One down, one to go: coronary anomaly dual LAD blood supply with worsening chronic stable angina and 100% occluded left short LAD type IV variant.

Although rare, usually asymptomatic, and without concurrent disease, dual left anterior descending arteries (LAD) poses great challenges. We describe a 55-year-old male with no history of coronary disease, who presented with worsening substernal chest pain with exertion, and was ruled out for myocardial infarction. On left heart catheterization and subsequent computed tomography angiogram, he was determined to have a dual LAD with a long LAD emerging from the right coronary artery. Moreover, this long LAD gave collaterals to a native long diagonal that ran parallel to this vessel from the left system and was chronically occluded. The long LAD, consistent with type IV classification, traveled in the anterior intraventricular groove to supply left ventricular myocardium; the chronically occluded long left native diagonal supplying lateral walls and apex is a unique variant. It is important to be aware of these anomalies to establish correct diagnoses and determine treatment options.