Good Wilson W, Zenger Brian, Bergquist Jake A, Rupp Lindsay C, Gillette Karli, Plank Gernot, MacLeod Rob S
Scientific Computing and Imaging Institute, University of Utah, SLC, UT, USA.
Department of Biomedical Engineering, University of Utah, SLC, UT, USA.
Comput Cardiol (2010). 2020 Sep;47. doi: 10.22489/cinc.2020.279. Epub 2021 Feb 10.
Acute myocardial ischemia compromises the ordered electrical activation of the heart, however, because of sampling limitations, volumetric changes in activation have not been measured. We used a large-animal experimental model and high-resolution volumetric mapping to study the effects of ischemia on conduction speeds (CS) throughout the myocardium. We estimated CS and electrocardiographic changes (ST segments) and evaluated the spatial and temporal correlations between them across 11 controlled episodes. We found that ischemia induces significant conduction slowing, reducing the global median speed by 25 cm/s. Furthermore, there was a high between the development of ischemic severity and CS (corr. = 0.93) through each episode. The between ST-segment changes and CS slowing were more spatially complex than expected with substantial slowing at the periphery of the zones that showed ST-segment changes. This is the first study that has documented in an experimental model volumetric changes of CS during acute myocardial ischemia and explored the relationships between ischemia development in space and time. We showed that conduction speed changes are spatiotemporally correlated to ischemic severity and illustrated the biphasic response long proposed from cellular studies.
急性心肌缺血会损害心脏有序的电激活，然而，由于采样限制，尚未测量激活过程中的容积变化。我们使用大型动物实验模型和高分辨率容积映射来研究缺血对整个心肌传导速度（CS）的影响。我们估计了CS和心电图变化（ST段），并评估了它们在11次对照发作中的空间和时间相关性。我们发现缺血会导致显著的传导减慢，使整体中位数速度降低25厘米/秒。此外，在每次发作中，缺血严重程度的发展与CS之间存在高度相关性（相关系数=0.93）。ST段变化与CS减慢之间的相关性在空间上比预期更复杂，在显示ST段变化的区域周边有明显减慢。这是第一项在实验模型中记录急性心肌缺血期间CS容积变化并探索缺血在空间和时间上发展关系的研究。我们表明传导速度变化在时空上与缺血严重程度相关，并阐明了长期以来细胞研究中提出的双相反应。
