Afib

Question 1

Afib is almost always a chronic disorder, except for when it is caused by:

Answer 1

1. hyperthyroidism

2. surgery

Question 2

Afib comorbidities

Answer 2

Age
HTN
DM
hyperthyroidism
heart failure
CAD
valvular heart disease
COPD
obstructive sleep apnea (hypoxia)

Question 3

Holiday heart

Answer 3

Afib after alcohol binge, large meal, or vigorous exercise

Question 4

Afib pathophys

Answer 4

Trigger-premature atrial depolarizations (most commonly originating in pulmonary veins)

Susceptibility to afib is increased by changes in left atrium electrical fx…which afib also causes, so ‘afib begets afib’

-> loss of atrial contribution to ventricular filling

Question 5

primary morbidity a/w afib

Answer 5

thromboembolism

Question 6

mc origination site of thromboembolism 2/2 afib

Answer 6

left atrial appendage

Question 7

afib symptoms

Answer 7

same as other supraventricular tachyarrythmias:

• fatigue
• palpitations
• SOB
• chest discomfort
• syncope

also can be asymptomatic

Question 8

diagnosis

Answer 8

1. ECG

- alternatives: Holter monitor or continuous loop event

Question 9

effect of carotid massage or other vagal maneuvers on afib

Answer 9

Will slow the rate, but will not determine the arrythmia (vs AVNRT and AVRT)

Question 10

Afib Tx

Answer 10

rate control (1st choice)

• BB (esmolol, metoprolol) or CCB (verapamil, diltiazem)
• digoxin can be used, but is less effective

rhythm control

• cardiovert first (electrical vs pharm)
• if >48h duration, mitigate risk for clot prior to cardioverting
  - first do TEE: if no evidence of clot, no anticoagulation prior to cardioversion
  - if there IS evidence of clot, at least 4w of INR>2
• pharm options: IV ibutilide (better for aflutter), oral amiodarone
• one time oral pills: flecainide, propafenone

Question 11

Assessing afib pt for anticooagulation:

Answer 11

CHADS2-Vasc: if 2 or more pts requires anticoagulation

CHF
HTN
Age>65 (2pts if >75)
DM
Stroke (2 pts)

Vascular dz
female gender

Question 12

long term afib tx

Answer 12

procedural

• cather-based ablation in LA
• electrical isolation of the pulmonary veins and removal of left atrial appendage

pharmacological

• block Na, K, or both to slow electrical conduction
• amiodarone is commonly used
• Na and K blocking: quinidine, procainamide, disoopyramide
• Na blocking: propafenone, flecainide
• K blocking: dofetilide

Question 13

Amiodarone followup

Answer 13

drug interactions (WARFARIN, digoxin)
toxicity: thyroid, liver, lungs

Question 14

anticoagulation options

Answer 14

warfarin-if kidney dz
dabigatran-avoid in pts >80yo (highest risk of bleed)
rivaroxaban-use in pts who prefer once daily dosing
apixaban-use in pts with the highest risk of bleeding

Question 15

target INR

Answer 15

2-3