title: EKG of the month. A problem in pacing.
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects; D004562:Electrocardiography; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial / Q000009:adverse effects*; D013610:Tachycardia / Q000209:etiology*