Kapelko V I, Abramov A A, Lakomkin V L, Lukoshkova E V
National Medical Research Center of Cardiology, Ministry of Health of the Russian Federation, Moscow, Russia.
Bull Exp Biol Med. 2021 May;171(1):15-18. doi: 10.1007/s10517-021-05162-y. Epub 2021 May 28.
This work was designed to study changes in the mechanical properties of rat myocardium during short-term (2-3 sec) compression of the lower vena cava. A catheter was inserted into the left ventricle, allowing simultaneous measurement of left-ventricular volume and pressure. The decrease in the left-ventricular end-diastolic volume caused by inflow restriction was accompanied by less pronounced decrease in the left-ventricular stroke volume and maximum rate of left-ventricular pressure development. This was coincided with accelerated relaxation and deeper fall of the minimum left-ventricular diastolic pressure. The lower was left-ventricular end-systolic volume, the greater was the degree of these changes. It is assumed that the "restoring force" that naturally appears under conditions of low filling of the left ventricle is determined by elastic N2B part of the titin molecule that is compressed during strong shortening of myofibrils and accelerates their return to the previous length during relaxation. As a result of better filling of the left ventricle, the heart can maintain left-ventricular stroke volume at the appropriate level.
本研究旨在探讨下腔静脉短期（2 - 3秒）受压期间大鼠心肌力学性能的变化。将导管插入左心室，以便同时测量左心室容积和压力。流入受限导致左心室舒张末期容积减少，同时左心室搏出量和左心室压力最大上升速率的下降不太明显。这与舒张加速和左心室舒张末期最小压力的更深下降相吻合。左心室收缩末期容积越低，这些变化的程度就越大。据推测，在左心室低充盈状态下自然出现的“恢复力”由肌联蛋白分子的弹性N2B部分决定，该部分在肌原纤维强烈缩短时被压缩，并在舒张时加速其恢复到先前长度。由于左心室充盈改善，心脏能够将左心室搏出量维持在适当水平。
