Atrial fibrillation resident survival guide
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: | ||||||||||||||||||
Identify possible triggers: | ||||||||||||||||||
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
| ||||||||||||||
❑ 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: Algorithm 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 upto 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)
Risk Factors for Stroke and Recommended Antithrombotic 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 |
Shown below is a table illustrating anticoagulant therapy based on risk factors:
Risk Category & Recommended Therapy |
▸ No risk factors - Aspirin 81-325 mg daily OR ▸ 1 Moderate risk factor - Aspirin 81-325 mg daily or Warfarin (INR 2.0 to 3.0, target 2.5) OR ▸ Any high risk factor or more than 1 moderate risk factor - Warfarin (INR 2.0 to 3.0, target 2.5) |
Pharmacological Agents for Heart Rate Control
Shown below is a table summarizing the list of recommended agents for control of heart rate and their dosage:
Drug | Loading dose | Maintenance dose |
Acute Setting | ||
Heart rate control in patients without accessory pathway | ||
▸ Esmolol (Class of recommendation I Level of evidence C) | ▸ 500 mcg/kg IV over 1 min | ▸ 60 to 200 mcg/kg/min IV |
▸ Propanolol (Class of recommendation I Level of evidence C) | ▸ 0.15 mg/kg IV | ▸ NA |
▸ Metoprolol (Class of recommendation I Level of evidence C) | ▸ 2.5 to 5 mg IV bolus over 2 min; up to 3 doses | ▸ NA |
▸ Diltiazem (Class of recommendation I Level of evidence B) | ▸ 0.25 mg/kg IV over 2 min | ▸ 5 to 15 mg/h IV |
▸ Verapamil (Class of recommendation I Level of evidence B) | ▸ 0.075 to 0.15 mg/kg IV over 2 min | ▸ NA |
Heart rate control in patients with accessory pathway | ||
▸ Amiodarone (Class of recommendation IIa Level of evidence C) | ▸ 150 mg over 10 min | ▸ 0.5 to 1 mg/min IV |
Heart Rate Control in patients with heart failure and without accessory pathway | ||
▸ Amiodarone (Class of recommendation IIa Level of evidence C) | ▸ 150 mg over 10 min | ▸ 0.5 to 1 mg/min IV |
▸ Digoxin (Class of recommendation I Level of evidence B) | ▸ 0.25 mg IV each 2 h, up to 1.5 mg | ▸ 0.125 to 0.375 mg daily IV or orally |
Non-Acute Setting and Chronic Maintenance Therapy | ||
Heart rate control | ||
▸ Metoprolol (Class of recommendation I Level of evidence C) | ▸ Same as maintenance dose | ▸ 25 to 100 mg twice a day, orally |
▸ Propanolol (Class of recommendation I Level of evidence C) | ▸ Same as maintenance dose | ▸ 80 to 240 mg daily in divided doses, orally |
▸ Verapamil (Class of recommendation I Level of evidence B) | ▸ Same as maintenance dose | ▸ 120 to 360 mg daily in divided doses; slow release available, orally |
▸ Diltiazem (Class of recommendation I Level of evidence B) | ▸ Same as maintenance dose | ▸ 120 to 360 mg daily in divided doses; slow release available, orally |
Heart Rate Control in patients with heart failure and without accessory pathway | ||
▸ Digoxin (Class of recommendation I Level of evidence B) | ▸ 0.5 mg by mouth daily | ▸ 0.125 to 0.375 mg daily, orally |
▸ Amiodarone (Class of recommendation IIb Level of evidence C) | ▸ 800 mg daily for 1 wk, orally 600 mg daily for 1 wk, orally 400 mg daily for 4 to 6 wk, orally |
▸ 200 mg daily, orally |
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
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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
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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
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