Atrial fibrillation (main): Difference between revisions

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==Background==
==Background==
*Chronic and paroxysmal a-fib are associated with thrombus formation
{{Afib background}}
{{Afib background}}


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


==Diagnosis==
===Physical===
*Irregularly irregular heart rate
 
==Differential Diagnosis==
{{Tachycardia (narrow) DDX}}
{{Tachycardia (wide) DDX}}
{{Palpitations DDX}}
 
==Evaluation==
===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:
**Patient 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 (Afib increased in subclinical [[hyperthyroidism]])
 
===ECG Patterns===
[[File:Afib.jpg|thumb|Atrial fibrillation at approximately 150 beats per minute]]
[[File:Afib.jpg|thumb|Atrial fibrillation at approximately 150 beats per minute]]
*3 patterns on ECG:
''3 patterns on ECG:''
#Typical
#Typical
#*Irregularly, irregular R waves
#*Irregularly, irregular R waves
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*Rate > 250? (think preexcitation)
*Rate > 250? (think preexcitation)


==Work-Up==
==Management==
#ECG
''See [[atrial fibrillation with RVR]] for emergent treatment''
#Digoxin level (if appropriate)
===Rate vs. Rhythm Control===
#Chem-10
*Consider [[EBQ:Ottawa Aggressive ED Cardioversion Protocol|rhythm control]] for younger patients (<65 years old) with new or paroxysmal episode<ref>Atrial Fibrillation: Would You Prefer a Pill or 150 Joules? Ann Emerg Med. 2015;66:655-657.</ref>
#TSH & free T4 (AF increased in subclinical hyperthyrodism)
**If <48 hours of symptoms, do not need to anticoagulate prior to rhythm control (may perform in ED)<ref>EBQ:48hr Cardioversion for Afib]]</ref>
#Eval for ACS only in:
**If >48 hours of symptoms, may have rhythm control as out patient referral
##Pt with ECG changes suggestive of ischemia, hypotension, angina
*Rate control for all others or cardioversion failure
##AF is rarely only manifestation of ACS, although RVR and hypotension can provoke demand ischemia
**[[Beta-blocker]] or [[calcium channel blocker]]
#Bedside echo if available can provide info in LV function and underlying structural abnormalities


==Differential Diagnosis==
{{Anticoagulation in atrial fibrillation}}
{{Palpitations DDX}}
 
==Treatment==
*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
*Anti-thrombotic therapy
**Chronic and paroxysmal a fib are associated with thrombus formation
**Contraindications to warfarin include alcoholism, recent trauma/surgery, active GI/GU/resp bleed, prior ICH while on OAC, suspected aortic dissection, malignant hypertension, high risk for falls.


===CHADS2-VAsc Score===
====CHADS2-VAsc Score====
{| class="wikitable"
{| class="wikitable"
| align="center" style="background:#f0f0f0;"|'''Risk Factor'''
| align="center" style="background:#f0f0f0;"|'''Risk Factor'''
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| [[CHF]]||1
| [[CHF]]||1
|-
|-
| [[HTN]]||1
| [[hypertension]]||1
|-
|-
| [[DM]]||1
| [[DM]]||1
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| Vascular disease (e.g. IHD, PVD)||1
| Vascular disease (e.g. IHD, PVD)||1
|-
|-
| Female gender||1
| Female sex||1
|-
|-
!colspan="6" | Age
!colspan="6" | Age
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*All patients with significant valvular disease should be on anticoagulation
*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>===
====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
''Used to assess 1 yr risk of bleeding on OAC medications''
{| {{table}}
{| {{table}}
| align="center" style="background:#f0f0f0;"|'''Risk Factor'''
| align="center" style="background:#f0f0f0;"|'''Risk Factor'''
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*Score 4: 8.7 bleeds per 100 patient-years
*Score 4: 8.7 bleeds per 100 patient-years
*Score 5-9: Insufficient Data
*Score 5-9: Insufficient Data
===Anticoagulation in Atrial Fibrillation/Flutter===
{{Anticoagulation in atrial fibrillation}}


==Disposition==
==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>
''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===
===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>
*"Limit hospital admission to highly symptomatic patients in whom adequate rate control cannot be achieved"<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===
===American===
Indications for hospitalization:
Indications for hospitalization:
*Pt with acute heart failure or hypotension after rhythm or rate control
*Patient with acute heart failure or hypotension after rhythm or rate control
*AF 2/2 HTN, infection, COPD exacerbation, PE, ACS/MI  
*AF secondary to hypertension, infection, COPD exacerbation, PE, ACS/MI  
*Age > 60 (high risk of thromboembolism, more likely to have comorbidities)
*Age > 60 (high risk of thromboembolism, more likely to have comorbidities)
*Initiation of heparin or other anticoagulant
*Initiation of heparin or other anticoagulant
*If considering ablation of accessory pathway in pt with AF
*If considering ablation of accessory pathway in patient with AF
*Symptomatic recurrence in the ED
*Symptomatic recurrence in the ED
*Hemodynamic instability
*Hemodynamic instability


