User's Manual

Ultraview Care Network
10-6
The SINGLE ST alarm allows you to monitor for localized changes that may only
be detectable in a single lead. An ST alarm for a SINGLE LEAD will activate if the
ST level for any one lead exceeds the SINGLE ST alarm limit, with respect to its
current reference level.
The factory default setting for the single lead ST alarm limit is 1.00 mm.
The MULTI ST alarm allows you to monitor for global changes that may be
detectable in multiple leads. An ST alarm for MULTIPLE LEADS will activate if the
ST level for three or more leads exceeds the MULTI ST alarm limit, with respect to
each lead’s current reference level.
The factory default setting for the multi-lead ST alarm limit is 0.50 mm.
At the time that ST monitoring is initiated, the current reference level for all leads
is set to 0.00 mm (isoelectric). A SINGLE ST alarm will activate if any lead has an
initial ST level that exceeds the SINGLE ST alarm limit. Or, a MULTI ST alarm will
activate if three or more leads have initial ST levels that exceed the MULTI ST
alarm limit.
Whenever a SINGLE or MULTI ST alarm is activated, the reference level for all
leads is automatically reset based on each lead’s current ST level. This allows
changes in ST levels to be dynamically tracked throughout the patient’s course of
treatment.
As shown in Figure 10-4: ST segment alarm function, when the patient’s ST
segment trend line rises and violates the first alarm threshold, a new baseline and
a new upper alarm threshold are established (the amount of change needed to set
off another alarm is denoted by Delta). The lower alarm threshold remains
unchanged. Though the patient’s ST segment continues to climb, it does not
reach the new alarm threshold, so a new upper limit is not set. When the ST level
declines, the alarm threshold also declines until the original alarm thresholds are
re-established. As the patient’s ST level continues to decline, a new threshold is
established when an alarm condition occurs.
Figure 10-4: ST segment alarm function
!
• The MULTI ST alarm limit cannot be set above the SINGLE ST
alarm limit if both alarms are enabled.
Thick line is the measured ST level.
Solid line is the ST alarm baseline.
Dashed line is the alarm threshold.