Real-time 3-Dimensional Transthoracic Echocardiography Improves the Diagnosis of Isolated Ventricular Noncompaction

Abstract

In a 26-year-old man, an echocardiographic examination was performed for recurrent episodes of syncope. He had no familial history of cardiovascular diseases or sudden cardiac death. Traditional standard 2-dimensional (2D) echocardiography showed left ventricular (LV) dilatation with prominent trabeculations and diffuse contractility impairment (ejection fraction, 0.35) (Figure 1). Although the presence of isolated ventricular noncompaction of the myocardium (IVNC) was suspected, such findings did not fulfill the established criteria for the diagnosis as proposed by Jenni et al. 1 When transthoracic real-time 3-dimensional echocardiography (RT3DE) was performed with a model sonography system (IE33RD; Philips Medical Systems, Bothell, WA), a thickened myocardium with extensive trabeculations of both ventricles, especially in the LV apical and midventricular areas of both the inferior and lateral segments, clearly appeared, and the typical 2-layered structure of the myocardium was disclosed, with a thin, compacted outer band and a much thicker, noncompacted inner layer. The maximal end-systolic ratio of the noncompacted endocardial layer to the compacted myocardium was greater than 2 (Figure 2A). The 3-dimensional (3D) color images were able to denote the deep intertrabecular recess flow (Figure 2B). Thus, all the proposed diagnostic criteria for IVNC were fulfilled. Cardiac nuclear magnetic resonance (NMR) imaging subsequently performed confirmed the findings with the presence of extensive trabeculations and deep intratrabecular recesses involving the right ventricular apex and LV lateral and posterior walls, as shown on RT3DE (Figure 3).