title: A case of chloroquine-induced cardiomyopathy that presented as sick sinus syndrome.
abstract: A 52-year-old woman with rheumatoid arthritis who had been treated with prednisone and hydroxychloroquine for >12 years presented with chest discomfort and a seizure. She was diagnosed with restrictive cardiomyopathy combined with sick sinus syndrome. A myocardial muscle biopsy was performed to identify the underlying cardiomyopathy, which showed marked muscle fiber hypertrophy, fiber dropout, slightly increased interstitial fibrous connective tissue, and extensive cytoplasmic vacuolization of the myocytes under light microscopy. Electron microscopy of the myocytes demonstrated dense, myeloid, and curvilinear bodies. The diagnosis of hydroxychloroquine-induced cardiomyopathy was made based on the clinical, hemodynamic, and pathologic findings. This is the first case report describing chloroquine-induced cardiomyopathy involving the heart conduction system.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Jae Hak
authors.initials: JH
authors.lastname: Lee
authors.forename: Woo-Baek
authors.initials: WB
authors.lastname: Chung
authors.forename: Ju Hyun
authors.initials: JH
authors.lastname: Kang
authors.forename: Hyung Woo
authors.initials: HW
authors.lastname: Kim
authors.forename: Jin Jin
authors.initials: JJ
authors.lastname: Kim
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Hui-Jeong
authors.initials: HJ
authors.lastname: Hwang
authors.forename: Jea Beom
authors.initials: JB
authors.lastname: Lee
authors.forename: Jong Won
authors.initials: JW
authors.lastname: Chung
authors.forename: Hyo Lim
authors.initials: HL
authors.lastname: Kim
authors.forename: Yun Seok
authors.initials: YS
authors.lastname: Choi
authors.forename: Chul Soo
authors.initials: CS
authors.lastname: Park
authors.forename: Ho-Joong
authors.initials: HJ
authors.lastname: Youn
authors.forename: Man Young
authors.initials: MY
authors.lastname: Lee