Subclavian artery stenosis: An unusual cause of periprocedural myocardial infarction following the surgical myocardial revascularization

The introduced case report explains the atypical periprocedural myocardial infarction following the surgical myocardial revascularization. 60-year-old man has undergone the coronary bypass surgery with arterial graft of left mammary artery (LIMA) to left anterior descending artery (LAD) and venous graft to posterior interventricular branch of right coronary artery. Early in the post-surgery period a perioperative myocardial infarction (PMI) developed, with laboratory correlation of cardio-specific enzymes elevation and ECG changes in terms of ischaemia in the diaphragmatic region. Echocardiography showed akinesia of the apex, apical septal and apical inferior segments accompanied by the decrease in ejection fraction (EF) of the left ventricle. Selective coronarography was performed showed the proper functionality of arterial as well as venous graft, however, examination also showed severe stenosis of the left subclavian artery (LSA) with limitation of flow through LIMA. Percutaneous angioplasty of the LSA and implantation of the stent was performed in the emergency regime with optimal results. In severe stenosis of the LSA, the progression of the so-called coronary-subclavial steal syndrome is developed, with retrograde flow into LIMA resulting in ischaemia of the supplied part of the myocardium. Nevertheless, steal phenomenon with reverse flow in LIMA is not an absolute requisite for development of the myocardial ischaemia. In some cases stenosis of the LSA manifests in similar fashion as the proximal stenosis of LIMA, which was the case of with the patient shown here.