Characteristics of fibrillatory activities during spontaneous termination of paroxysmal atrial fibrillation: new insight from high-density right atrium frequency mapping.
BACKGROUND
Sinus node (SN) activity is difficult to assess during atrial fibrillation (AF). The aim of the present study was to investigate SN activity by frequency analysis during AF.


METHODS
Thirteen patients with paroxysmal AF and atrial flutter in the right atrium (RA) underwent 3-dimensional noncontact mapping. The fibrillatory activity was recorded from a multielectrode array in the RA. A frequency analysis with 2- and 6-second time-segment lengths was performed. Spectral characteristics (dominant frequency and harmonic index) and isopotential activation maps were used to investigate the spatiotemporal activity of the SN region and the rest of the RA (crista terminalis, septum, and free wall) during the initiation, while ongoing, and before the termination of AF.


RESULTS
With duration of 6 seconds, the whole RA had similar trends of frequency distribution. With duration of 2 seconds prior to termination, the SN region exhibited a trend of low-frequency pattern and high-organization distribution, compared with the segments for the 2 to 4 and 4 to 6 seconds before termination. The isopotential activation maps showed the spontaneous earliest activities had wave front propagation patterns similar to those during sinus rhythm (after termination).


CONCLUSIONS
The fibrillatory activity of the SN region was organized, and slow activation was detected, by frequency analysis and isopotential mapping, within 2 seconds just prior to AF termination.
Institute of Biomedical Engineering, National Yang-Ming University, Taipei, Taiwan.
Han-Wen
HW
Tso
Yenn-Jiang
YJ
Lin
Ching-Tai
CT
Tai
Shin-Ann
SA
Chen
Tsair
T
Kao
D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology*; D018780:Body Surface Potential Mapping / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012849:Sinoatrial Node / Q000503:physiopathology*; D013614:Tachycardia, Paroxysmal / Q000175:diagnosis / Q000503:physiopathology*