Engberding R, Yelbuz T M, Breithardt G
I. Medical Clinic, Klinikum Wolfsburg, 38440 Wolfsburg, Germany.
Clin Res Cardiol. 2007 Jul;96(7):481-8. doi: 10.1007/s00392-007-0528-6. Epub 2007 Jun 4.
Isolated noncompaction of the left ventricular myocardium (INVM), first described in 1984, is an unclassified cardiomyopathy and is assumed to occur as an arrest of the compaction process during the normal development of the heart. Between weeks 5 to 8 of human fetal development, the ventricular myocardium undergoes gradual compaction with transformation of the relatively large intertrabecular spaces into capillaries while the residual spaces within the trabecular meshwork gradually flatten or disappear. In the case of INVM, the spaces within the intertrabecular meshwork persist while no other cardiac abnormalities exist. Although there is substantial evidence supporting the developmental hypothesis, other pathogenetic processes responsible for INVM have been discussed. It can be assumed that INVM will be better understood in the future as the molecular genetic basis of cardiomyopathies will be further unravelled. Echocardiography has been shown to be the method of choice in diagnosis of INVM. The diagnostic criteria can be summarized as: 1) appearance of at least four prominent trabeculations and deep intertrabecular recesses; 2) appearance of blood flow from the ventricular cavity into the intertrabecular recesses as visualized by color Doppler imaging; 3) the segments of noncompacted myocardium mainly involve the apex and the inferior mid and lateral mid of the left ventricular wall and typically show a two-layered structure with an endsystolic ratio greater than two between the noncompacted subendocardial layer and the compacted subepicardial layer; 4) absence of coexisting cardiac abnormalities. Magnetic resonance imaging using modern gradient echo sequences has also been shown to diagnose INVM accurately. The clinical presentation of INVM is characterized by a high prevalence of heart failure, thromboembolic events and arrhythmias including ventricular tachycardia and atrial fibrillation. The establishment of a registry, which was initiated by the "Arbeitsgemeinschaft Leitende Kardiologische Krankenhausärzte (ALKK)" recently, may provide further clues for diagnosis, risk stratification, and management of this disease.
孤立性左心室心肌致密化不全（INVM）于1984年首次被描述，是一种未分类的心肌病，被认为是在心脏正常发育过程中致密化过程停滞所致。在人类胎儿发育的第5至8周期间，心室心肌逐渐致密化，相对较大的小梁间隙转变为毛细血管，而小梁网内的残余间隙逐渐变平或消失。在INVM的情况下，小梁网内的间隙持续存在，而不存在其他心脏异常。尽管有大量证据支持发育假说，但也讨论了导致INVM的其他致病过程。可以假设，随着心肌病分子遗传基础的进一步阐明，未来对INVM将有更好的理解。超声心动图已被证明是诊断INVM的首选方法。诊断标准可总结为：1）至少出现四个突出的小梁和深陷的小梁间隙；2）彩色多普勒成像显示血流从心室腔流入小梁间隙；3）未致密化心肌节段主要累及左心室壁的心尖、下壁中部和侧壁中部，通常显示两层结构，收缩末期未致密化的心内膜下层与致密化的心外膜下层之比大于2；4）不存在并存的心脏异常。使用现代梯度回波序列的磁共振成像也已被证明能准确诊断INVM。INVM的临床表现以心力衰竭、血栓栓塞事件和心律失常（包括室性心动过速和心房颤动）的高发生率为特征。最近由“德国心脏病医院领导医生工作小组（ALKK）”发起的登记册的建立，可能为这种疾病的诊断、风险分层和管理提供进一步线索。
