Anomalous Right Coronary Artery From the Pulmonary Trunk In very rare cases, the RCA may arise from the pulmonary trunk (ARCAPT) This occurs an estimated 10 times less frequently than ALCAPT Patients with ARCAPT tend to have less severe symptoms and can present later in childhood or into adulthood However, they are still at risk for sudden cardiac death and myocardial ischemia When ARCAPT is identified, the treatment is typically surgical correction in a manner similar to repairing ALCAPT.34 Anomalous Aortic Origin of a Coronary Artery Anomalous aortic origin of a coronary artery (AAOCA) occurs when either the RCA arises from the left sinus of Valsalva (AAORCA) or the left coronary artery arises from the right sinus of Valsalva (AAOLCA) The proximal course of the anomalous coronary artery determines the potential risk of sudden cardiac death and thus the clinical significance of the anomalous coronary artery Courses anterior to the pulmonary trunk, or posterior to the aorta, are generally considered benign If the anomalous coronary artery, typically a left coronary artery, courses through the infundibular septum (intraseptal or intraconal course) (Fig 46.17), it is also generally considered benign Interarterial AAOCA occurs when the anomalous coronary artery courses between the aorta and the pulmonary trunk This course has been associated with an increase in the risk of sudden cardiac death, particularly in young, athletic, otherwise healthy patients, with a significantly greater risk for AAOLCA than AAORCA The prevalence of AAOCA ranges from 0.1% to 0.7% of the population, depending on the modality used and definition of coronary anomaly.35,36 In other studies, AAORCA has been noted to be anywhere from three to seven times more common than AAOLCA.36,37 FIG 46.17 Magnetic resonance image showing a common origin of the right coronary artery (RCA) and left anterior descending (LAD) from the left sinus of Valsalva (left) The LAD has a course directed posterior (left) and inferior (right) to the right ventricular outflow tract with a course through the infundibular septum Ao, Aorta; LCA, left coronary artery; PA, pulmonary artery Pathophysiology The interarterial course of the anomalous coronary artery, commonly intramural, is associated with an increased incidence of sudden cardiac death.38–42 Sudden death seems most likely to occur during or just after maximal exertion in young athletes, typically in the teenage and early adulthood years Although both AAOLCA and AAORCA can be associated with sudden death, AAOLCA confers a much higher risk than AAORCA It is hypothesized that sudden cardiac death occurs due to a mismatch between myocardial oxygen demand and myocardial oxygen delivery It is thought that the myocardial oxygen delivery through the anomalous coronary artery may fail to increase in relation to increased myocardial oxygen demand or may even decrease during exertion This decrease in coronary blood flow is probably the result of one or many anatomic and physiologic factors, including: an initial intramural course of the anomalous coronary that leads to variable degree of stenosis and hypoplasia that can be stretched out and flattened as the aorta dilates during exercise; an acute angle take-off from the aorta with a slit-like orifice; vasospasm of the anomalous vessel; intussusception of the proximal intramural segment; and myocardial scar that can lead to arrhythmogenic foci This can result in myocardial ischemia leading to limited cardiac output or ventricular tachyarrhythmias, or both.43 Clinical Presentation Commonly, patients with AAOCA are asymptomatic, and the coronary arterial anomaly is incidentally found when an echocardiogram is performed for an unrelated reason, such as a cardiac murmur or family history of congenital heart disease.37 Rarely, patients present after an episode of aborted sudden cardiac death Others may have symptoms, usually occurring during exercise, such as chest pain, palpitations, dizziness, presyncope, or syncope Although these symptoms may not be pathophysiologically related to the anomalous coronary artery, they typically prompt referral to a pediatric cardiologist, who may obtain an echocardiogram identifying the abnormal coronary artery ... symptoms may not be pathophysiologically related to the anomalous coronary artery, they typically prompt referral to a pediatric cardiologist, who may obtain an echocardiogram identifying the abnormal coronary artery