--- abstract: "Atrial fibrillation occurs in 10 – 15% of patients with hyperthyroidism. Low serum thyrotropin concentration is an independent risk factor for atrial fibrillation. Thyroid hormone contributes to arrythmogenic activity by altering the electrophysiological characteristics of atrial myocytes by shortening the action potential duration, enhancing automaticity and triggered activity in the pulmonary vein cardio myocytes. Hyperthyroidism results in excess mortality from increased incidence of circulatory diseases and dysrhythmias. Incidence of cerebral embolism is more in hyperthyroid patients with atrial fibrillation, especially in the elderly and anti-coagulation is indicated in them. Treatment of hyperthyroidism results in conversion to sinus rhythm in up to two-third of patients. Beta-blockers reduce left ventricular hypertrophy and atrial and ventricular arrhythmias in patients with hyperthyroidism. Treatment of sub clinical hyperthyroidism is controversial. Optimizing dose of thyroxine treatment in those with replacement therapy and beta-blockers is useful in exogenous subclinical hyperthyroidism.\n" altloc: - http://www.ipej.org/0504/jayaprasad.htm chapter: ~ commentary: ~ commref: ~ confdates: ~ conference: ~ confloc: ~ contact_email: ~ creators_id: [] creators_name: - family: Jayaprasad given: N honourific: '' lineage: '' - family: Francis given: Johnson honourific: '' lineage: '' date: 2005-10 date_type: published datestamp: 2005-11-12 department: ~ dir: disk0/00/00/45/97 edit_lock_since: ~ edit_lock_until: ~ edit_lock_user: ~ editors_id: [] editors_name: - family: Singh given: Balbir honourific: '' lineage: '' - family: Lokhandwala given: Yash honourific: '' lineage: '' - family: Francis given: Johnson honourific: '' lineage: '' - family: Gupta given: Anup honourific: '' lineage: '' eprint_status: archive eprintid: 4597 fileinfo: /style/images/fileicons/text_html.png;/4597/1/jayaprasad.htm|/style/images/fileicons/application_pdf.png;/4597/2/jayaprasad.pdf full_text_status: public importid: ~ institution: ~ isbn: ~ ispublished: pub issn: ~ item_issues_comment: [] item_issues_count: 0 item_issues_description: [] item_issues_id: [] item_issues_reported_by: [] item_issues_resolved_by: [] item_issues_status: [] item_issues_timestamp: [] item_issues_type: [] keywords: Atrial fibrillation; hyperthyroidism; embolism lastmod: 2011-03-11 08:56:13 latitude: ~ longitude: ~ metadata_visibility: show note: ~ number: 4 pagerange: 305-311 pubdom: TRUE publication: Indian Pacing and Electrophysiology Journal publisher: Indian Pacing and Electrophysiology Group refereed: TRUE referencetext: | 1. 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