High-rate pacing-induced atrial fibrillation effectively reveals properties of spontaneously occurring paroxysmal atrial fibrillation in humans.
OBJECTIVE
Research on paroxysmal atrial fibrillation (AF) assumes that fibrillation induced by rapid pacing adequately reproduces spontaneously occurring paroxysmal AF in humans. We aimed to compare the spectral properties of spontaneous vs. induced AF episodes in paroxysmal AF patients.


RESULTS
Eighty-five paroxysmal AF patients arriving in sinus rhythm to the electrophysiology laboratory were evaluated prior to ablation. Atrial fibrillation was induced by rapid pacing from the pulmonary vein-left atrial junctions (PV-LAJ), the coronary sinus (CS), or the high right atrium (HRA). Simultaneous recordings were obtained using multipolar catheters. Off-line power spectral analysis of 5 s bipolar electrograms was used to determine dominant frequency (DF) at recording sites with regularity index >0.2. Sixty-eight episodes were analysed for DF. Comparisons were made between spontaneous (n = 23) and induced (n = 45) AF episodes at each recording site. No significant differences were observed between spontaneous and induced AF episodes in HRA (5.18 ± 0.69 vs. 5.06 ± 0.91 Hz; P = 0.64), CS (5.27 ± 0.69 vs. 5.36 ± 0.76 Hz; P = 0.69), or LA (5.72 ± 0.88 vs. 5.64 ± 0.75 Hz; P = 0.7) regardless of pacing site. Consistent with these results, paired analysis in seven patients with both spontaneous and induced AF episodes, showed no regional DFs differences. Moreover, a left-to-right DF gradient was also present in both spontaneous (PV-LAJ 5.71 ± 0.81 vs. HRA 5.18 ± 0.69 Hz; P = 0.005) and induced (PV-LAJ 5.62 ± 0.72 vs. HRA 5.07 ± 0.91 Hz; P = 0.002) AF episodes, with no differences between them (P = not specific).


CONCLUSIONS
In patients with paroxysmal AF, high-rate pacing-induced AF adequately mimics spontaneously initiated AF, regardless of induction site.
Hospital General Universitario Gregorio Marañón, Madrid,  Spain.
David
D
Calvo
Felipe
F
Atienza
José
J
Jalife
Nieves
N
Martínez-Alzamora
Loreto
L
Bravo
Jesús
J
Almendral
Esteban
E
González-Torrecilla
Ángel
Á
Arenal
Javier
J
Bermejo
Francisco
F
Fernández-Avilés
Omer
O
Berenfeld
D000200:Action Potentials; D000328:Adult; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D002304:Cardiac Pacing, Artificial; D016009:Chi-Square Distribution; D054326:Coronary Sinus / Q000503:physiopathology; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006325:Heart Atria / Q000503:physiopathology; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011667:Pulmonary Veins / Q000503:physiopathology; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors; D056969:Voltage-Sensitive Dye Imaging