Welch Allyn Cardioperfect Workstation, PEDMEANS ECG Interpretation Module - Physicians - User Manual - Manual (Page 13)

CardioPerfect Workstation
PEDMEANS ECG Interpretation Module Physicians Manual
DIR 80015051 Rev. C 13 / 55
2.4 Right Bundle Branch Block (RBBB)
In RBBB, the right ventricle (RV) is not depolarized directly through the Purkinje system. Thus, the RV
depolarizes through the ventricular myocardium at a much slower rate due to the slower conduction
velocity. This results in a sequential depolarization of the ventricles. Because the right ventricle is
located in the right and anterior part of the myocardial mass, the terminal slow depolarization is
directed rightward and anteriorly. This is manifested in the ECG by wide and slurred R

waves in V1,
V3R, and aVR and wide and slurred S waves in I, II, V6, and V7. The QRS duration is longer than
normal for age. In the decision rule, the duration of the second half of depolarization should be at least
twice as long as the duration of the first half. The duration criteria should be fulfilled in at least three
leads to make an RBBB statement.
If the R
 wave in V1 is absent, the statement “probable RBBB” is made.
Skip tests
if:
QRS duration

ULN
prolonged R

: R

duration > ULN
and R

duration > 2 * S duration
and R

amplitude > R amplitude
prolonged S: S duration > ULN
and S duration > 2 * R duration
Say:
“RBBB”
if: R

wave in V1
and three or more leads with
prolonged R

in V3R, V1, aVR
or prolonged S in I, II, V6, V7
Say:
“probable RBBB”
if: three or more leads with
prolonged R

in V3R, V1, aVR
or prolonged S in I, II, V6, V7