Histopathological features of delayed enhancement cardiovascular magnetic resonance in isolated left ventricular noncompaction.

To the Editor: Contrast-enhanced magnetic resonance imaging (CE-MRI) is an important imaging modality for the evaluation of isolated left ventricular noncompaction (LVNC). The delayed gadolinium enhancement has been identified in both compacted and noncompacted myocardium, and it may correlate with the clinical severity of LVNC (1–3). However, little is known about the histological basis of myocardial delayed enhancement in LVNC patients, especially in the noncompacted myocardium. In this study, we made a comparison between the myocardial delayed enhancement and histological findings in a patient with LVNC who underwent heart transplantation. A 27-year-old man was admitted with exertional dyspnea. Chest roentgenogram showed cardiomegaly with pulmonary venous congestion, and the cardiothoracic ratio was 72%. The LVNC was diagnosed by echocardiography, and the ratio of the noncompacted to compacted myocardium was 3.2. The left ventricular end-diastolic dimension was 63 mm, and left ventricular ejection fraction was 18%. Contrast-enhanced MRI was performed, and deep intertrabecular recesses presented in the apical and lateral wall of the left ventricle. The near-transmural delayed enhancement occurred in the interventricular septum, and diffuse enhancement presented in the free wall and the trabecular meshwork region of the left ventricle. In addition, CE-MRI detected the left ventricular thrombus and pericardial and pleural effusions. One week later, informed consent was obtained, and heart transplantation was carried out. The pathological findings of the explanted heart were compared with the previous in vivo CE-MRI (Fig. 1). In the compacted myocardium with delayed enhance-