardiology
Rate control medications are beta blockers (metoprolol, esmolol), calcium
channel blockers (diltiazem), or digoxin. In the acute setting, such as the
emergency department, these agents should be given intravenously.
Once the rate has been controlled, anticoagulation with warfarin or dabigatran
to a target INR of 2–3 is the next best step in all patients with an atrial
arrhythmia persisting beyond 2 days. If the question does not state the duration,
you are to treat it as if it were persisting for longer than 2 days.
Stroke/TIA = 2 points
Dabigatran, rivaroxiban, and apixaban are oral anticoagulants with similar
efficacy to warfarin but without the need to monitor the INR.
The long-term use of rate control medications, such as metoprolol, diltiazem,
or digoxin, combined with anticoagulation is equal or better than cardioversion
with electricity or medications.
CHADS 2 (CHF, hypertension, age > 75, diabetes, or stroke/TIA) is a scoring
system to indicate the need for warfarin, dabigatran, rivaroxiban, or apixaban.
A score of 2 or more means warfarin, dabigatran, or rivaroxaban. A score of 0
or 1 means aspirin.
Routine cardioversion of
atrial fibrillation is not
indicated.
When CHADS 2 is at 2 or more points, control the rate and anticoagulate.
Novel oral anticoagulants (NOACs) such as rivaroxaban, dabigatran, or
apixaban become therapeutic in a few hours: Unlike warfarin, NOACs do not
need several days to reach therapeutic levels. Even when warfarin is used for
atrial fibrillation, there is no need to bolus the patient with heparin. Why?
Because atrial fibrillation is a long-term disease that takes months or years to
develop a risk of stroke, while full-dose heparin carries a risk of bleeding. Just
start the warfarin and wait a few days. It is safe.
Atrial Flutter (A-Flutter)
Atrial flutter is managed in the same way as atrial fibrillation. The only difference
is that the rhythm is regular on presentation.
The following table shows how to choose the right rate control medication for
a-fib and a-flutter.
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