10
ST Analysis
Contents Directory of Keys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 Display Detail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Setting Up ST Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 Adjusting Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 Selecting Leads for ST Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 Reviewing ST Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 Clearing ST Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 Viewing ST Trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 Selecting the ST Trend Timebase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 Printing ST Segment Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 ST Analysis Troubleshooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Overview The ST analysis function monitors changes to the ST segment level.
!
•
The significance of ST changes can only be determined by a clinician.
•
The value of ST segment measurements may be affected by: - wide complex QRSs (for example, bundle branch block). - Wolff-Parkinson-White (WPW) syndrome. - fusion beats classified as dominants.
Since the ST segment is composed of frequencies at the lower end of the frequency range (0.05 Hz), the system automatically analyzes the ST segment at 0.05 Hz regardless of whether the display mode is set to monitor or extended. ST segment analysis starts during the ECG learn sequence. Based on the dominant waveform, the PR (isoelectric), J, and ST points are automatically identified for each beat. The amplitude difference between the ST point and the PR point is referred to as the ST segment level.
!
10-2
•
You can define your own default settings for alarm limits. Refer to Default Alarm Limits on page 2-4 for further details.