Pseudo-Focal Atrial Tachycardia Case Series
Short title: Nakatani, et al. Macroreentries with
epicardial bypass
Yosuke Nakatani, MD; Takashi Nakashima, MD; Josselin Duchateau, MD;
Konstantinos Vlachos, MD; Philipp Krisai, MD; Takamitsu Takagi, MD;
Tsukasa Kamakura, MD; Clémentine André, MD; Cyril Goujeau, MD; F. Daniel
Ramirez, MD; Remi Chauvel, MD; Romain Tixier, MD; Masateru Takigawa, MD;
Takeshi Kitamura, MD; Ghassen Cheniti, MD; Arnaud Denis, MD; Frédéric
Sacher, MD; Mélèze Hocini, MD; Michel Haïssaguerre, MD; Pierre Jaïs, MD;
Nicolas Derval, MD; Thomas Pambrun, MD
Hôpital Cardiologique du Haut-Lévêque, CHU Bordeaux, L’Institut de
RYthmologie et modélisation Cardiaque (LIRYC), Université Bordeaux,
France.
Data availability statement: The data that support the
findings of this study are available on request from the corresponding
author. The data are not publicly available due to privacy or ethical
restrictions.
Funding statement: Dr. Nakatani is supported by the
JHRS-EHRA Fellowship. Dr. Krisai is supported by the University of
Basel, the Mach-Gaensslen foundation, and the Bangerter-Rhyner
foundation. Dr. Ramirez is supported by the Canadian Institutes of
Health Research Banting Postdoctoral Fellowship. This work is supported
by the Agence Nationale de la Recherche (grant number; IHU LIRYC
ANR-10-IAHU-04).
Conflict of interest disclosure: Drs. Haïssaguerre,
Hocini, Jaïs, Derval, Sacher and Pambrun have received lecture fees from
Biosense Webster. Drs. Derval, Sacher and Jaïs have received lecture
fees from Boston Scientific.
Address for correspondence: Yosuke Nakatani, MD
Hôpital Cardiologique du Haut-Lévêque, Avenue de Magellan, 33604
Bordeaux-Pessac, France. Telephone: +33-5-57656542; E-mail:yosuke3gbst@gmail.com
ABSTRACT
Introduction: Human atria comprise distinct epicardial
layers, which can bypass endocardial layers and lead to downstream
centrifugal propagation at the ”epi-endo” connection. We sought to
characterize anatomical substrates, electrophysiological properties, and
ablation outcomes of
”pseudo-focal” atrial tachycardias
(ATs), defined as macroreentrant ATs mimicking focal ATs.
Methods and Results: We retrospectively analyzed ATs
showing centrifugal propagation with post-pacing intervals (PPIs) after
entrainment pacing suggestive of a macroreentry. A total of 26 patients
had pseudo-focal ATs consisting of 15 perimitral, 7 roof-dependent, and
5 cavotricuspid isthmus (CTI)-dependent flutters. A low-voltage area was
consistently found at the collision site and co-localized with
epicardial layers like the: (1) coronary sinus-great cardiac vein bundle
(22%); (2) vein of Marshall bundle (15%); (3) Bachmann bundle (22%);
(4) septopulmonary bundle (15%); (5) fossa ovalis (7%); and (6) low
right atrium (19%). The mean missing tachycardia cycle length (TCL) was
67 ± 29 ms (22%) on the endocardial activation map. PPI was 9
[0-15] ms and 10 [0-20] ms longer than TCL at the breakthrough
site and the opposite site, respectively. While feasible in 25
pseudo-focal ATs (93%), termination was better achieved by blocking the
anatomical isthmus than ablating the breakthrough site [24/26 (92%)
vs. 1/6 (17%); p < 0.001].
Conclusion: Perimitral, roof-dependent, and
CTI-dependent flutters with centrifugal propagation are favored by a
low-voltage area located at well-identified epicardial bundles.
Comprehensive entrainment pacing maneuvers are crucial to distinguish
pseudo-focal ATs from true focal ATs. Blocking the anatomical isthmus is
a better therapeutic option than ablating the breakthrough site.
Keywords: Atrial tachycardia; Macroreentry; Epicardial
connection; Catheter ablation; Entrainment pacing.