Left Ventricular Asynchrony Caused by an Intramuscular Lipoma
Computed Tomographic and Magnetic Resonance Detection
Routine chest x-ray of a 67-year-old woman revealed a mass contiguous with the cardiac silhouette. Echocardiogram located the mass in the anterior wall of the left ventricle. Magnetic resonance (MR) and computed tomography (CT) imaging showed a solitary mass with a clear margin resembling a balloon arising from myocardium of the left ventricle (Figure 1; Figure 2A and 2B). The mass extended from the left ventricular myocardium to the epicardial space. On CT, the nonenhanced mass showed low density with a mean CT value of -120 Hounsfield units (HU), which was compatible with fat. In cardiac MR imaging, the signal intensity of the mass on several pulse sequences was consistent with that of fat (Figure 2A and 2B and Figure 3). For kinetic analysis of the left ventricular wall, cine MR imaging was done. This revealed asynchronic motion of the left ventricle due to the tumor (Movies I and II). The tumor contracted just after the systolic phase of the left ventricle. During contraction, the tumor was first pushed out and appeared constricted just after contraction. On the basis of CT and MR imaging, the lesion was thought to represent a lipoma arising within the myocardium with paracardiac extension. The inner myocardium of the mass was very thin, and surgical debulking was not considered an appropriate option because of the possibility of cardiac rupture.
↵*Drs Naotsugu Oyama and Noriko Oyama contributed equally to this article.
Movies I and II are available in the online-only Data Supplement at http://www.circulationaha.org.
The editor of Images in Cardiovascular Medicine is Hugh A. McAllister, Jr, MD, Chief, Department of Pathology, St Luke’s Episcopal Hospital and Texas Heart Institute, and Clinical Professor of Pathology, University of Texas Medical School and Baylor College of Medicine.
Circulation encourages readers to submit cardiovascular images to the Circulation Editorial Office, St Luke’s Episcopal Hospital/Texas Heart Institute, 6720 Bertner Ave, MC1-267, Houston, TX 77030.