Wolff-Parkinson-White Syndrome (WPW) is recognized as an abnormality of cardiac rhythm that manifests as supraventricular tachycardia. Few practitioners today appreciate how much the development of clinical cardiac electrophysiology owes to Wolff-Parkinson-White Syndrome. In the early 1960s, it became the test bed for electrophysiological theory and new therapies. Surgical electrophysiological techniques were developed, the pathways were severed, and the patient was often left with an entirely normal heart. This was an important first in modern cardiology - a complete cure. The aim of the Clinical Approaches to Tachyarryhthmias series is to update the physician, cardiologist, and all those responsible for the the care of patients with cardiac arrhythmias. In this volume, the authors unfold the story of WPW, its precise diagnosis by use of electrocardiography, its successful management and its near extinction in parts of the world reached by modern medical technology, and the remaining challenge it represents in pediatric medicine and in other parts of the globe.