Welch Allyn Cardioperfect Workstation, PEDMEANS ECG Interpretation Module - Physicians - User Manual - Manual (Page 30)

CardioPerfect Workstation
PEDMEANS ECG Interpretation Module Physicians Manual
DIR 80015051 Rev. C 30 / 55
3.5 Group 2: Non-dominant QRS complexes
Non-dominant QRS complexes can be classified in different categories. First, a test is performed on
the occurrence of short paroxysms of at least three complexes (“runs”). To qualify as a run, its rate
should exceed the inherent rate of the subsidiary pacemaker by 20% and the number of complexes
belonging to the run should be less than 90% of the total number of QRS complexes. The identified
non-dominant complexes are discarded and the program continues with the classification of the non-
dominant complexes which are still present in the recording.
Second, consecutive non-dominant complexes without an acceleration of the QRS rate are searched
for. Depending on the number of complexes found, the term “doublet” (two consecutive complexes) or
“sequence” (three or more complexes) is used. One of the parameters considered here is the length
of the RR interval preceding the first non-dominant complex of the doublet or sequence (the coupling
interval) relative to the RR interval of the basic rhythm (RR ratio). This parameter is used to distinguish
between premature beats and an escape rhythm. Again, complexes are discarded after their
classification.
Following this, a test is performed for the presence of a bigeminy, i.e., for the alternation of the
dominant QRS type with another (or others), whether continuously or only during part of the recording.
If an alternation of QRS types is present during the entire recording, a special test is made for the
presence of a ventricular escape-capture bigeminy.
Finally, the remaining single non-dominant complexes are classified type by type according to QRS
width and duration of preceding RR interval. Coupling intervals (the interval between the ectopic
complex and the preceding dominant QRS complex) are considered constant if the range of these
intervals does not exceed 80 ms.
The classification of non-dominant complexes may need adjustment in the presence of some rhythms
that are classified at a later stage of the rhythm analysis. The adaptations are explained in the last
paragraph of this section.
Run of non-dominant complexes
Say: “with run of multiform premature ventricular complexes”
if: more than one type of non-dominant complexes in run
Say:
“with accelerated ectopic rhythm”
if: one type of non-dominant complexes in run
and run rate

ULN
Say:
“with supraventricular tachycardia with aberrant ventricular conduction,”
“ consider ventricular tachycardia”
if: one type of non-dominant complexes in run
and run rate > ULN
and QRS duration in run

ULN + 20 ms
Say:
“with (probably) ventricular tachycardia, consider supraventricular”
“ tachycardia with aberrant ventricular conduction”
if: one type of non-dominant complexes in run
and run rate > ULN
and QRS duration in run > ULN + 20 ms