Thyrotoxicosis, unstable angina and normal coronary angiogram

Area of Science:

• Cardiology
• Endocrinology
• Internal Medicine

Background:

• Thyrotoxicosis, a condition of excess thyroid hormones, is known to cause cardiovascular complications.
• Acute myocardial ischemia can occur in thyrotoxicosis patients even without significant coronary artery disease.
• The precise mechanisms underlying thyrotoxicosis-induced myocardial ischemia remain incompletely understood.

Observation:

• A 54-year-old woman with Graves' disease presented with unstable angina and thyrotoxicosis.
• Echocardiography during chest discomfort revealed left ventricular apical akinesis and impaired systolic function.
• Coronary angiography showed normal epicardial vessels.

Findings:

• High-dose methimazole and propranolol treatment led to normalization of left ventricular systolic function.
• The patient later developed paroxysmal atrial fibrillation, necessitating thyroidectomy and L-T4 substitution therapy.
• The case highlights the link between thyrotoxicosis and myocardial ischemia.

Implications:

• This case underscores the importance of considering thyrotoxicosis in patients presenting with myocardial ischemia and normal coronary arteries.
• Understanding the mechanisms of thyrotoxicosis-induced cardiac dysfunction is crucial for effective management.
• Further research into the pathogenesis of myocardial ischemia in thyrotoxicosis is warranted.