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Effect of Short Pulse Width Programming in AutoCapture Devices
Author(s) -
KOK LAI CHOW,
HANNA GEORGE P.,
BROWNSTEIN SHELDON,
KIM MICHAEL,
LEVINE PAUL A.,
VIJAYARAMAN PUGAZHENDHI,
GO ANDRE,
SYED ZAFFER A.
Publication year - 2005
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/j.1540-8159.2005.00086.x
Subject(s) - medicine , cardiology , pulse (music) , optics , detector , physics
Pacing chronaxie can increase over time. The impact of a short pulse duration on threshold (THR) variations, frequency of noncapture episodes, and overall patient safety has not been fully studied. AutoCapture (AC) pacemakers are capable of memorizing THR trends and loss of capture (LOC) episodes. The study included 20 recipients of AC pacemakers (mean age = 76 ± 9 years, 15 men) followed for 6 months. They were randomly assigned to pulse durations of 0.2 versus 1.0 ms at 1 month, and crossed over to the alternate programming at 3 months. Evoked response (ER) and AC tests were performed at follow‐up. At 0.2 ms and 1.0 ms, the mean number of LOC/day was 2.37 ± 5.81 and 0.91 ± 0.49, respectively (ns). LOC trends between follow‐up were significantly different with 0.2 versus 1.0 ms pulse duration (P < 0.01). AC THR at 1.0 ms was significantly lower (0.44 ± 0.77) than at 2.0 ms (0.97 ± 0.26, P < 0.05). No patient reported symptoms related to LOC during the study. Pulse duration programmed near the strength‐duration curve is associated with greater variations in THR and LOC. AC responds to these changes by delivering 4.5 V pulses and keeping the capture THR at low, though safe values.