Two conditions must exist to suspect bundle branch block. First, the QRS complex must have an abnormal duration (0.12 second or more in width), and second _____.
A) an RSR' complex must be seen in leads V1-V6
B) a QS pattern must be seen in leads I, II, and III
C) a slurred upstroke of the QRS complex must exist
D) the QRS complex must arise as the result of supraventricular activity

Question

Quizplus · Accepted Answer

Essentially two conditions must exist to suspect bundle branch block. First, the QRS complex must have an abnormal duration (i.e., 0.12 second or more in width if a complete BBB). Second, the QRS complex must arise as the result of supraventricular activity, excluding ventricular beats. If these two conditions are met, delayed ventricular conduction is assumed to be present, and bundle branch block is the most common cause of this abnormal conduction.

Two Conditions Must Exist to Suspect Bundle Branch Block