Atrial septal pacing to resynchronize atrial contraction and improve atrial transport function.
OBJECTIVE
Atrial septal pacing via a trans-septal breakthrough site within the right atrial septum can shorten global atrial activation time, resulting in significant reduction of recurrence of atrial fibrillation events. This study examined whether this pacing method will lead to resynchronization of atrial contraction and its benefit on hemodynamic function can be maintained for 24 months.


METHODS
Thirty patients with atrial fibrillation and delayed atrial conduction were enrolled (17 males, 13 females, mean age 73 +/- 7 years). Trans-septal breakthrough site within the right atrial septum was identified through pacing from the dorsal left atrium. Continuous atrial septal pacing at the trans-septal breakthrough site was performed for 24 months. Time difference (TD) between right and left atrial contractions was measured during atrial septal pacing and sinus rhythm by pulse Doppler echocardiography of the trans-tricuspid (P-At) and mitral (P-Am) blood flows (TD = P-Am - P-At).


RESULTS
The atrial lead was screwed near the fossa ovalis in 29 of 30 patients. Atrial septal pacing yielded significantly shorter P wave duration (101.9 +/- 10.4 vs 139.6 +/- 14.7 msec, p < 0.001), leading to significant reduction of TD in atrial contraction (-8.8 +/- 10.0 vs 29.8 +/- 13.6 msec, p < 0.001)as compared to sinus rhythm. Both shorter P wave duration and reduced TD during atrial septal pacing remained statistically significant during the follow-up period as compared to sinus rhythm. Both left atrial diameter and A to E ratio of filling waves at mitral valve were significantly decreased at 12 months and remained decreased at 24 months.


CONCLUSIONS
Atrial septal pacing at the trans-septal breakthrough site can resynchronize atrial contraction and results in improved hemodynamic effects during 24 months of follow-up.
Division of Cardiology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo. dr.hidekazu.m@jikei.ac.jp
Hidekazu
H
Miyazaki
Kenji
K
Noma
Taro
T
Date
Akimitsu
A
Kobayashi
Atsushi
A
Koga
Mamoru
M
Kuno
Satoshi
S
Takeda
Keiji
K
Iwano
Shingo
S
Seki
Keiichi
K
Inada
Seiichiro
S
Matsuo
Satoru
S
Miyanaga
Kunihiko
K
Abe
Teiichi
T
Yamane
Kenichi
K
Sugimoto
Seibu
S
Mochizuki
D000368:Aged; D001281:Atrial Fibrillation / Q000503:physiopathology* / Q000628:therapy; D016275:Atrial Function; D002304:Cardiac Pacing, Artificial; D004562:Electrocardiography; D005260:Female; D006325:Heart Atria / Q000503:physiopathology; D006346:Heart Septum / Q000503:physiopathology; D006801:Humans; D008297:Male; D009200:Myocardial Contraction; D055502:Secondary Prevention