Atrial Fibrillation

CFPC Key Features

1. In a patient who presents with new onset atrial fibrillation, look for an underlying cause (e.g., ischemic heart disease, acute myocardial infarction, congestive heart failure, cardiomyopathy, pulmonary embolus, hyperthyroidism, alcohol, etc.)

2. In a patient presenting with atrial fibrillation,

   1. Look for hemodynamic instability,

   2. Intervene rapidly and appropriately to stabilize the patient.

3. In an individual presenting with chronic or paroxysmal atrial fibrillation,

   1. Explore the need for anticoagulation based on the risk of stroke with the patient,

   2. Periodically reassess the need for anticoagulation.

4. In patients with atrial fibrillation, when the decision has been made to use anticoagulation, institute the appropriate therapy and patient education, with a comprehensive follow-up plan.

5. In a stable patient with atrial fibrillation, identify the need for rate control.

6. In a stable patient with atrial fibrillation, arrange for rhythm correction when appropriate.

Acute Management of Unstable AF

• Always ABCs!

• Unstable if Hypotension or ACS or pulmonary edema (heart failure)

  • Consider other causes of hypotension if HR<130 (MI, PE, sepsis, hypovolemia)

• Urgent Electrical DC cardioversion (AP pads, 200J synchronized) if hemodynamic instability (especially if >150) or if rate control not effective

  • Consider procedural sedation, eg. Etomidate 0.1mg/kg (7-10mg) IV

  • Immediate anticoagulation x 4 weeks

• Manage hypotension

  • Fluids (care for pulmonary edema)

  • Vasopressors

Acute Management of Stable AF

• Treat underlying/reversible causes

  • Review medications

  • Avoid beta-adrenergic vasopressors (epi/norepi/dobutamine), consider using phenylephrine instead

  • Optimize volume status

  • Treat pain, anxiety, withdrawal

  • Treat electrolyte abnormalities (potassium, magnesium)

    • Consider empiric magnesium 2-4g IV if magnesium levels not available

  • Treat hypoxemia or respiratory distress (CPAP/BiPAP/HFNC)

  • r/o sepsis, PE, thyrotoxicosis, etc…

• r/o WPW or pre-excitation syndrome (bizarre QRS change in width beat to beat and HR >220)

  • If WPW, do NOT start AV node slowing medications (Amiodarone, BB, CCB), consider only electrical cardioversion

• Rate vs. Rhythm

  • Consider Acute Rate-Control

    • Asymptomatic

    • Chronic AF (eg. >1y diagnosed AF)

    • Onset AF>48h and not anticoagulated (risk of thrombus)

    • Medication choice depending on LV function:

      • LVEF≥40%:

        • Beta-blockers

          • Metoprolol IV 5mg q5mins x 3 PRN (max 15mg)

            • Convert to PO with a 1:2.5 (IV:PO) ratio, start 30mins after effective IV rate control

          • Esmolol IV

• ND-CCBs

  • Diltiazem 15-25mg IV bolus (0.25mg/kg) x1, can repeat q15 mins once, then infusion at 2.5-15mg/h (consider reduce dose after target heart rate reached as diltiazem can accumulate)

• • • • LVEF<40%:

        • B-blockers

        • Severe heart failure and longstanding AF: Digoxin 0.25mg IV x1

        • Borderline hemodynamic instability: Amiodarone

  • Consider Acute Rhythm-Control if

    • Highly symptomatic (especially if symptomatic despite adequate rate control)

    • Risk of hemodynamic instability (heart failure, pulmonary hypertension, mitral stenosis)

    • Newly diagnosed AF (within 1 year)

    • Low risk (NVAF<12h with no recent stroke/TIA, or <48h with CHADS2<2) or if on OAC≥3w

    • Atrial Flutter

    • Associated with reduced CV deaths and rates of stroke

  • Choice DCCV vs pharmacological depending on situation:

    • Electrical more effective (150J biphasic, or greater)

      • Ideal if unknown medical history

      • Consider paddles with force in obese patients

      • Consider preparation of atropine and pacing in the event of prolonged sinus pause

      • Consider second trained operator managing sedation and airway

    • Pharmacological ideal on non-fasting patient and does not require procedural sedation

      • AVOID if hypotension, ischemic heart disease, heart failure, conduction system disease/significant structural heart disease, and Brugada syndrome.

