An 80-year-old man with no significant medical history was referred to our department for cardiovascular magnetic resonance (CMR) because of an abnormal echocardiogram. The patient's left ventricular ejection fraction was 0.38. The CMR revealed prominent, deep trabeculae arising from the interventricular septum (Fig. 1), with associated thinning and hypokinesia of the anterior, apical, and distal inferior walls. These trabeculae extended to the anterior and lateral walls, resembling the stripes of a tiger. Late gadolinium-enhancement imaging showed viable myocardium and absent myocardial hyperenhancement (Fig. 2).
Fig. 1 Balanced gradient-echo image of the left ventricle. A) Four-chamber orientation shows prominent and deep trabeculae arising from the interventricular septum. B) Left ventricular outflow tract orientation shows trabeculae that extend from the anteroseptum toward the inferolateral wall, resembling the stripes of a tiger.
Fig. 2 Late gadolinium-enhancement images in A) 4-chamber and B) left ventricular outflow tract orientations show viable myocardium and the absence of hyperenhancement.
Comment
Noncompaction cardiomyopathy is a congenital condition characterized by prominent trabeculation in the left ventricle that might be attributable to the arrested compaction of loose, interwoven myocardial fibers during intrauterine life or to the abnormal persistence of the trabecular layer.1 It can lead to heart failure, atrial and ventricular arrhythmias, and thromboembolic events.2 Noncompaction usually involves the apical, lateral, and anterior walls and appears as a layer of finely trabeculated myocardium adjacent to a layer of compacted myocardium3; a typical example is shown in Figure 3. In our patient, the very prominent trabeculation of the septum was distinctly unusual and could have been due to a rare genetic variant of noncompaction. To our knowledge, only 1 other similar variant has been reported.4 Cardiovascular magnetic resonance can be useful for delineating atypical variants of noncompaction and may show noncompaction to be more common than previously believed.
Fig. 3 A typical example of noncompaction in a different patient. Balanced gradient-echo image (4-chamber orientation) shows left ventricular noncompaction with trabeculation involving the distal half of the left ventricle.
Acknowledgment
Nicole Stancel, PhD, ELS, provided editorial assistance with this manuscript.
Footnotes
Address for reprints: Benjamin Y.C. Cheong, MD, FRCP (Edin), Department of Diagnostic & Interventional Radiology, MC 2-270, Texas Heart Institute at St. Luke's Episcopal Hospital, 6720 Bertner Ave., Houston, TX 77030, E-mail: bcheong@sleh.com
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