Collateral myocardial blush in inferior wall myocardial infarction: a new diagnostic tool to differentiate between occluded right coronary and circumflex arteries.

OBJECTIVES: The infarct-related artery (IRA) in inferior wall myocardial infarction (IMI) may be problematic to identify due to occasional instances in which the right coronary (RCA) and left circumflex (CX) arteries are both occluded. We sought to investigate if impaired collateral myocardial blush (CMBG) identifies the correct IRA. METHODS: Between 2002 and 2010, we retrospectively analyzed 1907 patients who underwent primary angioplasty at our institution. Of these, 44 had an IMI together with total occlusion of both the RCA and CX. RESULTS: Thirty of these had good collaterals to both distal vessels. Ten of this group had impaired CMBG, indicating the IRA. In 2 patients, angioplasty was attempted in the wrong artery in retrospect. CONCLUSIONS: The correct IRA may be difficult to identify in patients with IMI and occlusion of both RCA and CX arteries. Impaired CMBG is a new tool to aid in this challenge.