Fig 1. No filling of the LMS during aortic root injection.
There was suspicion of a separate narrowing in the collateralizing vessel and disease in the posterior descending artery. The computerized tomography (CT) coronary angiogram refuted the initial diagnosis, and instead confirmed the absence the LMS stump. A gated angiogram and a 3D complete reconstruction confirmed atresia of the LMS. The most interesting finding was that the LAD was supported by a conus branch of the RCA antegradely, while a collateral from the left ventricular branch of the RCA was feeding the LAD from apex of the heart. There was a tight narrowing in the antegrade feeding vessel and a calcified lesion at the junction of collaterals with the LAD.