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


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


==See Also==
==See Also==
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==References==
==References==
<references/>
<references/>
[[Category:Cards]]
[[Category:Cardiology]]

Revision as of 17:34, 19 September 2019

Background

  • Chronic and paroxysmal a-fib are associated with thrombus formation

Atrial fibrillation categories[1]

Atrial Fibrillation Category Definition
Paroxysmal
  • Terminates spontaneously or with intervention within 7 days of onset.
  • Episodes may recur with variable frequency.
Persistent
  • Continuous sustained >7 days
Long-standing persistent
  • Continuous >12 mo in duration.
Permanent
  • Used when the patient and clinician make a joint decision to stop further attempts to restore and/or maintain sinus rhythm.
  • Acceptance represents a therapeutic attitude on the part of the patient and clinician rather than an inherent pathophysiological attribute.
  • May change as symptoms, efficacy of therapeutic interventions, and patient and clinician preferences evolve.
Nonvalvular
  • In the absence of rheumatic mitral stenosis, a mechanical or bioprosthetic heart valve, or mitral valve repair.
With Rapid Ventricular Response (RVR)
  • With persistent ventricular heart rate >100 beats per minute

Causes of atrial fibrillation

Clinical Features

History

Physical

  • Irregularly irregular heart rate

Differential Diagnosis

Narrow-complex tachycardia

Wide-complex tachycardia

Assume any wide-complex tachycardia is ventricular tachycardia until proven otherwise (it is safer to incorrectly assume a ventricular dysrhythmia than supraventricular tachycardia with abberancy)

^Fixed or rate-related

Palpitations

Evaluation

ED Work-Up

  • ECG[2]
  • Eval for ACS only in:
    • Patient 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 (Afib increased in subclinical hyperthyroidism)

ECG Patterns

Atrial fibrillation at approximately 150 beats per minute

3 patterns on ECG:

  1. Typical
    • Irregularly, irregular R waves
    • QRS rate 140-160/min
  2. Large fibrillatory waves
    • May look like flutter waves
      • Unlike a-flutter, the fibrillatory waves are irregular
  3. 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 rhythm control for younger patients (<65 years old) with new or paroxysmal episode[3]
    • If <48 hours of symptoms, do not need to anticoagulate prior to rhythm control (may perform in ED)[4]
    • If >48 hours of symptoms, may have rhythm control as out patient referral
  • Rate control for all others or cardioversion failure

Anticoagulation Therapy

  • ACCP Recommendations
    • In patients with AF, including those with paroxysmal AF, with only one of the risk factors listed immediately above, we recommend long-term antithrombotic therapy (Grade 1A), either as anticoagulation with an oral VKA, such as warfarin (Grade 1A), or as aspirin, at a dose of 75-325 mg/d (Grade 1B)[5]
    • In patients with AF, including those with paroxysmal AF, who have two or more of the risk factors we recommend long-term anticoagulation with an oral VKA (Grade 1A).[5]
  • CCS Recommendations
    • Oral anticoagulants are recommended for all AF patients aged 65 or older or who have any one of the traditional CHADS2 risk factors of stroke, hypertension, heart failure, or diabetes (remember as CHADS-65). Otherwise, patients with a history of coronary artery disease or arterial vascular disease should be prescribed ASA. CCS recommends that the first choice for oral anticoagulation should be the novel direct-acting oral anticoagulants (i.e. NOACs, for non-valvular AF). The big paradigm change is that ED physicians should prescribe OACs to at-risk AF patients before they leave the ED.[6]

CHADS2-VAsc Score

Risk Factor Points
CHF 1
hypertension 1
DM 1
Previous stroke/TIA 2
Vascular disease (e.g. IHD, PVD) 1
Female sex 1
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[7]

Used to assess 1 yr risk of bleeding on OAC medications

Risk Factor 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[8]

Canadian

  • "Limit hospital admission to highly symptomatic patients in whom adequate rate control cannot be achieved"[9]

American

Indications for hospitalization:

  • Patient with acute heart failure or hypotension after rhythm or rate control
  • AF secondary to hypertension, 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 patient with AF
  • Symptomatic recurrence in the ED
  • Hemodynamic instability

Indications for discharge (low-risk patients): Discharge with urgent cardiology follow up

  • <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

References

  1. ↑ 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
  2. ↑ 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
  3. ↑ Atrial Fibrillation: Would You Prefer a Pill or 150 Joules? Ann Emerg Med. 2015;66:655-657.
  4. ↑ EBQ:48hr Cardioversion for Afib]]
  5. ↑ 5.0 5.1 Singer DE et al. Antithrombotic therapy in atrial fibrillation: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition).Chest. 2008 Jun;133(6 Suppl):546S-592S
  6. ↑ Verma A, et al. 2014 Focused Update of the Canadian Cardiovascular Society Guidelines for the Management of Atrial Fibrillation Canadian Journal of Cardiology 30 (2014) 1114e1130
  7. ↑ 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.
  8. ↑ Rising KL. Home is Where the Heart Is. Annals of Emergency Medicine. 2013;62(6):578-579
  9. ↑ 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
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