title: Unusual QRS wave forms associated with permanent pacemakers.
mesh_terms: D000328:Adult; D000368:Aged; D002037:Bundle-Branch Block / Q000175:diagnosis / Q000503:physiopathology; D004562:Electrocardiography; D005260:Female; D006327:Heart Block / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial / Q000009:adverse effects; D014680:Veins