Pollock Joshua D., Makaryus Amgad N.
NYITCOM/NUMC
Donald and Barbara Zucker School Medicine at Hofstra/Northwell
The cardiac cycle is a series of pressure changes within the heart. These pressure changes result in blood movement through different chambers of the heart and the body as a whole. These pressure changes originate as conductive electrochemical changes within the myocardium that result in the concentric contraction of cardiac muscle. Valves within the heart direct blood movement, which leads to the organized propulsion of blood to the next chamber. This rhythmic sequence causes changes in pressure and volume that are often seen graphically in the form of a Wiggers diagram or venous pressure tracings (see Wiggers Diagram). This information is vital to the clinical understanding of cardiac auscultation, pathology, and interventions.
心动周期是心脏内一系列的压力变化。这些压力变化导致血液在心脏的不同腔室以及整个身体中流动。这些压力变化源于心肌内的传导性电化学变化，进而导致心肌的同心收缩。心脏内的瓣膜引导血液流动，从而将血液有组织地推进到下一个腔室。这种有节奏的序列会引起压力和容积的变化，这些变化通常以威格尔斯图或静脉压描记图的形式直观呈现（见威格尔斯图）。这些信息对于临床理解心脏听诊、病理学及干预措施至关重要。
