title: A survey of familial heart block.
mesh_terms: D000328:Adult; D000368:Aged; D002037:Bundle-Branch Block / Q000235:genetics; D004562:Electrocardiography; D005260:Female; D006327:Heart Block / Q000235:genetics*; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010375:Pedigree