Ventricular fibrillation threshold is influenced by left ventricular stretch and mass in the absence of ischaemia.
Ventricular fibrillation threshold is influenced by left ventricular stretch and mass in the absence of ischaemia.
复制标题
在没有缺血的情况下，心室颤动阈值受到左心室牵张和质量的影响。
DOI：
10.1093/cvr/25.6.458
复制
发表时间：
1991
影响因子：
10.8
通讯作者：
Buttrick,P
中科院分区：
文献类型：
--
作者：
Rosen,S;Lahorra,M;Cohen,MV;Buttrick,P
研究目标——众所周知，缺血性心脏病会导致室性心律失常的发生。然而，非缺血变量的作用尚未明确定义。因此，我们研究了心肌拉伸和心室质量对大鼠心脏对心室颤动的脆弱性的影响。 设计和实验材料——在隔离的缓冲液灌注装置中对两组大鼠心脏进行了研究：第一组是成熟雌性动物，平均左心室干重为 73 毫克，第二组是退休饲养员，平均左心室重量为 122 毫克。心脏在低（0 mm Hg）或高（20 mm Hg）左心室舒张末压下进行等容功。测量和主要结果——心室颤动是由电流不断增加的一系列心室额外刺激引起的，直至发生心律失常。在左心室舒张末压高的情况下，两组中引发心室颤动所需的电流均降低，并且第二组中较大的心脏比第一组更容易发生心室颤动。心室颤动阈值的降低发生在心肌乳酸生成不增加或心内膜与心外膜血流比率不降低的情况下。结论—本研究因此确定了两个变量，即心肌拉伸和心室质量，它们影响心室的发展在此动物模型中，颤动与心肌缺血无关。这些观察结果可能与了解扩张型心肌病患者致命性心律失常的发生率增加有关。
Study objective— Ischaemic heart disease is known to contribute to the development of ventricular arrhythmias. However, the role of non-ischaemic variables has been less well defined. We therefore studied the effect of myocardial stretch and ventricular mass on the vulnerability of the rat heart to ventricular fibrillation.Design and experimental material— Two groups of rat hearts were studied in an isolated buffer perfused apparatus: group I, mature female animals with an average dry left ventricular weight of 73 mg and group II, a group of retired breeders with an average left ventricular weight of 122 mg. Hearts performed isovolumetric work at either low (0 mm Hg) or high (20 mm Hg) left ventricular end diastolic pressures.Measurements and main results— Ventricular fibrillation was provoked by trains of ventricular extrastimuli delivered at increasing current until development of the arrhythmia. The current required to provoke ventricular fibrillation decreased in both groups at the high left ventricular end diastolic pressure and the larger hearts in group II were more vulnerable to ventricular fibrillation than those in group I. The decrease in ventricular fibrillation threshold occurred in the absence of an increase in myocardial lactate production or a decrease in endocardial to epicardial flow ratios.Conclusions— This study thus identified two variables, myocardial stretch and ventricular mass, which influence the development of ventricular fibrillation and which are independent of myocardial ischaemia in this animal model. These observations may be relevant to an understanding of the increased incidence of lethal arrhythmias which occur in patients with dilated cardiomyopathies.