Atrial fibrillation resident survival guide: Difference between revisions
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* [[Sotalol]] | * [[Sotalol]] | ||
== | ==Anticoagulation Therapy== | ||
Shown below is a table used to categorize the risk of stroke in a patient with AF: <br> | Shown below is a table used to categorize the risk of stroke in a patient with AF: <br> | ||
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! style="height: 30px; line-height: 30px; background: #4479BA; border: 0px; font-size: 100%; text-shadow: 0 -1px 0 rgba(0, 0, 0, 0.5);" align=center; colspan="2"| {{fontcolor|#FFF|Anticoagulation Therapy}} | |||
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| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left | '''''No risk factors''''' ||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left | ▸ '''''[[Aspirin]] 81-325 mg daily''''' | |||
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| style="padding: 0 5px; font-size: | | style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |'''''1 Moderate risk factor''''' || style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |▸ '''''[[Aspirin]] 81-325 mg daily''''' <br> ''OR'' <br> ▸ '''''[[Warfarin]] (INR 2.0 to 3.0, target 2.5)''''' | ||
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| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left | | |style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |'''''Any high risk factor or <br> more than 1 moderate risk factor''''' || style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |▸ '''''[[Warfarin]] (INR 2.0 to 3.0, target 2.5)''''' | ||
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Revision as of 16:09, 9 March 2014
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Vidit Bhargava, M.B.B.S [2]; Hilda Mahmoudi M.D., M.P.H.[3]; Priyamvada Singh, M.D. [4]; Rim Halaby, M.D. [5]
Synonyms and keywords: AF, Afib
Definitions
Atrial fibrillation is a supraventricular tachyarrhythmia characterized by uncoordinated atrial activation leading to an irregularly irregular rhythm and absent P waves on ECG.
▸ Paroxysmal | AF lasting < 7 days (mostly < 24 hours), usually self terminating |
▸ Persistent | AF lasting > 7 days, usually does not terminate on its own |
▸ Permanent | AF lasting for a longer period, an attempted cardioversion has failed or promises no improvement |
▸ Lone AF | AF in patients > 60 years without any pre-existing cardiopulomunary diseases |
Causes
Life Threatening Causes
Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated. Atrial fibrillation can be a life-threatening condition and must be treated as such irrespective of the causes.
Common Causes
- Alcohol abuse
- Congestive heart failure
- Coronary artery disease
- Dehydration
- Electrolyte disturbance
- Hypertensive heart disease
- Hyperhtyroidism
- Hypothermia
- Hypoxia
- Myocardial infarction[1]
- Myocarditis
- Pericarditis
- Pulmonary embolism[2]
- Rheumatic heart disease
- Uremic pericarditis
Management
Shown below is an algorithm summarizing the initial approach to evaluation of AF.
Characterize the symptoms:
Characterize the timing of the symptoms:
❑ Duration
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Identify possible triggers: | ||||||||||||||||||
❑ Examine the patient ❑ Order an EKG ♦ Atrial fibrillation rhythm
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❑ Order a transthoracic echocardiogram
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Newly Discovered Atrial Fibrillation
Shown below is an algorithm depicting the pharmacological management of patients with newly discovered atrial fibrillation based on the 20011 ACCF/AHA/HRS updates for the management of atrial fibrillation.[3]
Newly discovered AF | |||||||||||||||||||||||
Paroxysmal AF | Persistent AF | ||||||||||||||||||||||
Accept progression to permanent AF | Restore sinus rhythm | ||||||||||||||||||||||
❑ Do not administer therapy unless the patient has ant of the following symptoms requiring DC cardioversion ❑ Administer long term anticoagulation therapy based on the risk of stroke
| ❑ Administer long term anticoagulation therapy based on the risk of stroke | ❑ Administer anticoagulation therapy based on the risk of stroke | |||||||||||||||||||||
Note: For the treatment of newly persistent AF, choose the therapy depending on the severity of symptoms and the risk of administration of anti-arrhythmic.
Recurrent Paroxysmal Atrial Fibrillation
Shown below is an algorithm depicting the pharmacological management of patients with recurrent paroxysmal atrial fibrillation: Algorithm based on the 20011 ACCF/AHA/HRS updates for the management of atrial fibrillation.[3]
Recurrent paroxysmal AF | |||||||||||||||
Minimal or no symptoms | Disabling symptoms in AF | ||||||||||||||
❑ Administer rate control ❑ Administer anticoagulation based on the risk of stroke | ❑ Administer rate control
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❑ Consider AF ablation if antiarrhythmic treatment fails | |||||||||||||||
Recurrent Persistent Atrial Fibrillation
Shown below is an algorithm depicting the pharmacological management of patients with recurrent persistent atrial fibrillation: Algorithm based on the 20011 ACCF/AHA/HRS updates for the management of atrial fibrillation.[3]
Recurrent persistent AF | |||||||||||||||
Minimal or no symptoms | Disabling symptoms in AF | ||||||||||||||
❑ Administer rate control ❑ Administer anticoagulation based on the risk of stroke | ❑ Administer rate control | ||||||||||||||
❑ Continue anticoagulation therapy ❑ Continue antiarrhythmic | |||||||||||||||
In case of recurrence of AF, proceed with: ❑ Left atrial ablation | |||||||||||||||
Permanent Atrial Fibrillation
Shown below is an algorithm depicting the pharmacological management of patients with permanent atrial fibrillation:Algorithm based on the 20011 ACCF/AHA/HRS updates for the management of atrial fibrillation.[3]
Permanent AF | |||||||
❑ Administer anticoagulation based on the risk of stroke | |||||||
Antiarrhythmic Drug Therapy in Atrial Fibrillation
Shown below is an algorithm depicting the antiarrhythmic drug therapy for maintaining sinus rhythm in patients with recurrent paroxysmal or persistent atrial fibrillation based on the 20011 ACCF/AHA/HRS updates for the management of atrial fibrillation.[3]
Maintenance of sinus rhythm | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
No or minimal heart disease | Hypertension | Coronary artery disease | Heart failure | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Substantial LVH | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
❑ Catheter ablation | No | Yes | ❑ Amiodarone | ❑ Catheter ablation | ❑ Catheter ablation | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
❑ Amiodarone | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
❑ Catheter ablation | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
❑ Catheter ablation | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Note:
- Drugs are listed alphabetically and not in order of suggested use.
- In vagally mediated AF, disopyramide and flecainide are recommended.
- In adrenergically mediated AF, beta blocker and sotalol are recommended.
Shown below is a table summarizes the list of most commonly used drugs and their dosages for maintenance of sinus rhythm:
Drug & Dosage |
▸ Amiodarone (100 to 400 mg) OR ▸ Disopyramide (400 to 750 mg) OR ▸ Dofetilide (500 to 1000 mcg) OR ▸ Flecainide (200 to 300 mg) OR ▸ Procainamide (1000 to 4000 mcg) OR ▸ Propafenone (450 to 900 mg) OR ▸ Quinidine (600 to 1500 mg) OR ▸ Sotalol (160 to 320 mg) |
Pharmacological Cardioversion
Cardioversion up to 7 Days
Drug | Dosage |
Agents with proven efficacy | |
▸ Dofetilide (Class of recommendation I Level of evidence A) | ▸ Creatinine clearance(ml/min): > 60 - 500 mg 40 to 60 - 250 mg 20 to 40 - 125 mg < 20 - contraindicated |
▸ Flecainide (Class of recommendation I Level of evidence A) | ▸ Oral: 200 to 300 mg Intravenous: 1.5 to 3.0 mg/kg over 10 to 20 min |
▸ Ibutilide (Class of recommendation I Level of evidence A) | ▸ 1 mg over 10 min; repeat 1 mg when necessary |
▸ Propafenone (Class of recommendation I Level of evidence A) | ▸ Oral: 600 mg Intravenous: 1.5 to 2.0 mg/kg over 10 to 20 min |
▸ Amiodarone (Class of recommendation IIa Level of evidence A) | ▸ Oral:
Intravenous:
|
Cardioversion after 7 Days
Drug | Dosage |
Agents with proven efficacy | |
▸ Dofetilide (Class of recommendation I Level of evidence A) | ▸ Creatinine clearance(ml/min): > 60 - 500 mg 40 to 60 - 250 mg 20 to 40 - 125 mg < 20 - contraindicated |
▸ Ibutilide (Class of recommendation I Level of evidence A) | ▸ 1 mg over 10 min; repeat 1 mg when necessary |
▸ Amiodarone (Class of recommendation IIa Level of evidence A) | ▸ Oral:
Intravenous:
|
Drugs which enhance the efficacy of electric cardioversion when given prior to the procedure: (Level of recommendation: IIa B)
Anticoagulation Therapy
Shown below is a table used to categorize the risk of stroke in a patient with AF:
Low Risk Factors | Moderate Risk Factors | High Risk Factors |
▸ Female gender OR ▸ Age 65-74 years OR ▸ Coronary artery disease OR ▸ Thyrotoxicosis |
▸ Age ≥ 75 years OR ▸ Hypertension OR ▸ Heart failure OR ▸ LV ejection fraction ≤ 35% OR ▸ Diabetes mellitus |
▸ Previous stroke, TIA or embolism OR ▸ Mitral stenosis OR ▸ Prosthetic heart valve |
|
Heart Rate Control
Shown below is a table summarizing the list of recommended agents for control of heart rate and their dosages.
