Chapter 5

Question 1

Identify this ECG

Answer 1

WPW syndrome. Current is held up by the normal delay at the AV node but races unimpeded down the bundle of Kent. The EKG shows the short PR interval and delta wave.

Question 2

Identify this ECG

Answer 2

In LGL syndrome, the PR interval is short, but there is no delta wave.

Question 3

What are the two most common tachyarrhythmias seen in WPW?

Answer 3

(A) Paroxysmal supraventricular tachycardia. ( B) Atrial fibrillation.

Question 4

When will you see PSVT with wide QRS?

Answer 4

PSVT in WPW syndrome with antegrade reentry loop. Current moves antegrade down the bundle of Kent and then retrograde through the AV node, establishing an independent revolving circuit. The ventricles are activated through the accessory pathway, generating wide QRS. It’s also called antidromic tachycardia

Question 5

What’s going on here?

Answer 5

A Fib in WPW. The bundle of Kent can act as a free conduit for chaotic atrial activity, W/o the AV node to act as a barrier, the ventricular rates can rise as high as 300bpm, which can induce V Fib.

Question 6

Criteria for WPW

Answer 6

PR<0.12

Wide QRS

Delta waves

Question 7

Criteria for LGL

Answer 7

PR<0.12

Normal QRS

No delta waves

Question 8

Identify this ECG

Answer 8

WPW