Rönsberg D, Benn M, Karsch K R, Kreuzer H, Neuhaus K L
Z Kardiol. 1978 Sep;67(9):595-600.
The influence of an instantaneous increase in afterload on the hemodynamics and regional myocardial function was studied in five anesthetized dogs before and after occlusion of the left anterior descending coronary artery. By inflation of an intaaortic balloon during single ejections, an instantaneous increase in afterload was obtained. From biplane cineventriculograms, the following parameters were calculated: left ventricular volumes (EDV, ESV), stroke volume (SV), ejection fraction (EF). Mean circumferential fiber shortening (V CF) was calculated in three ventricular diameters in the RAO projection. Simultaneously PLV, PLVED, PAo, and LV dp/dt were obtained. In the control ventriculograms, an increased afterload (delta PLV 16.4 +/- 8 mm Hg) caused only a minor decrease of SV (2.6 +/- 2.5 ml), EF (4.2 +/- 2.4%), and V CF (0.20 circ . s -1). After coronary occlusion (delta PLV 14.5 +/- 6.7 mm Hg),the reduction of SV (5.9 +/- 2.7 ml) and EF (8.2 +/- 2.6%) was more pronounced. This was caused mainly by a significant reduction of V CF in the center of ischemia (delta V CF -93%). For the evaluation of regional myocardial function by ventriculography, the marked influence of afterload in ischemic areas must be taken into consideration. This is of special interest in comparative ventriculograms, such as those before and after coronary bypass surgery.
在五只麻醉犬身上，研究了左前降支冠状动脉闭塞前后，后负荷瞬间增加对血流动力学和局部心肌功能的影响。通过在单次射血期间向主动脉内气囊充气，实现后负荷的瞬间增加。从双平面心血管造影图中，计算出以下参数：左心室容积（舒张末期容积、收缩末期容积）、每搏输出量、射血分数。在右前斜位投影的三个心室直径处计算平均圆周纤维缩短率。同时获取左心室压力、左心室舒张末期压力、主动脉压力和左心室压力变化率。在对照心血管造影图中，后负荷增加（左心室压力变化 16.4±8 毫米汞柱）仅导致每搏输出量轻微下降（2.6±2.5 毫升）、射血分数轻微下降（4.2±2.4%）和平均圆周纤维缩短率轻微下降（0.20 周/秒）。冠状动脉闭塞后（左心室压力变化 14.5±6.7 毫米汞柱），每搏输出量（5.9±2.7 毫升）和射血分数（8.2±2.6%）的降低更为明显。这主要是由于缺血中心的平均圆周纤维缩短率显著降低（平均圆周纤维缩短率变化-93%）。为了通过心室造影评估局部心肌功能，必须考虑后负荷对缺血区域的显著影响。这在比较心室造影图时尤为重要，例如冠状动脉搭桥手术前后的造影图。
