Atrial tachycardia (ATc)
ATc basics
The below diagram shows common locations of atrial tachycardias.
​
Atrial tachycardias may be automatic or re-entrant, but are both treated the same
​The diagram below is often utilised to determine approximate atrial tachycardia origin location, based on 12 lead ECG
ATc ablation
Equipment
-
Multiple venous access
-
Often involves a coronary sinus decapolar catheter
-
1-3 other quadripolar JSN catheters may be used depending on Dr preference. This traditionally are placed into the high right atrium, HIS and RV apex. If only 1 JSN is used it can be moved around to several positions to perform testing and analyse results.
-
If ablation is to be performed RF ablation (either non irrigated or irrigated) can be used. Focal cryothermy ablation may be considered if there is higher risk of AV block (AP close to AV node)
-
3D mapping can be utilised if desired
Basic EP study procedure
-
Basic EP study is usually performed 1st to induce and confirm arrhythmia diagnosis
​
Click here for more info on determining retrograde conduction
Ablation
Success rates
>80%
​​
Complications
​​
Complications depend on location of the pathway
(e.g., proximity to AV node, left sided - transeptal access, etc)
Mapping the origin
-
Mapping must occur during the tachycardia.
​
-
The earliest atrial signal is mapped to a stable reference (ECG - only if onset is definitivelty clear; or CS is often utilised).
​
-
Atrial signal should ideally be >30ms pre p wave onset (in tachycardia).
​
-
Bracketing the earliest activation is important to ensure the absolute earliest signal is found.
