Case #1 Answers:
Awaiting answer review
Answer 1
Ventricular response is determined by AV conduction system, usually AV node rather
than His-Purkinje is limiting factor. Factors affecting this include
sympathetic/parasympathetic tone, circulating catecholamines, and medications.
Other modifying factors in general may be metabolic derangements, fever, illicit
drugs, and thyroid status.
Answer 2
History: Assess ETOH use, sx of thyroid disease, prior BP readings, GI bleeding.
Tests: CBC, CMP, TSH, possibly INR. Echo to exclude SHD.
Answer 3
Rate vs rhythm control vs prn management, depends on severity and frequency of
sx.
Answer 4
Rate control could be with a Beta Blocker or Calcium Blocker with negative chronotropic effects. Digoxin in this high catecholamine state would not be effective.
Answer 5
No, but duration suggests need for 3-4 weeks of anticoagulation before and
after, and/or TEE. Could consider electrical or chemical conversion.
Answer 6
Low risk for thromboembolism and ASA (or nothing) is adequate long term.
Answer 7
Antiarrhythmic drug tx could be daily or possibly a "pill in pocket" approach may
suffice depending on frequency, severity. May be candidate for Class Ic or III
agent. Ischemia, hepatic or renal dysfunction should be excluded. Amiodarone
would be a second or third line agent in this setting. AF ablation should also
be considered if he fails at least one antiarrhythmic drug, is intolerant, or
prefers to avoid a long term antiarrhythmic agent.