Right and Left Bundle Branch Block
-- QRS > 0.12 sec in Limb leads;
-- Note: w/ LBBB, MI can't be accurately; dx'ed on EKG; (can't identify the Q waves)
-- Note: the mean QRS Vector and Vent. Hypertrophy Can't be accurately calculated in the presence of B.B.B.
-- May represent (pending) MI;
- Right B.B.B. (V1,2) Left B.B.B. (V5,6) Lft. V. / Rt. V. Rt.V. // Lft.V. / / / __/ / __ / / __/ __ /
- RR in V1, V2
- RR in V5, V6, (I & aVL)
- S wave in Lead I, V6, & aVL
- Loss of normal Q's: I, aVL, V6
- may result from Ant MI
- Complete LBBB lesion, Axis >
- may occur w/ Ant Hemiblock
- QS complex in V1, V2
- Loss of R in V1, V2;
- Right bundle branch block can occur during passage of the Swan catheter through the right heart;
- in a patient with preexisting left bundle branch block, this condition can lead to complete heart block.
- in patient w/ left bundle branch block, transvenous pacing catheter should be be available
Original Text by Clifford R. Wheeless, III, MD.
Last updated by Data Trace Staff on Monday, December 19, 2011 3:24 pm