Germans Tjeerd, Wilde Arthur A M, Dijkmans Pieter A, Chai Wenxia, Kamp Otto, Pinto Yigal M, van Rossum Albert C
Department of Cardiology, VU University Medical Center, Amsterdam, The Netherlands.
J Am Coll Cardiol. 2006 Dec 19;48(12):2518-23. doi: 10.1016/j.jacc.2006.08.036. Epub 2006 Nov 28.
The purpose of this study was to evaluate whether structural left ventricular (LV) abnormalities can be observed in hypertrophic cardiomyopathy (HCM) mutation carriers who have not yet developed echocardiographic signs of hypertrophy by using cardiac magnetic resonance imaging (CMR).
Hypertrophic cardiomyopathy is caused by mutations of genes encoding for sarcomeric proteins. Myocyte disarray and interstitial fibrosis precede the development of regional hypertrophy in HCM mutation carriers (carriers). No macroscopic LV structural abnormalities have been observed in carriers without LV hypertrophy.
A CMR, echocardiogram, and electrocardiogram (ECG) were performed in 16 carriers. Delayed contrast enhancement imaging was used with CMR to detect fibrosis. In 16 age- and gender-matched control subjects, CMR and ECG were performed and an echocardiogram was made when structural abnormalities were detected with CMR. All carriers had an LV wall thickness <13 mm in the year before the study, measured by echocardiography.
In 13 carriers (81%), crypts were discerned with CMR in the basal and mid inferoseptal LV wall, not detected by routine echocardiography and not observed in healthy volunteers. In 4 of the crypt-positive carriers, both the echocardiogram and ECG were normal. Two HCM carriers revealed regional hypertrophy of the inferoseptum not detected by echocardiography, and in both carriers, focal fibrosis was present.
In carriers who have not yet developed frank hypertrophy, crypts can be detected with CMR in the inferoseptal LV wall, even when echocardiography and ECG are normal. The crypts might represent one of the early pathological alterations of myocardium in carriers that ultimately progress into manifest HCM.
本研究旨在评估通过心脏磁共振成像（CMR），能否在尚未出现超声心动图肥厚征象的肥厚型心肌病（HCM）突变携带者中观察到左心室（LV）结构异常。
肥厚型心肌病由编码肌节蛋白的基因突变引起。在HCM突变携带者（携带者）中，心肌细胞排列紊乱和间质纤维化先于局部肥厚的发生。在无左心室肥厚的携带者中未观察到宏观的左心室结构异常。
对16名携带者进行了CMR、超声心动图和心电图（ECG）检查。CMR采用延迟对比增强成像检测纤维化。对16名年龄和性别匹配的对照受试者进行了CMR和ECG检查，当CMR检测到结构异常时进行了超声心动图检查。所有携带者在研究前一年经超声心动图测量左心室壁厚度<13mm。
在13名携带者（81%）中，CMR在左心室下间隔基底段和中段发现了隐窝，常规超声心动图未检测到，健康志愿者中也未观察到。在4名隐窝阳性携带者中，超声心动图和心电图均正常。两名HCM携带者显示下间隔局部肥厚，超声心动图未检测到，且两名携带者均存在局灶性纤维化。
在尚未出现明显肥厚的携带者中，即使超声心动图和心电图正常，CMR也可在左心室下间隔壁检测到隐窝。这些隐窝可能代表携带者心肌早期病理改变之一，最终发展为明显的HCM。
