Diagnosis of Isolated Noncompaction of the Myocardium by Magnetic Resonance Imaging

Abstract

A 15-year-old asymptomatic, physically active man, who had a history of syncope at the age of 12 and a family history of arrhythmogenic right ventricular dysplasia (father), presented for evaluation. Physical examination revealed no abnormal findings. The ECG demonstrated sinus rhythm, Ϫ20°QRS, incomplete right bundle-branch block, and left ventricular hypertrophy; the 24-hour Holter monitoring excluded ventricular arrhythmias. Normal exercise capacity (15 metabolic equivalent) without arrhythmias was confirmed by treadmill exercise testing. The echocardiogram showed apical hypertrophy of the left ventricle and an interatrial pseudo-aneurysm without shunt ( Figure 1). To rule out right ventricular dysplasia, an ECG-gated cardiac MRI was performed. Surprisingly, the "black-blood" cardiac MRI examination demonstrated thickened apical segments of the myocardium and areas suspicious for deep intertrabecular recesses that were not observed at echocardiography (Figure 2). The diagnosis of isolated left ventricular noncompaction was confirmed through the use of a high-resolution cine gradient echo sequence that is particularly sensitive to slow flow (Figure 3). The presence of deep recesses filled with blood and trabeculations of the myocardium were evident during diastole, whereas during systole, the recesses collapsed and the myocardium appeared compacted. The right ventricle was normal.Noncompaction of the ventricular myocardium is a rare congenital cardiomyopathy characterized by an altered structure of the myocardial wall resulting from intrauterine arrest in normal endomyocardial embryogenesis and compaction of the myocardial fibers in absence of any coexisting congenital lesions. The morpho-pathological findings consist of multiple, prominent myocardial trabeculations and deep intertrabecular recesses communicating with the left ventricular cavity. The clinical manifestations are not specific for this cardiomyopathy and include heart failure, tachyarrhythmias (which predispose to sudden death), and cardioembolic events.This case provides evidence of the potential of cardiac MR imaging in the evaluation of the right ventricle and of cardiac anomalies such as noncompaction.

Isolated Ventricular Non-Compaction in Adults With Idiopathic Cardiomyopathy: Cardiac Magnetic Resonance and Pathologic Characterization of the Anomaly

“…These findings correlated well with the morphopathologic findings. 2,4,9 Only CMR, however, accurately identified the characteristic features of isolated non-compacted myocardium, including the alterations in myocardial architecture and the prominent and excessive trabecular meshwork. 6 Prominent trabeculations can also be seen in healthy hearts or in hearts with dilated, valvular or hypertensive cardiomyopathy.…”

“…8 The diagnosis has been based on findings of Doppler 2-dimensional echocardiography (2D-echo) and cardiac magnetic resonance imaging (CMR), which can identify endomyocardial thickening and abnormal trabeculations. 4,9 Severe isolated ventricular non-compaction is associated with a poor prognosis and a high mortality rate. 2,5 This report describes 3 cases of severe, isolated ventricular non-compaction in adults who ultimately required heart transplantation.…”

Left ventricular non-compaction: Genetic heterogeneity, diagnosis and clinical course

“…Magnetic resonance imaging is being increasingly employed in the diagnosis of LVNC, [48] (Fig. 5) but as is the case with echocardiography, the interpretation of findings rests heavily on the experience of the operator.…”

End-stage Cardiac Failure Caused by Isolated Ventricular Non-compaction: Cardiac Transplantation in a 5-Year-Old Boy

“…5 Adults tend to have overt heart failure and show increased incidence of ventricular arrhythmias and of embolic events. 4,10 In an adult population with IVNC, Oechslin et al 4 have reported 4 cases that required heart transplantation for end-stage cardiac failure. Ichida et al 5 looked at 27 pediatric patients with IVNC and described 3 patients who experienced progressive left ventricular dysfunction during a median follow-up of 6 years.…”