Key Points
            - Use the highest‑yield diagnostic test early; do not let testing delay time‑critical therapy.
- Set objective targets and reassess frequently.
- Plan definitive source control or disease‑specific therapy when indicated; document follow‑up and patient education.
                                        Algorithm
            - Unstable → synchronized cardioversion + anticoagulation plan.
- Stable → rate control (β‑blocker/CCB) ± amiodarone (HFrEF).
- Rhythm control if symptoms persist or new onset; TEE if ≥48 h/unknown duration.
- Start/continue anticoagulation per CHA₂DS₂‑VASc; address triggers (sepsis, alcohol, thyroid).
                                        Clinical Synopsis & Reasoning
            Rapid AF can cause hypotension, ischemia, or heart failure. Stabilize ABCs; if unstable, perform synchronized cardioversion. If stable, choose rate control (β‑blocker or nondihydropyridine CCB; amiodarone if LV dysfunction/hypotension) versus rhythm control based on duration and comorbidities, and address anticoagulation using CHA₂DS₂‑VASc and bleeding risk.
                                        Treatment Strategy & Disposition
            Stabilize ABCs. Initiate guideline‑concordant first‑line therapy with precise dosing and continuous monitoring. Escalate to advanced/procedural interventions based on explicit failure criteria. Define ICU, step‑down, and ward disposition triggers; involve specialty teams early.
                                        Epidemiology / Risk Factors
            - Risk varies by comorbidity and precipitants; see citations for condition‑specific data.
                                        Investigations
            
              
                | Test | Role / Rationale | Typical Findings | Notes | 
|---|
                
                  | 12‑lead ECG and telemetry | Diagnosis | Irregularly irregular rhythm; exclude pre‑excitation | QT/QRS monitoring | 
| Electrolytes, TSH, troponin, echo (selected) | Etiology/complications | Hypo‑K/Mg, thyrotoxicosis, structural heart disease | Guide therapy | 
| Stroke risk/bleed risk scores (CHA₂DS₂‑VASc, HAS‑BLED) | Anticoagulation | Risk stratification | Shared decision | 
                
              
             
                                        High-Risk & Disposition Triggers
            
              
                | Trigger | Why it matters | Action | 
|---|
                
                  | Instability or organ dysfunction | High risk | ICU; escalate care | 
| Failure of first-line therapy | Refractory | Advance pathway; consult subspecialists | 
| Severe comorbidity/pregnancy/immunosuppression | Higher risk | Lower threshold to admit | 
| Poor follow-up access | Safety | Prefer observation/admission | 
| Diagnostic uncertainty with red flags | Missed diagnosis risk | Serial exams and monitoring | 
                
              
             
                                        Pharmacology
            
              
                | Medication/Intervention | Mechanism | Onset | Role in Therapy | Limitations | 
|---|
                
                  | Diltiazem IV bolus/infusion or Metoprolol IV | AV nodal blockade | Minutes | Rate control in stable patients | Avoid diltiazem in decompensated HFrEF | 
| Amiodarone IV (if rate control failure or HFrEF) | Antiarrhythmic | Hours | Rate/rhythm in LV dysfunction | Monitor QT/LFTs | 
| Electrical cardioversion (unstable) or TEE‑guided cardioversion (≥48 h or unknown duration) | Rhythm control | Immediate/Hours | Restore sinus rhythm | Anticoagulation per guideline | 
| Anticoagulation: DOACs preferred; heparin bridge if needed | Stroke prevention | Hours‑days | Based on CHA₂DS₂‑VASc | Adjust for renal function | 
                
              
             
                                        Prognosis / Complications
            - Outcome depends on timeliness of diagnosis and definitive therapy; monitor for complications.
                                        Patient Education / Counseling
            - Provide red‑flag education, adherence guidance, and explicit return precautions; arrange timely specialty follow‑up.
                  
        
                  References
                      - AHA/ACC/HRS AF management guideline — Link