Regional Thicknesses and Thickening of Compacted and Trabeculated Myocardial Layers of the Normal Left Ventricle Studied by Cardiovascular Magnetic Resonance

Abstract

Background-We used cardiovascular magnetic resonance (CMR) to study normal left ventricular (LV) trabeculation as a basis for differentiation from pathological noncompaction. Methods and Results-The apparent end-diastolic (ED) and end-systolic (ES) thicknesses and thickening of trabeculated and compacted myocardial layers were measured in 120 volunteers using a consistent selection of basal, mid, and apical CMR short-axis slices. All had a visible trabeculated layer in 1 or more segments. The compacted but not the trabeculated layer was thicker in men than in women (PϽ0.01 at ED and ES). When plotted against age, the trabeculated and compacted layer thicknesses demonstrated opposite changes: an increase of the compact layer after the fourth decade at both ED and ES (PϽ0.05) but a decrease of the trabeculated layer. There was age-related preservation of total wall thickness at ED but an increase at ES (PϽ0.05). The compacted layer thickened, whereas the trabeculated layer thinned with systole, but neither change differed between sexes. With age, the most trabeculated LV segments showed significantly greater systolic thinning of trabeculated layers and, conversely, greater thickening of the compact segments (PϽ0.05). Total wall thickening is neither sex nor age dependent. There were no sex differences in the trabeculated/ compacted ratio at ES or ED, but the ES trabeculated/compacted ratio was smaller in older (50 to 79 years) versus younger (20 to 49 years) groups (PϽ0.05). Conclusions-We demonstrated age-and sex-related morphometric differences in the apparent trabeculated and compacted layer thicknesses and systolic thinning of the visible trabeculated layer that contrasts with compacted myocardial wall thickening. (Circ Cardiovasc Imaging. 2011;4:139-146.)

Fractal Analysis of Myocardial Trabeculations in 2547 Study Participants: Multi-Ethnic Study of Atherosclerosis

“…In keeping with previously published data (7,17), the fractal complexity of P , .001; Fig E2b [online]) and it retained association after it was adjusted for LV mass at multivariable analysis (sb= 0.044; P = .033). LV hypertrophy, defined as an increased LV mass or increased compacted wall thickness (compacted value), resulted in higher FD MaxApical (increased LV mass: sb = 0.215, P , .001; increased compacted wall thickness: sb = 0.266, P , .001; Fig E2c, E2d [online]) even after adjustment for hypertension.…”

Left Ventricular Wall Thickness and the Presence of Asymmetric Hypertrophy in Healthy Young Army Recruits

“…Dawson et al 18 have recently published wall thickness measurements in 20 cases, aged 20-to 30-year olds (10 men) that seem slightly lower than ours (eg, basal anterolateral, 9.0±2.5 versus 10.0±1.3 mm). Again this may reflect the high baseline levels of physical fitness of our army recruits or simply the low numbers in their cohort.…”

Cardiac Magnetic Resonance of Left Ventricular Trabeculation

“…5 The current work evaluated CMR findings from 120 normal healthy individuals of varying ages and both sexes to establish the norms for the compacted and trabecular layers of LV myocardium. 8 Wall thickness was not found to differ between men and women, and only in the oldest group was there evidence of significant increase in wall thickness. However, with progressive age, the trabecular layer thinned and the compact myocardium thickened.…”

“…8 The endocardial layer of the septum was least likely to demonstrate a trabecular layer, whereas the anterior and lateral segments were most likely to display obvious trabeculation. Four individuals in this noncardiomyopathic population were noted to have increased trabeculation, although this was observed at end diastole where thickness is greater than at end systole.…”

“…However, the finding that 4 of 120 individuals demonstrated increased trabeculation is consistent with the autopsy findings of Boyd et al 7 This number also is consistent with the findings of Kohli et al, 9 who noted in their heart failure population that increased trabeculation was more likely to occur in those of remote African descent. However, the ethnicity of the population studied by Dawson et al 8 was not described. 10 Together, these findings may suggest that in some circumstances, hypertrabeculation may be a normal variant.…”