Advanced Learn EP · AT

Focal Atrial Tachycardia

Intermediate–AdvancedMechanism basedTechnologist focus

Atrial tachycardia can arise from a focal atrial source; mechanisms may include automaticity, triggered activity, or microreentry depending on the tachycardia.

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

1. What might the surface ECG tell us?

P-wave morphology and atrial rate/relationship to the QRS can provide localization and mechanism clues.

2. What might we see intracardially?

Intracardiac atrial activation identifies where activation appears earliest relative to other atrial sites.

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

Induction behavior and responses to pacing may help distinguish focal AT from AV node–dependent tachycardias.

4. Mapping concept

Activation mapping seeks the earliest consistent atrial activation and interprets it in anatomical context.

5. Ablation concept

When ablation is appropriate, therapy is directed at the responsible focal source or critical tissue.

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 AT?

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.