Bogun Frank, Krishnan Subramaniam, Siddiqui Mukarram, Good Eric, Marine Joseph E, Schuger Claudio, Oral Hakan, Chugh Aman, Pelosi Frank, Morady Fred
University of Michigan Medical Center, Ann Arbor, Michigan, USA.
J Am Coll Cardiol. 2005 Aug 16;46(4):667-74. doi: 10.1016/j.jacc.2005.01.064.
The purpose of this study was to correlate infarct age with characteristics of the endocardial electrograms (EGM) obtained in patients undergoing mapping procedures for postinfarction ventricular tachycardia (VT).
Experimental studies have demonstrated that infarct age influences EGM duration in the subepicardial left ventricle (LV). The relationship between infarct age and endocardial EGM characteristics has not been investigated in patients with postinfarction VT.
In a consecutive series of 23 patients with a history of remote infarction (range 1 to 31 years) and VT, endocardial LV mapping was performed with an electroanatomical mapping system (CARTO, Biosense Webster Inc., Diamond Bar, California) during sinus rhythm. Electrogram morphology and width were analyzed and correlated with infarct age. Isthmus sites of the VT re-entry circuits were identified by entrainment mapping and related to the results of substrate mapping.
There was a significant correlation between infarct age and width of the bipolar endocardial EGM during baseline rhythm in the peri-infarct zone (r = 0.84; p < 0.0001). Increasing infarct age was associated with progressive activation delays in the scar and with isolated potentials separated by an isoelectric interval, the duration of which also correlated with infarct age (r = 0.77; p < 0.001). Among all endocardial sites, the VT isthmus sites displayed the most delay and broadest EGMs during sinus rhythm.
The presence of broad, fractionated EGMs and isolated potentials indicates a healed myocardial infarction; the older the infarction, the broader the EGM width. Remodeling over time alters the electrophysiologic properties of the peri-infarct tissue.
本研究旨在将梗死年龄与心肌梗死后室性心动过速（VT）患者在标测过程中获得的心内膜电图（EGM）特征相关联。
实验研究表明，梗死年龄会影响左心室心外膜下的EGM持续时间。心肌梗死后VT患者的梗死年龄与心内膜EGM特征之间的关系尚未得到研究。
在连续的23例有陈旧性梗死病史（范围为1至31年）且发生VT的患者中，在窦性心律期间使用电解剖标测系统（CARTO，Biosense Webster公司，加利福尼亚州钻石吧）进行左心室心内膜标测。分析电图形态和宽度，并将其与梗死年龄相关联。通过拖带标测确定VT折返环路的峡部部位，并将其与基质标测结果相关联。
梗死区域周围在基线心律时双极心内膜EGM的宽度与梗死年龄之间存在显著相关性（r = 0.84；p < 0.0001）。梗死年龄增加与瘢痕中的渐进性激动延迟以及由等电位间期分隔的孤立电位相关，该等电位间期的持续时间也与梗死年龄相关（r = 0.77；p < 0.001）。在所有心内膜部位中，VT峡部部位在窦性心律期间显示出最延迟和最宽的EGM。
存在宽阔、碎裂的EGM和孤立电位表明心肌梗死已愈合；梗死时间越长，EGM宽度越宽。随着时间的推移，重塑会改变梗死周围组织的电生理特性。
