# Case Report: Acute inferior myocardial infarction and third-degree atrioventricular block in a patient with hyperthyroidism

## TL;DR

A hyperthyroid patient experienced an atypical heart attack and a severe heart block, highlighting the need for careful diagnosis in such cases.

## Contribution

This case report highlights atypical symptoms of myocardial infarction in hyperthyroid patients and explores thyroid-related mechanisms in coronary artery disease.

## Key findings

- The patient's atypical presentation of acute inferior myocardial infarction was complicated by third-degree AV block.
- Coronary angiography revealed complete occlusion of the right coronary artery, which was treated with stent placement.
- Anti-thyroid therapy improved the patient's symptoms, suggesting a link between hyperthyroidism and cardiac complications.

## Abstract

We describe the management of a middle-aged male with hyperthyroidism who presented acute inferior myocardial infarction (AIMI) complicated by third-degree atrioventricular (AV) block. The symptoms of AIMI in the patient were atypical. However, his atypical presentation raised clinical suspicion. The electrocardiogram (ECG) was immediately conducted to confirm the patient's AIMI and third-degree AV block. Further coronary angiography revealed that the patient's right coronary artery was completely occluded at the second bend. A stent was placed in the right coronary artery. Following anti-thyroid therapy, the patient's clinical symptoms improved. This case underscores the importance of recognizing atypical presentations in hyperthyroid patients and is followed by a literature review exploring the mechanisms by which thyroid dysfunction influences coronary artery disease (CAD).