GE HEALTHCARE MAC 2000, Operator'S Manual

Page: 202 / 226

Master’s Step Data
ST-T Changes
The existence of any ST-T change is assessed by classifying ST-T into three assessment
levels:
• Positive
One of the following criteria must be met on 2 or more leads:
• ST Depression ≥ 0.1 mV
• ST Elevation≥ 0.2 mV
• T wave change ≥ 1.0 mV
• Borderline
One of the following criteria must be met on any lead:
• ST Depression ≥ 0.05 mV
• ST Elevation ≥ 0.1 mV
• T wave change ≥ 0.5 mV
• Negative
This is assessed if neither the Positive nor Borderline criteria are met.
To following formulas are used to calculate the values in the previous criteria:
• ST depression = (rest ST - post J) - (post exercise ST - post J)
• ST depression = (rest ST - post J) - (post exercise ST - post J)
• T wave change = absolute value of (rest T wave amplitude - post-exercise T wave
amplitude)
• (ST - post J: amplitude at the post J point)
When the assessment is positive or borderline, the lead with the largest change prints.
202 MAC™ 2000 2053535-002K