Mishiro Y, Oki T, Iuchi A, Tabata T, Yamada H, Abe M, Onose Y, Ito S, Nishitani H, Harada M, Taoka Y
Second Department of Internal Medicine, School of Medicine, The University of Tokushima, Japan.
Jpn Circ J. 1999 Jun;63(6):442-6. doi: 10.1253/jcj.63.442.
Global left ventricular (LV) pump function is generally preserved in patients with hypertrophic cardiomyopathy (HCM). However, it is unknown whether regional myocardial contractility is impaired, especially in nonhypertrophied regions. The purpose of this study was to evaluate regional LV myocardial contraction in patients with HCM using magnetic resonance (MR) spatial modulation of magnetization (SPAMM) myocardial tagging. The study group comprised 20 patients with asymmetric septal hypertrophy (HCM group) and 16 age-matched normal patients (control group), and data were collected using transthoracic M-mode and 2-dimensional echocardiography, and MR SPAMM myocardial tagging. The systolic strain ratio, maximum systolic strain velocity, and time from end-diastole to maximum systolic strain (deltaT) in the anterior, ventricular septal, inferior and lateral regions for 2 LV short-axis sections at the levels of the chordae tendineae and papillary muscles were measured at 50-ms intervals by MR myocardial tagging. The end-diastolic anterior and ventricular septal wall thicknesses and LV mass index were significantly different between the HCM and control groups. The systolic strain ratio for all 4 walls, particularly the anterior and ventricular septal regions, was significantly lower in the HCM group. In the HCM group, the maximum systolic strain velocity was significantly lower and deltaT was significantly shorter for all 4 walls, particularly the anterior and ventricular septal regions. The standard deviation for the deltaT, calculated from the deltaT for the 8 regions of the 2 LV short-axis sections, was significantly greater in the HCM group. In conclusion, regional LV myocardial contraction is impaired in both hypertrophied and nonhypertrophied regions, and systolic LV wall asynchrony occurs in patients with HCM.
肥厚型心肌病（HCM）患者的左心室（LV）整体泵功能通常得以保留。然而，尚不清楚局部心肌收缩力是否受损，尤其是在非肥厚区域。本研究的目的是使用磁共振（MR）磁化空间调制（SPAMM）心肌标记技术评估HCM患者的左心室局部心肌收缩情况。研究组包括20例不对称性室间隔肥厚患者（HCM组）和16例年龄匹配的正常患者（对照组），通过经胸M型和二维超声心动图以及MR SPAMM心肌标记技术收集数据。通过MR心肌标记技术，以50毫秒的间隔测量在腱索和乳头肌水平的两个左心室短轴切面的前壁、室间隔、下壁和侧壁区域的收缩期应变率、最大收缩期应变速度以及从舒张末期到最大收缩期应变的时间（deltaT）。HCM组和对照组之间舒张末期前壁和室间隔壁厚度以及左心室质量指数存在显著差异。HCM组所有4个壁的收缩期应变率，尤其是前壁和室间隔区域，显著降低。在HCM组中，所有4个壁，尤其是前壁和室间隔区域的最大收缩期应变速度显著降低，deltaT显著缩短。根据两个左心室短轴切面8个区域的deltaT计算得出的deltaT标准差，在HCM组中显著更大。总之，HCM患者肥厚和非肥厚区域的左心室局部心肌收缩均受损，且左心室壁出现收缩期不同步。
