coronary anomalies are reported in 1 to 5% of coronary angiographic examinations ; they are usually asymptomatic , and are discovered accidentally.1 an anomalous origin of the left anterior descending artery ( lad ) from both right and left sinus of valsalva is considered one of the rarest anomalies.27 the following report describes a patient presenting with an acute coronary syndrome , whose coronary angiography revealed an unusual course of the lad from the right and left coronary arteries . as he stated , he had been suffering from pain without radiation for the past 30 minutes , accompanied by nausea , vomiting , and diaphoresis . he claimed that he had had a previous similar episode the day before his admission , but the pain had resolved spontaneously after about one hour . he had a history of cigarette smoking , hypertension , and respiratory disease , for which he had received no appropriate and regular medical care . no abnormal findings were detected on his physical examination ( blood pressure = 140/80 mmhg , heart rate = 60 bpm , and normal breathing and heart sounds ) . his initial electrocardiogram ( ecg ) showed a left - axis deviation and left anterior hemiblock with ischemic changes ( inverted t wave ) on its pericardial leads . he had elevated cardiac troponin , and no other significant abnormalities were detected in his blood tests . he underwent medical management for acute coronary syndrome , and his pain was reduced within his first hour of admission . echocardiography was performed for the patient and revealed a moderate left ventricular ( lv ) dysfunction with an lv ejection fraction of 40% and anterior and lateral wall hypokinesia . the patient was scheduled for coronary angiography on the following day . no chest pain or other symptoms the next morning , the ecg showed the evidence of a posterior ( lateral ) myocardial infarction ( mi ) . the selective angiography of the left coronary artery showed a critical and thrombotic stenosis on the midportion of the lad as well as a moderate lesion on the midportion of the left circumflex ( lcx ) artery ( figure 1 ) . mild stenoses were also detected at the proximal end of the lad and high obtuse marginatus . the lad ran through the interventricular groove but at the end of the midportion , it deviated from its usual course and transformed to a diagonal and supplied the anterolateral area of the lv . on the right side , the selective coronary artery injection revealed a dominant right coronary artery ( rca ) and also an anomalous coronary artery arising just after the origin the rca ( figure 2 ) . the accessory vessel ran into the left side and coursed into the mid and distal portions of the anterior interventricular groove and supplied the apex area . the culprit lesions on the lad were stented with a drug - eluting stent ( des ) , and the patient was discharged from the hospital with an acceptable condition on the fourth day of his hospitalization . different types of congenital coronary anomalies have been reported , most of them having been discovered incidentally through routine coronary angiography . a double lad is among the rarest anomalies and its incidence ranges from 0.01 to 0.03% in different studies.5 in their classification , spindola - franko described four types of double lad8 : type i  iii arises from the left side , and the last type ( apparently the rarest ) emerges from the right coronary sinus . here , we present a patient whose coronary anatomy consisted of a double lad type iv . he was admitted to our department with acute coronary syndrome , and his ecg showed evidence of anterior and posterior ( lateral ) mi . on selective coronary angiography , the lad had a thrombotic lesion on its mid course and it turned toward the anterolateral region , which is usually supposed to be supplied by a diagonal . probably the lesion at the midportion of the lad temporarily blocked the blood flow in the posterolateral area and caused the mi . on the right side , the rca was dominant , and an anomalous branch arose from the origin of the rca and coursed to the left side through the distal interventricular groove . the septal arteries branching from the anomalous vessel and also its left - sided course proved its identity as the lad . as was mentioned before , the last type of a double lad has a very low incidence . more often than not , the anomaly is suspected by visualization of an  avascular area  in the distribution of the left coronary artery and the absence of collaterals.3 in the present report , the lad changed its usual destination and ran into the posterolateral area ; and the apex , which is usually supplied by the distal portion of the lad , was supplied by the anomalous branch : the second lad . the anatomical and physiological understandings of coronary artery anomalies have both clinical and therapeutical applications . the relationship between an anomalous coronary artery , aorta , and pulmonary trunk and the possibility of the compression of the aberrant vessel by the two great arteries could be a source of different clinical presentations ( i.e. , angina , syncope , mi , and sudden cardiac death ) and sometimes mandate surgical correction . apart from the interarterial course , recent studies have shown that an intramural course could be identified in some anomalous coronary artery emerging from the opposite valsalva sinus.9 the clinical impact of such entity remains unclear . fortunately , the course of the anomalous branch usually could be detected by conventional angiography . the operator should always pay attention to the avascular region and search for a possible anomalous circulation . reported , sometimes the aberrant vessel can not be found by coronary artery angiography and multi - detector - row computed tomography may be helpful.10 beside the clinical consequences of anomalous vessels , knowing the anatomical variation is crucial at the time of surgery . grave surgical complications may occur by cutting an aberrant vessel.3 in conclusion , we presented a rare anatomical variation of the lad , known as a double lad type iv . the lad arose aberrantly from the right sinus of valsalva and supplied the area abandoned by the main lad . operators should always be aware of an anomalous circulation and seek to define its anatomical and clinical roles .
a double left anterior descending ( lad ) coronary artery emerging from the left and right coronary arteries is classified among rare coronary anomalies . 
 we herein report a 73-year - old man presenting with acute coronary syndrome ( posterolateral myocardial infarction ) . 
 he was admitted with typical chest pain , and due to his progressive ischemic changes on electrocardiography ( ecg ) and elevated cardiac enzyme , he was candidated for cardiac catheterization . 
 the coronary angiography revealed an anomalous lad from the right sinus of valsalva . 
 the unusual coronary anatomy was perfectly matched with the distribution of ischemia and its clinical evidence on echocardiography and ecg . 
 the culprit lesion was stented , and the patient was discharged in good physical condition from the hospital .