Right atrial substrate properties associated with age in patients with typical atrial flutter.
BACKGROUND
Data detailing the age-related difference in the atrial substrate for formation of typical atrial flutter (AFL) are sparse.


OBJECTIVE
The purpose of this study was to characterize the difference in the right atrial substrate related to aging using noncontact mapping of the right atrium.


METHODS
A total of 54 patients (23 young [<60 years; 45 +/- 12 years] and 31 old [>or=60 years; 74 +/- 6 years]) with typical AFL who underwent three-dimensional noncontact mapping of typical AFL were enrolled in the study. The atrial substrate was characterized according to (1) regional wavefront activation mapping, (2) regional conduction velocity, and (3) regional voltage distribution by dynamic substrate mapping.


RESULTS
During activation mapping of the crista terminalis, two activation patterns were observed: (1) around the upper end of the crista terminalis (67%) and (2) through a gap in the crista terminalis. The presence of a crista terminalis gap was associated with a high incidence of induced atypical AFL/atrial fibrillation (P <.001). The conduction velocities of the medial cavotricuspid isthmus were slower in the old group than in the young group. In regional activation mapping of the AFL, the location of the slowest conduction shifted from the lateral cavotricuspid isthmus (71%) in the young group to the medial cavotricuspid isthmus (40%) in the old group. More cases with a low-voltage zone (<or=30% peak negative voltage) extending to the medial side of the cavotricuspid isthmus occurred in the old group than in the young group (55% vs 17%, P = .012).


CONCLUSIONS
The atrial substrate responsible for formation of typical AFL differed between young and old patient groups.
Huang
Jin-Long
JL
Heart Failure Division, Cardiovascular Center, Taichung Veterans General Hospital, Taipei, Taiwan. golden@vghtc.gov.tw
Tai
Ching-Tai
CT
Lin
Yenn-Jiang
YJ
Ueng
Kwo-Chang
KC
Huang
Bien-Hsien
BH
Lee
Kun-Tai
KT
Higa
Satoshi
S
Yuniadi
Yoga
Y
Chang
Shih-Lin
SL
Lo
Li-Wei
LW
Wongcharoen
Wanwarang
W
Hu
Yu-Feng
YF
Lee
Pi-Chang
PC
Tuan
Ta-Chuan
TC
Ting
Chih-Tai
CT
Chen
Shih-Ann
SA
D000367:Age Factors; D000368:Aged; D001282:Atrial Flutter / Q000503:physiopathology*; D018780:Body Surface Potential Mapping / Q000379:methods; D054849:Cardiac Electrophysiology; D005260:Female; D006325:Heart Atria / Q000503:physiopathology*; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects