Objectives To observe the atrial capture management in Zephyr5826 pacemaker. By calculating the open rate of ACapTMcomfirm in different circumstances and comparing atrial thresholds measured automatically and manually, we evaluate its safety and veracity in clinical practice.
Methods 40 patients implanted with Zephyr 5826 pacemaker from December 2008 to September 2012 in our hospital were enrolled in the study. Data were collected by case report forms at enrollment and visits scheduled 2 months and 4 months after opening ACapTMcomfirm function. The number of candidates with ACapTMcomfirm open was recorded. By statistical analysis, we evaluate the effect of ACapTMcomfirm and discuss its influencing factors.
Results Among the 40 candidates enrolled, ACapTMcomfirm function in 14 patients was turned on, while in 16 not. Causes of the unsuccessful attempts to perform automatic atrial threshold includes pacemaker replacement (6, 23.1%), tachycardia (1, 3.8%), high atrial threshold (1, 3.8%) and atrial safety margin not met (18, 69.2%). A total of 22 pairs of atrial thresholds measured automatically and manually were gained. The auto threshold was 0.528 ± 0.270V, and the manual threshold was 0.580 ± 0.223 V. There is a strict correlation between the automatic measurements and those conducted manually by the physician with a sig.< 0.05. No significant differences were observed during the 1-month, 2-month and 4-month follow-up. The open rate for ACapTMcomfirm was 35.00% in total and 41.12% after excluding patients with pacemaker replacement. No significant differences of open rate were observed in patients with different heart arrhythmias, with or without atrial fibrillation and with different implantation years.
Conclusions Feasibility of ACapTMcomfirm in Zephyr5826 pacemaker is good. Results of the study show excellent correlation between the two methods for atrial threshold. There is no statistical difference between manual and automatic measurements during follow-up. It is estimated that atrial capture management can benefit the patients by reducing energy cost and enhancing pacemaker safety.