TY - JOUR
T1 - Effect of short pulse width programming in AutoCapture devices
AU - Lai, Chow Kok
AU - Hanna, George P.
AU - Brownstein, Sheldon
AU - Kim, Michael
AU - Levine, Paul A.
AU - Vijayaraman, Pugazhendhi
AU - Go, Andre
AU - Syed, Zaffer A.
N1 - 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. T ...
PY - 2005/1
Y1 - 2005/1
N2 - 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 ± 5.82 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.
AB - 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 ± 5.82 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.
KW - AutoCapture
KW - Cardiac pacing
KW - Pacing pulse width
KW - Pacing thresholds
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U2 - 10.1111/j.1540-8159.2005.00086.x
DO - 10.1111/j.1540-8159.2005.00086.x
M3 - Article
C2 - 15683530
SN - 0147-8389
VL - 28
SP - S70-S72
JO - Pacing and Clinical Electrophysiology
JF - Pacing and Clinical Electrophysiology
IS - SUPPL. 1
ER -