Ver el código de «Atrial fibrillation (main)»

==Background==
*Chronic and paroxysmal a fib are associated with thrombus formation

{{Afib background}}

==Clinical Features==
===History===
*Asymptomatic - 44%
*[[Palpitations]] - 32%
*[[Dyspnea]] - 10%
*[[Stroke]] - 2%
*Also can present with [[congestive heart failure]]/acute pulmonary edema

===Physical===
*Irregularly irregular heart rate

==Differential Diagnosis==
{{Palpitations DDX}}

==Diagnosis==
===ED Work-Up===
*[[ECG]]<ref>2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation: Executive Summary. J Am Coll Cardiol. 2014;64(21):2246-2280.  doi:10.1016/j.jacc.2014.03.021</ref>
*Eval for [[ACS]] only in:
**Pt with ECG changes suggestive of ischemia, [[hypotension]], [[angina]]
**A fib is rarely only manifestation of ACS, although RVR and hypotension can provoke demand ischemia
*Also consider:
**Digoxin level (if appropriate)
**Chem-10
**Magnesium level
**TSH & free T4 (A fib increased in subclinical [[hyperthyroidism]])

===ECG Patterns===
[[File:Afib.jpg|thumb|Atrial fibrillation at approximately 150 beats per minute]]
''3 patterns on ECG:''
#Typical
#*Irregularly, irregular R waves
#*QRS rate 140-160/min
#Large fibrillatory waves
#*May look like flutter waves
#**Unlike a-flutter, the fibrillatory waves are irregular 
#Slow, regular A-fib
#*Due to complete AV block with escape rhythm 
*Ischemic changes?
*Rate > 250? (think preexcitation)

==Management==
''See [[atrial fibrillation with RVR]] for emergent treatment''
===Rate vs. Rhythm Control===
*Consider ED rhythm control for younger patients (<65 years old) with new or paroxysmal episode lasting <48hrs of symptoms<ref>Atrial Fibrillation: Would You Prefer a Pill or 150 Joules? Ann Emerg Med. 2015;66:655-657.</ref>
**Do not need to anticoagulate prior to rhythm control if less that 48 hours of symptoms<ref>EBQ:48hr Cardioversion for Afib]]</ref>
*Rate control
**See: [[Atrial fibrillation with RVR]] 
**May observe with cardiac monitoring for 24 hrs without rate control meds if holiday heart syndrome<ref>Yealy DM, Delbridge TR: Dysrhythmias, in Marx JA, Hockberger RS, Walls RM, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 7. St. Louis, Mosby, Inc., 2010, (Ch) 77:p 1010-1012.</ref>
**Past 24 hrs, pts remaining tachycardic will require rate control

{{Anticoagulation in atrial fibrillation}}

====CHADS2-VAsc Score====
{| class="wikitable"
| align="center" style="background:#f0f0f0;"|'''Risk Factor'''
| align="center" style="background:#f0f0f0;"|'''Points'''
|-
| [[CHF]]||1
|-
| [[HTN]]||1
|-
| [[DM]]||1
|-
| Previous [[stroke]]/[[TIA]]||2
|-
| Vascular disease (e.g. IHD, PVD)||1
|-
| Female gender||1
|-
!colspan="6" | Age
|-
| ≥ 75 years old||2
|-
| 65 to 74 years old||1
|}

*Score 0: consider no treatment or [[ASA]]
*Score 1: consider [[warfarin]] or [[ASA]] 
*Score 2-6: consider [[warfarin]] (INR goal = 2-3)
*All patients with significant valvular disease should be on anticoagulation

====HAS-BLED<ref>Pisters R, Lane DA, Nieuwlaat R, et al. A novel user-friendly score (HAS-BLED) to assess 1-year risk of major bleeding in patients with atrial fibrillation: the Euro Heart Survey. Chest 2010; 138:1093.</ref>====
''Used to assess 1 yr risk of bleeding on OAC medications''
{| {{table}}
| align="center" style="background:#f0f0f0;"|'''Risk Factor'''
| align="center" style="background:#f0f0f0;"|'''Point'''
|-
| Hypertension||1
|-
| Abnormal renal and/or hepatic function||1 point each
|-
| Stroke||1
|-
| Bleeding tendency/predisposition||1
|-
| Labile INR on warfarin||1
|-
| Elderly (age >65 years)||1
|-
| Drugs (aspirin or NSAIDs) and/or alcohol||1 point each
|-
|}
*Score 1: 1.0 bleeds per 100 patient-years
*Score 2: 1.9 bleeds per 100 patient-years
*Score 3: 3.7 bleeds per 100 patient-years
*Score 4: 8.7 bleeds per 100 patient-years
*Score 5-9: Insufficient Data

==Disposition==
''Similar outcomes for Canadian vs. American strategies, despite lower admission rates in Canada<ref>Rising KL. Home is Where the Heart Is. Annals of Emergency Medicine. 2013;62(6):578-579</ref>''
===Canadian===
*"Limit hospital admission to highly symptomatic patients in whom adequate rate control cannot be achived"<ref>Stiell, et al. Atrial Fibrilation Guidelines. Canadian Cardiovascular Society Atrial Fibrillation Guidelines 2010: management of recent-onset atrial fibrilation and flutter in the emergency department. Can J Cardiolol. 2011;27:38-46</ref>

===American===
Indications for hospitalization:
*Pt with acute heart failure or hypotension after rhythm or rate control
*AF 2/2 HTN, infection, COPD exacerbation, PE, ACS/MI 
*Age > 60 (high risk of thromboembolism, more likely to have comorbidities)
*Initiation of heparin or other anticoagulant
*If considering ablation of accessory pathway in pt with AF
*Symptomatic recurrence in the ED
*Hemodynamic instability

Indications for discharge (low-risk pts):
Discharge with urgent cardiology f/u
*<60 years old
*No significant comorbid disease
*No clinical suspicion for PE or MI
*Conversion in ED or rate control

==Complications==
*Hemodynamic compromise
**A-fib lowers CO by 20-30%
**Impaired coronary blood flow 
*Arrhythmogenesis
*Arterial thromboembolism

==See Also==
*[[Atrial fibrillation with RVR]]
*[[ACLS (Main)]]

==References==
<references/>
[[Category:Cards]]