Intraventricular Conduction Abnormalities

Question 1

RBBB, incomplete

Answer 1

Criteria for RBBB but with QRS duration 0.09-0.11 secs

Question 2

Left anterior fascicular block?

Answer 2

• left axis deviation between -30 a -90 degrees.
• a positive terminal deflection in aVL and AVR with the peak of the terminal R wave in AVR ocurring later than in AVL.
• normal or slightly prolonged QRS duration (less than 0.12)
• no other causes of left axis deviation.

Additional supporting findings: a qR complex in lead I and aVL; and a rS complex in lead II, III and aVF, and a S wave in lead III larger than in lead II.

Question 3

RBBB, complete

Answer 3

• QRS duration of 0.12 or greater
• a R’ wave in the right precordial leads with the terminal R greater than the initial R
• secondary ST-T wave abnormalities in right precordial leads.
• additional supporting findings: slurred S wave in leads I and aVL and in the left precordial leads.