Advanced Learn EP · AFL

Atrial Flutter

Intermediate–AdvancedMechanism basedTechnologist focus

Typical atrial flutter is a macroreentrant atrial tachycardia, classically involving the cavotricuspid isthmus; atypical flutters use other circuits.

1Surface ECG
2Intracardiac signals
3Pacing clues
4Mapping concept
5Ablation concept

1. What might the surface ECG tell us?

Flutter-wave morphology and atrial activity can suggest typical versus atypical patterns, but EP confirmation may be needed.

2. What might we see intracardially?

Sequential atrial electrograms demonstrate organized atrial activation around a circuit.

Technologist mindset

Describe the sequence before naming the mechanism. Ask what is earliest, what follows, whether atrial and ventricular activation are linked, and whether the pattern changes with pacing.

3. Pacing clues

Entrainment and activation mapping can help determine whether a site participates in the reentrant circuit.

4. Mapping concept

Mapping defines activation around the circuit and identifies a critical isthmus that can be interrupted.

5. Ablation concept

For typical flutter, the procedural concept is interruption of conduction through the cavotricuspid isthmus with confirmation of block.

Important: This is conceptual education, not a procedural protocol. Diagnostic maneuvers, mapping decisions, energy delivery, endpoints, and patient-specific treatment decisions require qualified EP physician leadership, institutional training, and current device/manufacturer guidance.

Quick knowledge check

What is the best learning sequence for AFL?

Professional reference

2015 ACC/AHA/HRS SVT Guideline
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Founder-authored educational summary. External expert review is not implied unless specifically stated.