An Anomalous LAD Originating Separately From Right Coronary Sinus: A Case Report.

Anomalous origination of left anterior descending branch (LAD) from the right sinus (LAD-ACAOS) is extremely rare in anomalous aortic origin of a coronary artery from the opposite sinus of Valsalva (ACAOS), which is prone to be missed during invasive coronary angiography (CAG). We present a case with acute non-ST elevation myocardial infarction (NSTEMI), in whom LAD-ACAOS was demonstrated by CAG and computed tomography angiography (CTA). A 71-year-old man presented with ischemic chest pain and mildly elevated troponin I. He underwent CAG, and was found to have a separate ostium of LAD. CTA showed that the anomalous LAD originated from right sinus with a higher ostium than right coronary artery, and surrounded the lateral and anterior wall of pulmonary conus, ultimately went into anterior interventricular groove with myocardial bridging (MB) in the mid part. This is very rare case LAD-ACAOS. The LAD-ACAOS is of pre-pulmonary subtype with a high ostium in right sinus of Valsava, and MB in the mid part. The case shows us a special anatomy of LAD-ACAOS, and also suggests this subtype of non-interarteries anomaly is not always be benign.