It is difficult to quantitate the ab- solute risk of SCD associated with anomalous aortic origin of the left coronary from the right sinus, and data demonstrating that surgery ameliorates the SCD risk have not been published. Until studies suggest otherwise, limited data and expert con- sensus suggest that it is reasonable that adults with this malformation should undergo surgical unroof- ing unless there are extenuating circumstances that would make surgery high risk. 3. In patients with ventricular arrhythmias presumed related to ischemia caused by anomalous origin of a coronary artery, repair is an option to alleviate the ischemia and presumably mitigate the recurrence of ventricular arrhythmias. However, care should be individualized, as there may be other factors (eg, CAD, cardiomyopathy, residual ischemia) contrib- uting to ventricular arrhythmias that warrant con- tinued vigilance and additional therapy. 4. Anomalous aortic origin of the right coronary from the left sinus is more common than anomalous aortic origin of the left coronary from the right sinus. The risk of SCD with the former malformation is difficult to quantitate. There is some physiological rationale to believe that asymptomatic patients without ev- idence of compromised blood flow would benefit from unroofing, but there are not data to demon- strate that surgical interventions alter the risk of SCD. Thus, watchful waiting may be an appropriate course as well, particularly for a patient with an anomalous right coronary arising from the left sinus. 4.4.7.3. Anomalous Coronary Artery Arising From the PA Recommendations for Anomalous Coronary Artery Arising From the PA Referenced studies that support recommendations are summarized in Online Data Supplement 51. 