Cameron J S, Myerburg R J, Wong S S, Gaide M S, Epstein K, Alvarez T R, Gelband H, Guse P A, Bassett A L
J Am Coll Cardiol. 1983 Sep;2(3):481-7. doi: 10.1016/s0735-1097(83)80275-7.
Cardiac electrophysiologic alterations were evaluated 1 to 8 months after partial supracoronary aortic constriction in cats. This procedure induced left ventricular systolic hypertension and hypertrophy with marked connective tissue infiltration. In situ, premature ventricular complexes were observed during or after vagal slowing of sinus rate in 8 (26%) of the 31 experimental animals, while an additional 3 of the 31 developed ventricular fibrillation. No arrhythmias were recorded in 31 normal or 7 sham-operated cats. In vitro, 29% of the left ventricular preparations from cats with pressure overload and 5% from control cats showed spontaneous ectopic activity. During stimulation at cycle lengths of 800 to 1,000 ms, multiple site impalements of subendocardial muscle cells within fibrotic regions revealed heterogeneous electrical abnormalities. These included short action potential duration, low amplitude action potentials generated from low resting potentials, split upstrokes and electrically silent areas. Impalements in nonfibrotic areas of the left ventricle showed prolongation of muscle action potential duration. Long-term disturbances in cellular electrophysiologic properties may favor the development of arrhythmias and thereby contribute to sudden cardiac death in left ventricular hypertension and hypertrophy.
在猫进行部分冠状动脉上主动脉缩窄术后1至8个月，对心脏电生理改变进行了评估。该手术诱发了左心室收缩期高血压和肥厚，并伴有明显的结缔组织浸润。在实验动物中，31只中有8只（26%）在迷走神经减慢窦性心律期间或之后于原位观察到室性早搏，另外31只中有3只发生了心室颤动。31只正常猫或7只假手术猫未记录到心律失常。在体外，压力超负荷猫的左心室标本中有29%表现出自发性异位活动，而对照猫的这一比例为5%。在800至1000毫秒的周期长度刺激期间，对纤维化区域内心内膜下肌细胞的多部位穿刺显示出异质性电异常。这些异常包括动作电位时程缩短、由低静息电位产生的低幅度动作电位、分裂的上升支和电静息区。左心室非纤维化区域的穿刺显示肌肉动作电位时程延长。细胞电生理特性的长期紊乱可能有利于心律失常的发生，从而导致左心室高血压和肥厚患者的心源性猝死。
