Brandon Fainstad, MD
Expert review – Zach Goldberger, MD (Division of Cardiovascular Medicine and Electrophysiology at the University of Wisconsin)
- Characterize the electrophysiology of the seven supraventricular tachycardias.
- Differentiate the supraventricular tachycardias based on regularity and P wave morphology.
- Identify the best acute management for each rhythm.
Plan to spend at least 30 minutes preparing for this talk by using the Interactive Board for Learning/Preparing and clicking on each of the eight buttons to reveal the graphic representation of the electrophysiology, ECG pattern and defining characteristics for each rhythm. After you feel comfortable with the content you can prepare to present this talk in one of two ways. 1. Project the Interactive Board for Presentation or 2. Reproduce a drawing of the presentation on a whiteboard.
With either method, print out enough copies of the Learner's Handout and Practice ECGs so they can follow along during the presentation and practice interpretations of ECGs after the talk. Start by reviewing the objectives of the talk. Then introduce the concept that all forms of tachycardia result from either, 1. increased automaticity by a node or ectopic pacemaker, or 2. a re-entry circuit. In general, re-entry circuits are faster. Secondly, you can significantly narrow down the potential SVTs based solely on the regularity of the rhythm and the presence or morphology of P waves. Occasionally, this will require you to slow down the rate for better interrogation of the rhythm strip (e.g. atrial flutter) or give adenosine to resolve the rhythm (e.g. AVRT or AVNRT). After working through the seven rhythms have the audience practice by interpreting the Practice ECGs using the printouts or by projecting them on a screen. The entire talk will take 30-45 minutes to deliver.
For Self-Directed Learning and Preparing to Present
For Presenting (Less Text and Fewer Pop-ups)
*See Printouts above for printable version
Take Home Points
- Tachycardia is due to either increased automaticity of a pacemaker (nodal or ectopic) or a re-entry circuit. Re-entry circuits are generally faster.
- There are only 7 SVTs that are distinguished by regular vs. irregular rhythm and the presence or morphology of the p wave.
- Hemodynamically stable SVTs are acutely managed one of 3 ways:
- Address underlying disease (for sinus tach, atrial tach, and multi-atrial tach)
- Resolve the re-entry circuit by interrupting AV conduction with vagal maneuvers or adenosine (for AVnRT and AVRT)
- Rate control with AV nodal blockers (for afib and aflutter)
Goldberger, Ary Louis, Zachary D. Goldberger, and Alexei Shvilkin. Goldberger's Clinical Electrocardiography: a Simplified Approach. Philadelphia: Elsevier, 2018
Nelson, William Paul, Henry J. L. Marriott, and Douglas D. Schocken. Concepts and Cautions in Electrocardiography. Northglenn, CO: MedInfo Inc., 2007.