Piscione Federico, Manganiello Vincenzo, Viola Orazio, Chiariello Massimo
Cattedra di Cardiologia Università degli Studi Federico II Via S. Pansini, 5 80131 Napoli.
Ital Heart J Suppl. 2003 Feb;4(2):85-95.
During liver cirrhosis many important changes occur in the cardiovascular system and these abnormalities appear more evident as portal hypertension and liver dysfunction progress. The cirrhotic heart develops a series of structural and functional abnormalities consisting in diastolic dysfunction and reduced myocardial reactivity during exercise, likely due to a diminished myocardial beta-adrenergic receptor function. Nevertheless, the peculiarity of the cardiovascular involvement during liver cirrhosis is represented by a progressive development of a hyperdynamic circulation that seems to be due to portal hypertension rather than to liver insufficiency. In fact, it has been hypothesized that this syndrome raise from the venous portal bed and is primarily determined by an increase in blood volume that leads to an enhanced cardiac output. Later, as liver cirrhosis progresses, new important pathogenetic elements occur and lead to a reduction in peripheral vascular resistances and to the full clinical expression of hyperdynamic circulation. The pathogenesis of hyperdynamic circulation is very interesting for scientific research because of the complex and still in part unknown origin. In addition, this syndrome has an important clinical meaning for its severely adverse prognostic value and it represents the pathogenetic background for a number of severe complications of advanced liver cirrhosis.
在肝硬化过程中,心血管系统会发生许多重要变化,随着门静脉高压和肝功能障碍的进展,这些异常会变得更加明显。肝硬化性心脏会出现一系列结构和功能异常,包括舒张功能障碍和运动时心肌反应性降低,这可能是由于心肌β-肾上腺素能受体功能减弱所致。然而,肝硬化时心血管受累的特点是高动力循环的逐渐发展,这似乎是由于门静脉高压而非肝功能不全引起的。事实上,有人推测这种综合征起源于门静脉床,主要由血容量增加导致心输出量增加所决定。后来,随着肝硬化的进展,新的重要致病因素出现,导致外周血管阻力降低和高动力循环的完全临床表现。高动力循环的发病机制因其复杂且部分仍不明的起源而对科学研究非常有意义。此外,这种综合征因其严重的不良预后价值而具有重要的临床意义,它代表了晚期肝硬化许多严重并发症的发病背景。