A unicorn is a mythical, legendary creature—a beast, with a single, pointed spiral horn thought to live on the edge of the earth in ancient times and to have the power to purify water and heal sickness. Here, we introduce this new section, Case Unicorns as an educational tool for electrophysiologists to help them improve their practice and assist them in treating their patients with greater
... [Show full abstract] insight. Our goal for this section is to present unique and challenging cases that provide mechanistic understanding of the electrophysiological properties and the nature of the condition, in order to help others deal with specific issues in their general practices. Our first unicorn involves a supraventricular tachycardia with two-to-one going to one-to-one atrioventricular conduction.