Refinement of echocardiographic criteria for left ventricular noncompaction

BackgroundLeft ventricular hypertrabeculation/noncompaction (LVNC) is a cardiac abnormality whose echocardiographic criteria are still controversial. Cooperation between echocardiographic laboratories may contribute to uniformly accepted criteria, as illustrated by the following pilot study.Methods and resultsEchocardiograms proposed for inclusion into a registry were reviewed. Three experts with 17-26 years experience with LVNC agreed on a common definition of LVNC: 1. > 3 prominent trabeculous formations along the left ventricular endocardial border visible in end-diastole, distinct from papillary muscles, false tendons or aberrant bands; 2. trabeculations move synchronously with the compacted myocardium, 3. trabeculations form the noncompacted part of a two-layered myocardial structure, best visible at end-systole; and 4. perfusion of the intertrabecular spaces from the ventricular cavity is present at end-diastole on color-Doppler echocardiography or contrast echocardiography.During 3 sessions 115 cases (37% females, mean 57 years) were reviewed. Eleven patients(18% females, mean 60 years) were excluded because of < 4 trabeculations(n = 5), lack of a two-layered myocardial structure(n = 1) and poor image quality(n = 5). The observers agreed on inclusion or exclusion in all cases. Consensus was achieved that measurements of the thickness of the myocardial layers, and calculation of the noncompacted:compacted ratio is not feasible due to a lack of uniformly accepted standards for measurements.ConclusionsWhen diagnosing LVNC, end-systolic as well as end-diastolic images have to be considered. The presence of more than three trabeculations as well as a two-layered myocardium are required. Since these criteria are not anatomically controlled, a comparison of echocardiographic images with pathoanatomic findings for assessing sensitivity and specificity is urgently needed.