Triggered activity due to delayed afterdepolarizations in sites of focal origin of ischemic ventricular tachycardia
Triggered activity due to delayed afterdepolarizations in sites of focal origin of ischemic ventricular tachycardia
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DOI：
10.1152/ajpheart.00027.2004
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发表时间：
2004-11-01
影响因子：
4.8
通讯作者：
Martins, JB
中科院分区：
文献类型：
--
作者：
Xing, DZ;Martins, JB
本研究首次系统评价了犬急性冠状动脉结扎后1 ~ 3 h诱发局灶性室性心动过速（VT）的起源部位。我们确定是否迟发性后除极（DADs）和触发活动（TA）更经常记录从缺血性endocardial切除的VT起源的局灶性网站。共研究了145只α-氯醛糖麻醉的狗：在54只无诱导性VT的狗中，体外研究了正常或缺血性内皮细胞;在91只狗中，通过三维激活标测研究了诱导性VT，对51个内皮细胞病灶与40个非VT起源的内皮细胞缺血部位进行了体外研究。缺血性浦肯野组织中DADs（71%vs.33%，P < 0.05）和TA（32%vs.11%，P < 0.05）的发生率高于正常浦肯野组织。室性心动过速起源的浦肯野部位DAD和TA的发生率最高，分别为92%和75%，P <0.05，以重复性TA为主。类似的结果，在endobacterium网站的起源。动作电位轻度去极化，并在起源的局灶性部位延长。这些异常在记录的2.5小时内保持稳定。本研究表明，DAD和TA可能是缺血性内皮细胞和浦肯野组织中大多数局灶性VT的基础。
This study for the first time systematically evaluated the site of origin of focal ventricular tachycardia (VT) induced 1 - 3 h after acute coronary artery ligation in dogs. We determined whether delayed afterdepolarizations (DADs) and triggered activity ( TA) are more often recorded from ischemic endocardium excised from focal sites of VT origin. A total of 145 alpha-chloralose-anesthetized dogs were studied: in 54 dogs without inducible VT, normal or ischemic endocardium was investigated in vitro; in 91 dogs, inducible VT was studied by three-dimensional activation mapping, with in vitro study of 51 endocardial foci compared with 40 endocardial ischemic sites not of VT origin. Incidence of DADs (71% vs. 33%, P < 0.05) and TA (32% vs. 11%, P < 0.05) was greater in ischemic than in normal Purkinje tissues. Purkinje sites of origin of focal VT demonstrated the greatest frequency of DADs (92%, P < 0.05) and TA (75%, P < 0.05), with repetitive TA predominating. Similar results were obtained in endocardial sites of origin. Action potentials were mildly depolarized and prolonged in the focal sites of origin. These abnormalities were stable up to 2.5 h of recording. This study demonstrated that DADs and TA may underlie a majority of focal VTs in ischemic endocardium and Purkinje tissue.