Harasawa H, Li K S, Nakamoto T, Coghlan L, Singleton H R, Dell'Italia L J, Santamore W P
Philadelphia Heart Institute, Presbyterian Medical Center, PA 19104.
Cardiovasc Res. 1993 Aug;27(8):1470-6. doi: 10.1093/cvr/27.8.1470.
The aim was to examine how regional variations in pericardial pressure affect the mechanical coupling between the ventricles.
Canine hearts from 14 dogs (14.5-18 kg) were removed and placed in cold cardioplegia solution. Balloons were inserted into the left and right ventricles and the atria. Pericardial pressure over the left ventricle (Pclv) and the right ventricle (Pcrv) was measured with thin balloon catheters. Ventricular and pericardial pressures were measured, and ventricular and pericardial coupling was calculated, under control conditions and with increases in pericardial tension and fluid.
At baseline, regional differences in pericardial pressure occurred [Pclv > Pcrv, 4.0(SD 0.9) v 2.9(0.6) mm Hg, p < 0.05]. Ventricular coupling via the pericardium was defined as delta Pclv/delta Pcrv for right ventricular volume increases and delta Pcrv/delta Pclv for left ventricular volume increases. This ratio increased more after increasing right ventricular volume than after increasing left ventricular volume [delta Pclv/delta Pcrv > delta Pcrv/delta Pclv, 1.14(0.33) v 0.51(0.15), p < 0.05]. Increasing the pericardial tension by clamping the pericardium increased pericardial pressures, yet did not alter the regional variations in pressure [Pclv > Pcrv, 8.4(2.2) v 6.4(2.5) mm Hg, p < 0.05] or pericardial coupling [delta Pclv/delta Pcrv > delta Pclv/delta Pcrv, 1.18(0.46) v 0.54(0.16), p < 0.05]. In contrast, creating a mild tamponade increased pericardial pressures, eliminated regional differences in pressure, and altered the coupling between ventricles [delta Pclv/delta Pcrv approximately delta Pclv/delta Pcrv, 0.95(0.11) v 1.05(0.08), p = NS]. These regional differences in pericardial pressure might have a geometrical basis. In four in vivo canine experiments using cine magnetic resonance, the short axis radius of curvature for the right ventricle was greater than for the left ventricle [38.3(4.4) mm v 29.2(3.8) mm, p < 0.05].
The pericardium partially protects right ventricular filling: regional differences in pericardial pressure normally occurred with lower pericardial pressure over the right ventricle, and left to right ventricular coupling was less. This protection of right ventricular filling was lost with even a small pericardial effusion.
本研究旨在探讨心包压力的区域差异如何影响心室之间的机械耦合。
从14只犬（体重14.5 - 18千克）取出心脏，置于冷心脏停搏液中。将球囊插入左、右心室及心房。用细球囊导管测量左心室（Pclv）和右心室（Pcrv）上方的心包压力。在对照条件下以及心包张力和液体增加时，测量心室和心包压力，并计算心室与心包的耦合。
基线时，心包压力存在区域差异[Pclv > Pcrv，4.0（标准差0.9）对2.9（0.6）mmHg，p < 0.05]。通过心包的心室耦合定义为右心室容积增加时的ΔPclv/ΔPcrv以及左心室容积增加时的ΔPcrv/ΔPclv。右心室容积增加后该比值的增加幅度大于左心室容积增加后[ΔPclv/ΔPcrv > ΔPcrv/ΔPclv，1.14（0.33）对0.51（0.15），p < 0.05]。通过钳夹心包增加心包张力会增加心包压力，但不会改变压力的区域差异[Pclv > Pcrv，八.4（2.2）对6.4（2.5）mmHg，p < 0.05]或心包耦合[ΔPclv/ΔPcrv > ΔPclv/ΔPcrv，1.18（0.46）对0.54（0.16），p < 0.05]。相比之下，造成轻度心包填塞会增加心包压力，消除压力的区域差异，并改变心室之间的耦合[ΔPclv/ΔPcrv约等于ΔPclv/ΔPcrv，对0.95（0.11）对1.05（0.08），p = 无显著差异]。心包压力的这些区域差异可能有几何学基础。在四项使用电影磁共振的犬体内实验中，右心室的短轴曲率半径大于左心室[38.3（4.4）mm对29.2（3.8）mm，p < 0.05]。
心包部分保护右心室充盈：心包压力通常存在区域差异，右心室上方心包压力较低，左至右心室耦合较小。即使少量心包积液也会使这种对右心室充盈的保护作用丧失。