      • Procainamide 1g (or 15-18 mg/kg) IV over 60 min

        • Time to conversion 60 minutes, avoid in Brugada

      • Amiodarone 150-300mg IV bolus then infusion at 1mg/min, can repeat bolus x1

      • OAC x 4w, then as per CHADS65

• Need for hospital admission?

  • YES if highly symptomatic with acute medical illness/complex medical conditions, inability to achieve rate control, or require monitoring/testing not available as outpatient

• Need for OAC?

  • Short-term OAC x 4 weeks after cardioversion

  • Long-term OAC if CHADS65, see Anticoagulation section below

• Follow-up, ideally early within one week (lower risks of morbidity/mortality)

Longterm Rate Control

• • AVOID if pre-excitation syndrome

  • Target resting HR<100bpm, if

    1. CHF: BB preferred+/- Digoxin

    2. CAD: BB preferred

    3. No CHF/CAD: CCB preferred if no compelling indication for BB, Digoxin or combo

    4. HTN or reactive airway disease: CCB

  • Beta-blockers as initial therapy in MI or LV systolic dysfunction:

• • • Bisoprolol 2.5mg PO daily (target 10mg PO daily)

      • Preferred if LV dysfunction

    • Metoprolol 12.5-25mg PO BID (target 100-200mg PO BID)

      • Preferred if CAD, HTN

    • Carvedilol 6.25mg BID (target 25 mg BID)

      • Preferred if LV dysfunction

• • Non-dihydropyridine CCB:

• • • Diltiazem extended release 120-360mg PO daily

    • Verapamil extended release 180-480 mg PO daily or immediate release divided TID-QID

    • Digoxin 0.0625-0.25mg PO daily (max trough 1.2mcg/mL) in selected older/sedentary individuals with HF and for those with inadequate response or contraindication to BB/CCB

Longterm Rhythm Control

• • Consider rhythm in rate-controlled patients with

    • Symptoms or extreme impairment QOL

    • Recently diagnosed within 1 year

    • Multiple recurrences

    • Arrhythmia-induced cardiomyopathy.

    • However long-term oral antiarrhythmic therapy when AF becomes permanent

    • AVOID IF: advanced sinus or AV nodal disease unless PPM or ICD

  • Intermittent antiarrhythmic "pill in pocket” if 1-2 episodes / year

  • Normal Systolic Function

    • Dronedarone 400mg PO BID (avoid in permanent AF or CHF)

    • Flecainide (50-75mg daily, max 150mg) or Propafenone (150mg daily, max 300mg) used with BB (eg. Metoprolol 25mg) or ND-CCB

      • Time to convert 2-6h

      • Administer BB or ND-CCB ≥ 30mins before Class Ic antiarrhythmic (prevent risk of Atrial Flutter 1:1 AV conduction)

    • Sotalol (40mg BID, max 160mg)

    • Amiodarone

  • LV systolic dysfunction or CHF

    • Amiodarone:

      • Loading: 400 mg PO twice daily x 1 week then 400 mg daily x 2 weeks, or 400 mg daily x 1 month

      • Maintenance: 100-200mg daily

    • CAD:

      • Amiodarone, Dronedarone, Sotalol

  • Catheter Ablation

    • First line for symptomatic Atrial Flutter

    • Consider if symptomatic despite antiarrhythmics, if rhythm control strategy remains desired

  • Not an alternative to anticoagulation – still need anticoagulation after successful catheter ablation