A rare case of premature and parallel posterior descending artery and posterior left ventricular branch with conus crossing the right ventricular outflow tract causing provocative coronary ischemia

We report a rarely encountered case of premature and parallel posterior descending artery (PDA) and posterior left ventricular branch (PLVB) in a case of 22-year-old male with effort angina Class II for the last 6 months in whom treadmill test (TMT) was strongly positive for provocative coronary ischemia with structurally normal heart and good biventricular function. Interestingly, all the coronaries were normal without any obstructive coronary lesion. Paradoxically, those two prematurely separating branches were small making the distal right coronary artery (RCA) territory relatively ischemic attributing toward a strongly positive TMT. Small anomalous coronary is a well-known cause of demand ischemia, but our case is unique to describe small prematurely originating PDA and PLVB were the culprit behind coronary ischemia in a young male without conventional risk factors. Furthermore, much premature separation of PDA and PLVB is rarely encountered in routine clinical practice, and recognition of this anomaly is important as it should not be mistaken for duplicate RCA, dual RCA, or split RCA. Our case is also unique to illustrate the association of the premature and parallel PDA and PLVB with a conus crossing the right ventricular outflow tract without the presence of structural heart disease.