💓 Cardioversion Mechanism Simulator

Confirming Anticoagulation Before Cardioversion

Rhythm reversion is deferred until anticoagulation is verified adequate.

• 3 wks: Minimum duration (therapeutic anticoagulation)
• TEE: Alt. pathway (transesophageal echo screen)
• 2–3: Target INR (if on warfarin)
• Yes: DOAC option (direct oral anticoagulants)

Why anticoagulation comes first

Placeholder: cardioversion is delayed until anticoagulation is confirmed adequate.

Placeholder: skipping this step risks dislodging an unseen clot.

Thrombus Formation in the Left Atrial Appendage

Stasis in the fibrillating LAA is the main source of cardioembolic stroke.

• ~90%: Clot source (of AF-related emboli)
• TEE: Detection (gold standard imaging)
• CHA₂DS₂-VASc: Risk score (stroke risk stratification)
• Loss of atrial kick: Stasis cause (during fibrillation)

Why the appendage is high-risk

Placeholder: the LAA is prone to stasis and clot formation during AF.

Placeholder: unrecognized thrombus is the key hazard of early cardioversion.

Synchronized Direct-Current Shock

A synchronized shock depolarizes the atria simultaneously to reset rhythm.

• ~90%: Success rate (immediate reversion)
• R-wave: Synchronization (avoids vulnerable period)
• Required: Sedation (brief procedural sedation)
• 100–200 J: Energy (biphasic waveform)

How the shock restores order

Placeholder: the shock simultaneously resets chaotic atrial cells.

Placeholder: timing to the R-wave avoids inducing ventricular fibrillation.

Antiarrhythmic Drug-Induced Reversion

Antiarrhythmic drugs slow or block the reentrant circuit driving fibrillation.

• ~50–70%: Success rate (lower than electrical)
• Hours: Onset (slower than shock)
• Flecainide: Example agents (class Ic/III drugs)
• No: Sedation needed (unlike electrical method)

How drugs terminate fibrillation

Placeholder: antiarrhythmics interrupt the reentrant electrical circuit.

Placeholder: slower onset means longer monitoring is needed.

Post-Cardioversion Anticoagulation

Anticoagulation continues after cardioversion to cover atrial stunning.

• ≥4 wks: Post-op duration (minimum continuation)
• Atrial stunning: Cause of risk (delayed mechanical recovery)
• Risk-based: Long-term therapy (per CHA₂DS₂-VASc score)
• 0 emboli: Goal (prevent delayed stroke)

Why coverage continues after success

Placeholder: mechanical atrial function lags behind electrical recovery.

Placeholder: stopping anticoagulation too early risks a delayed clot.