title: Effect of amiodarone-induced hyperthyroidism on left ventricular outflow obstruction after septal myectomy for hypertrophic cardiomyopathy.
abstract: Patients with obstructive hypertrophic cardiomyopathy who undergo septal myectomy are at risk for developing postoperative atrial fibrillation. Amiodarone is effective in treating this arrhythmia but is associated with multiple adverse effects, often with delayed onset. A novel case is described of a patient who developed type 2 amiodarone-induced hyperthyroidism that presented as recurrence of outflow obstruction after septal myectomy. The patient's symptoms and echocardiographic findings of outflow obstruction resolved substantially with the treatment of the amiodarone-induced hyperthyroidism. Amiodarone-induced hyperthyroidism of delayed onset can be a subtle diagnosis, requiring a high index of suspicion. In conclusion, recognition of this diagnosis in patients with recurrence of outflow obstruction by symptoms and cardiac imaging after septal myectomy may avoid unnecessary repeat surgical intervention.
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
authors.forename: Sean D
authors.initials: SD
authors.lastname: Pokorney
authors.forename: Neil J
authors.initials: NJ
authors.lastname: Stone
authors.forename: Rod
authors.initials: R
authors.lastname: Passman
authors.forename: David
authors.initials: D
authors.lastname: Oyer
authors.forename: Vera H
authors.initials: VH
authors.lastname: Rigolin
authors.forename: Robert O
authors.initials: RO
authors.lastname: Bonow
mesh_terms: D000369:Aged, 80 and over; D000638:Amiodarone / Q000009:adverse effects* / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects; D001281:Atrial Fibrillation / Q000517:prevention & control; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D004452:Echocardiography; D005500:Follow-Up Studies; D006346:Heart Septum / Q000601:surgery*; D006801:Humans; D006980:Hyperthyroidism / Q000139:chemically induced* / Q000150:complications; D008297:Male; D014694:Ventricular Outflow Obstruction / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology
chemical_list: D000889:Anti-Arrhythmia Agents; D000638:Amiodarone