Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
Eur Heart J. 2011 Jan;32(1):104-14. doi: 10.1093/eurheartj/ehq345. Epub 2010 Sep 23.
Substrate-based ablation of ventricular tachycardia (VT) relies on electroanatomical voltage mapping (EAVM). Integration of scar information from contrast-enhanced magnetic resonance imaging (CE-MRI) with EAVM may provide supplementary information. This study assessed the relation between electrogram voltages and CE-MRI scar characteristics using real-time integration and reversed registration.
Fifteen patients without implantable cardiac defibrillator (14 males, 64 ± 9 years) referred for VT ablation after myocardial infarction underwent CE-MRI. Contours of the CE-MRI were used to create three-dimensional surface meshes of the left ventricle (LV), aortic root, and left main stem (LM). Real-time integration of CE-MRI-derived scar meshes with EAVM of the LV and aortic root was performed using the LM and the CARTO surface registration algorithm. Merging of CE-MRI meshes with EAVM was successful with a registration error of 3.8 ± 0.6 mm. After the procedure, voltage amplitudes of each mapping point were superimposed on the corresponding CE-MRI location using the reversed registration matrix. Infarcts on CE-MRI were categorized by transmurality and signal intensity. Local bipolar and unipolar voltages decreased with increasing scar transmurality and were influenced by scar heterogeneity. Ventricular tachycardia reentry circuit isthmus sites were correlated to CE-MRI scar location. In three patients, VT isthmus sites were located in scar areas not identified by EAVM.
Integration of MRI-derived scar maps with EAVM during VT ablation is feasible and accurate. Contrast-enhanced magnetic resonance imaging identifies non-transmural scars and infarct grey zones not detected by EAVM according to the currently used voltage criteria and may provide important supplementary substrate information in selected patients.
基于基质的室性心动过速（VT）消融依赖于心电图电压测绘（EAVM）。将对比增强磁共振成像（CE-MRI）中的瘢痕信息与 EAVM 整合，可能会提供补充信息。本研究采用实时整合和逆向配准评估了电图电压与 CE-MRI 瘢痕特征之间的关系。
15 例心肌梗死后因 VT 消融而就诊的患者（14 名男性，64±9 岁）进行了 CE-MRI 检查。使用 CE-MRI 轮廓创建了左心室（LV）、主动脉根部和左主干（LM）的三维表面网格。采用 LM 和 CARTO 表面配准算法，对 LV 和主动脉根部的 CE-MRI 衍生瘢痕网格与 EAVM 进行实时整合。CE-MRI 网格与 EAVM 的融合，配准误差为 3.8±0.6mm，成功率为 100%。手术后，使用逆向配准矩阵，将每个标测点的电压幅度叠加到相应的 CE-MRI 位置上。根据 CE-MRI 上的透壁程度和信号强度对梗死进行分类。局部双极和单极电压随着瘢痕透壁程度的增加而降低，并且受到瘢痕异质性的影响。VT 折返环峡部部位与 CE-MRI 瘢痕位置相关。在 3 例患者中，VT 峡部位于 EAVM 未识别的瘢痕区域。
在 VT 消融过程中，将 MRI 衍生的瘢痕图与 EAVM 整合是可行且准确的。CE-MRI 根据目前使用的电压标准，可识别 EAVM 无法检测到的非透壁性瘢痕和梗死灰区，可为特定患者提供重要的补充基质信息。
