Anatomy and Development Even in the normally structured heart, the coronary arteries can have multiple anomalous origins and epicardial courses.1 However, such lesions involving the coronary arteries are also frequent when the heart is congenitally malformed Patterns of origin from the aortic valvar sinuses other than normal are particularly common in lesions such as transposition or the Taussig-Bing variant of double-outlet right ventricle An abnormal epicardial course is a significant finding in the setting of tetralogy of Fallot These aspects are addressed in the relevant chapters in this book pertaining to these lesions This chapter is concerned with abnormal patterns found in individuals having concordant atrioventricular and ventriculoarterial connections and with intact septal structures The coronary arterial malformation can be the major lesion in this setting, such as when one, or rarely both, of the coronary arteries arises from the pulmonary trunk rather than the aorta However, not all the variations are overtly of clinical significance Even some of the arrangements known to cause sudden death can remain asymptomatic until underscoring the catastrophic event It is a truism, nonetheless, that diagnosis is enhanced by knowledge of the possible arrangements and their potential significance At present, there is no consensus as how best to classify the multiple variations The old approach, in which lesions were considered to be major or minor,2 has foundered simply because many of the allegedly major variations fail to produce symptoms during life A simple categorization, from the anatomic stance, recognizes first the anomalous sinusal origin of an artery, with subsequent attention being paid to any anomalous epicardial course, not forgetting other abnormal situations, such as myocardial bridging, abnormal communications, duplication of arteries, and a solitary coronary artery (Box 46.1) Box 46.1 Anatomic Variations in Origin and Course of the Coronary Arteries Ectopic Origin of Coronary Artery ■ From pulmonary trunk ■ From right pulmonary artery ■ From left pulmonary artery ■ From brachiocephalic artery Anomalous Aortic Sinusal Origin ■ Right coronary artery arising from sinus 2 ■ Main stem of left coronary artery arising from sinus 1 ■ Circumflex artery arising from sinus 1 ■ Anterior interventricular artery arising from sinus 1 Anomalous Epicardial Course ■ Retro-aortic ■ Interarterial ■ Prepulmonary ■ Intramural Solitary Coronary Artery ■ Solitary coronary artery from sinus 1 ■ Solitary coronary artery from sinus 2 Abnormal Fistulous Connections ■ Connections with a cardiac cavity ■ Coronary arteriovenous fistulas ■ Coronary to extracardiac arterial or venous connections Duplication of Coronary Arteries ■ Duplication of major epicardial coronary artery ■ Woven coronary artery Clinically, particular congenital abnormalities of the coronary arteries can result in sudden cardiac death, a dilated, poorly functioning ventricle due to myocardial infarction, or chronic ischemia due to a myocardium that is dependent on collateral vessels Those lesions most at risk include an anomalous origin of the left main coronary artery from the pulmonary artery trunk, some variations of anomalous aortic origin of the coronary artery from the aorta (Table 46.1), and coronary ostial atresia These risks are discussed later with the clinical information on each lesion Table 46.1 Common Anomalous Origins of the Coronary Arteries From the Aorta and Their Association With Sudden Cardiac Death Anomaly Anomalous aortic origin of the right coronary artery from the left sinus with an intramural course Anomalous aortic origin of the left main coronary artery from the right sinus with an intramural course Anomalous aortic origin of the left main coronary artery from the right sinus with intraseptal/intraconal course Association With Sudden Cardiac Death? Yes, but rare; greatest risk in young athletes Yes; greatest risk in young athletes None reported Ectopic Origin of the Coronary Arteries Coronary arteries can rarely arise from a brachiocephalic artery (Fig 46.1).3 However, the most significant ectopic origin is when one or more of the coronary arteries arises from the pulmonary trunk, or from the right or left pulmonary artery Either the left coronary artery or right coronary artery (RCA) can arise from the pulmonary trunk,4 or very rarely both coronary arteries.5 Anomalous origin of the left coronary artery is most frequent (Fig 46.2), producing Bland-White-Garland syndrome