Gaide M S, Cameron J S, Altman C B, Myerburg R J, Bassett A L
Life Sci. 1985 Jun 24;36(25):2391-401. doi: 10.1016/0024-3205(85)90343-1.
The cellular electrophysiology of left ventricular preparations from guinea pig hearts was studied 1 hour, 24 hours, and 4-6 weeks after myocardial infarction produced by 6-8 single ties of the distal left coronary artery system or after sham operation. Microelectrode recordings were used to monitor cells from the endocardial surface of each preparation in tissue bath. All coronary ligated preparations displayed accelerated spontaneous activity compared to normal and sham operated preparations. Single and multiple premature ventricular depolarizations occurred frequently in coronary ligated and rarely in normal and sham operated preparations. Premature stimuli delivered to areas overlying and bordering the area of infarction, induced short bursts of self-terminating rapid repetitive ventricular activity in 4 of 8 (50%) acute (1-hour), 5 of 9 (55%) subacute (24-hour), and 14 of 20 (70%) healed (4-6-week) infarcted preparations. Such activity could not be induced in normal and sham operated preparations. The preparations with healed infarction were unique in that they demonstrated runs of self-terminating repetitive ventricular activity which occurred spontaneously or was inducible with premature stimulation. Recordings from multiple sites in acute, subacute, and healed preparations revealed a variety of transmembrane action potential abnormalities (i.e., reduced action potential amplitude and resting potential, decreased and increased action potential duration, and depressed maximum rates of phase 0 depolarization) in cells overlying and bordering areas of infarction. Only Purkinje fiber action potentials were recorded over the healed infarcts. These data demonstrate that a spectrum of electrophysiological alterations occur in response to ischemic injury and persist after healing of the injury in this new model of myocardial infarction utilizing the guinea pig.
在通过对豚鼠心脏左冠状动脉远端系统进行6 - 8次单次结扎造成心肌梗死后1小时、24小时以及4 - 6周，或者在假手术后，研究了豚鼠心脏左心室组织的细胞电生理学。使用微电极记录来监测置于组织浴中的每个标本心内膜表面的细胞。与正常和假手术标本相比，所有冠状动脉结扎的标本均显示出自发活动加速。单发性和多发性室性早搏在冠状动脉结扎标本中频繁出现，而在正常和假手术标本中很少出现。向梗死区域上方及周边区域施加过早刺激时，在8个急性（1小时）标本中的4个（50%）、9个亚急性（24小时）标本中的5个（55%）以及20个愈合（4 - 6周）梗死标本中的14个（70%）中诱发了短阵自限性快速重复心室活动。在正常和假手术标本中无法诱发这种活动。愈合梗死的标本具有独特之处，即它们表现出了自限性重复心室活动的发作，这些活动可自发出现或可通过过早刺激诱发。对急性、亚急性和愈合标本多个部位的记录显示，梗死区域上方及周边的细胞存在多种跨膜动作电位异常（即动作电位幅度和静息电位降低、动作电位时程缩短和延长以及0期去极化最大速率降低）。在愈合梗死区域仅记录到浦肯野纤维动作电位。这些数据表明，在这个利用豚鼠的心肌梗死新模型中，一系列电生理改变是对缺血性损伤的反应，并在损伤愈合后持续存在。
