title: Complete Atrioventricular Block Presenting With Syncope Caused by Severe Hypothyroidism.
abstract: A 75-year-old man was admitted to our hospital with syncope. Electrocardiogram showed complete atrioventricular block and bradycardia with the minimum heart rate of 22 beats/ min. There was a possible indication for temporary cardiac pacemaker implantation. Laboratory data on admission revealed high TSH level with low free T4 level. To rule out functional atrioventricular block, we treated several days with thyroxine. A follow-up electrocardiogram showed improved heart rate without any atrioventricular block. We found that severe hypothyroidism caused a complete atrioventricular block with syncope, and thyroxine replacement completely improved these conditions.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Inje University College of Medicine, Haeundae Paik Hospital, Busan, Korea.
authors.forename: Sang-Hoon
authors.initials: SH
authors.lastname: Seol
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Inje University College of Medicine, Haeundae Paik Hospital, Busan, Korea.
authors.forename: Doo-Il
authors.initials: DI
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Inje University College of Medicine, Haeundae Paik Hospital, Busan, Korea.
authors.forename: Bo-Min
authors.initials: BM
authors.lastname: Park
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Inje University College of Medicine, Haeundae Paik Hospital, Busan, Korea.
authors.forename: Dong-Kie
authors.initials: DK
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Inje University College of Medicine, Haeundae Paik Hospital, Busan, Korea.
authors.forename: Pil-Sang
authors.initials: PS
authors.lastname: Song
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Inje University College of Medicine, Haeundae Paik Hospital, Busan, Korea.
authors.forename: Ki-Hun
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Inje University College of Medicine, Busan Paik Hospital, Busan, Korea.
authors.forename: Han-Young
authors.initials: HY
authors.lastname: Jin
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Inje University College of Medicine, Busan Paik Hospital, Busan, Korea.
authors.forename: Jeong-Sook
authors.initials: JS
authors.lastname: Seo
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Inje University College of Medicine, Busan Paik Hospital, Busan, Korea.
authors.forename: Jae-Sik
authors.initials: JS
authors.lastname: Jang
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Inje University College of Medicine, Busan Paik Hospital, Busan, Korea.
authors.forename: Tae-Hyun
authors.initials: TH
authors.lastname: Yang
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Inje University College of Medicine, Busan Paik Hospital, Busan, Korea.
authors.forename: Dae-Kyeong
authors.initials: DK
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Inje University College of Medicine, Busan Paik Hospital, Busan, Korea.
authors.forename: Dong-Soo
authors.initials: DS
authors.lastname: Kim
keywords: Atrioventricular block; Hypothyroidism; Syncope