Related Experiment Video
Updated: Feb 9, 2026

Shaping the Amplitude and Phase of Laser Beams by Using a Phase-only Spatial Light Modulator
Published on: January 28, 2019
Phase 3 and phase 4 block of the accessory pathway in Wolff-Parkinson-White syndrome--a case report
M F Rattes1, J A Boone, S Milstein
1Clinical Electrophysiology Laboratory, University Hospital, London, Ontario.
Abstract:
A 12-year-old girl presented with recurrent episodes of supraventricular tachycardia. A 12 lead electrocardiogram showed normal sinus rhythm with a normal PR interval and no evidence of preexcitation. A 24 h Holter monitor showed intermittent preexcitation. Both phase 3 and phase 4 block in the accessory pathway were demonstrated with introduction of atrial extrastimuli during sinus rhythm at electrophysiology study. However, Holter recording failed to reveal a consistent relationship between coupling intervals and accessory pathway conduction. The discrepancy between the Holter monitor and the electrophysiologic study can be explained by variability of factors such as autonomic tone during the Holter recording. This case illustrates a potential mechanism for intermittent preexcitation in the Wolff-Parkinson-White syndrome.
Related Concept Videos
Phase Diagrams
Phase Transitions
Inductance: Single-Phase And Three-Phase Line
Single-Phase Two-Wire Line:
A single-phase line consists of two solid cylindrical conductors, denoted as x and y. Each conductor carries phasor currents ix and iy, respectively. Given that the sum of these currents is...
Capacitance: Single-Phase And Three-Phase Line
Single-Phase Lines
Consider a single-phase, two-wire transmission line with equal phase spacing energized by a voltage source. One conductor carries a uniform positive charge, while the other carries an equal negative charge. The capacitance C of the line can be derived from the voltage V between the conductors. For a one-meter section of the line, the capacitance is given...
Phase Changes
A substance melts or freezes at a temperature called its melting point and boils or condenses at its boiling point. These temperatures depend on pressure. High pressure favors the denser form of the substance, so typically, high pressure...
Phase-lead and Phase-lag Controllers

