Electroanatomic mapping of right atrial activation in patients with and without paroxysmal atrial fibrillation

Area of Science:

• Electrophysiology
• Cardiology
• Cardiac Arrhythmias

Background:

• Inter-atrial conduction delay is a known factor in atrial fibrillation (AF).
• The precise anatomical location of this conduction delay remains unclear.
• Understanding these delays is crucial for managing AF patients.

Purpose of the Study:

• To investigate and pinpoint the area of inter-atrial conduction delay in patients with paroxysmal atrial fibrillation (AF).
• To compare right atrial endocardial activation patterns between AF patients and controls during sinus rhythm.

Main Methods:

• Utilized the CARTO mapping technique to assess endocardial activation times and conduction velocities in the right atrium.
• Evaluated 6 patients with paroxysmal AF and 11 control subjects during sinus rhythm.
• Measured conduction parameters from the earliest activation site to key anatomical landmarks and between adjacent myocardial sites.

Main Results:

• No significant differences were found in mean activation times or conduction velocities between the AF and control groups to the superior septum, His bundle area, or coronary sinus ostium.
• Total right atrial activation times did not differ significantly between the groups.
• Local conduction velocities between adjacent sites in the free wall, septum, and inferior right atrium were comparable in both groups.

Conclusions:

• The study suggests that previously reported posteroseptal conduction delays in paroxysmal AF patients may be specifically located within the posterior inter-atrial septum.
• These findings refine the understanding of electrophysiological abnormalities contributing to AF.
• Further research may focus on the posterior inter-atrial septum for targeted AF therapies.