Non compaction cardiomyopathy (NC) is a rare condition, affecting less than 0,05% of general population. It may be seen isolated, or associated with other congenital heart malformations, specially valvular, such as the Ebstein’s anomaly.
A 46-year-old woman was referred to our center because of right heart failure semiology and a presystolic murmur at left sternal edge. Previous clinical history showed stage 3 chronic kidney disease and paroxysmal atrial fibrillation, along with the implant of a tricuspid annuloplasty ring because of an Ebstein’s-like anomaly. The transthoracic echocardiogram (TTE) revealed persisting moderate tricuspid regurgitation (TR) despite the ring, besides significant left ventricle (LV) trabeculation. To better characterise both the valvular regurgitation and the myocardial involvement, cardiac magnetic resonance (CMR) was requested. The study was performed using a 1,5 T scanner. Ventricle anatomy, volumes, mass and ejection fraction were assessed using the short, long and outflow tract axis steady-state free-precession (SSFP) imaging. Tricuspid regurgitant volume (TRV) and regurgitation fraction (TRF) were calculated indirectly combining cine and phase contrast sequences. Gadolinium enhacement was not conducted because of renal dysfunction. Moderate tricuspid regurgitation (TRV: 17,9 mL; TRF 24%) due to incompetent ring was confirmed. Neither left nor right ventricle (RV) were dilated: LV end-diastolic volume (LVEDV) 58 ml/m²; LV end-systolic volume (LVESV) 23 ml/m²; RVEDV 70,7 ml/m²; RVESV 22,3 ml/m². LV end-diastolic non-compacted to compacted thickness ratio (NC:C) was measured: 3.8. Trabeculated left mass was 35%. Mid anterior, mid anterolateral and apical anterior and lateral were the affected segments. CMR imaging allowed the characterization of a remarkable hypertrabeculated RV, unnoticed in the TTE study (Picture 1. A,B: horizontal long axis and short axis SSFP cine images, biventricular hypertrabeculation. C: RV outflow tract view: annuloplasty ring, vast trabeculation, thin compacted layer).
The association between Ebstein’s anomaly and LVNC has been reported, although it is unknown if this is a cause-and-effect relationship or not. Besides, biventricular NC incidence in this context has not been exactly described as diagnostic criteria for RVNC are not well defined. Multimodality imaging examination to try to characterise precisely this combination is needed.