the prevalence of congenital anomalies of the coronary arteries ( caas ) is reported to be approximately 0.2 - 1.4% in the general population . of them , . it may be benign appearing as an incidental finding on routine coronary angiogram or sometimes , may be complicated with atherosclerosis and present with spectrum from stable coronary artery disease to acute coronary syndrome with stormy course . a 34-year - old male was admitted to emergency department with retrosternal chest pain at rest of 4 h duration with perspiration and occasional dizziness . electrocardiogram showed st elevation in leads ii , iii , and avf , reciprocal changes in leads i and avl , and complete heart block ( fig . 1a ) . he was preloaded with 325 mg aspirin , 40 mg rosuvastatin and 60 mg prasugrel along with iv fluids and vasopressors . the left coronary arteries were of normal origin and distribution with normal flow in left anterior descending artery ( lad ) and circumflex artery ( lcx ) . rca was hooked with a 3.5 judkin s right 6 f guiding catheter ( medtronic , usa ) . lesion was crossed with a 0.014 " 140 cm fielder fc wire with help of a finecross microcatheter ( asahi , japan ) ( fig . 3 ) . once parked distally , finecross was advanced and fielder fc was exchanged with a 0.014 " 140 cm bmw wire ( abott , usa ) . distal tip of bmw wire was not in typical distribution of rca but as we encountered , no resistance and movement of distal tip along with the feel was sufficient to say that it was in true lumen ( fig . we treated him with upstream tirofiban ( 10 g / kg/3 min ) and dilated with a 2  10 mm minitrak balloon ( abott , usa ) ( fig . contrast injection this time showed one large branch going beyond crux giving posterior descending artery and two parallel large coronary arteries distally . lesion was stented with a 3.5  23 mm xience prime drug - eluting stent ( abott , usa ) ( fig . 4c ) and post - dilated by a 3.5  10 minitrak nc balloon ( abott , usa ) achieving timi iii flow ( fig . control coronary angiogram demonstrated atypical double rca as there were two parallel coronary arteries distal to the occlusion ( fig . stay , complete heart block reverted to 2:1 atrioventricular block , and then went back to normal sinus rhythm on third day ( fig . he was discharged in stable condition with dual antiplatelets , statin , and beta blocker . ( a ) electrocardiogram showing complete heart block ; ( b ) 2:1 atrioventricular block ; ( c ) wenckebach phenomenon ; ( d ) normal sinus rhythm . ( a ) bmw guide wire parked distally after exchange with feider wire ; ( b ) lesion being predilated with 2  10 minitrak balloon ; ( c ) stent being deployed across the lesion ; ( d ) stent being post - dilated with non - compliant balloon . double rca is a very rare coronary anomaly , whose true definition and correct diagnosis remain controversial [ 2 , 3 ] . sometimes , it is very difficult to distinguish double rca with single orifice from rca which has a high take - off of a large right ventricular artery . right anterior oblique ( rao ) view may be helpful in differentiating double rca from a large right ventricular branch as it provides better demonstration of artery courses in such circumstances . sato et al have proposed that double rcas are defined when they supply the blood to the inferior left myocardium , thus both of the rcas should course downwardly to reach the interventricular sulcus whether or not they cross the crux . the first report about double rca anomaly in the literature was by barthe et al . after the origin of a conus artery and a ventricular branch , the most anterior rca descended toward the acute margin of the heart and terminated in a small posterior descending artery . the second rca terminated in a small posterior descending and posterolateral branches . in our cases , both rcas were almost identical in size and both gave rise to a pda . by using this reasonable classification , we diagnosed our case as atypical double rca . since the first report , this rare anomaly has been accepted as a benign entity . however , its involvement with atherosclerosis has also been reported , where revascularisation had been performed either by coronary artery by - pass surgery or elective percutaneous coronary intervention ( pci ) [ 7 , 8 ] . rohit et al have reported primary pci of double rca presenting with acute inferior wall infarction but there was no rhythm disturbance in their case . to the best of our knowledge and after extensive search in medical literature , we are reporting for the first time , double rca presenting with complete heart block with cardiogenic shock where primary pci was performed . rca maintains a course in the atrioventricular groove and forms the uppermost portion of the posterior descending branch . the length of each of the two posterior descending branches varies from patient to patient : in our patient , both the branches were large ; therefore , their occlusion was responsible for the symptoms .