Welch Allyn Cardioperfect Workstation, PEDMEANS ECG Interpretation Module - Physicians - User Manual - Manual (Page 43)

CardioPerfect Workstation
PEDMEANS ECG Interpretation Module Physicians Manual
DIR 80015051 Rev. C 43 / 55
3.18 Group 15: Rhythms with constant PR interval
In this group rhythms with constant PR interval are classified that either did not qualify for analysis in
one of the previous groups or have only partly been analyzed there (see Figure 1). Rhythms that were
not yet analyzed comprise regular and irregular rhythms with 0.9 < P/QRS ratio

1.0 and PR range

30 ms. The rhythms of this group may be classified as uncomplicated sinus rhythm as far as SA and
AV conduction are concerned, provided they have a normal P wave axis and PR interval.
First, a test for premature supraventricular complexes is performed as these complexes may still be
present if the rate variation is large. Second, if the rhythm is regular with a PR interval variation
between 30 and 60 ms while the number of P waves found is less than the number of QRS
complexes, a pacemaker shift should be considered. (If the PR range exceeds 60 ms, the rhythm has
been taken care of in group 5.) Third, if the program detects a negative P axis with a sufficiently
negative P-wave amplitude in aVF, an ectopic atrial rhythm or an AV junctional rhythm is considered
present, depending on the length of the PR interval and the program halts. If not, various types of
sinus rhythm can be classified, with or without arrhythmia dependent on the rate variation. Finally, the
presence of first degree AV block, corrected for heart rate, is tested at different levels of severity. The
limit used for the PR interval is normalized for heart rate (normalized PR = PR interval / RR interval).
Say: “premature supraventricular complexes”
if: test PSVC passed
Say:
“PR interval variation: pacemaker shift?”
if: 30 < PR range

60 ms
and P/QRS

0.9
Say:
“AV junctional rhythm”
if: P axis
 
30 degrees
and negative P amplitude in aVF > 70 µV
and PR interval

80 ms
Say:
“ectopic atrial rhythm”
if: P axis
 
30 degrees
and negative P amplitude in aVF > 70 µV
and PR interval > 80 ms
Say:
“sinus bradycardia with sinus arrhythmia”
if: heart rate < LLN – 10 BPM
and rate variation > 30%
Say:
“sinus arrhythmia”
if: LLN – 10 BPM 
heart rate < ULN
and rate variation > 30%
Say:
“sinus tachycardia with sinus arrhythmia”
if: heart rate

ULN
and rate variation > 30%
Say:
“extreme bradycardia, consider sinus rhythm with 2:1 AV conduction”
if: heart rate < LLN – 20 BPM
and rate variation

30%
Say:
“sinus bradycardia”
if: LLN – 20 BPM 
heart rate < LLN – 10 BPM
and rate variation

30%
Say:
“sinus rhythm (slow)”
if: LLN – 10 BPM 
heart rate < LLN
and rate variation

30%