(FIT)-Module 2 Lectures: Invasive Diagnosis and Treatment Part 1-Catheter Ablation of Atrial Tachycardia and Typical Atrial Flutter (Stevenson)

Video Transcription

Video Summary

In this talk, Bill Stevenson from Vanderbilt University Medical Center explores catheter ablation for atrial tachycardia and atrial flutter, focusing on mapping approaches determined by arrhythmia types. Atrial tachycardias fall into two categories: focal and macro-reentrant. Focal tachycardias arise from a single point, characterized by early activation and typically involve automaticity or small re-entry circuits. They feature discrete P waves and are often managed with pace mapping or activation sequence mapping to determine the earliest site of activation. Conversely, macro-reentrant tachycardias do not have a single point of earliest activation, and activation sequences or entrainment mapping are used to define re-entry circuits. This distinction is crucial as these tachycardias travel through continuous activation in circuits without an earliest point.<br /><br />Focal atrial tachycardias can mimic other supraventricular tachycardias depending on their location and behavior. They can be of idiopathic origin or associated with structural heart disease, presenting as incessant or paroxysmal arrhythmias, commonly experiencing gradual onset and offset. Their P-wave morphology helps determine their origin within the atrium, with an initial focus on assessing P-wave configurations interpreted through leads. Ablation for focal arrhythmias often hinges on identifying this site via activation mapping, with electrographic and unipolar signals analyzed for precision.<br /><br />Macro-reentrant tachycardias, particularly cavotricuspid isthmus dependent atrial flutters, have characteristic circuit patterns often provoked by episodes like rapid tachycardia or non-sustained fibrillation. Typical flutters exhibit distinct P-wave morphologies across leads and require rigorous mapping techniques to identify circuit components. Current mapping systems and electroanatomic mapping techniques facilitate the detailed assessment and ablation of complex circuits identified through geography or structural scar presence. This ensures the successful identification and interruption of arrhythmogenic pathways critical for treatment efficacy.

Keywords

catheter ablation

atrial tachycardia

atrial flutter

mapping approaches

arrhythmia types

focal tachycardia

macro-reentrant tachycardia

pace mapping

activation sequence mapping

entrainment mapping

P-wave morphology

electroanatomic mapping

cavotricuspid isthmus

arrhythmogenic circuits