Background http://spermup.blogspot.com/ In 1930, Wolff, Parkinson, and White described a series of young patients who had a bundle branch block pattern on electrocardiography (ECG) findings, a short PR interval, and paroxysms of tachycardia. Case reports began appearing in the literature in the late 1930s and early 1940s, and the term Wolff-Parkinson-White (WPW) syndrome was coined in 1940. In 1943, the existence of an accessory connection between atria and ventricles was confirmed, which is about 50 years after Kent's description of myocardial fibers that were believed to conduct from atria to ventricle. The term preexcitation was first published by Ohnell in 1944 (the same year that the term delta wave was coined); Ohnell stated, "preexcitation indicates an additional excitatory spread in the ventricles of the heart, coupled to auricular excitation." WPW syndrome is not the only form of preexcitation but is the most common. The first surgical