The effects of cycle length on the fragmented atrial activity zone in patients with sick sinus syndrome.
To determine whether atrial pacing effectively decreases the fragmented atrial activity zone (FAZ) in patients with sick sinus syndrome (SSS), we compared FAZ at atrial pacing cycle lengths of 1000-1500 msec (CL1) with that of 750 msec (CL2) in 19 patients with SSS. The FAZ decreased in all patients except two when CL was reduced from CL1 to CL2. The mean decrease was 61.1 msec and was significant (P less than 0.001). Seven patients had frequent episodes of paroxysmal atrial fibrillation or flutter (AFF) prior to atrial pacemaker implantation. Chronic atrial pacing effectively prevented paroxysmal AFF in five of them. We concluded that the normalization of the slow atrial rate decreased FAZ in patients with SSS and may be helpful in preventing atrial tachyarrhythmia in some patients with SSS.
Division of Cardiology, National Cardiovascular Center, Osaka, Japan.
T
T
Ohe
K
K
Shimomura
M
M
Inagaki
D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000517:prevention & control*; D001282:Atrial Flutter / Q000517:prevention & control*; D002304:Cardiac Pacing, Artificial; D004562:Electrocardiography; D005260:Female; D006325:Heart Atria / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D012804:Sick Sinus Syndrome / Q000628:therapy*