What Is the Real Identity of the Mysterious Potential P1, and What Is the Most Important Segment of the Fascicular Ventricular Tachycardia Circuit?

In 1845, Johannes Evangelista Purkinje (Purkyně) discovered gelatinous fibers in the ventricular subendocardium. Later, they were called Purkinje fibers. However, he could not determine the function of that strange tissue and thought it was muscular. In 1906, Sunao Tawara finally described its function as the conducting system (Figure). In the last 3 decades, there has been rapid progress in the treatment of ventricular arrhythmias, and the Purkinje system has been found to be responsible for the mechanism of some ventricular tachyarrhythmias. These ventricular tachyarrhythmias can be called Purkinje-related arrhythmias and are manifested as monomorphic ventricular tachycardia (VT) and polymorphic VT, including ventricular fibrillation.