Thyrotoxic Cardiomyopathy - A reversible entity
S Qureshi, S G Wijetilleka, K Yoganathan, A Stevenson, S Wright, S Ladbrokes, R Kaushal
Graves thyrotoxicosis rarely causes heart failure in healthy patients. It is a presentation in only 6% of thyrotoxicosis patients and conventional treatment for hyperthyroidism normally reverses these cardiovascular manifestations.
We present a patient who presented with 3 week history of progressive breathlessness, palpitations and sleeping in chair. She had a past history of being seen in the endocrine clinic 8 weeks prior to the presentation with a relapsed Graves disease treated with small dosage of Carbimazole. She had a past medical history of subtotal thyroidectomy with subsequent hypothyroidism in 1967. She remained asymptomatic until her current presentation with no active treatment. Her thyroid ultrasound thyroid showed multi-nodular goitre and a fine needle aspiration was not advised.
Her examination revealed various features of congestive cardiac failure, moderate goitre and thyroid eye disease. Her echocardiogram showed an ejection fraction of 20-25% on admission and akinetic cardiac wall abnormality (figure 1). Her previous echocardiogram 7 years early was within normal parameters. Her biochemical tests on admission were T4 38 p mol TSH <0.01 m IU/L and TSH antibodies were positive. She was initiated on Carbimazole 20 mg and Propanolol 40 mg three times and she showed dramatic improvement in her congestive cardiac failure. She was subsequently discharged from hospital on anti-thyroid therapy. She was scheduled for a follow up echocardiogram in 4-6 weeks and we hope to find that her repeat echocardiogram will improve with biochemical improvement in her thyroid function tests.
The clinical manifestations of thyrotoxic cardiomyopathy are secondary to an unknown aetiology. An assessment of thyroid hormone status in all patients with congestive cardiac failure may permit identification of a potentially reversible cause in this patient group.
Figure 1. Echocardiogram