Pericardial effusion associated with subclinical hypothyroidism.

Previous studies have suggested that subclinical thyroid dysfunction, as manifested by abnormalities in thyroid-stimulating hormone (TSH) levels, are associated with detrimental effects on the cardiovascular system. Subclinical hyperthyroidism is an increasingly recognized entity that is defined as a normal serum free thyroxine and free triiodothyronine levels with a thyroid-stimulating hormone level suppressed below the normal range and usually undetectable. It has been reported that subclinical hyperthyroidism is not associated with coronary heart disease or mortality from cardiovascular causes but it is sufficient to induce arrhythmias including atrial fibrillation and atrial flutter. It has also been reported that increased factor X activity in patients with subclinical hyperthyroidism represents a potential hypercoagulable state. Subclinical hypothyroidism is defined by elevated serum levels of TSH with normal levels of free thyroid hormones. Subclinical hypothyroidism is characterized by abnormal lipid metabolism, cardiac dysfunction, diastolic hypertension conferring an elevated risk of atherosclerosis, and ischemic heart disease. It has been reported that sub-clinical hypothyroidism is associated with both, a significant risk of coronary heart disease at baseline and at follow-up and that mortality from cardiovascular causes is significantly higher at follow-up. However subclinical thyroid dysfunction is currently the subject of numerous studies and remains controversial, particularly as it relates to cardiovascular morbidity and mortality and clinical applications. Pericardial effusion can be present in systemic disorders including hypothyroidism. We present a case of subclinical hypothyroidism in a 41-year-old Italian woman with an ubiquitary pericardial effusion. Also this case focuses attention on subclinical hypothyroidism.