Endocrine Abstracts

Introduction: Heart failure is a complication of thyrotoxicosis. We present 2 unusual cases presenting with pulmonary hypertension with isolated right heart failure that reversed after treatment.

Case description: Case 1: A 55-year-old man presented with weight loss, dyspnoea and leg swelling. HR: atrial fibrillation 51/min. He had a raised JVP, tricuspid regurgitation and severe pitting oedema. Pro-BNP: 4995 pg/ml, TSH: 0.06 mU/l, FT4: 54.1 pmol/l, FT3:10.5 pmol/l. TSH receptor antibodies (TRAb) were positive. CTPA: no pulmonary embolism. Echo: PAP 45 mmHg, LVEF preserved. Carbimazole, diuretics, ACE inhibitors and Apixaban were commenced. Right heart catheterization showed non-obstructive coronary artery disease and pulmonary hypertension. Repeat ECHO 7 months later revealed normal right heart pressure and size when euthyroid. Tricuspid regurgitation and Pulmonary Hypertension were resolved.

Case 2: A 34-year-old male presented with oedema, elevated JVP, tricuspid regurgitation and atrial fibrillation. Pro-BNP: 2064 pg/ml TSH: 0.05 mU/l, Free T4: 72.6 pmol/l, TRAb positive. CTPA negative for PE. ECHO: PAP 60 mmHg. Right cardiac catheterisation when euthyroid demonstrated a RVSP of 32 mm Hg, pulmonary artery systolic pressure of 27 mmHg and a wedge pressure of 14 mmHg indicating a resolution of his RHF.

Learning point: Selective right heart failure may occur in thyrotoxicosis perhaps due to altered metabolism of pulmonary vasodilators resulting in raised pulmonary vascular resistance.