Incremental value of contrast echocardiography in the diagnosis of left ventricular noncompaction

Contrast echocardiography with left ventricular opacification （LVO） improves the definition of endocardium in two-dimensional echocardiography （2DE）. This study was aimed to determine whether LVO offered added diagnostic value in noncompaetion of left ventricular myocardium （NCVM）. A total of 85 patients （40± 20 years, 54 males） with suspected NCVM were subjected to transthoracic 2DE and LVO, and 40 healthy volunteers were examined with 2DE and assigned as control subjects. The location of NCVM, the thickness ratio of noncompacted to compacted myocardium （NCR）, and the cavity size and ejection fraction of LV were quantified. Results revealed that NCVM was mainly located in the LV medium （53.2%）, apical （46.2%） segments, and lateral wall （39.8%）. The NCR obtained through LVO was greater than that detected through 2DE （4.2 ±1.3 vs. 3.3 ±1.2, P 〈 0.001）, and higher inter-correlations and less intra- and inter-observer variabilities were determined in the former than in the latter. The NCVM detection rates were also increased from 63.5% via 2DE to 83.5% via LVO and 89.4% via 2DE combined with LVO （2DE ＋ LVO） （P = 0.0004）. The LV cavity size was greater and the LV ejection fraction （LVEF） was lower in the NCVM patients than in the control group （P 〈 0.01）. In the NCVM group, the LV cavity size was higher and the LVEF was lower in LVO than in 2DE （P 〈 0.01）. In conclusion, contrast echocardiography contributes significant sensitivity and reproducibility to routine transthoraeic echoeardiography in NCVM diagnosis. Therefore, this technique should be clinically performed to diagnose suspected NCVM.

An eIF3a gene mutation dysregulates myocardium growth with left ventricular noncompaction via the p-ERK1/2 pathway

Left ventricular noncompaction(LVNC)is a heterogeneous disorder with undlear genetic causes and an unknown mechanism.elF3a,an important member of the Eukaryotic translation initiation factor 3(elF3)family,is involved in multiple biological processes,indluding cell prolif eration and migration during myocardial development,suggesting it could play a role in LVNC development.To investigate the association between a novel variant(C.1145 A->G)in elF3a and LVNC,and explore potential mechanisms that could lead to the development of LVNC.A novel elF3a variant,C.1145 A->G,was identified by whole-exome sequencing in a familial pedigree with LVNC.Adenovirus vectors containing wild-type elF 3a and the mutated version were constructed and co-infected into H9C2 cells.Cell proliferation,apoptosis,cell migration,and differentiation,as well as phosphorylation of ERK1/2 were stud-ied and were measured by proliferation assays,flow cytometry,real-time PCR and Westem blot,respectively.The elF3a mutation inhibited the proliferation of H9C2 cells,induced apoptosis,promoted cell migration,and inhibited the dif ferentiation of human induced plurip-otent stem cell-derived cardiomyocytes(hiPSC-CMs).The effect of the elF3a mutation may be attributed to a decrease in expression of p-ERK1/2.A novel elF3a gene mutation disrupted the p-ERK1/2 pathway and caused decreased myocardium proliferation,differentiation,acceler-ated migration.This finding may provide some insight into the mechanism involved in LVNC development.