Untreated hypothyroidism can lead to fluid retention and increase bleeding risk, which in extreme cases can manifest as cardiac tamponade.
A 66 year old female with chronic atrial fibrillation on rivaroxaban, hypertension, diabetes and a previous history of untreated Hashimoto’s disease, presented with progressive symptoms of heart failure. Echocardiography demonstrated a moderate pericardial effusion without features of tamponade. 24 hours into her admission she had new left sided hemiparesis, with CT brain showing a right parietal lobe intraparenchymal haemorrhage. Following this diagnosis, she deteriorated with evidence of respiratory distress and subsequent PEA cardiac arrest. Bedside echo showed progressive effusion with tamponade. Emergency pericardiocentesis was performed, with 1 litre of blood-stained fluid being drained.
Biochemistry revealed a TSH of 53 mU/L (N 0.3-4.5) and free T4 <3.2 pmol/L (N 7-17). She was subsequently commenced on regular thyroxine 100mcg daily, but due to limited adherence she was transitioned to thrice weekly thyroxine administered by community nurses.
Untreated hypothyroidism is well known to cause heart failure symptoms, with pericardial effusions occurring in 3-6% (1). Cardiac tamponade as a presentation is however, rare. Bleeding or thrombosis can also occur in the setting of hypothyroid induced coagulation and platelet dysfunction (2). Spontaneous intracerebral haemorrhage is even rarer than cardiac tamponade. We surmise that poor renal clearance of her rivaroxaban, compounded by increased bleeding tendency from chronically untreated hypothyroidism contributed to her intracerebral haemorrhage and hastened the development of cardiac tamponade. Although daily thyroxine is ideal, in patients with suboptimal adherence, increased doses of thyroxine can be taken less frequently due to the long medication half-life.
This case highlights the extreme multi-organ manifestations of untreated hypothyroidism. Avoiding rare life-threating complications of hypothyroidism can be overcome with judicious and early thyroid replacement.