title: [Auricular fibrillation in hyperthyroidism. Incidence of associated cardiopathy and of dilatation of the left auricle].
abstract: In this study the mechanism responsible for atrial fibrillation (AF) in hyperthyroidism was investigated by standard cardiovascular exploration and echocardiography. Fifty four patients (43 women, 11 men, mean age 44 years) were examined during, and after successful treatment of a thyrotoxicosis episode associated with Graves' disease in 43 cases, with a secondarily toxic goitre in 7 cases and with a toxic adenoma in 4 cases. Nineteen patients presented with a heart disease: mitral valve prolapse (MVP) in 11 (including 4 with AF) and another cardiopathy in 8 (including 4 with AF). Among the 34 patients without heart disease, only 2 had AF during thyrotoxicosis. In all groups the antero-posterior diameter of the left atrium was greater in patients with AF than in those with normal sinus rhythm, but it remained within normal limits in patients with MVP. It may be assumed that in these cases AF resulted from synergism between the arrhythmogenic potential of MVP and that of the thyroid hormones. In contrast, prior dilatation of the left atrium seemed to play a predominant role in patients with another cardiopathy. The 4 patients with AF in the latter group remained with AF after the thyrotoxicosis was cured, whereas the 2 patients without heart disease and 3 of the 4 MVP patients reverted to sinus rhythm without anti-arrhythmic therapy or cardioversion. It is concluded that the presence of an underlying heart disease accounts for most cases of AF developed during thyrotoxicosis, but in 1 out of 2 cases the heart disease in a minor one, consisting of MVP.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology; D004108:Dilatation, Pathologic; D005260:Female; D006325:Heart Atria / Q000473:pathology; D006331:Heart Diseases / Q000150:complications; D006334:Heart Function Tests; D006801:Humans; D008297:Male; D008875:Middle Aged; D008945:Mitral Valve Prolapse / Q000150:complications; D013971:Thyrotoxicosis / Q000150:complications*
vernacular_title: Fibrillation auriculaire au cours de l'hyperthyroïdie. Incidence de la cardiopathie associée et de la dilatation de l'oreillette gauche.