(FIT)-Module 2 Workshop 3: SVT Mechanisms and Maneuvers-Stevenson Case 1 Answer

Video Transcription

Video Summary

So, the correct answer is B, stop RF and reassess catheter position. So, here we see that sinus rhythm is present, and there's clear pre-excitation with a short PR interval and a wide QRS. RF on is labeled at the far left of the tracing, and you can see that after four beats, the QRS narrows. But the QRS is not preceded by a normal PR interval. In fact, it's a short PR interval on the first, and then we don't really see a P wave on the second. So, these are junctional beats, which are emerging during RF, and those are a sign that we're heating the AV node. The narrowing of the QRS indicates that with the junctional beat, we have propagation down the Purkinje system, no propagation through the accessory pathway. And so, it's one of these situations where you can be faked out and think that you've got block in the pathway with RF, when what you've really got is a junctional rhythm. So, it's important to immediately recognize that and stop the RF application and reassess your catheter position.

Keywords

sinus rhythm

pre-excitation

short PR interval

junctional beats

catheter position reassessment