Background:

Thyrotoxicosis is a clinical syndrome with high amounts of free thyroid hormone levels causing elevated thyroid hormone function in body tissues. Prolonged effects of free thyroid hormones may lead to cardiac complications such as atrial fibrillation (AF) and heart failure (HF).

Case 1:

A 31-year-old female, was admitted due to difficulty in breathing, generalised body swelling and jaundice. She was dyspnoeic with an irregular heart rate, and presented with abnormal vitals, liver and thyroid function tests which were diagnostic for thyroid storm. She was managed over 32 days in-hospital stay with carbimazole, propranolol, hydrocortisone, digoxin and furosemide. Unfortunately, she was readmitted 6 months later with worsened HF symptoms and passed away.

Case 2:

A 57-year-old female, was admitted due to difficulty in breathing, bilateral lower limb swelling and jaundice. She was tachypnoeic with an irregular heart rate, and presented with abnormal liver enzymes and thyroid function tests which were diagnostic for thyrotoxicosis. She was managed with carbimazole, propranolol, digoxin and furosemide, and was discharged on the 6th hospital day.

Conclusion:

Prolonged untreated thyrotoxicosis increases the risk of AF and HF. Early and monitored treatment and follow-up of hyperthyroidism is key to the management of AF and HF in achieving a better outcome.