Amplitude Reporting of ECG signal from moving subjects

Telemetry of ECG signals from conscious freely moving animals has both advantages and disadvantages.  Among the advantages is the ability to collect a large amount of data.  Telemetry ECG collection is generally done for hours or days of continuous recording. Traditional “hard-wired” collection is most often done for no more than a few minutes and the animals are restrained by physical or chemical means and the animals are placed in a standard position. Telemetry allows the researcher to collect data in a non-restrained animal throughout the experiment. Continuous recording provides a better overall understanding of any changes to ECG intervals than is possible using hard-wired recordings.

One of the limitations of telemetry ECG collection is the loss of ability to evaluate ECG waveform amplitudes.  While intervals (PR, ST, and QT) are very accurate in telemetry collection, amplitudes such as ST depression, ST elevation, or R height are not scientifically useful, as amplitude changes are associated with changes in posture/position and physical activity.  Additionally, amplitude analysis is most accurate when multiple leads are available. For the reasons listed above, we do not advise reporting any amplitude parameters from freely moving animals as the information collected is unreliable because of the animal’s movement and non-static position.

Ponemah's Derived Parameter of ST-I and ST-E

Two ST interval-relating derived parameters can be reported using the ECG analysis module (see Ponemah Analysis Module Manual for more information), ST-I and ST-E.    

ST-Interval (ST-I)

One of them is the ST-I, which is the duration of time, in milliseconds, from the end of the S wave to the end of the T wave. 

ST-Elevation (ST-E)

The ST-E is the amplitude from the iso-electric of the cycle at a fixed user-defined time interval from the end of the S wave.  This fixed user-defined time interval is called ST Measure.  The user can set the fixed time, in milliseconds, in the analysis attribute setting of the ECG module, in the Advanced tab (see screenshot below).

Ponemah Iso-electric

Ponemah determines iso-electric baseline at the amplitude at the Q mark.