title: Unusual manifest and concealed bigeminy.
mesh_terms: D000328:Adult; D005117:Cardiac Complexes, Premature / Q000175:diagnosis* / Q000209:etiology; D004562:Electrocardiography; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000150:complications; D009203:Myocardial Infarction / Q000150:complications