(FIT)-Module 2 Lectures: Invasive Diagnosis and Treatment Part 1-Techniques of Differentiating SVT Mechanisms

Techniques of Differentiating SVT Mechanisms - Part II (Michaud)

Video Transcription

Video Summary

In this lecture from Vanderbilt University Medical Center, the focus is on diagnosing supraventricular tachycardia (SVT), with an emphasis on using ventricular and atrial pacing to differentiate various tachycardia mechanisms. The key takeaway is the differentiation between orthodromic AVRT and AVNRT, which typically involves identifying atrial activation patterns. Important diagnostic tools include measuring the post-pacing interval minus the tachycardia cycle length, and examining QRS or intracardiac fusion to determine the presence of an accessory pathway. The discussion delves into complex cases involving decremental accessory pathways, which can confuse the differentiation between atypical AVNRT and orthodromic tachycardias. Key maneuvers like overdrive pacing and observing the response, such as the post-pacing intervals and VA times, help make the distinction clearer. Emphasis is placed on careful measurement and observation, using systematic approaches, understanding exceptions, and using multiple diagnostic factors to form a reliable diagnosis, particularly in distinguishing pathways in SVT cases.

Keywords

supraventricular tachycardia

ventricular pacing

atrial pacing

orthodromic AVRT

AVNRT differentiation

post-pacing interval

accessory pathway diagnosis