Posture-Dependent STEMI Due to Extrinsic Compression of the Right Coronary Artery.

BACKGROUND: Extrinsic coronary compression is a rare, nonatherosclerotic mechanism of myocardial infarction, most often linked to acute aortic pathology. Posture-dependent right coronary artery obstruction has not been described. CASE SUMMARY: An 84-year-old woman presented with inferior ST-segment elevation myocardial infarction (STEMI). Chest pain and ST-segment elevation worsened in the supine position and improved in the lateral decubitus position. Coronary angiography and intravascular ultrasound revealed extrinsic compression of the right coronary artery ostium between the sternum and a dilated aortic annulus. Percutaneous coronary intervention (PCI) with a high-radial force stent secured adequate lumen area to relieve ischemia and resolved symptoms. DISCUSSION: This case illustrates a unique, posture-dependent mechanical cause of STEMI. Recognition of positional symptoms was crucial for diagnosis. Although surgery could address the underlying anatomy, PCI was chosen as destination therapy owing to age, frailty, and patient preference. TAKE-HOME MESSAGES: Posture-dependent chest pain may indicate dynamic coronary compression. PCI can be an option in inoperable patients, but surveillance is essential.