Is there really an electic-like system in the heart? how do you reset it?

Yes: Instead of wires, there are bundles or tracts of specialized, electrically conducting cells. The timing of the 4 chambers is critical to optimize blood flow. The entire system can be reset with a carefully timed electrical shock that passes the current through the entire heart, called defibrillation or cardioversion. This is a routine procedure performed under sedation in hospitals.