Right bundle branch block
QRS
Duration
Complete RBBB is > 0.13 sec.
Incomplete RBBB is between 0.09 and 0.12 sec
Morphology
Precordial leads
V1 = rsR' with CRBBB or V1 = rSr' with IRBBB
V6 = qRs with CRBBB or IRBBB
Limb leads
Axis can be right, left, or normal
Terminal 0.08 vector should be ignored when calculating axis
Lead I = qRs.
Orthogonal leads
Lead X = qRS (with IRBBB = qrS)
Lead Z = qRS (with CRBBB = qRs)
T wave always in the opposite direction from terminal S wave
Conduction abnormalities
Using the usual criteria, both LAFB and LPFB can occur with RBBB
Using the ususal criteria, LVH, ASMI, AMI, ACMI, and IMI can be diagnosed with RBBB.
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