<prompt> Antiarrhythmic classification into class1a,1b,1c,2,3,4,5 were given by:Vaughan WilliamsRamnath chopraOswaldDavid sackett  <response>: The Vaughan Williams classification was introduced in 1970 by Miles Vaughan Williams. five main classes in the Vaughan Williams classification of antiarrhythmic agents are: Class I agents interfere with the sodium Na channel. Class II agents are anti-sympathetic nervous system agents. Most agents in this class are beta blockers. Class III agents affect potassium K efflux. Class IV agents affect calcium channels and the AV node. Class V agents work by other or unknown mechanisms. Vaughan Williams, EM 1970 Classification of antiarrhythmic drugs. In Symposium on Cardiac Arrhythmias Eds. Sandoe E, Flensted- Jensen E, Olsen KH. Astra, Elsinore. Denmark 1970 Ref: Tripati 8th ed. 