Rate control during AF using cellular intervention to modulate AV node

A biologic intervention method and apparatus generates a persistent modification to an AV node that is physiologically stable after the agent has matured but is alterable with subsequent application of an agent. Specifically, the generic agent is used to modulate a node in a cardiac conduction system including rate control using one and a combination of a family of K + channel or equivalent. Specifically, the channel is implemented to slow conduction by generating an outward current during optimization of action potential and repolarization phase thus decreasing the current that is available to excite downstream cells. A Kv 1.3 channel, for example, may be used as the biologic channel. The invention enables reversal of the modulation or adjustment for various heart rates (BPM) based on medical and patient-specific needs.