Operator's Manual

Monitoring ECG QT/QTc Interval Monitoring
TM80/TM70 Telemetry Monitor Operator’s Manual 7 - 21
4. In the [Alarms] section, configure the options described in the following table.
7.8 QT/QTc Interval Monitoring
The QT interval is defined as the time between the beginning of the Q-wave and the end
of the T-wave. It measures the total duration of ventricular depolarization (QRS duration)
and repolarization (ST-T). QT interval monitoring can assist in the detection of long QT
syndrome.
The QT interval has an inverse relationship to heart rate. Faster heart rates shorten the
QT interval and slower heart rates prolong the QT interval. Therefore, several formulas
can be used to correct the QT interval for heart rate. The heart rate corrected QT interval
is abbreviated as QTc.
Options Description Settings*
ST-I,
ST-II,
ST-III,
ST-aVR,
ST-aVF,
ST-V,
ST-Va,
ST-Vb
These options are displayed
when [ST Alarm Mode] is set to
[Absolute].
The lead label behind ST is con-
sistent with the ECG cable type
selected.
On, Off
Upper alarm limit range:
0.2 mV to 2.0 mV; the default is 0.2mV; the
step is 0.01mV
Lower alarm limit range:
-2.0 mV to 0 mV; the default is -0.2mV; step is
0.01mV
Alarm priority: Low, Med, High
ST Single These options are displayed
when [ST Alarm Mode] is set to
[Relative].
On, Off
Upper alarm limit range:
0 mV to 2.0 mV; the default is 0.1mV; the step
is 0.01mV
Lower alarm limit range:
-2.0 mV to 0 mV; the default is -0.1mV; step is
0.01mV
Alarm priority: Low, Med, High
ST Dual On, Off
Upper alarm limit range:
0 mV to 2.0 mV; the default is 0.1mV; the step
is 0.01mV
Lower alarm limit range:
-2.0 mV to 0 mV; the default is -0.1mV; step is
0.01mV
Alarm priority: Low, Med, High
* The factory default settings are in bold.