Total occlusion of the circumflex artery with collateral supply from the conus artery.

The conus artery has long been recognized as an important source of collateral blood supply to a significantly diseased left anterior descending artery. This artery which arises 50% of the time from a separate orifice in the right sinus of Valsalva may also provide collateral circulation to a diseased right coronary artery. To date, there have been no reported instances of the conus artery supplying collateral flow to a totally occluded circumflex artery. In this report we describe such a case in a patient with severe three vessel disease. The implications of such a finding in patient management are also discussed.