Congestive Heart Failure Complicated with Chylothorax as the Manifestation in A Patient with Thyrotoxicosis: A Case Report

Although thyrotoxicosis is not rare, congestive heart failure as the manifestation of thyrotoxicosis is relatively uncommon. Coexistence of congestive heart failure and chylothorax is even rarer in hyperthyroid patients. A 37-year-old male patient had been well until 3 years ago when tachycardia and body weight loss developed and a diagnosis of Graves’ disease was made. Due to an improvement in the patient’s clinical condition, there was non-adherence to his antithyroid therapy. On admission, he presented with symptomatic congestive heart failure and bilateral pleural effusion. Thoracocentesis revealed a high triglyceride level in the pleural effusion, consistent with chylothorax. Survey for other common causes of congestive heart failure and chylothorax was negative. The only concurrent illness identified was thyrotoxicosis and the underlying cause of congestive heart failure and chylothorax was finally determined to be hyperthyroidism. Treatment of heart failure and hyperthyroid state led to a remarkable improvement in the clinical status including recovery of heart function and disappearance of chylothorax. To the best of our knowledge, there were only two adult cases in the literature presenting with congestive heart failure and chylothorax resulting from hyperthyroidism. (J Intern Med Taiwan 2011; 22: 57-62)