An 18-year-old girl presented to the emergency department in our hospital with syncopal attack for 30 s. The patient had experienced palpitation, external dyspnea and chest discomfort for a week before admission. She did not have recent history of trauma, immobilization and infectious disease. She did not have any known underlying disease and was not pregnant. She has never smoked, drunken alcohol, or taken oral contraceptive. She was alert but complained mild dizziness. Her neurologic examination showed normal findings. Her vital signs were as follows: blood pressure, 70/50 mmHg; pulse rate, 110 beats/minute; temperature, 36.5oC; respiratory rate, 34/min; and oxygen saturation, 94.3% in ambient conditions. Blood studies revealed the following: white blood cell count, 11,440/muL; hemoglobin, 14.4 g/dL; non-fasting glucose, 104 mg/dL; blood urea nitrogen, 13.1 mg/dL; creatinine, 0.7 mg/dL; aspartate transaminase, 118 IU/L; and alanine transaminase, 88 IU/L. A thyroid function test indicated a state of thyrotoxicosis [T3 236.5 ng/dL (normal range, 80-200), free T4 28 pg/mL (8.9-17.9), thyroid-stimulating hormone, 0.08 mIU/L (0.17-4.05), thyrotropin binding inhibiting immunoglobulins (TBII), less than 0.3 (0 - 1 IU/L)]. Several coagulation factors were abnormal [D-dimer, 6.77 mg/L (0-0.55); protein S activity, 18% (55-123); protein S antigen, 19.2% (50-150); protein C Ag, 76% (72-160); and protein C activity, 81% (70-130)]. Other immunological workup did not reveal any evidence of connective tissue disease or antiphospholipid syndrome. An electrocardiogram showed T wave inversions in the inferior and precordial leads (Fig. 1). Chest computed tomography (CT) showed massive PTE in both central pulmonary arteries and diffuse goiter (Fig. 2a, b). However, there were no DVT in lower extremities, upper extremities and jugular veins. An echocardiogram showed severe pulmonary hypertension (right ventricular systolic pressure (RVSP) = 64 mmHg), and a dilated RV, right atrium and main pulmonary artery (Fig. 3a-c). Therefore, the patient was diagnosed with massive PTE, thyrotoxicosis, and partial protein S deficiency. To manage the PTE, we administered low molecular weight heparin for 5 days and added warfarin while adjusting the prothrombin time such that the internal normalized ratio was between 2.0 and 3.0. On the 7th day after admission, she was discharged with oral warfarin and methimazole. A follow-up echocardiogram obtained 3 months after anticoagulation therapy demonstrated normal dimensions and systolic function of the RV and disappearance of the D-shaped left ventricle (LV) (Fig. 3d-f). After thyrotoxicosis was treated with methimazole for a month, a euthyroid state was achieved and the goiter decreased to a normal size (Fig. 4). The methimazole was gradually tapered off and stopped at 4 months. At a 6-month follow up visit, PTE and pulmonary hypertension had disappeared (Fig. 2c, d) but the patient still had a partial protein S deficiency. We decided to stop all medication with careful monitoring. During a 4-year follow-up period after the episode, she was asymptomatic without any evidence of recurrent systemic thromboembolism or hyperthyroidism and had still a partial protein S deficiency.
Repeated CT scan performed six months after anticoagulation therapy showing complete resolution of the thromboemboli of the main branches of both pulmonary arteries (c and d).