An isolated single coronary artery (SCA) is a rare anomaly. A SCA originating from the left sinus of Valsalva is even rarer than one arising from the right. Most patients with a congenital coronary artery anomaly are asymptomatic. Herein, we report an extremely uncommon variant, where the right coronary artery arose from the distal segment of the left circumflex artery with slow coronary flow leading to myocardial ischemia.