Beta blockers are antiarrhythmic agents of class: (A) 1, (B) 11, (C) 111, (D) 1V
Answer is B. Refer kDT 6/e p 511 The 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. ... Class III agents affect potassium (K+) efflux. Class IV agents affect calcium channels and the AV node.