Operator's Manual Part 2

Revision D ApexPro Telemetry System 11-31
2001989-134
ECG Monitoring: ST Analysis
ST Analysis
The patient’s most dominant, normal beat is used for ST measurement.
This beat is identified by the arrhythmia analysis program. Turn ST on
to display the numerics calculated for ST at the clinical information
center.
GE Medical Systems Information Technologies identifies the ST segment
of the QRS complex as beginning at the J point and ending 60
milliseconds following the J point. The ST numeric displayed
(millimeters) indicates either a positive or negative elevation in relation
to the isoelectric reference point (which is also determined by the
arrhythmia program and the patient’s age).
When ST is on, numerics are displayed under each ECG lead label on the
screen. (A negative deflection is preceded by a minus sign.) These
numerics are updated about every 15 seconds.
The ST value shown in the ECG parameter window is the lead with the
greatest ST deviation. This may or may not be the lead that is in alarm,
since a lead with a lesser deviation from the isoelectric line may have
changed more than the lead with the greatest deviation.
NOTE
ST numerics are always calculated with reference to 1X size.
Displaying the ECG waveform at a different size does NOT affect the
ST values.
NOTE
When a new dominant beat is detected or a relearn occurs, the
arrhythmia program calculates ST based on the new beat. This could
affect the ST values displayed. This may not necessarily represent a
change in the patient’s condition. The clinician needs to assess the
patient any time there is an ST change.