Pill-sized pacemaker system including a pill-size pacemaker and a lead connector, the pacemaker having a distal end including a first screw hook and a proximal end including a first magnetic coupler, the lead connector having a distal end including a second screw hook and a proximal end including a second magnetic coupler, the first and second magnetic couplers being disc-shaped, each including at least one depth-wise electrode, wherein the first screw hook is for screwing the pacemaker to inner heart tissue and for sensing at least one signal from the inner heart tissue, the second screw hook is for screwing the lead connector to inner heart tissue and for sensing at least one signal from the inner heart tissue, and the pacemaker and the lead connector are electrically coupled via each depth-wise electrode of the first and second magnetic couplers when the first and second magnetic couplers are magnetically coupled.