RESUMO
OBJECTIVE: Although there are several echocardiographic criteria, there is not yet a general consensus about the diagnosis of left ventricular noncompaction. The current criteria are mostly based on the areas with maximal noncompaction in the heart. The echocardiographer may miss this maximal point leading to a misdiagnosis. Accordingly, we suggested a new method to measure the percentage of myocardial noncompaction using two-dimensional echocardiography. METHODS: In this study, the new method was examined on 4 noncompaction and 26 dilated cardiomyopathies, and 25 normal subjects. The percentage of noncompaction was measured at 3 levels (apical, papillary muscle and mitral valve) and averaged. FINDINGS: The mean percentages of myocardial noncompaction were 3.59±2.27, 8.86±5.52 and 34.7±26.1 in the control, dilated cardiomyopathy and noncompaction groups, respectively. A value of 17% or greater could distinguish left ventricular noncompaction from dilated cardiomyopathy with 92% specificity and 100% sensitivity and from normal subjects with 100% specificity and sensitivity. This percentage had a statistically significant association with noncompacted to compacted myocardial thickness ratio (P<0.001). CONCLUSION: This method showed good correlations with the existing echocardiographic and magnetic resonance criteria. However, it is not dependent on finding the area of maximal involvement. Being comparable to magnetic resonance imaging in accuracy, it is easier to perform and more available.
