Long-term efficacy and stability of atrial sensing in VDD pacing.
BACKGROUND
The efficacy and stability of atrial electrode sensing function is essential in maintaining atrioventricular (AV) synchrony and activity response in VDD pacing. Studies to evaluate the relationship between atrial sensing efficacy, stability, and implantation strategy are few.


OBJECTIVE
This study sought to determine the possible predictors, among the recipients' underlying clinical conditions and the implantation strategies used, of achieving the most stable and effective atrial sensing.


METHODS
Eighty consecutive adults implanted with VDD pacemakers were studied retrospectively. Atrial electrodes were positioned where the optimal atrial potentials (APs) were measured during implantation. Interrogation parameters, including AV-synchrony ratio, were acquired immediately post implantation, at 1 year, and at 2 years after pacemaker implantation. Appropriate atrial sensing efficacy was defined as AV-synchrony ratio > or = 90%. The stability of atrial sensing was evaluated by the variation ranges of measured APs.


RESULTS
The measured APs showed no statistical difference when age, gender, or comorbidity was considered. However, with pacing-lead bending angles < or = 90 degrees, patients may have presented with larger APs and narrower AP variation than patients with obtuse angles. There were no clinical parameters in our study that could have predicted the proper atrial sensing efficacy with an AV-synchrony ratio > or = 90%.


CONCLUSIONS
The long-term sensing efficacy and stability of VDD pacing is reliable. More sophisticated implantation strategies may further improve the atrial sensing stability and efficacy in VDD pacing.
Huang
Chun-Yao
CY
Division of Cardiovascular Disease, Department of Internal Medicine, Taipei Veterans General Hospital, Taiwan.
Tuan
Ta-Chuan
TC
Lee
Wen-Shin
WS
Cheng
Chien-Ming
CM
Lin
Shing-Jong
SJ
Kong
Chi-Woon
CW
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D015716:Electrocardiography, Ambulatory; D004567:Electrodes, Implanted; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000503:physiopathology*; D006327:Heart Block / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome