Isolated Left Ventricular Noncompaction Enhanced by Echocontrast Agent
A 58-year-old woman presented to our emergency room with chest discomfort and syncope. Prior to admission, a transthoracic echocardiogram performed at another laboratory showed an apical lateral wall motion abnormality with decreased left ventricular systolic function (Figure 1 and Data Supplement Movie I) and a persantine cardiolite scan showed reversible defect in the lateral wall. While in the hospital, the patient continued to have chest pain. Diagnostic cardiac catheterization showed normal epicardial coronary arteries, but the contrast left ventriculogram revealed an unusual apical wall abnormality (Figure 2 and Data Supplement Movie II). A transthoracic echocardiogram with intravenous echo contrast enhancement subsequently showed prominent trabeculations and deep intertrabecular recesses that primarily involved the distal lateral wall at the apex (Figure 3 and Data Supplement Movie III). A cardiac magnetic resonance imaging scan subsequently confirmed the diagnosis of isolated left ventricular noncompaction (Figure 4 and Data Supplement Movie IV).
Isolated left ventricular noncompaction is a rare type of cardiomyopathy not yet “classified” by the World Health Organization. It is thought to be caused by arrest of the normal process of endomyocardial morphogenesis during embryonic development. Clinical manifestations are highly variable and range from no symptoms to systolic and diastolic heart failure, arrhythmias, and systemic thromboemboli. Treatment of isolated left ventricular noncompaction focuses on these 3 clinical manifestations.
Two-dimensional and color Doppler echocardiography has been the diagnostic procedure of choice, but the diagnosis is often missed because of the limitations of near field imaging, especially in cases with focal involvement such as the case presented here. Echo contrast imaging improves the endocardial border definition and could improve the detection of this rare type of cardiomyopathy, which could otherwise be misdiagnosed.
Dr Howard Leong-Poi has received research support from Bristol-Myers Squibb Medical Imaging. The remaining authors report no conflicts.
The online-only Data Supplement, which contains movies, can be found at http://circ.ahajournals.org/cgi/content/full/116/4/e90/DC1.