Li K S, Santamore W P
Philadelphia Heart Institute, Presbyterian Medical Center, PA 19104.
Cardiovasc Res. 1993 May;27(5):792-800. doi: 10.1093/cvr/27.5.792.
Common muscle fibres encircle both ventricles and the ventricles share a common septal wall. This close anatomical association suggests that regional ischaemia and structural integrity may alter systolic function in both the right and the left ventricle. To examine this possibility, we investigated the contribution of each wall to biventricular function.
Isolated hearts, obtained from anaesthetised rabbits, were perfused with physiological salt solution under constant pressure. Balloons were placed in the right and left ventricles to measure isovolumetric pressure, and pressure-volume curves were obtained. In separate sets of experiments, the left ventricular free wall, right ventricular free wall, or septum was made ischaemic, incised, or injected with glutaraldehyde, respectively. Pressure-volume curves were obtained again.
After left ventricular free wall ischaemia (n = 11), right ventricular developed pressure decreased significantly from 27.9(SD 8.9) to 14.1(6.6) mm Hg (p < 0.05), and remained depressed when the left ventricular free wall was further damaged by glutaraldehyde. Cutting the left ventricular free wall (n = 6) decreased right ventricular developed pressure from 28.9(8.6) to 17.8(4.8) mm Hg (p < 0.05), while reapproximating the left ventricular free wall by suturing re-established right ventricular developed pressure. After right ventricular free wall ischaemia (n = 7), right ventricular developed pressure decreased from 26.8(6.6) to 24.1(5.7) mm Hg (NS) and left ventricular developed pressure was unaltered. Cutting the right ventricular free wall (n = 7) had no effect on left ventricular developed pressure. Cutting the septum (n = 7) had no obvious influence on right ventricular developed pressure, but dramatically decreased left ventricular developed pressure from 79.2(55.2) to 43.7(32.2) mm Hg (p < 0.05). Injecting glutaraldehyde into the septum (n = 7) decreased both right and left ventricular developed pressures from 22.1(8.5) to 14.0(8.8) and from 78.2(50.5) to 47.9(37.9), respectively.
The results show that the heart should be viewed as a mechanical syncytium. The left ventricular free wall plays a critical role in right ventricular systolic function and may help to explain the right ventricular response to left ventricular ischaemia. On the other hand, in the isolated heart preparation, right ventricular free wall ischaemia has only a minimal effect on left ventricular systolic developed pressure. Altering ventricular septal function affects both right and left ventricular systolic function.
常见的肌纤维环绕着两个心室，且两个心室共享一个共同的间隔壁。这种紧密的解剖学关联表明，局部缺血和结构完整性可能会改变右心室和左心室的收缩功能。为了研究这种可能性，我们调查了每个心室壁对双心室功能的贡献。
从麻醉的兔子身上获取离体心脏，在恒压下用生理盐溶液灌注。将球囊置于右心室和左心室内以测量等容压力，并获得压力-容积曲线。在单独的几组实验中，分别使左心室游离壁、右心室游离壁或间隔缺血、切开或注射戊二醛。再次获得压力-容积曲线。
左心室游离壁缺血后（n = 11），右心室的舒张末压力从27.9（标准差8.9）显著降至14.1（6.6）mmHg（p < 0.05），当左心室游离壁进一步被戊二醛损伤时仍处于降低状态。切开左心室游离壁（n = 6）使右心室的舒张末压力从28.9（8.6）降至17.8（4.8）mmHg（p < 0.05），而通过缝合使左心室游离壁重新对合则恢复了右心室的舒张末压力。右心室游离壁缺血后（n = 7），右心室的舒张末压力从26.8（6.6）降至24.1（5.7）mmHg（无统计学意义），左心室的舒张末压力未改变。切开右心室游离壁（n = 7）对左心室的舒张末压力无影响。切开间隔（n = 7）对右心室的舒张末压力无明显影响，但显著降低了左心室的舒张末压力，从79.2（55.2）降至43.7（32.2）mmHg（p < 0.05）。向间隔注射戊二醛（n = 7）使右心室和左心室的舒张末压力分别从22.1（8.5）降至14.0（8.8）以及从78.2（50.5）降至47.9（37.9）。
结果表明，心脏应被视为一个机械性合胞体。左心室游离壁在右心室收缩功能中起关键作用，这可能有助于解释右心室对左心室缺血的反应。另一方面，在离体心脏标本中，右心室游离壁缺血对左心室收缩舒张末压力的影响极小。改变室间隔功能会影响右心室和左心室的收缩功能。
