7 ECG, Arrhythmia, ST and QT Monitoring
Modified 12-Lead ECG
Choosing Standard or Modified Electrode Placement
If your institution uses modified 10 Lead ECG electrode placement (the Mason-Likar Lead System),
you must switch Mod.Lead Placment to On in the monitor. To do this,
in the Setup ECG menu, select Mod.LeadPlacment to toggle between
– When Mod.Lead Placment is set to On, 12 Lead ECG Reports will be labelled 12 Lead
ECG Report (Mason-Likar), and captured 12-lead ECGs will be labelled Mason-
Likar to the right of the bandwidth annotation at the Information Center.
– When Mod.LeadPlacment is set to Off, 12 Lead ECG Reports will be labelled 12 Lead
ECG Report, and captured 12-lead ECGs will not be annotated at the Information Center.
Do not use ECG analysis interpretation statements and measurements for 12-lead ECGs obtained
using the modified (Mason-Likar) limb electrode placement. This may lead to misdiagnosis since the
modified (Mason-Likar) limb electrode placement does not look the same as the conventional 12-lead
ECG and may mask inferior infarction due to calculated axis, R, P and T wave magnitudes shifts and
Do not export 12-lead ECGs obtained using the modified (Mason-Likar) limb electrode placement.
Captured 12-Lead ECGs using the modified (Mason-Likar) limb electrode placement exported from
the Information Center are not annotated with the Mason-Likar label.
If the monitor is connected to an Information Center via a wired network, the Capture 12-Lead
SmartKey may be configured. Selecting this exports 12-Lead ECG information to the Information
Center for analysis. For details see the Instructions for Use supplied with the Information Center.
1 - LA
2 - V1 - V6
3 - LL
4 - RL
5 - RA
6 - Angle of Lewis
If your institution uses modified 10
Lead ECG electrode placement (the
Mason-Likar Lead System), place the
four limb electrodes close to the
shoulders and lower abdomen.
The six V electrodes are placed on the
chest in the same position as the
conventional 12-lead placement.