|
Do's
Rate control during AF:
- Begin therapy with either a beta blocker, diltiazem, or verapamil. (Class of recommendation I Level of evidence B) Use a combination of digoxin and either a beta blocker, diltiazem, or verapamil if AF not controlled by monotherapy. (Class of recommendation IIa Level of evidence B)
- Use ablation of the arterioventricular (AV) node or accessory pathway, if pharmacological therapy is insufficient. (Class of recommendation IIa Level of evidence B)
- If rate is not controlled by above measures use oral or IV amiodarone, either alone or in combination with other agents. (Class of recommendation IIb Level of evidence C)
- Dabigatran may be used as an alternative to warfarin in those wdo don't have: (Class of recommendation I Level of evidence B)
- Prosthetic heart valve
- Hemodynamically significant valve disease
- Severe renal failure (creatinine clearance <15 mL/min) or
- Advanced liver disease (impaired baseline clotting function).
- Give anticoagulants 3 weeks prior to & 4 weeks after cardioversion for patients with unknown duration of AF or AF > 48 hours. (Class of recommendation I Level of evidence B) Those requiring immediate cardioversion should be given IV heparin, followed by 4 weeks of oral anticoagulant therapy.
- If patient on anticoagulants with AF sustains stroke or systemic embolism, target INR may be raised to 3.0 - 3.5 (Class of recommendation IIb Level of evidence C) .
- Anticoagulation therapy can be interrupted for upto 1 week, if patients needs a procedure that carries a risk of bleeding (Class of recommendation IIa Level of evidence C) . For periods > 1 week unfractionated or low molecular weight heparin may be given IV (Class of recommendation IIb Level of evidence C) .
- Use a rate control agent such as beta blocker, diltiazem or verapamil before initiating antiarrhythmic medication to prevent rapid AV conduction. (Class of recommendation IIa Level of evidence C)
- Perform cardioversion immediately in AF < 48 hours without a need for anticoagulation. (Class of recommendation I Level of evidence C)
- Transesophageal echocardiography may be used to search for thrombus prior to cardioversion, if none are found patient may be treated with 4 weeks of anticoagulants after the procedure. (Class of recommendation IIa Level of evidence B) If thrombus is found, 3 weeks of anticoagulant therapy prior and 4 weeks afterwards is a must. (Class of recommendation IIa Level of evidence C)
Don't
- Do not wait to give anticoagulants in a patient with hemodynamic instability, perform cardioversion immediately. Administer IV unfractionated heparin or SC injection of a low-molecular-weight heparin.
- Don't use digoxin as a single agent for rate control in patients with paroxysmal AF. (Class of recommendation III Level of evidence B)
- Do not attempt catheter ablation unless a trial of medication to control ventricular rate has been made. (Class of recommendation III Level of evidence C)
- Do not give IV nondihydropyridine calcium channel antagonist in a patient with decompensated heart failure and AF.
- Do not use digoxin and sotalol for pharmacological cardioversion of AF. (Class of recommendation III Level of evidence A)
- Do not start quinidine, procainamide, disopyramide, and dofetilide in out of hospital setting. (Class of recommendation III Level of evidence B)
- Do not perform repeated electric cardioversion in those with short periods of normal sinus rhythm in between. (Class of recommendation III Level of evidence C)
- Do not perform electric cardioversion in those with digitalis toxicity and/or hypokalemia. (Class of recommendation III Level of evidence C)
- Don't use calcium channel blocker, beta blocker, and digoxin in atrial fibrillation patients with WPW.
References
- ↑ Zimetbaum, PJ.; Josephson, ME.; McDonald, MJ.; McClennen, S.; Korley, V.; Ho, KK.; Papageorgiou, P.; Cohen, DJ. (2000). "Incidence and predictors of myocardial infarction among patients with atrial fibrillation". J Am Coll Cardiol. 36 (4): 1223–7. PMID 11028474. Unknown parameter
|month=
ignored (help) - ↑ Goldhaber, SZ.; Visani, L.; De Rosa, M. (1999). "Acute pulmonary embolism: clinical outcomes in the International Cooperative Pulmonary Embolism Registry (ICOPER)". Lancet. 353 (9162): 1386–9. PMID 10227218. Unknown parameter
|month=
ignored (help) - ↑ 3.0 3.1 3.2 3.3 3.4 Fuster, V.; Rydén, LE.; Cannom, DS.; Crijns, HJ.; Curtis, AB.; Ellenbogen, KA.; Halperin, JL.; Kay, GN.; Le Huezey, JY. (2011). "2011 ACCF/AHA/HRS focused updates incorporated into the ACC/AHA/ESC 2006 guidelines for the management of patients with atrial fibrillation: a report of the American College of Cardiology Foundation/American Heart Association Task Force on practice guidelines". Circulation. 123 (10): e269–367. doi:10.1161/CIR.0b013e318214876d. PMID 21382897. Unknown parameter
|month=
ignored (help)