what is the mechanism of action for class ii antiarrhythmics?
The primary action of Class II antiarrhythmics is to block beta adrenoceptors. Class II includes propranolol, acebutolol, and the short-acting beta-adrenoreceptor antagonist esmolol. Class III drugs, which prolong action potential duration and effective refractory period, act primarily by blocking potassium channels, although other mechanisms may be involved.