August 1987

Extreme Bradycardia During Sleep Apnea Caused by Myxedema

Author Affiliations

From the Endocrine (Drs Abouganem and Taylor) and Pulmonary (Drs Donna and Baum) Divisions, Miami Veterans Administration Medical Center, and the Department of Medicine (Drs Abouganem, Taylor, Donna, and Baum), University of Miami School of Medicine.

Arch Intern Med. 1987;147(8):1497-1499. doi:10.1001/archinte.1987.00370080135024

• A 52-year-old man with myxedema was evaluated for anterior chest pain that was considered to be compatible with myocardial ischemia. The night after admission he developed extreme bradycardia, hypotension, and apneic episodes lasting up to 25 s. Continuous positive airway pressure and administration of medroxyprogesterone acetate prevented further episodes and relieved much of the somnolence and lethargy that had contributed to the evidence for myxedema. Alveolar hypoventilation caused by decreased sensitivity to carbon dioxide, inadequate central neural drive, peripheral muscle force, and obesity all may have contributed to the apnea. Chest pain has not recurred, and results of electrocardiography have remained normal following full thyroid hormone replacement. The early recognition of myxedema causing sleep apnea will allow specific treatment to avoid the cardiovascular risks related to prolonged apnea and will help avoid confusion with other etiologies of cardiovascular abnormalities.

(Arch Intern Med 1987;147:1497-1499)