Peak frequency mapping of atypical atrial flutter

Area of Science:

• Electrophysiology
• Cardiac Arrhythmia Mapping

Background:

• Peak frequency (PF) mapping is an emerging technique for identifying critical myocardial substrates that support reentrant arrhythmias.
• Understanding these substrates is crucial for effective catheter ablation of complex atrial arrhythmias.

Purpose of the Study:

• To evaluate the utility of combining PF mapping with omnipolar voltage mapping.
• To identify critical isthmuses in the left atrium (LA) associated with atypical atrial flutters.

Main Methods:

• Generated LA omnipolar voltage and PF maps in 12 patients with atypical flutter using specialized mapping systems.
• Defined voltage criteria for normal, low-voltage, and scar tissue.
• Analyzed PF distributions in relation to myocardial voltage and arrhythmia termination sites.

Main Results:

• Atypical flutters commonly involved the mitral isthmus (58%) and anterior wall (25%).
• Mean PF significantly differed across voltage states: normal (335.5 Hz), low-voltage (274.6 Hz), and scar (71.6 Hz) (p < .0001).
• Arrhythmia termination sites were located in low-voltage areas with higher PF compared to the global myocardium (p < .0001).

Conclusions:

• Low-voltage regions exhibiting high PF are critical targets for catheter ablation.
• This combined mapping approach aids in precisely identifying ablation targets for atypical atrial flutter.