Multidetector CT angiography characterisation of Type 4 dual left anterior descending coronary artery

Duplication of the left anterior descending (LAD) coronary artery is a rare anomaly (incidence 1%) characterized by a short LAD that terminates high in the anterior interventricular groove and a long LAD that has a proximal course outside the anterior interventricular groove and returns to the groove in its distal course. The Type 4 variant of this anomaly is extremely rare whereby a long LAD arises from the right coronary sinus with a short LAD arising from the left mainstem. We present a case of Type 4 dual LAD which was characterised with multi-detector computed tomography (CT).