Electrophysiological and hemodynamic characteristics associated with obesity in patients with atrial fibrillation.
OBJECTIVE
The authors sought to characterize the left atrial (LA) and pulmonary vein (PV) electrophysiological and hemodynamic features in obese patients with atrial fibrillation (AF).


BACKGROUND
Obesity is associated with increased risk for AF.


METHODS
A total of 63 consecutive patients with AF who had normal left ventricular (LV) ejection fraction and who underwent catheter ablation were studied. Atrial and PV electrophysiological studies were performed at the time of ablation with hemodynamic assessment by cardiac catheterization, and LA/LV structure and function by echocardiography. Patients were compared on the basis of body mass index (BMI): <25 kg/m(2) (n = 19) and BMI ≥30 kg/m(2) (n = 44).


RESULTS
At a 600-ms pacing cycle length, obese patients had shorter effective refractory period (ERP) in the left atrium (251 ± 25 ms vs. 233 ± 32 ms, p = 0.04), and in the proximal (207 ± 33 ms vs. 248 ± 34 ms, p < 0.001) and distal (193 ± 33 ms vs. 248 ± 44 ms, p < 0.001) PV than normal BMI patients. Obese patients had higher mean LA pressure (15 ± 5 mm Hg vs. 10 ± 5 mm Hg, p < 0.001) and LA volume index (28 ± 12 ml/m(2) vs. 21 ± 14 ml/m(2), p = 0.006), and lower LA strain (5.5 ± 3.1% vs. 8.8 ± 2.8%; p < 0.001) than normal BMI patients.


CONCLUSIONS
Increased LA pressure and volume, and shortened ERP in the left atrium and PV are potential factors facilitating and perpetuating AF in obese patients with AF.
Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, USA.
Thomas M
TM
Munger
Ying-Xue
YX
Dong
Mitsuru
M
Masaki
Jae K
JK
Oh
Sunil V
SV
Mankad
Barry A
BA
Borlaug
Samuel J
SJ
Asirvatham
Win-Kuang
WK
Shen
Hon-Chi
HC
Lee
Suzette J
SJ
Bielinski
David O
DO
Hodge
Regina M
RM
Herges
Traci L
TL
Buescher
Jia-Hui
JH
Wu
Changsheng
C
Ma
Yanhua
Y
Zhang
Peng-Sheng
PS
Chen
Douglas L
DL
Packer
Yong-Mei
YM
Cha
D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications / Q000503:physiopathology* / Q000628:therapy; D017115:Catheter Ablation; D004452:Echocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006325:Heart Atria / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009765:Obesity / Q000150:complications / Q000503:physiopathology*; D011667:Pulmonary Veins / Q000503:physiopathology*