[Cardiac manifestations of hyperthyroidism in the elderly].
PURPOSE: To evaluate the cardiocirculatory abnormalities of hyperthyroidism in the elderly. PATIENTS AND METHODS: Twenty-four hyperthyroid patients, 18 women and six men, aged 60 to 87 (average 73.5) years were studied. Seventeen (70.9%) patients had associated cardiocirculatory diseases. The evaluation was made on clinical grounds complemented by electrocardiographic, radiologic, phonomechanocardiographic and echocardiographic examinations. RESULTS: Cardiocirculatory symptoms were observed in 17 (70.9%) patients and congestive heart failure in nine (37.5%) of them. The electrocardiogram was abnormal in 20 (83.3%) patients and the tachyarrhythmias were the commonest abnormality (62.5%). Eight (33.3%) patients had chronic atrial fibrillation and five (20.8%) had sinus tachycardia. There was no significant statistical difference on the electrocardiograms of patients with and without cardiocirculatory abnormalities. Cardiomegaly was significantly more prevalent in hyperthyroid patients, with (64.7%) or without (57.1%) cardiocirculatory abnormalities, than in normal elderly (23.9%). Left ventricular performance was studied in 14 patients through the systolic quotient and was found normal or high in 12 (85.7%). The percentage of fractional shortening (delta D%) was higher than 30 in all patients. None of the patients was found to have symmetric or asymmetric hypertrophic cardiomyopathy and mitral valve prolapse on echocardiogram. CONCLUSION: Hyperthyroidism in the elderly patient determines frequently cardiocirculatory abnormalities that may be misdiagnosed with those caused by the ageing process or by associated cardiopathies. This diagnosis should be suspected in all elderly patients having tachyarrhythmias and/or cardiac failure resistant to usual therapy, mainly in patients without clear cardiocirculatory pathology.