Afib is almost always a chronic disorder, except for when it is caused by:
- hyperthyroidism
2. surgery
Afib comorbidities
Age HTN DM hyperthyroidism heart failure CAD valvular heart disease COPD obstructive sleep apnea (hypoxia)
Holiday heart
Afib after alcohol binge, large meal, or vigorous exercise
Afib pathophys
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
primary morbidity a/w afib
thromboembolism
mc origination site of thromboembolism 2/2 afib
left atrial appendage
afib symptoms
same as other supraventricular tachyarrythmias:
- fatigue
- palpitations
- SOB
- chest discomfort
- syncope
also can be asymptomatic
diagnosis
- ECG
- alternatives: Holter monitor or continuous loop event
effect of carotid massage or other vagal maneuvers on afib
Will slow the rate, but will not determine the arrythmia (vs AVNRT and AVRT)
Afib Tx
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
Assessing afib pt for anticooagulation:
CHADS2-Vasc: if 2 or more pts requires anticoagulation
CHF HTN Age>65 (2pts if >75) DM Stroke (2 pts)
Vascular dz
female gender
long term afib tx
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
Amiodarone followup
drug interactions (WARFARIN, digoxin) toxicity: thyroid, liver, lungs
anticoagulation options
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
target INR
2-3
