Abstract 10199: Right Atrial Fibrillation in Humans -Evidence for A Right Atrial Driver Activated by Right Atrial Ectopies
Background: A left-to-right dominant frequency (DF) gradient exists in acute atrial fibrillation (AF) in animals and in paroxysmal AF (PAF) in humans. PAF initiated by right atrial ectopy (PAF-RAE) is rare. Adenosine triphosphate (ATP) can be effective to unmask such a rare non-pulmonary vein (PV) ectopy and accelerate the frequency of a reentrant source of AF (driver).
Objective: This study aimed to investigate characteristics of patients with PAF-RAE using pharmacological maneuvers and spectral analysis.
Methods: Enrolled were 111 consecutive patients referred for catheter ablation of lone PAF. Infusions of isoproterenol and ATP were used to induce AF. Patients with PAF initiated only by PV ectopies and with PAF-RAE were classified into the PV-ectopy group (N=32) and RA-ectopy group (N=6), respectively. ATP was also injected during ongoing AF to unmask the AF driver. High RA, coronary sinus (CS), and PV-left atrial junction (PV-LAJ) electrograms underwent spectral analyses.
Results: RA-ectopy group patients were younger (49±13 vs. 63±7 years, p<0.001), more commonly had a family history of AF (67% vs. 9%, p<0.001), and had a higher RA appendage/RA volume ratio (0.22±0.022 vs. 0.15±0.055, p=0.002) than PV-ectopygroup patients. The most common origin of RA ectopy was the base of the RA appendage (67%). There was a baseline right-to-left DF gradient in the RA-ectopy group (PV-LAJ: 6.0±0.4, CS: 5.7±0.7, RA: 7.4±0.8 Hz, p<0.05), in contrast to a left-to-right DF gradient in the PV-ectopy group (PV-LAJ: 5.9±0.8, CS: 5.3±0.7, RA: 5.2±0.8 Hz, p<0.01). ATP injection mainly increased the DF of the high RA, augmenting a right-to-left DF gradient in the RA ectopy group (PV-LAJ: 8.0±2.0, CS: 7.8±1.0, RA: 10.7±0.7 Hz, p<0.05), whereas it augmented a left-to-right DF gradient in the PV-ectopy group (PV-LAJ: 7.9±1.0, CS: 6.4±0.5, RA: 6.6±1.2 Hz, p<0.05).
Conclusions: PAF-RAE may be maintained by a reentrant driver localized in the RA (so-called right atrial fibrillation).
Author Disclosures: H. Hasebe: None. K. Yoshida: None. M. Iida: None. N. Hatano: None. T. Muramatsu: None. K. Aonuma: None.
- © 2015 by American Heart Association, Inc.