Ingels N B, Daughters G T, Nikolic S D, DeAnda A, Moon M R, Bolger A F, Komeda M, Derby G C, Yellin E L, Miller D C
Department of Cardiovascular Physiology and Biophysics, Palo Alto Medical Foundation 94301.
Am J Physiol. 1994 Jul;267(1 Pt 2):H354-62. doi: 10.1152/ajpheart.1994.267.1.H354.
A novel technique is presented to study suction of the in situ left ventricle in open-chest experimental animals without requiring cardiopulmonary bypass or disturbing the native mitral valvular apparatus. In 17 dogs, left ventricular pressure (LVP) and left atrial pressure (LAP) were measured, the left atrium was cannulated and connected to a servo pump, and LAP was controlled to a setpoint near 0 mmHg by withdrawing blood from the left atrium. Heart rate [103 +/- 17 (SD) min-1], peak pressure (100 +/- 13 mmHg), minimum pressure (1.4 +/- 0.8 mmHg), and maximum rate of change of pressure with respect to time during isovolumic contraction and relaxation (2,506 +/- 775 and -1,761 +/- 855 mmHg/s, respectively) were normal. Servo control of LAP was possible to +/- 1 mmHg. LV suction was demonstrated in each heart (mean negative LVP -2.3 +/- 1.1 mmHg; P < 0.0001). This new technique demonstrates that the left ventricle can generate negative diastolic suction pressures when examined in vivo and in situ with an undisturbed mitral valve and physiologically normal preload and afterload. This adds to a growing body of evidence that, under appropriate circumstances, the heart can suck blood into itself and thereby aid in its own filling.
本文介绍了一种新的技术，用于研究开胸实验动物原位左心室的抽吸功能，该技术无需体外循环，也不会干扰天然二尖瓣装置。在17只犬中，测量左心室压力（LVP）和左心房压力（LAP），将左心房插管并连接到伺服泵，通过从左心房抽血将LAP控制在接近0 mmHg的设定点。心率[103±17（标准差）次/分钟]、峰值压力（100±13 mmHg）、最低压力（1.4±0.8 mmHg）以及等容收缩和舒张期间压力随时间的最大变化率（分别为2,506±775和-1,761±855 mmHg/s）均正常。LAP的伺服控制精度可达±1 mmHg。每颗心脏均显示出左心室抽吸现象（平均LVP负压为-2.3±1.1 mmHg；P<0.0001）。这项新技术表明，在体内原位且二尖瓣未受干扰、前负荷和后负荷生理正常的情况下，左心室能够产生舒张期负压抽吸。这进一步证明了在适当情况下，心脏能够将血液吸入自身，从而有助于自身充盈，这方面的证据越来越多。
