User Manual Part 4

CLINICAL STUDY - SUMMARY OF GDT1000 SEN
SING ACUTE STUDY
H-7
Undersense Events
LV undersense events (223) in the first phase of the study primarily occurred
in one patient whose LV intrinsic amplitude was less than 1.0 mV, which is
much smaller than the clinically acceptable threshold. This small LV intrinsic
amplitude resulted in undersensing some LV events.
Tw o LV undersense events occurred in the second phase of the study. A
potential cause for the LV undersense events was premature ventricular
contractions while atrial pacing.
CONCLUSIONS
This acute study demonstrated excellent sensitivity (100% in the RA, 100% in
the RV, and 99.98% in the LV channels), specificity (98.64% in the RA, 100% in
the RV, and 99.99% in the LV channels), and positive predictive values (98.54%
in the RA, 100% in the RV, and 99.99% in the LV channels). In conclusion, the
new sensing platform evaluated in the GDT1000 study will be implemented in
COGNIS/TELIGEN devices.
By excluding one patient’s oversensed events that could be eliminated by
programming a longer atrial blanking period, the modified specificity and
positive predictive values in the RA channel are 100% and 100% (oversensing
eliminated). While the GDT1000 protocol did not pre-specify acceptable
sensitivities, specificities, or PPV values, a Sensing Tape Testing DAT report
for COGNIS/TELIGEN on file at Boston ScientificCRM
1
reported a 99.96%
sensitivity (0.04% Undersensing) and a 99.97% positive predictive value
(0.03% Oversensing) for the RV channel in normal sinus rhythm. Using the RV
values as a benchmark (RA and LV values were not calculated), the results of
this study compare favorably.
1. Sensing Tape Testing Design Analysis Test report 10001 9-687 Revision A describes te sting
p
erformed in which the COGNIS/TELIGEN sensing platform is modeled and compared to a
previous Guidant device, CONTAK RENEWAL TR. T he analysis was performed using 219
patient rhythms from the Gold Development Database, including normal sinus rhythm and
atrial and ventricular arrhythmias.
- DRAFT -