Atrial Fibrillation / Flutter
The three pillars — rate control, rhythm control, and stroke prevention — plus cardioversion logic.
Learning Objectives
- 1.Apply the rate/rhythm/anticoagulation framework to AFib.
- 2.Use CHA₂DS₂-VASc and bleeding risk to guide anticoagulation.
- 3.Understand cardioversion and the anticoagulation timing around it.
Overview
AFib management rests on three pillars: control the rate, decide about rhythm, and prevent stroke. Stroke prevention is the one that saves lives and is most often under-done.
Why this matters
AFib raises stroke risk several-fold; appropriate anticoagulation dramatically reduces it. Rate vs rhythm strategy is individualized.
Classification
- •Paroxysmal (self-terminating <7 days), persistent (≥7 days/needs cardioversion), long-standing persistent (>12 months, still pursuing rhythm control), and permanent ("chronic AF" — rhythm control abandoned, rate control only). Flutter is a related organized atrial rhythm (often ~150 ventricular rate).
Pillar 1 — rate control
- •Beta-blockers or non-dihydropyridine CCBs (diltiazem/verapamil) for rate.
- •Avoid non-dihydropyridine CCBs in significantly reduced EF.
- •Digoxin as add-on in select patients.
Pillar 2 — rhythm control
- •Consider for symptomatic patients, younger patients, HF, or when rate control fails.
- •Antiarrhythmic drugs and catheter ablation are options (ablation is the EP’s domain).
- •Rhythm control does not remove the need for anticoagulation based on stroke risk.
Pillar 3 — stroke prevention
- •Estimate stroke risk with CHA₂DS₂-VASc; anticoagulate when indicated (generally ≥2 in men, ≥3 in women; consider at 1).
- •Apply CHA₂DS₂-VASc across ALL AFib patterns (paroxysmal → permanent) — the decision is risk-based, not pattern-based. Paroxysmal AFib is not "low-risk" enough to skip indicated anticoagulation, and most non-paroxysmal AFib already lands in the OAC-reasonable-to-recommended zones.
- •DOACs preferred over warfarin for most (except mechanical valves/moderate-severe mitral stenosis → warfarin).
- •Assess/modify bleeding risk (e.g., HAS-BLED) — high bleeding risk is not, by itself, a reason to withhold indicated anticoagulation.
- •Left atrial appendage occlusion (e.g., Watchman) for selected patients who can’t tolerate long-term anticoagulation.
Cardioversion logic
- •AFib >48 hours (or unknown duration): anticoagulate ~3 weeks before and ≥4 weeks after, OR a TEE to exclude thrombus before cardioversion.
- •Unstable AFib → urgent cardioversion regardless.
- •Anticoagulate for ≥4 weeks after cardioversion and continue long-term based on stroke risk.
Monitoring & red flags
- •Rapid AFib with instability (hypotension, ischemia, pulmonary edema) → urgent escalation/cardioversion.
- •Stroke symptoms (FAST) → 911.
- •Bleeding on anticoagulation → evaluate/escalate.
Escalate
Unstable rapid AFib or stroke symptoms are emergencies — escalate immediately rather than titrating an oral rate agent.
Common beginner mistakes
- •Under-anticoagulating an at-risk patient (the costliest error).
- •Withholding indicated anticoagulation solely for "fall risk" or HAS-BLED.
- •Cardioverting without addressing the anticoagulation window.
- •Using non-DHP CCBs in low EF.
Tools
- •CHA₂DS₂-VASc, HAS-BLED, SAMe-TT₂R₂, and CrCl/DOAC dosing are under Clinical Tools.
Mini cases
74-year-old woman with hypertension and diabetes, new AFib, not anticoagulated.
Anticoagulation?
Show answer
CHA₂DS₂-VASc is clearly elevated (age, sex, HTN, DM) — she warrants anticoagulation, generally a DOAC. Don’t defer for vague "fall risk"; the stroke-prevention benefit is substantial.
AFib of unknown duration, hemodynamically stable; the team wants to cardiovert today.
What about anticoagulation?
Show answer
Stable AFib >48h/unknown duration needs ~3 weeks of pre-cardioversion anticoagulation OR a TEE to exclude thrombus first, plus ≥4 weeks after. Cardioverting now without this risks stroke.