CMR reference values of right ventricular volumetric variables in patients with hypoplastic left heart syndrome

Background Cardiovascular magnetic resonance (CMR) has established itself as the gold standard for serial assessment of systemic right ventricular (RV) performance but due to the lack of standardized RV reference values for HLHS patients, the interpretation of RV volumetric data in HLHS remains difficult. Therefore, this study aimed to close this gap by providing CMR reference values for the systemic RV in HLHS patients. Methods CMR scans of 160 children, adolescents and young adults (age range 2.2 to 25.2 years, 106 males) with HLHS were retrospectively evaluated. All patients were studied following total cavopulmonary connection. Short axis stacks were used to measure RV end-diastolic and end-systolic volumes (RVEDV, RVESV), stroke volume (RVSV), ejection fraction (RVEF) and end-diastolic myocardial mass (RVEDMM). Univariable and multiple linear regression analyses was performed to assess associations between RV parameters and demographic and anthropometric characteristics. Following the results of the regression analysis, reference graphs and tables were created with the LMS-method. Results Multiple linear regression analysis showed strong associations between body height and RVEDV, RVESV as well as RVSV. Age was highly associated with RVEDMM. Therefore, percentile curves and tables were created with respect to body height (RVEDV, RVESV, RVSV) and age (RVEDMM). The influence of demographic and anthropometric parameters on RVEF was mild, thus no percentile curves and tables for RVEF are provided. Conclusion We were able to define CMR reference values for RV volumetric variables for HLHS patients. These data might be useful for the assessment and interpretation of CMR scans in these patients and for research in this field.