User manual

How the M2662A Measures ECGs
3-4 Revision 0.1
In each lead, the measurements for all the beats belonging to the selected beat group
are averaged. The lead measurements are representative of the dominant waveform
present in each lead.
3Atrial Rhythm Analysis
Atrial rhythm is determined by examining leads V1, aVF, II and III in succession
until the program can report conclusively that there are multiple P waves, that there
are no P waves, or that there is one P wave per QRS complex. If a conclusive result
is achieved, then the last lead analyzed will be used to calculate group and global
atrial rhythm parameters. If no conclusive result is achieved, no atrial rhythm
parameters are calculated.
3Global Measurements
The global measurements for the ECG, including the frontal and horizontal plane
axis measurements, are reported to the right of the lead measurements in the
Morphology Analysis section of the Extended Measurements report.
These interval, duration, and segment measurements are weighted averages of the
lead measurements. The global rate reported is the mean ventricular rate over the
entire ECG unless the ECG criteria program determines that one of the group mean
ventricular rates is more representative of the underlying rhythm.
3Axis Measurements
Although when making axis measurements manually, it is most convenient to use
waveform amplitudes, using areas yields more accurate results. The M2662A uses
the waveform areas from the lead measurements in calculating the P, QRS and T
axes, while the sum of the ST onset, middle and end amplitudes is used in
calculating the ST axis. For the frontal plane axis measurements, which use the limb
leads, nine lead pairs, all at least 60 degrees apart, are used to estimate the axes. The
resulting estimates are examined to ensure that they converge to a single result. If
so, they are averaged to form the representative axis measurement. The horizontal
plane axis measurements, which use leads V1 -V6, are calculated similarly from
seven lead pairs.
Auto measurement and interpretation are not always correct. Computerized ECG
analysis must be overread and validated by a qualified physician.
NOTE