I. Initial Evaluation
History
Symptoms: Palpitations, fatigue, dizziness, chest discomfort, dyspnea, syncope
Onset: Sudden vs gradual; known triggers (e.g., alcohol binge, infection, hyperthyroidism)
History: Prior AF/flutter, structural heart disease, heart failure, hypertension, thyroid disease
Physical Exam
Vitals: Irregularly irregular pulse (AF), rapid HR; stable vs unstable signs
Cardiac: Irregular rhythm in AF; sawtooth conduction in flutter may have regular or variable conduction
Signs of underlying causes: CHF signs, thyromegaly, murmurs
II. Diagnostic Workup
EKG
Atrial Fibrillation: Irregularly irregular rhythm, absence of P waves, fibrillatory baseline
Atrial flutter: Sawtooth flutter waves (esp. leads II, III, aVF), often with 2:1 or variable conduction
Labs
Electrolytes (K⁺, Mg²⁺)
TSH/Free T4 (hyperthyroidism evaluation)
Troponin if ischemia suspected
CBC, CMP to evaluate underlying or precipitating causes
Imaging
Chest X-ray: Evaluate for CHF
Echo: Assess for left atrial enlargement, valvular disease, LV function
III. Classification
Type Description Paroxysmal AF Terminates spontaneously within 7 days Persistent AF Persists >7 days or requires cardioversion Long-standing persistent AF Continuous AF >12 months Permanent AF Decision made to accept and not pursue rhythm control
IV. Treatment
Acute Management
If unstable (hypotension, ischemia, pulmonary edema): Immediate synchronized cardioversion
Rate control (stable): IV diltiazem or beta-blocker (e.g., metoprolol)
Diltiazem full dose is 0.25mg/kg IV. This can be broken down into 10-15mg IV pushes.
Repeat dosing until desired HR is achieved (usually aim for less than 105 bpm)
Metoprolol can be given in doses from 2.5mg to 5mg IV pushes
Consider diltiazem drip if the patient is requiring multiple (>3 IV pushes) without sustained response
Consider digoxin 250mcg IV if hypotensive or arrhythmia is refractory (esp. in CHF)
Anticoagulation considerations based on duration & risk factors
Anticoagulation
Calculate CHA₂DS₂-VASc score
Initiate anticoagulation (DOACs preferred) if score ≥2 (male) or ≥3 (female)
For AF >48h or unknown duration: Anticoagulate ≥3 weeks before or use TEE-guided strategy before cardioversion
Rhythm Control
Electrical cardioversion if appropriate (stable + anticoagulated)
This may be done on an inpatient basis (or through a cardiology clinic) once a TEE has confirmed no atrial thrombus is present
Pharmacologic cardioversion options: Amiodarone, flecainide, propafenone (consider contraindications)
Referral to EP for ablation in recurrent symptomatic AF/flutter
V. Disposition Planning
Scenario Disposition Notes New-onset AF/flutter, stable, rate controlled, CHA₂DS₂-VASc indicates low risk Discharge with outpatient cardiology follow-up Start anticoagulation if indicated, arrange follow-up Persistent rapid AF/flutter, unstable, or evidence of end-organ damage or high CHA₂DS₂-VASc risk Admit to telemetry, PCU or ICU Initiate IV therapy, possible cardioversion, continuous monitoring
VI. Red Flags / Escalation Triggers
Hemodynamic instability (SBP <90 mmHg)
Chest pain with dynamic ECG changes suggestive of ischemia
Acute heart failure with pulmonary edema
Signs of stroke or TIA
Pre-excitation (WPW) with wide complex irregular tachycardia
✅ Discharge Checklist
Stable rate & rhythm with clear follow-up plan
Initiated anticoagulation if indicated
Patient educated on symptoms, medications, when to return
Follow-up with primary care or cardiology scheduled
References
January CT, Wann LS, Calkins H, et al. 2019 AHA/ACC/HRS Focused Update on the Management of Patients With Atrial Fibrillation . Circulation. 2019;140(2):e125–e151. https://doi.org/10.1161/CIR.0000000000000665
Additional Keywords: A-fib, Afib, A-flutter, Aflutter, RVR, Rapid Ventricular Response