A medical device comprises: a feeding tube (70) including a feeding lumen (80) with an opening (152) at a distal end of the feeding tube and an electrical lumen (84) having access openings (120) spaced apart along the feeding tube a set of insulated electrical conductors (82) disposed in the electrical lumen, the set of insulated electrical conductors having electrically exposed portions (132, 132a, 132b) proximate to the access openings and electrodes (72, 73, 74, 75, 78, 79, 140) comprising electrically conductive material portions (140) disposed in the access openings and electrically contacting the proximate electrically exposed portions of the set of insulated electrical conductors disposed in the electrical lumen. The electrodes include at least one upper or proximal electrode (74, 75, 78, 79) disposed above an expected patient heart electrical centerline (CL) and at least one lower or distal electrode (72, 73) disposed below the expected patient heart electrical centerline.