In this episode of Hospital Medicine Unplugged, we sprint through atrial flutter—spot the sawtooth, choose the fastest safe path to sinus, and keep strokes off the table.

We open with the do-firsts: confirm the rhythm and triage the “why.” Grab a 12-lead ECG—regular narrow tachycardia with classic sawtooth F-waves (atrial ~240–300 bpm, often 2:1 AV → ~150 bpm). Don’t confuse variable conduction with AF. Put the patient on telemetry; replete K/Mg (K ≥4, Mg ≥2). Hunt triggers (infection, hypoxia, decomp HF, stimulants, post-op). Get an echo to size up structure/valves; plan TEE if cardioversion and duration ≥48 h or unknown.

Acute decisions—match stability to action:
• Unstable (hypotension, ischemia, pulmonary edema, shock): synchronized cardioversion now. Start 50–100 J biphasic (AP pads), escalate as needed.
• Stable: pick rate vs rhythm based on symptoms, duration, and comorbids.
– Rate control first line: β-blocker (esmolol/metoprolol) or diltiazem/verapamil; avoid NDHP-CCBs in HFrEF. Add digoxin as adjunct if needed. If decomp HF/hypotension, IV amiodarone can slow the ventricle.
– Rhythm control when rate control is tough or symptoms/high stakes: synchronized cardioversion (near-certain success), or ibutilide 1 mg IV over 10 min (give Mg 2 g IV; strict QT monitoring) or dofetilide (inpatient initiation, QT monitoring). Class IC (flecainide/propafenone) can provoke 1:1 conduction—never give without AV-nodal blockade and avoid in structural heart disease.
– Pre-excitation (WPW pattern): avoid AV-nodal blockers; urgent cardioversion.

Anticoagulation—same rules as AF: use CHA₂DS₂-VASc for long-term decisions. If duration ≥48 h or unknown, choose ≥3 weeks of therapeutic anticoagulation or TEE-guided cardioversion, and continue OAC ≥4 weeks post-cardioversion. Many hospitalized adults meet OAC criteria—don’t skip stroke prevention.

When to favor rhythm early: persistent rapid rates despite meds, ischemia/HF, poor tolerance, or procedural timing needs. A quick shock back to sinus simplifies everything.

Think definitive: CTI ablation for typical (isthmus-dependent) flutter is >90–95% effective with low risk—strong option after a first significant hospitalization or if recurrent. Expect incident AF (~50%) after flutter—monitor and keep OAC per risk, not just rhythm appearance.

ICU/complex plays: in decompensated HF or shock, cardiovert early; if meds needed, amiodarone is often the hemodynamically friendliest for rate control. Correct hypoxemia, fever, and volume—they’re gasoline on the circuit.

Special populations, quick hits:
• HFrEF: β-blocker if stable; avoid diltiazem/verapamil; amiodarone for rate/rhythm if needed; early ablation is attractive.
• Post-cardiac surgery: often transient—rate control, consider amiodarone/ibutilide if symptomatic; map/ablate for recurrent cases.
• Pre-excited flutter: no AV-nodal blockers; shock or procainamide (if truly stable and expert-guided).

Procedure pearls (make it boring-safe): Anterior–posterior pad placement, sedation ready, sync ON, start low energy (flutter needs less than AF), and re-check rhythm + anticoagulation plan before leaving the bedside.

We close with the system moves: an atrial-flutter bundle that (1) auto-flags sawtooth at ~150 bpm and fires a cardioversion pathway for instability; (2) hard-stops electrolytes to K ≥4/Mg ≥2; (3) blocks NDHP-CCBs in HFrEF and blocks AV-nodal agents if pre-excitation seen; (4) offers ibutilide with QT/Mg guardrails and dofetilide inpatient-initiation checklist; (5) forces TEE-or-≥3-weeks-OAC when duration ≥48 h/unknown, and locks in ≥4 weeks post-CV OAC; (6) auto-consults EP for CTI ablation after first significant admission or recurrence; (7) adds AF-surveillance plan (patch/tele) and leaves OAC tied to CHA₂DS₂-VASc, not wishful thinking.

Fast, ECG-led, and stroke-savvy—see the sawtooth, fix the rate or flip the rhythm, and never miss the anticoagulation.