Welch Allyn Means ECG Physicians Manual for CP Series Electrocardiographs - User Manual User Manual
Page 43
MEANS Physicians Manual
Welch Allyn
43
3.6 Group 3: Rhythms with atrial flutter or tachycardia
In atrial flutter, the atrial activity is represented in the ECG by regular, saw-tooth like
oscillations (F waves) which occur at rates between 220 and 400 beats per minute (BPM).
The measurement part of the program contains a routine for the detection of F waves. If F
waves are detected, but the rate of the atrial activity is less than 220 BPM, a classification of
atrial tachycardia is made.
Say:
“atrial tachycardia”
if:
atrial rate
220 BPM
Say:
“atrial flutter”
if:
atrial rate > 220 BPM
Say:
“with second degree AV block at variable conduction ratio”
if:
rate variation > 20%
Say:
“with second degree AV block at N:1 conduction ratio”
if:
rate variation
20%
and
atrial rate is an integer multiple N of ventricular rate
Say:
“with complete AV block”
if:
rate variation
20%
and
atrial rate is not an integer multiple of ventricular rate
and
heart rate < LLN
Say:
“with block or interference in the AV junction”
if:
rate variation
20%
and
atrial rate is not an integer multiple of ventricular rate
and
heart rate
LLN
In the presence of atrial flutter without the characteristic saw-tooth appearance, F waves may
be mistaken for P waves by the program. If the shortest PP interval found is shorter than 300
ms, corresponding with an atrial rate exceeding 220 BPM, atrial flutter may still correctly be
classified.
Say:
“atrial flutter with advanced AV block”
if:
shortest PP interval < 300 ms
and
rate variation
20%
Say:
“atrial flutter with second degree AV block at variable conduction ratio”
if:
shortest PP interval < 300 ms
and
rate variation > 20%