A Man in His Early 30s with Chest Pain and a Peculiar Coronary Angiogram

We present the case of a patient with chest pain whose history suggested vasospastic angina. Despite the absence of ischemic electrocardiographic changes, the patient underwent coronary angiography, which showed no atherosclerotic lesions but a diffuse stenosis of the right coronary artery that was resolved promptly by intracoronary nitrate injection, therefore confirming spasm. Angiography also showed a straight vessel in the posterior atrioventricular sulcus, which was recognized as an intercoronary communication that connected the right coronary artery with the left circumflex artery and enabled bidirectional flow. The intercoronary communication likely served to partially protect the right coronary artery-dependent myocardium from ischemia during spasm. This case highlights the significance of a detailed history in constructing an investigation plan in order to make the correct diagnosis. By precluding concurrent ischemic electrocardiographic changes, the intercoronary communication made the diagnosis more challenging.