Endocrine Abstracts

Introduction: Graves’ disease (GD) is associated with cardiac complications like tachydysrythmias, coronary ischaemia and cardiomyopathy. They are uncommon in the young. We present three individuals without previous cardiac disease, who developed significant cardiac complications of GD.

Case presentations Subject 1: A 34-year-old female smoker, presented with breathlessness, palpitations, tremors and agitation for several weeks. Her fT4 was 98.4 (11–25 pmol/L), fT3 46.9 (3.1–6.8 pmol/L), TSH<0.01 (0.27–4.2 mU/l) and thyrotrophin receptor antibody (TRAb) 34.8 (<0.9 U/l). A thyroid storm was diagnosed, and she was given carbimazole, betablockers, steroids, antibiotics and intravenous fluids. A few days later, she became breathless and on echocardiography, cardiomegaly and pericardial effusion (2.9 cm) was seen, despite improving thyroid function (fT4 27.8; fT3 12.8). She had steroids and nonsteroidal agents with good response. There were no other identifiable causes for her pericardial effusion.

Subject 2: A 28-year-old previously fit male presented with weight loss, palpitations, sweating and diarrhoea, with a goitre and bruit. His fT4 was 38, fT3 13.9, TSH<0.01 (abnormal for over 6 months) and TRAb 9.3. He was given carbimazole, but one month later presented with acute heart failure (HF) despite improving thyroid function. Echocardiography revealed severe dilated cardiomyopathy (DCM) with an ejection fraction (EF) of 12% and lisinopril, bumetanide, epleronone and ivabradine were given. Echocardiography 4 months later (when euthyroid), showed improvement in EF to 21%. Further investigations (including angiography and MRI) ruled out other causes for DCM. He awaits thyroidectomy.

Subject 3: A 42-year-old previously healthy woman presented acutely with palpitations, breathlessness and leg swelling, and was found to be in fast atrial fibrillation and HF. She had been thyrotoxic for several months (free T4 54.3; free T3 >46.1; TSH <0.01; TRAb 4.5) and had bisoprolol, digoxin, propylthiouracil and HF treatment. Echocardiography at presentation showed cardiomegaly, pleural effusion, and EF of 29%. Myocardial perfusion scans did not show inducible ischaemia. She had early total thyroidectomy and remains in sinus rhythm with EF of 50%.

Conclusions: Significant cardiac complications of GD (pericardial effusion, DCM, and tachycardiomyopathy) may occur in fit young patients without previous cardiac disease, who usually have had thyrotoxicosis for several months. There should be a high index of suspicion in those who remain symptomatic despite control of their thyrotoxicosis. Though the majority of patients respond well to thionamides with reversal of cardiac abnormalities, definitive treatment should be discussed early to avoid GD relapse and a recurrence of cardiac decompensation.