Left main coronary artery occlusion by external compression with a large pulmonary artery in Eisenmenger syndrome

The compression of the left main coronary artery (LMCA) with a dilated pulmonary artery (PA) is an important and life-threatening issue, possibly related to sudden death in patients with advanced pulmonary arterial hypertension (PAH). Here we present an exceptional and extreme case with an LMCA occlusion, who fortunately survived due to well-developed coronary collateral retrograde flow.