The Intern At Work: Internal Medicine 129. Too Fast, Too Furious - An Approach to SVT
Mar 6, 2022
Exploring the complexities of superventricular tachycardia (SVT) including AVRT and AVNRT, understanding symptoms, triggers, and initial assessment methods. Detailed guide on diagnosing SVT with emphasis on rhythm differentiation and diagnostic tests. Strategies for managing SVT such as synchronized cardioversion, vagal maneuvers, medication options, and insights from the Revert trial on a modified balsalva maneuver.
AI Snips
Chapters
Transcript
Episode notes
Anatomical Basis Of AVRT
- AVRT uses an accessory anatomical pathway that bypasses the AV node and can conduct antegrade, retrograde, or both directions.
- This creates a re-entry circuit when impulses loop from atria to ventricles and back, producing SVT.
Functional Mechanism Of AVNRT
- AVNRT arises from two functional pathways within the AV node: a fast pathway and a slow pathway with differing refractory periods.
- A premature atrial beat can initiate a retrograde loop between these pathways, creating continuous re-entry and tachycardia.
Who Gets SVT And Why
- SVT symptoms vary from palpitations and dizziness to being asymptomatic, and triggers include substances, withdrawal, thyroid disease, pregnancy, and stressors.
- SVTs are common in infants and children and occur more often in women, especially during pregnancy.