Key EGM Selection Criteria
Each arrhythmia episode was characterized by the episode duration and
representative rate, defined as follows. The episode duration was
defined as the time from device detection to end-of-episode for AF,
tachycardia, and bradycardia episodes; and the duration of the pause
itself for pause episodes. The representative rate was defined as the
mean ventricular rate over the entire episode (i.e., mean rate, number
of ventricular beats divided by AF episode duration) for AF; the minimum
R-R interval during the episode (i.e., maximum rate) for tachycardia;
and the maximum R-R interval during the episode (i.e., minimum rate) for
bradycardia.
For each arrhythmia type, up to 3 “key EGMs” per day (starting at 12
AM in the patient’s local time zone) were prioritized for review, as
follows. For AF, the EGMs with the fastest mean rate, longest duration,
and 2nd longest duration were selected. For
tachycardia, the EGMs with the fastest maximum rate, longest duration,
and 2nd longest duration were selected. For
bradycardia, the EGMs with the fastest minimum rate, longest duration,
and 2nd longest duration were selected. For pause, the
EGMs with the shortest duration, longest duration, and
2nd longest duration were selected.
If 3 or fewer EGMs of one arrhythmia type were detected on a particular
day, all of those EGMs would be prioritized for review. Exceptions
include cases in which a single EGM satisfies more than one criterion;
in such cases, fewer than 3 EGMs may be prioritized for review. For
example, if there were 3 AF EGMs on a single day, but one EGM had both
the fastest mean rate and the longest duration, only 2 EGMs would be
selected for transmission. Patient-initiated “symptom” EGMs were not
impacted by the prioritization rules, and all symptom EGMs were
prioritized for review.