Noncompaction in Healthy Subjects, Dilated and Hypertrophic Cardiomyopathy, and Neuromuscular Disorders Is the Same Entity

With interest we read the article by Khosroshahi et al. about a novel method for quantification of left ventricular hypertrabeculation/noncompaction (LVHT) using two-dimensional echocardiography in children (1). We appreciate their efforts to contribute to an improvement and unification of echocardiographic diagnostic criteria for LVHT, which is urgently needed. Concerning their proposed method, we have the following questions and concerns: We are confused about the echocardiographic views in which the measurements should be performed. In the methods it is described that the percentages of LVHT were measured at three short-axis levels. However, in the mentioned figure, only the apical level is a short-axis view. At the papillary level, the outline of the left ventricle is oval and thus not a short-axis view. At the mitral valve level, the section is a modified apical 4 -chamber view. Additionally we want to ask how it was possible to exactly delineate the left ventricular cavity from the surface of the trabeculations, a border which is extremely irregular and variable and thus difficult to determine even on a two-dimensional plane? The examples given in the mentioned figures showed that the tracing lines were coarse and did not follow each of the trabeculations. Additionally, it remains uncertain how the area was measured in the original article number 1A and 1B since the tracing lines cannot be seen in the region of the posterior wall. Thus we want to know if the authors assessed inter- and intraobserver variability of the measurements.