BIOTRONIK Evia DR, Technical Manual

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Evia Technical Manual 31
ACC Algorithm Performance - Effectiveness
The objective was to evaluate the effectiveness of the ACC
feature through an analysis of the number of pauses during
24-hour Holter recordings. A pause is defined as a ventricular
rate interval longer than the previous rate interval plus 400 ms in
the normal tracking mode. The two types of pauses are defined
as:
•
Case 5 - Ventricular pacing with loss of capture that is
not recognized by the algorithm
•
Case 6 - Ventricular pacing with loss of capture and
delivery of back-up pacing with loss of capture but with
no escape beat within 400 ms of the initial ventricular
pacing pulse
The ACC feature demonstrated efficacy as evidenced by the
absence of documented case 5 or 6 pauses in 41 Holter
recordings. For every loss of capture recorded by the Holters,
the ACC algorithm recognized the loss of capture and delivered
an appropriate back-up pulse. A total of 3189 non-captured
events were documented on the Holter recordings and analyzed
on a beat-to-beat basis. The Holter recordings documented that
3189 back-up pulses were delivered appropriately by the
Philos DR ACC in response to the non-capture events. With
41 evaluable Holter recordings, there were 82.5% ventricular
paced events, demonstrating an adequate sample of paced
events to provide the necessary analysis of the ACC feature.
Overall, the percentage of Case 5 or 6 pauses was 0.0%, with
an exact lower confidence interval of 0.1%, which supports the
effectiveness of the ACC algorithm.
The 24 hour Holter recordings clearly demonstrate the
effectiveness of the ACC feature to recognize loss of capture
and provide safety back-up pulses with ventricular capture.
ACC Threshold Comparison - Effectiveness
The objective was to evaluate the effectiveness of the ACC
feature by comparing the ACC threshold with the manual
threshold measurement.
The ACC feature provided an absolute mean difference between
the ACC threshold and the manual threshold of 0.10 volt in 382
paired evaluations within 140 patients.