Rare Uhl’s Anomaly: The Role of Multiparametric CMR in Morphologic, Tissue, and Hemodynamic Assessment

Description of Clinical Presentation: We report the case of a 10-year-old girl admitted for congestive heart failure in the setting of a previously undefined cardiopathy. Her history included recurrent respiratory infections, reduced exercise tolerance, and a prior diagnosis of tricuspid regurgitation treated with oral diuretics. On admission, she presented with tachycardia and a mild systolic tricuspid regurgitation murmur. Echocardiography revealed extreme right ventricular (RV) dilatation, severe tricuspid regurgitation, right atrial enlargement, and preserved left ventricular (LV) systolic function. Family history was remarkable for first-degree parental consanguinity and the death of a sibling in early infancy due to an uncharacterized condition, raising suspicion for a congenital etiology. Given these findings, a cardiogenetic evaluation and advanced imaging with cardiac magnetic resonance (CMR) were performed.

Diagnostic Techniques and Their Most Important Findings: CMR demonstrated extreme RV dilatation (RVEDVi 618 mL/m², RVEDV/LVEDV ≈16) with global wall thinning, severe systolic dysfunction (RVEF 13%), and marked annular dilation leading to severe tricuspid regurgitation (regurgitant fraction ≈80%). RV myocardium appeared markedly thinned with diffuse linear late gadolinium enhancement (LGE), extending to the septal side of the RV, consistent with fibrotic replacement and strongly suggestive of Uhl’s anomaly (Figure 1). LV dimensions were preserved, but global systolic function was mildly–moderately impaired (LVEF 40%). Notably, there was a marked diastolic leftward shift of the interventricular septum (“D-shape”), reflecting abnormal ventricular interdependence (Figures 2 and 3). Cardiac catheterization excluded significant pulmonary hypertension (pulmonary artery pressures and resistances within normal limits, PVR < 3WU) but showed a markedly elevated LV end-diastolic pressure, indicating impaired LV compliance related to RV volume overload.

Learning Points from this Case: Uhl’s anomaly is an exceptionally rare congenital disorder characterized by the partial or complete absence of the RV myocardium. This case highlights how massive RV dilatation not only produces severe right-sided dysfunction but also exerts a profound impact on LV diastolic mechanics. The diastolic septal inversion observed on CMR did not reflect pulmonary hypertension, but rather resulted from RV volumetric overload. The elevated LV end-diastolic pressure measured during catheterization was consistent with this interpretation, impairing late diastolic LV filling during atrial systole. In extreme forms of RV disease, such interdependence can compromise LV filling, underscoring the importance of considering this mechanism to correctly interpret septal motion abnormalities and to ensure appropriate patient management; in the present case, the severity of biventricular compromise ultimately required cardiac transplantation. This case further emphasizes the unique role of multiparametric CMR, combining morphology, tissue characterization, and hemodynamic insights in rare congenital disorders.

Figure 1. Late gadolinium enhancement (LGE) images in four-chamber (a), short-axis (b), and RV two-chamber (c) views demonstrate the extremely thinned right ventricular myocardium with diffuse linear LGE, consistent with fibrotic replacement in Uhl’s anomaly.
Figure 2. Cine bSSFP images across different cardiac phases in four-chamber (top row) and short-axis (bottom row) views demonstrate a marked diastolic leftward shift of the interventricular septum (arrowheads in the four-chamber view and arrows in the short-axis view), resulting in the characteristic left ventricular “D-shape” and indicating abnormal ventricular interdependence.
Figure 3. Cine bSSFP images in end-systolic (top row) and end-diastolic (bottom row) phases at basal, mid-ventricular, and apical levels of the short-axis view demonstrate a consistent diastolic leftward septal shift across all sections, producing a uniform “D-shape” configuration of the left ventricle and highlighting the extent of right ventricular volumetric overload.