F. Duru et al., Threshold tracking pacing based on beat by beat evoked response detection:Clinical benefits and potential problems, J INTERV C, 4(3), 2000, pp. 511-522
Citations number
43
Categorie Soggetti
Cardiovascular & Respiratory Systems
Journal title
JOURNAL OF INTERVENTIONAL CARDIAC ELECTROPHYSIOLOGY
Continuous monitoring of pacemaker stimulation thresholds and automatic adj
ustment of pacemaker outputs were among the longstanding goals of the pacin
g community. The first clinically successful implementation of threshold tr
acking pacing was the Autocapture feature which has accomplished automatic
ventricular capture verification for every single stimulus by monitoring th
e Evoked Response (ER) signal resulting from myocardial depolarization. The
Autocapture feature not only decreases energy consumption by keeping the s
timulation output slightly above the actual threshold, but also increases p
atient safety by access to high-output back-up pulses if there is loss of c
apture. Furthermore, it provides valuable documentation of stimulation thre
sholds over time and serves as a valuable research tool. Current limitation
s for its widespread use include the requirements for implantation of bipol
ar low polarization leads and unipolar pacing in the ventricle. Fusion/pseu
dofusion beats with resultant insufficient or even non-existent ER signal a
mplitudes followed by unnecessary delivery of back-up pulses and a possible
increase in pacemaker output is not an uncommon observation unique to the
Autocapture feature. The recent incorporation of the Autocapture algorithm
in dual chamber pacemakers has been challenging because of more frequent oc
currence of fusion/pseudofusion beats in the presence of normal AV conducti
on. Along with a review of the previously published studies and our clinica
l experience, this article discusses the clinical advantages and potential
problems of Autocapture.