title: A study of chronic heart block using His bundle electrograms.
mesh_terms: D000219:Adams-Stokes Syndrome / Q000175:diagnosis; D000368:Aged; D002037:Bundle-Branch Block / Q000175:diagnosis; D006328:Cardiac Catheterization; D004562:Electrocardiography; D004594:Electrophysiology; D005260:Female; D006327:Heart Block / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D006329:Heart Conduction System / Q000503:physiopathology*; D006333:Heart Failure / Q000150:complications; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial