Adhyapak Srilakshmi M, Menon Prahlad G, Parachuri V Rao, Shetty Devi P, Fantini Fabio
Department of Cardiology, St John's Medical College Hospital, Bangalore, India
Electrical and Computer Engineering, SYSU-CMU Joint Institute of Engineering, Pittsburgh, PA, USA SYSU-CMU Shunde International Research Institute, Guangdong, China QuantMD, Pittsburgh, PA, USA.
Interact Cardiovasc Thorac Surg. 2014 Sep;19(3):368-74. doi: 10.1093/icvts/ivu162. Epub 2014 Jun 6.
In patients with previous myocardial infarction, the remote uninfarcted regions, although contractile, demonstrate dysfunctional wall kinetics because of increased afterload, which improves after surgical ventricular restoration (SVR). We characterized left ventricular (LV) mean myocardial velocity (MMV) through an analysis of endocardial motion and wall thickening (WT) over the cardiac cycle using standard cardiac magnetic resonance (cMR).
LV endocardial motion and WT from cMR data in 7 heart failure (HF) patients with postinfarction antero apical aneurysm were compared against normal controls to establish a baseline for the mean myocardial velocity during phases of the cardiac cycle. The HF patients' MMV and WT curves were compared with post-SVR data.
Global MMV showed significant postoperative improvements in the ejection phase of systole and the early filling phase of diastole. The aneurysmal wall was dyskinetic in both systole and diastole. The remote myocardium preoperatively had a delayed peak velocity during the ejection phase of systole and diminished velocity during early filling in diastole. After SVR, the remote myocardium had an increased MMV with an earlier peaking during the ejection phase and slightly improved early diastolic velocity. WT increased cumulatively during systole and decreased during diastole with improved end-systolic and end-diastolic wall thickness after SVR. The end-systolic wall thickness showed a significant correlation with left ventricular ejection fraction (r(2) = 0.89, P = 0.001) and stroke volume (r(2) = 0.80, P = 0.02). The MMV had a significant correlation with WT over the phases of the cardiac cycle (r(2) = 0.953, P ≤ 0.0001).
In patients with chronic ischaemic heart disease with LV aneurysms/large areas of scar, improvements in the remote myocardial MMV and WT underline LV systolic function improvements after SVR. The persistence of myocardial WT in early diastole is the likely mechanism for incomplete or absence of relief of LV diastolic dysfunction by SVR.
在既往有心肌梗死的患者中，尽管梗死区域外的心肌仍有收缩功能，但由于后负荷增加，其室壁运动动力学存在功能障碍，而手术性心室修复（SVR）后这种情况会得到改善。我们通过使用标准心脏磁共振成像（cMR）分析心动周期内心内膜运动和室壁增厚（WT）情况，对左心室（LV）平均心肌速度（MMV）进行了特征描述。
将7例患有心肌梗死后前壁心尖部室壁瘤的心力衰竭（HF）患者的cMR数据中的左心室内膜运动和WT与正常对照进行比较，以确定心动周期各阶段平均心肌速度的基线。将HF患者的MMV和WT曲线与SVR术后数据进行比较。
整体MMV在收缩期射血期和舒张期早期充盈期术后有显著改善。室壁瘤壁在收缩期和舒张期均运动障碍。术前梗死区域外的心肌在收缩期射血期峰值速度延迟，舒张期早期充盈时速度降低。SVR术后，梗死区域外的心肌MMV增加，射血期峰值提前，舒张期早期速度略有改善。WT在收缩期累积增加，舒张期减少，SVR术后收缩末期和舒张末期室壁厚度改善。收缩末期室壁厚度与左心室射血分数（r² = 0.89，P = 0.001）和每搏输出量（r² = 0.80，P = 0.02）显著相关。在心动周期各阶段，MMV与WT显著相关（r² = 0.953，P≤0.0001）。
在患有慢性缺血性心脏病伴左心室室壁瘤/大面积瘢痕的患者中，梗死区域外心肌MMV和WT的改善表明SVR术后左心室收缩功能得到改善。舒张早期心肌WT持续存在可能是SVR不能完全缓解或无法缓解左心室舒张功能障碍的原因。
