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IntroductionThe genotype of symptomatic left ventricular noncompaction phenotype (LVNC) subjects with preserved left ventricular ejection fraction (LVEF) and its effect on clinical presentation are less well studied. We aimed to characterize the genetic, cardiac magnetic resonance (CMR) and clinical background, and genotype-phenotype relationship in LVNC with preserved LVEF.MethodsWe included 54 symptomatic LVNC individuals (LVEF: 65 ± 5%) whose samples were analyzed with a 174-gene next-generation sequencing panel and 54 control (C) subjects. The results were evaluated using the criteria of the American College of Medical Genetics and Genomics. Medical data suggesting a higher risk of cardiovascular complications were considered “red flags”.ResultsOf the LVNC population, 24% carried pathogenic or likely pathogenic (P) mutations; 56% carried variants of uncertain significance (VUS); and 20% were free from cardiomyopathy-related mutations. Regarding the CMR parameters, the LVNC and C groups differed significantly, while the three genetic subgroups were comparable. We found a significant relationship between red flags and genotype; furthermore, the number of red flags in a single subject differed significantly among the genetic subgroups (p = 0.002) and correlated with the genotype (r = 0.457, p = 0.01). In 6 out of 7 LVNC subjects diagnosed in childhood, P or VUS mutations were found.DiscussionThe large number of P mutations and the association between red flags and genotype underline the importance of genetic-assisted risk stratification in symptomatic LVNC with preserved LVEF.

BackgroundCardiac rotational parameters in primary symptomatic left ventricular noncompaction (LVNC) with preserved left ventricular ejection fraction (LVEF) are not well understood. We aimed to analyze cardiac rotation measured with cardiac magnetic resonance feature-tracking (CMR-FT) and speckle-tracking echocardiography (Echo-ST) in LVNC morphology subjects with preserved LVEF and different genotypes and healthy controls.MethodsOur retrospective study included 54 LVNC subjects with preserved LVEF and 54 control individuals. We evaluated functional and rotational parameters with CMR in the total study population and with echocardiography in 39 LVNC and 40 C individuals. All LVNC subjects were genotyped with a 174-gene next-generation sequencing panel and grouped into the subgroups: benign (B), variant of uncertain significance (VUS), and pathogenic (P).ResultsIn comparison with controls, LVNC subjects had reduced apical rotational degree (p = 0.004) and one-third had negative apical rotation. While the degree of apical rotation was comparable between the three genetic subgroups, they differed significantly in the direction of apical rotation (pConclusionWhile measuring cardiac rotation using both CMR-FT and Echo-ST methods, subclinical mechanical differences were identified in subjects with LVNC phenotype and preserved LVEF, especially in cases with genetic involvement.

Highlights of right ventricular characteristics of left ventricular noncompaction using 3D echocardiography.The aspects of right ventricular volumes and function investigated with 3D echocardiography in a large cohort of left ventricular noncompaction morphology (LVNC) population remains unclear.The objective of our research was to study the left (LV) and right (RV) ventricular parameters using 3D echocardiography and analyze the clinical features of a LVNC population with preserved LV ejection fraction (EF > 50 %) in comparison with healthy controls (HC).We selected 41 LVNC subjects with preserved LV function (EF: 52.91 ± 3 %, male n = 26) and without any comorbidities and compared them with an age and sex-matched HC. Three dimensional endocardial contours were evaluated to determine the following LV and RV parameters: end-diastolic (EDV) and end-systolic (ESV) volumes, stroke volume, EF, LV global longitudinal and circumferential strain and RV septal and free wall longitudinal strain.Regarding the clinical characteristics, the family involvement had a notable proportion, accounting for 51%. The EF and strain values of the LVNC population were significantly decreased in both RV and LV compared to HC. Although the LV volumes of the LVNC group were significantly elevated, the RV volumetric parameters did not differ significantly compared to controls. We found significant correlations between LV and RV volumetric and functional parameters and linear regression models showed that LV EDV and LV ESV determined the RV volumetric values.While the alteration and relationship of the RV parameters may represent the potential of biventricular involvement, clinical characteristics of the LVNC group underlines the necessity of monitoring this population, even with preserved EF.