Jacobi Adam H, Gohari Arash, Zalta Benjamin, Stein Marjorie W, Haramati Linda B
Department of Radiology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10467, USA.
J Thorac Imaging. 2007 May;22(2):130-5. doi: 10.1097/01.rti.0000213576.39774.68.
Replacement of the myocardium by fat is a feature of arrythmogenic right ventricular dysplasia (ARVD). Pathology literature describes ventricular myocardial fat to be present not only in ARVD, but much more frequently related to aging, prior myocardial infarction (MI), and chronic ischemia. We noted focal ventricular myocardial fat in a group of patients who underwent chest computed tomography (CT) for varied indications. The aim of this study is to describe the noncontrast CT findings and clinical correlates of ventricular myocardial fat in this population.
We prospectively identified 26 patients whose noncontrast chest CT (5/03 to 6/04) demonstrated ventricular myocardial fat and whose clinical charts were available. There were 14 men and 12 women with a mean age of 70 years. Twenty-three percent (6/26) had prior CTs. Each CT was reviewed by 3 radiologists in consensus. The site of the ventricular fat was noted. Each patient was categorized based on the location of the fat as follows: group 1-right ventricle (RV) only, group 2-left ventricle (LV) only, group 3-biventricular. Results of cardiac history, laboratory tests, and cardiac imaging were noted.
The distribution of ventricular myocardial fat was: group 1 RV-27% (7/26), group 2 LV-46% (12/26), and group 3 biventricular-27% (7/26). Echocardiographic, nuclear cardiology, or electrocardiographic data localizing a prior MI to a specific site were available in 35% (9/26) of patients: 14% (1/7) of group 1, 50% (6/12) of group 2, and 29% (2/7) of group 3. Myocardial fat corresponded to the site of MI in 89% (8/9). The presence and distribution of ventricular fat on CT was unchanged from prior CT in 100% (6/6). When comparing group 1 and group 2, group 1 was older (77 vs. 64 y, P=0.005), more often female (57% vs. 17%, P=0.13) and had fewer prior MI (14% vs. 50%, P=0.17) than group 2. Only 1 patient in this series had ARVD. He was in group 3.
The significance of ventricular myocardial fat varies by location. Fat in the RV is most often related to aging. Prior RV MI and ARVD are less common etiologies. Fat in the LV is frequently related to prior MI. Recognition of myocardial fat on a noncontrast chest CT may be the first opportunity to diagnose a silent MI.
脂肪替代心肌是致心律失常性右室心肌病（ARVD）的一个特征。病理学文献表明，心室心肌脂肪不仅存在于ARVD中，而且更常见于与衰老、既往心肌梗死（MI）和慢性缺血相关的情况。我们在一组因各种适应证接受胸部计算机断层扫描（CT）的患者中发现了局灶性心室心肌脂肪。本研究的目的是描述该人群中心室心肌脂肪的平扫CT表现及其临床相关性。
我们前瞻性地确定了26例平扫胸部CT（2003年5月至2004年6月）显示有心室心肌脂肪且有临床病历的患者。其中男性14例，女性12例，平均年龄70岁。23%（6/26）的患者曾接受过CT检查。由3名放射科医生共同对每例CT进行阅片。记录心室脂肪的部位。根据脂肪的位置将每位患者分为以下几组：第1组——仅右心室（RV），第2组——仅左心室（LV），第3组——双心室。记录心脏病史、实验室检查和心脏影像学检查结果。
心室心肌脂肪的分布情况为：第1组RV占27%（7/26），第2组LV占46%（12/26），第3组双心室占27%（7/26）。35%（9/26）的患者有超声心动图、核医学心脏检查或心电图数据将既往MI定位到特定部位：第1组为14%（1/7），第2组为50%（6/12），第3组为29%（2/7）。心肌脂肪与MI部位相符的占89%（8/9）。100%（6/6）的患者CT上心脂肪的存在和分布与既往CT相比无变化。比较第1组和第2组时，第1组患者年龄更大（77岁对64岁，P = 0.005），女性比例更高（57%对17%，P = 0.13），既往MI更少（14%对50%，P = 0.17）。本系列中只有1例患者患有ARVD。他属于第3组。
心室心肌脂肪的意义因部位而异。右心室脂肪最常与衰老相关。既往右心室MI和ARVD是较不常见的病因。左心室脂肪常与既往MI相关。在平扫胸部CT上识别心肌脂肪可能是诊断无症状MI的首个机会。
