Can We Diagnose Isolated Left Ventricular Noncompaction by the Morphology?

Abstract

Isolated left ventricular noncompaction (LVNC) is a congenital disorder, but sporadic cases in adult are reported. Diagnosing LVNC depends on morphology of the endocardium; marked trabeculation with deep recesses, which may be a non-specific consequence of LV dysfunction. Methods and Results: 172 patients with LVEF≤40% out of consecutive 8265 echocardiographic studies were evaluated (mean age 62). They comprised 58 cases of dilated cardiomyopathy (DCM), 66 ischemic, and 21 valvular heart disease. Trabeculation and thickness of compacted myocardium were quantified in 2-dimensional echocardiographic images and expressed in a X-to-Y ratio (X=compacted myocarduim, Y=sum of compacted and noncompacted myocardium) as reported. Increased trabeculation was observed in the studied patients; Mean X-to-Y ratio was 0.51 (normal;>0.8). The X-to-Y ratio was not significantly different between the subgroups with different etiologies, but was correlated with left ventricular dimension and LVEF (P<0.05). Marked trabeculation with a X-to-Y ratio≤ 0.2, typical for LVNC, was seen in 5; 4 in the DCM group, 1 in the valvular group (2.9%). The one in the valvular group had less trabeculation in a past study before the onset of heart failure. Conclusion: Increased endocardial trabeculation is commonly seen in patients with LV dysfunction regardless of their etiology, suggesting that prominent trabeculation may partly be a result rather than a cause. Diagnosis of LVNC in adults should be carefully done.