左心室心肌脂肪替代的临床特征及意义

Clinical characteristics of fat replacement of left ventricular myocardium

目的 回顾性分析左心室心肌发生脂肪替代患者的临床特征及其意义。方法 心血管CT筛查示左心室心肌脂肪替代患者45例（男28例，女17例）纳入本研究，平均年龄（51．9±14．7）岁。以左心室心肌CT值≤－30Hu为左心室心肌脂肪替代标准。分析左心室心肌脂肪替代患者左心室受累节段、受累程度等。结果45例患者中冠心病患者25例（男20例，女5例），平均年龄（61．2±10．4）岁。非冠心病患者20例（男8例，女12例），平均年龄（57．8±13．3）岁。冠心病患者单支病变占56％，双支病变占20％，三支病变占24％，合并室壁瘤形成者3例，合并左心室附壁血栓者1例，平均左心室横径（54．5±9．4）mm，平均左心室射血分数（51．8±13）％。非冠心病组患者扩张型心肌病患者3例，房间隔缺损1例，风湿性心脏病1例，其余15例患者心内结构未见异常，平均左心室横径（51．1±9．1）mm，平均左心室射血分数（59．4±13．9）％。冠心病患者脂肪替代均位于左心室梗死区，表现为心内膜下条带状或线状低密度区，其中伴左心室室壁变薄（〈5mm）患者2l例，18例患者脂肪替代累及左心室心尖部，其次为室间隔远段（15例）和左心室前壁远段（11例），室间隔中段和前壁中段患者各7例，左心室基底段受累患者仅1例。非冠心病患者脂肪替代主要累及室间隔，表现为条带状脂肪替代17例，小片状替代3例，其中室间隔中段受累11例，室间隔远段10例，心尖部9例，脂肪替代累及左心室壁问患者14例，累及心内膜下患者10例，其中4例患者左心室壁间与心内膜下均受累。结论冠心病与非冠心病患者左心室心肌脂肪替代在受累部位、形态等方面不同，了解这些差异对判断左心室心肌脂肪替代的病因有重要意义，非冠心病患者左心室脂肪替代的临床意义有待于进一步研究。

Objective To evaluate the clinical characteristics of left ventricular fat replacement. Methods We identified 45 patients [28M/17F, mean age （51.9 ± 14.7 ）years] with left ventricular myocardial fat replacement （ CT value ≤ - 30 Hu） by cardiovascular CT. Results Among 45 patients, 25 patients[20M/5F, mean age （61.2 ± 10.4） years]were diagnosed as coronary artery disease （CAD）. There was 56% single-vessel disease, 20% double-vessel disease and 24% triple-vessel disease, true left ventricular aneurysm was detected in 3 patients and left ventricular thrombi in 1 patient, the dimension of left ventricle was （54.5±9.4） mm and the LVEF was （51.8 ±13 ）% in CAD group. In this group, fat replacement occurred in the region of myocardial infarction and presented as curvilinear band in subendocardial region. The left ventricular wall thickness was lower than 5 mm in 21 cases. The location of fat replacement in CAD group is as follows： apical region in 18 patients, distal septal in 15 patients, distal anterior in 11 patients, mid-septal in 7 patients, mid-anterior in 7 patients and basal in 1 patients. The age of remaining 20 patients （8M/12F） without CAD were （57.8 ±13.3） years. In the group of non-CAD,dilated cardiomyopathy was diagnosed in 3 patients, atrial septal defect in 1 patient, rheumatic heart disease in 1 patient, there was no structural heart disease in the remaining 15 patients. The dimension of left ventricle was （51.1 ±9. 1） mm and the LVEF was （59. 4 ±13.9）%. In non-CAD group, fat replacement mainly occurred in septal region, presented as curvilinear band in 17 patients and patch in 3 patients. The location of fat replacement in this group is as follows： mid-septal region in 11 patients, distal-septal in 10 patients and apical in 9 patients. The intramural fat replacement was detected in 14 patients ： subendocardial fat replacement in 10 patients and both intramural and subendocardial fat replacement in 4 patients. Conclusions Left ventricular fat replacement could be documented in CAD patients, non-CAD cardiomypathy patients and in patients without structural heart disease. Left ventricular fat replacement often positioned in apical region in CAD patients as a consequence of infarct healing while mostly positioned in septal region in non-CAD patients, the definite clinical implication of left ventricular fat replacement in non- CAD patients remains to be clarified.