Atrial Fibrillation with Rapid Ventricular Response

Elderly pt with h/o psychosis, depression presents s/p cardiac surgery with palpitations and s/sx suspicious for HF vs. MI vs. stroke. Reports fatigue, chest pain, syncope, dizziness, dyspnea, and orthopnea. Medical history includes coronary artery disease, structural heart disease, heart failure, collagen vascular disease, pulmonary disease, sleep apnea, thyroid disease, and ongoing substance abuse. Medications include OTC diet pills, albuterol, lithium, and QTc-prolonging agents. Hypothermia, tachycardia, JVD, pulmonary crackles, systolic heart murmur, S3 gallop, irregular peripheral pulses on exam.

Atrial fibrillation with Rapid Ventricular Response (RVR)

Atrial fibrillation with Rapid Ventricular Response (RVR)

  • Labs

    • Obtain CBC, CMP, TSH

    • Consider urine drug screen

  • EKG: Rapid, irregularly irregular rate with absent P-waves, narrow Q-waves

  • New onset with no previous echocardiogram: Obtain echocardiogram to evaluate for valvular A-Fib

  • Rate control

    1. Patient stable: Maintenance rate control with goal HR < 110 bpm at rest

      • SBP > 100 mmHg: Metoprolol tartrate 25 mg BID (MDD 100 mg BID)

      • SBP < 100 mmHg: Digoxin 0.125 mg daily (MDD 0.25 mg daily)

    2. Acute hypotension, altered mental status, chest discomfort or HR consistently > 120 BPM:

      • SBP > 100 mmHg: Cardizem 0.25 mg/kg bolus over 2.5 min then 10 mg/hr infusion for up to 24 hr

      • SBP < 100 mmHg and/or HFrEF: Digoxin 0.25 mg; re-dose q6h to achieve HR < 110 bpm

    3. Rate control ineffective

      • Obtain cardiac consult

      • Consider cardioversion if AFib duration < 48h or pt hemodynamically unstable

  • Stroke prevention

    • CHADSVASC > 1, HASBLED < 3, age > 80 years, weight > 60 kg, Cr < 1.5, and no valvular AFib on echocardiogram: Start abixaban (Eliquis) 5mg BID

    • Consider referral for

      • Cardiac and/or left atrial appendage ablation

      • Watchman device placement

      • Pacemaker placement

  • Refer for sleep apnea testing as outpatient

  • Counseling

    • Pt counseled that spontaneous A-Fib generally resolves within 7 days

    • Pt advised to limit alcohol consumption to < 1 drink per day

Notes

Considerations

  • QTc-prolonging drugs

    • Increase A-Fib risk

    • Commonly associated agents include anti-arrhythmics, antidepressants, anti-psychotics, fluoroquinolones, macrolides, and antifungals

  • Heart rate

    • A-Fib is a tachycardia with HR generally between 90-170 BPM; consider sick sinus syndrome in bradycardic patients

    • A-Fib with RVR (rapid ventricular response) rarely causes clinical instability unless HR > 150 bpm

Rate control

  • Rate control equivalent to rhythm control per AFFIRM trial (N Eng J Med. 2002;347(23):1825-1833)

  • Lenient control (HR < 110) per RACE II trial (N Eng J Med. 2010;362(15):1363-1373)

  • Rate control advanced organizers:

    • ABCD: A-Fib agents include Beta-blockers, Cardizem, Digoxin

    • Maintenance agents: Beta-blocker (metoprolol) or digoxin

    • Acute agents: Cardizem or digoxin

    • Rule of '0.25' for acute dosing, i.e. Cardizem 0.25 mg/kg bolus over 2.5 min or digoxin 0.25 mg

  • Metoprolol succinate

    • Long acting oral formulation

    • Provide most effective heart rate control at rest and during exercise

    • Contraindications: Systolic pressure <100 mmHg, h/o Wolff-Parkinson-White syndrome

  • Diltiazem (Cardizem): Often used off-label for maintenance dosing

    • Initial dose: Immediate release 60 mg BID

    • Maximum dose 120mg TID

    • Contraindication: Systolic <100 mmHg

  • Digoxin: Used off-label for maintenance dosing in patients with hypotension

Rhythm control

  • For stable patients with A-Fib duration >48h, one of the following is required before cardioversion:

    • Anti-coagulation for 4 weeks

    • TEE to rule out presence of atrial thrombus

  • Unstable patients

    • Amiodarone IV: 150 mg over 10 minutes, then 1 mg/minute x6 hours, then 0.5 mg/minute x18 hours, then oral maintenance dosing

    • Synchronized electrical cardioversion: 120-200J biphasic or 200 J monophasic

Stroke

  • Stroke risk

    • 5 times greater in patients with AFib

    • Further elevated if AFib is caused by valvular disease

      • Valvular disease includes mechanical heart valves, rheumatic heart disease/mitral stenosis, decompensated heart failure due to valve dysfunction

      • Use warfarin (Coumadin) to anticoagulate these patients

  • Stroke prevention

    • CHADSVASC: Aspirin if equal to 1, anticoagulation for score of 2 or greater

    • HASBLED determines bleeding risk; score of 3 or greater indicates high risk

    • Apixaban (Eliquis)

      • May not be covered by insurance

      • Not approved for use in pregnancy, dialysis, or valvular A-Fib

    • Watchman device occludes LA appendage and reduces embolization risk

CHADS-VASc

Used to calculate stroke risk in patients with atrial fibrillation.

  • CHF: +1

  • HTN: +1

  • Age: 65-74 [+1], >75 [+2]

  • DM: +1

  • Stroke: +2

  • Vascular disease: +1

  • Sex F: +1

HASBLED

1 point for each of the following:

  • Hypertension >160mmHg systolic

  • Abnormal renal function, i.e.

    • Dialysis

    • Transplant

    • Cr >2.26 mg/dL or >200 µmol/L

  • Abnormal liver function, i.e.

    • Cirrhosis

    • Bilirubin >2x normal + AST, ALT, or AP >3x normal

  • Stroke: Prior history of stroke

  • Bleeding: Prior Major Bleeding or Predisposition to Bleeding

  • Labile INR, i.e.

    • Elevated INR

    • INR within therapeutic Range < 60% of the time

  • Elderly: Age > 65 years

  • Drugs: Antiplatelet agents, NSAIDs, ≥ 8 drinks/week"