Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark.
Department of Clinical Medicine, MR Research Centre, Aarhus University, Aarhus, Denmark.
Europace. 2019 Dec 1;21(12):1919-1927. doi: 10.1093/europace/euz247.
Contact force (CF) between radiofrequency (RF) ablation catheter and myocardium and ablation index (AI) correlates with RF lesion depth and width in normal-voltage (>1.5 mV) myocardium (NVM). We investigate the impact of CF on RF lesion depth and width in low (<0.5 mV) (LVM) and intermediate-voltage (0.5-1.5 mV) myocardium (IVM) following myocardial infarction. Correlation between RF lesion depth and width evaluated by native contrast magnetic resonance imaging (ncMRI) and gross anatomical evaluation was investigated.
Twelve weeks after myocardial infarction, 10 pigs underwent electroanatomical mapping and endocardial RF ablations were deployed in NVM, IVM, and LVM myocardium. In vivo ncMRI was performed before the heart was excised and subjected to gross anatomical evaluation. Ninety (82%) RF lesions were evaluated. Radiofrequency lesion depth and width were smaller in IVM and LVM compared with NVM (P < 0.001). Radiofrequency lesion depth and width correlated with CF, AI, and impedance drop in NVM (CF and AI P < 0.001) and IVM (CF and AI depths P < 0.001; CF and AI widths P < 0.05). Native contrast magnetic resonance imaging evaluated RF lesion depth and width correlated with gross anatomical depth and width (NVM and IVM P < 0.001; LVM P < 0.05).
Radiofrequency lesions deployed by similar duration, power and CF are smaller in IVM and LVM than in NVM. Radiofrequency lesion depth and width correlated with CF, AI, and impedance drop in NVM and IVM but not in LVM. Native contrast magnetic resonance imaging may be useful to assess RF lesion depth and width in NVM, IVM, and LVM.
在正常电压（>1.5 mV）心肌（NVM）中，射频（RF）消融导管与心肌之间的接触力（CF）和消融指数（AI）与 RF 损伤深度和宽度相关。我们研究了心肌梗死后低电压（<0.5 mV）（LVM）和中间电压（0.5-1.5 mV）（IVM）心肌中 CF 对 RF 损伤深度和宽度的影响。评估了由原生对比磁共振成像（ncMRI）和大体解剖评估评估的 RF 损伤深度和宽度之间的相关性。
心肌梗死后 12 周，10 头猪进行了电解剖映射，在 NVM、IVM 和 LVM 心肌中进行了心内膜 RF 消融。在心脏被切除并进行大体解剖评估之前，对心脏进行了体内 ncMRI 检查。评估了 90（82％）个 RF 损伤。与 NVM 相比，IVM 和 LVM 中的 RF 损伤深度和宽度较小（P<0.001）。RF 损伤深度和宽度与 CF、AI 和阻抗下降在 NVM（CF 和 AI P<0.001）和 IVM（CF 和 AI 深度 P<0.001；CF 和 AI 宽度 P<0.05）中相关。ncMRI 评估的 RF 损伤深度和宽度与大体解剖深度和宽度（NVM 和 IVM P<0.001；LVM P<0.05）相关。
在 NVM 中，以相似的持续时间、功率和 CF 部署的 RF 损伤比在 IVM 和 LVM 中要小。在 NVM 和 IVM 中，RF 损伤深度和宽度与 CF、AI 和阻抗下降相关，但在 LVM 中则不相关。ncMRI 可能有助于评估 NVM、IVM 和 LVM 中的 RF 损伤深度和宽度。
