title: Letter: An unusual ECG pattern in two healthy identical twins.
mesh_terms: D000328:Adult; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D011247:Pregnancy; D011433:Propranolol / Q000494:pharmacology; D014427:Twins; D014430:Twins, Monozygotic
chemical_list: D011433:Propranolol