E2: IVCD

Question 1

What is the criteria to have a BBB?

Answer 1

QRS > 0.12 seconds

-RR’ configuration in the chest leads

Question 2

What is the criteria for a RBBB?

Answer 2

• QRS >0.12 s
• M shaped RR’ in V1
• Wide S wave in lead I and V6
• axis should be normal

Question 3

What conditions is RBBB commonly seen with?

Answer 3

CAD and PE

Question 4

What are the criteria for LBBB?

Answer 4

• QRS > 0.12 seconds
• Wide R wave in leads I and V6
• QRS complexes have tall R waves with prolonged duration and either notched or flattened tops of the complexes

Question 5

What is a hemiblock and what are the 3 types?

Answer 5

Occurs when one of thee fascicles of the LBB is blocked

• Anterior fascicle
• posterior fascicle
• septal fascicle

** the RBB does not divide into separate fasciciles

Question 6

What is the key to detecting a hemiblock?

Answer 6

A change in the QRS axis but the QRS duration is not prolonged

Question 7

What is the criteria to have left anterior hemiblock?

Answer 7

• Strong LAD
• Tall R waves in Lead 1
• Deep S waves in Lead III
• Usually normal in QRS duration

Question 8

What is the criteria for left posterior hemiblock?

Answer 8

• Strong RAD
• Tall R waves in Lead III
• Deep S waves in Lead I
• Usually normal QRS duration

Question 9

What is a Bi-fascicular block?

Answer 9

• RBBB plus either LAHB or LPHB

- Features of RBBB plus frontal place features of fascicular block

Question 10

What is a nonspecific IVCD?

Answer 10

When the QRS is prolonged without features of either RBBB or LBBB

Question 11

What are the potential causes of nonspecific IVCDs?

Answer 11

• Ventricular hypertrophy
• MI
• Certain antiarrythmic drugs
• Hyperkalemia
• paced complexes

Question 12

What are pre-excitation syndromes?

Answer 12

• Accessory conduction pathways that sometimes exist between atria and ventricles
• Bypass AV node and bundle of His and allow early depolarization of ventricles and results in short PR interval
• WPW and LGL

Question 13

What is Wolff-Parkinson White Syndrome?

Answer 13

• Pre excitation syndrome of the atrioventricular pathway Bundle of Kent
• Delta wave are seen in some leads
• PR interval is < 0.12 secs with a wide QRS

Question 14

What conditions are patients with WPW vulnerable to?

Answer 14

PSVT

Question 15

What is Lown-Ganong-Levine syndrome?

Answer 15

• pre excitation syndrome of the intranet always accessory pathway James fibers
• absence of delta waves
• PR interval is < 0.12 seconds and normal QRS