Switching Qt Analysis On And Off; Qt Display; Selecting Qt Analysis Lead; Selecting Calculation Formula - EDAN iM50 User Manual

Patient Monitor User Manual
Noise or the QRS wave variation is too big.
In these cases, the user should choose a lead with good T wave amplitude and no visible
oscillations, and without a dominant U wave or P wave.
In some conditions, such as left or right bundle branch block or cardiac hypertrophy causes
broaden QRS complex. If long QTc is observed, verify it to ensure that it is not caused by QRS
broadening.
Since normal beats followed by ventricular beats are not included in the analysis, QT
measurement could not be carried out when there was bigeminy rhythm.
When the heart rate changes, it may take several minutes for the QT interval to stabilize. In order
to obtain reliable QTc calculations, it is important to avoid areas where the heart rate changes.
NOTE:
QT/QTc measurements should always be validated by a qualified clinician.

9.10.2 Switching QT Analysis On and Off

To switch QT Analysis on or off, in the ECG Setup menu, select QT Analysis to toggle between
On and Off from the popup interface.

9.10.3 QT Display

The following figure is QT display for your reference only. The graphics on your monitor may be
slightly different.

9.10.4 Selecting QT Analysis Lead

There are two modes for selection:
All lead: Use all available leads (expect pressurized the limb lead) to produce an overall QT
measurement, user can select ALL through ECG Setup > QT Analysis > Analysis Lead.
Single lead: QT measurements were performed using all available single leads (except the
pressurized limb lead). User selects any lead in Analysis Lead menu to enter into single lead
mode.

9.10.5 Selecting Calculation Formula

The monitor uses Bazett formula to correct QT values by default. There are four alternative
formulas: Bazett, Fridericia, Framingham and Hodges.
Hodges: QTc
Bazett:
=
QTc
= + ×
QT 1.75 (HR
1
⎛ ⎞
HR
2
× ⎜ ⎜ ⎟ ⎟
QT
60
⎝ ⎠
−
60)
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Monitoring ECG