犬心右室、左室大面积梗塞时的容量负荷评价

VOLUME LOADING EXPERIMENT IN DOGS WITH LARGE AREA INFARCTION OF RIGHT AND LEFT VENTRICLES

在１２只犬，结扎四支冠脉，造成犬心右室、左室大面积梗塞和心源性休克时，左室收缩压（ＬＶＳＰ）及最大正负压力阶差（±ｄｐ／ｄｔｍａｘ．）分别下降５４％、５１％和４７％，而右室收缩压（ＲＶＳＰ）及±ｄｐ／ｄｔｍａｘ．仅降低９％、２５％和２７％。组Ⅰ（６只犬）快速扩容（低分子右旋糖酐３０ｍｌ／ｋｇ，２０ｍｉｎ内静脉输入），结果右室反向搏动增强，双心室±ｄｐ／ｄｔｍａｘ．进一步降低，右房压（ＲＡＰ）及左室舒张末压（ＬＶＥＤＰ）极度升高达２．９±０．２ｋＰａ和５．０±０．３ｋＰａ（Ｐ均＜０．０１），甚至诱发室颤。组Ⅱ缓慢静点多巴胺（１０μｇ／ｋｇ·ｍｉｎ）和硝酸甘油（１μｇ／ｋｇ·ｍｉｎ）３０ｍｉｎ，有效提高了动脉压（ＡＰ），心输出量（ＣＯ），ＬＶＳＰ及左室±ｄｐ／ｄｔｍａｘ．使休克逆转。结果表明，大面积左、右室梗塞伴休克时，右室残余心肌的代偿性收缩仍能造成ＲＶＳＰ与右室泵功能呈分离状态；此时快速扩容将进一步损害左、右室功能，而联合使用硝酸甘油和多巴胺能有效纠正休克同时不造成ＲＡＰ和ＬＶＥＤＰ的升高。

In order to study volume loading effect on large area myocardial infarction (MI) in right and left ventricles,large area MI in both ventricles and cardiogenic shock in 12 dogs were induced by occluding coronary arteries.Left ventricular systolic pressure (LVSP) and ±dp/dt max.dropped markedly by 54%,51% and 47% respectively,whereas right ventricular systolic pressure (RVSP) and ±dp/dt max.fell by 9%,25% and 27% respectively.The condition was obviously worse by rapid volume loading (dextran,30ml/kg,iv in 20 min.) in group Ⅰ(n=6),leading to increased retrograde beat of right ventricle,further decrease of ±dp/dt max.in both ventricles,significant increase of right atrial pressure (RAP) and left ventricular and diastolic pressure (LEVDP) (2.9±0.2kPa, P<0.01 and 5.0±0.3kPa,P<0.001,respectively),and even ventricular fibrillation.Shock was reversed by combined treatment of dopamine(10μg/kg·min) and glyceryl trinitrate (1μg/kg·min) in group Ⅱ(n=6) in 30 min,showing evident increase of arterial pressure,cardiac output,LVSP and ±dp/dt max.without rise in RAP and LVEDP.