Performance evaluation of a right atrial automatic capture verification algorithm using two different sensing configurations.
BACKGROUND
This acute data collection study evaluated the performance of a right atrial (RA) automatic capture verification (ACV) algorithm based on evoked response sensing from two electrode configurations during independent unipolar pacing.


METHODS
RA automatic threshold tests were conducted. Evoked response signals were simultaneously recorded between the RA(Ring) electrode and an empty pacemaker housing electrode (RA(Ring)-->Can) and the electrically isolated Indifferent header electrode (RA(Ring)-->Ind). The atrial evoked response (AER) and the performance of the ACV algorithm were evaluated off-line using each sensing configuration. An accurate threshold measurement was defined as within 0.2 V of the unipolar threshold measured manually. Threshold tests were designed to fail for small AER (< 0.35 mV) or insufficient signal-to-artifact ratio (SAR < 2). Manual threshold measurements were obtained during RA unipolar and bipolar pacing and compared across device indications.


RESULTS
Data were collected from 38 patients with RA bipolar leads from four manufacturers. AER signals were analyzed from 34 patients who were indicated for a pacemaker (five), implantable cardioverter-defibrillator (11), or cardiac resynchronization therapy pacemaker (six) or defibrillator (12). The minimum AER amplitude was larger (P < 0.0001) when recorded from RA(Ring)-->Can (1.6+/-0.9 mV) than from RA(Ring)-->Ind (1.3+/-0.8 mV). The algorithm successfully measured the pacing threshold in 96.8% and 91.0% of tests for RA(Ring)-->Can and RA(Ring)-->Ind, respectively. No statistical difference between the unipolar and bipolar pacing threshold was observed.


CONCLUSIONS
The RA(Ring)-->Can AER sensing configuration may provide a means of implementing an independent pacing/sensing method for ACV in the RA. RA bipolar pacing therapy based on measured RA unipolar pacing thresholds may be feasible.
Kerckhoff-Klinik GmbH, Kardiologie, Abt. Elektrophysiologie, Bad Nauheim, Germany. J.Sperzel@Kerckhoff-Klinik.de
Johannes
J
Sperzel
Stephan
S
Goetze
Charles
C
Kennergren
Mauro
M
Biffi
M Jason
MJ
Brooke
Elisa
E
Vireca
Sunipa
S
Saha
Bernd
B
Schubert
Christian
C
Butter
D000368:Aged; D000465:Algorithms; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000517:prevention & control*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013813:Therapy, Computer-Assisted / Q000379:methods*