He Ding Sheng, Bosnos Michael, Mays Mary Z, Marcus Frank
University of Arizona Medical Center, Tucson, AZ 85724-5037, USA.
IEEE Trans Biomed Eng. 2003 Jun;50(6):768-76. doi: 10.1109/TBME.2003.812161.
We report our experience with a system that utilizes changes in several biophysical characteristics of cardiac tissue to determine lesion formation and to estimate lesion size both on and off-line in vitro during radio frequency (RF) energy delivery. We analyzed the reactive and resistive components of tissue impedance and tracked the change of phase angle during RF ablation. We correlated the amount of tissue damage with these and other biophysical parameters and compared them with off-line analysis. We found that there are irreversible changes in the reactive and resistive components of impedance that occurred during tissue ablation. The irreversible changes of these components are greater in magnitude, and correlate better with the size of lesions than that of impedance alone that is currently used. Numerically, the best single on-line and off-line correlation for combined perpendicular and parallel electrode orientation was with phase angle. On-line and off-line capacitance and susceptance correlations were essentially similar suggesting that they may be useful as lesion size predictors, given these parameter's persistent change without temperature sensitivity. This study indicates that it is technically feasible to assess lesion formation using biophysical parameters.
我们报告了一个系统的使用经验，该系统利用心脏组织的几个生物物理特性的变化来确定病变形成，并在射频（RF）能量传递期间在体外在线和离线估计病变大小。我们分析了组织阻抗的电抗和电阻成分，并跟踪了射频消融期间相角的变化。我们将组织损伤量与这些及其他生物物理参数相关联，并与离线分析进行比较。我们发现，在组织消融期间，阻抗的电抗和电阻成分发生了不可逆的变化。这些成分的不可逆变化幅度更大，并且与病变大小的相关性比目前单独使用的阻抗更好。在数值上，对于组合的垂直和平行电极方向，最佳的在线和离线相关性是与相角相关。在线和离线电容及电纳相关性基本相似，这表明鉴于这些参数持续变化且不受温度影响，它们可能作为病变大小预测指标有用。这项研究表明，使用生物物理参数评估病变形成在技术上是可行的。
