Usefulness of filtered unipolar electrogram morphology for evaluating transmurality of ablated lesions during pulmonary vein isolation.
BACKGROUND
Although alteration of the amplitude and morphology of bipolar electrograms is used widely as a guide of the ablation effect, there is little information concerning unipolar electrograms. The amplitude and morphology of filtered bipolar (BP) and filtered unipolar (UP) electrograms were compared during pulmonary vein isolation in patients with atrial fibrillation.


METHODS
BP (30-250 Hz) and UP (30-100 Hz) signals from the ablation catheter were recorded before and after each ablation point at the pulmonary vein antrum in 6 patients with atrial fibrillation.


RESULTS
In the electrogram group with low-voltage amplitude in BP electrograms before ablation (<0.5 mV), the reduction in amplitude after ablation was significantly greater in the UP than in the BP electrograms, whereas the reduction was similar between the two recording methods in the electrogram group with high-voltage amplitude in BP electrograms (≥0.5 mV). Furthermore, the S wave in the UP electrograms disappeared at the sites of no pace capture after ablation, whereas no characteristic morphologic changes were observed in the BP electrograms.


CONCLUSIONS
Filtered UP electrograms may be useful in assessing the effectiveness of lesion formation.
Division of Cardiology, Department of Medicine, Nihon University School of Medicine, 30-1 Oyaguchi-kami, Itabashi-ku, Tokyo 173-8610, Japan.
Rikitake
R
Kogawa
Division of Cardiology, Department of Medicine, Nihon University School of Medicine, 30-1 Oyaguchi-kami, Itabashi-ku, Tokyo 173-8610, Japan.
Ichiro
I
Watanabe
Division of Cardiology, Department of Medicine, Nihon University School of Medicine, 30-1 Oyaguchi-kami, Itabashi-ku, Tokyo 173-8610, Japan.
Yasuo
Y
Okumura
Division of Cardiology, Department of Medicine, Nihon University School of Medicine, 30-1 Oyaguchi-kami, Itabashi-ku, Tokyo 173-8610, Japan.
Hiroaki
H
Mano
Division of Cardiology, Department of Medicine, Nihon University School of Medicine, 30-1 Oyaguchi-kami, Itabashi-ku, Tokyo 173-8610, Japan.
Kazumasa
K
Sonoda
Division of Cardiology, Department of Medicine, Nihon University School of Medicine, 30-1 Oyaguchi-kami, Itabashi-ku, Tokyo 173-8610, Japan.
Koichi
K
Nagashima
Division of Cardiology, Department of Medicine, Nihon University School of Medicine, 30-1 Oyaguchi-kami, Itabashi-ku, Tokyo 173-8610, Japan.
Naoko
N
Sasaki
Division of Cardiology, Department of Medicine, Nihon University School of Medicine, 30-1 Oyaguchi-kami, Itabashi-ku, Tokyo 173-8610, Japan.
Kimie
K
Ohkubo
Division of Cardiology, Department of Medicine, Nihon University School of Medicine, 30-1 Oyaguchi-kami, Itabashi-ku, Tokyo 173-8610, Japan.
Keiko
K
Takahashi
Division of Cardiology, Department of Medicine, Nihon University School of Medicine, 30-1 Oyaguchi-kami, Itabashi-ku, Tokyo 173-8610, Japan.
Kazuki
K
Iso
Division of Cardiology, Department of Medicine, Nihon University School of Medicine, 30-1 Oyaguchi-kami, Itabashi-ku, Tokyo 173-8610, Japan.
Sayaka
S
Kurokawa
Division of Cardiology, Department of Medicine, Nihon University School of Medicine, 30-1 Oyaguchi-kami, Itabashi-ku, Tokyo 173-8610, Japan.
Toshiko
T
Nakai
Division of Cardiology, Department of Medicine, Nihon University School of Medicine, 30-1 Oyaguchi-kami, Itabashi-ku, Tokyo 173-8610, Japan.
Atsushi
A
Hirayama
Atrial fibrillation; Durable pulmonary vein isolation; Filtered unipolar electrogram; Pulmonary vein isolation