Coronary flow reserve in adults with systemic right or single ventricles

Background Late failure of systemic right and single ventricles is difficult to predict. Approximately 1/3 of subjects with congenitally corrected transposition of the great arteries (ccTGA) have congestive heart failure by the fifth decade and 2/3 of subjects with ccTGA and significant associated defects have congestive heart failure by the age of 45 years. Perfusion defects have been identified at rest in 55 % of subjects with systemic right ventricles by dipyridamole sestamibi and with exercise in 45 %, which are not due to endovascular obstructive coronary disease. Subjects with perfusion defects typically have worse right ventricular function, but not always. It may be tied to coronary flow reserve and coronary mismatch in these hypertrophied ventricles. The objective of this study was to assess the technical feasibility of stress perfusion imaging by CMR and calculate coronary flow reserve in adults with systemic right or single ventricles.