Van Leeuwen Peter, Hailer Birgit, Beck Alexander, Eiling Gregor, Grönemeyer Dietrich
Department of Biomagnetism, Grönemeyer Institute for Microtherapy, University Witten/Herdecke, Universitätsstrasse 142, Bochum, Germany.
Ann Noninvasive Electrocardiol. 2011 Oct;16(4):379-87. doi: 10.1111/j.1542-474X.2011.00466.x.
Pathological changes in cardiac electrophysiology have been investigated in coronary artery disease using magnetocardiography. Aim of this work was to examine the structure of cardiac magnetic field maps (MFM) during ventricular depolarization and repolarization in patients with acute ST elevation myocardial infarction (STEMI).
Magnetocardiograms were recorded in 39 healthy subjects and 97 patients who had been successfully revascularized after STEMI. Using the Karhunen-Loeve transform, 12 eigenmaps were constructed for six intervals within the QT interval of each subject's signal-averaged data. The relative information content of the eigenmaps was compared between STEMI patients and healthy subjects.
Relative nondipolar content was between 0.03% and 0.52% higher in the STEMI group, (P < 0.001 for the repolarization intervals). Information content of the first dipolar eigenmap in the STEMI group was reduced by 2.6%-11.7% (P < 0.001 for the repolarization intervals). STT interval was best able to discriminate between groups: area-under-the-curve for nondipolar content was 85.8% (P < 0.001), for the first eigenmap 91.7% (P < 0.001). Severity of infarction was reflected in lower STT interval map 1 content for patients with anterior versus posterior infarction (83%± 11% vs. 87%± 10%, P < 0.05), with wall motion disturbances (84%± 11% vs. 92%± 7%, P < 0.001) and with microvascular obstruction (81%± 12% vs. 87%± 10%, P < 0.05). Regression analysis showed that patients with lower ejection fraction tended to have less information content (P < 0.001).
STEMI is associated with a loss of spatial coherence during repolarization, as quantified by principal component analysis of cardiac MFM.
利用心磁图对冠状动脉疾病患者的心脏电生理病理变化进行了研究。本研究的目的是检查急性ST段抬高型心肌梗死（STEMI）患者心室去极化和复极化期间心脏磁场图（MFM）的结构。
记录了39名健康受试者和97名STEMI后成功进行血运重建的患者的心磁图。使用卡尔胡宁-洛伊夫变换，为每个受试者信号平均数据的QT间期内的六个间期构建了12个特征图。比较了STEMI患者和健康受试者特征图的相对信息含量。
STEMI组的相对非偶极含量高出0.03%至0.52%（复极化间期P<0.001）。STEMI组第一个偶极特征图的信息含量降低了2.6%-11.7%（复极化间期P<0.001）。STT间期最能区分两组：非偶极含量的曲线下面积为85.8%（P<0.001），第一个特征图为91.7%（P<0.001）。梗死严重程度体现在前壁梗死与后壁梗死患者的STT间期图1含量较低（83%±11%对87%±10%，P<0.05）、有室壁运动障碍者（84%±11%对92%±7%，P<0.001）以及有微血管阻塞者（81%±12%对87%±10%，P<0.05）。回归分析表明，射血分数较低的患者往往信息含量较少（P<0.001）。
如通过心脏MFM的主成分分析所量化，STEMI与复极化期间空间相干性的丧失有关。
