Waldenberger F R, Pongo E, Meyns B, Flameng W
Department of Cardiac Surgery and Centre for Experimental Surgery and Anesthesiology, Katholieke Universiteit, Leuven, Belgium.
Thorac Cardiovasc Surg. 1995 Dec;43(6):313-9. doi: 10.1055/s-2007-1013802.
To assess the mechanical unloading properties of a new pneumatic cardiac assist device (60 ml Medos HIA-VAD) and its possible influence on recovery from myocardial stunning we performed a study in 12 anaesthetized sheep. After left thoracotomy measuring transducers were placed and the assist device connected between the left-atrial appendage and the descending thoracic aorta. Global hemodynamics were measured before and after unloading was performed. Myocardial stunning was induced by transient occlusion of a coronary artery for 15 minutes and regional myocardial wall thickening was measured. A group without unloading served as controls (group I, n = 4). In a second group unloading was performed during the last ten minutes of ischemia (group II, n = 4) and in a third group unloading was performed for 30 minutes starting after ten minutes of reperfusion (group III, n = 4). After starting the Medos HIA-VAD, significant unloading could be demonstrated: left-ventricular dP/dtmax decreased significantly (p < 0.05) to 54% and 61% in groups II and III and left-atrial pressure to 50% and 71%, respectively. Systolic and mean arterial pressure did not change significantly (p > 0.05), while the diastolic pressure increased (p < 0.05) to 134% and 138% in groups II and III. After mechanical unloading whether during ischemia or during reperfusion systolic wall thickening in the postischemic area recovered to 103% and 92% of preischemic control in groups II and III, respectively. Recovery was incomplete in the non-unloaded controls (76%) (p < 0.05 versus groups II and III). Post-ejection thickening, a diastolic measure of stunning, diminished significantly after unloading in both protocols (p < 0.05 for groups II and III versus group I). We conclude that mechanical unloading with the 60 ml Medos HIA-VAD significantly improves recovery from myocardial stunning.
为评估一种新型气动心脏辅助装置（60毫升美多斯HIA-VAD）的机械卸载特性及其对心肌顿抑恢复的可能影响，我们对12只麻醉绵羊进行了一项研究。左胸开胸后放置测量换能器，并将辅助装置连接在左心耳与降主动脉之间。在进行卸载前后测量整体血流动力学。通过冠状动脉短暂闭塞15分钟诱导心肌顿抑，并测量局部心肌壁增厚情况。一组不进行卸载作为对照组（I组，n = 4）。在第二组中，在缺血的最后10分钟进行卸载（II组，n = 4），在第三组中，在再灌注10分钟后开始进行30分钟的卸载（III组，n = 4）。启动美多斯HIA-VAD后，可证明有显著的卸载效果：II组和III组的左心室dP/dtmax显著降低（p < 0.05），分别降至54%和61%，左心房压力分别降至50%和71%。收缩压和平均动脉压无显著变化（p > 0.05），而舒张压升高（p < 0.05），II组和III组分别升至134%和138%。在机械卸载后，无论在缺血期间还是再灌注期间，II组和III组缺血后区域的收缩期壁增厚分别恢复到缺血前对照的103%和92%。未卸载的对照组恢复不完全（76%）（与II组和III组相比，p < 0.05）。射血后增厚是顿抑的一种舒张期测量指标，在两种方案中卸载后均显著降低（II组和III组与I组相比，p < 0.05）。我们得出结论，使用60毫升美多斯HIA-VAD进行机械卸载可显著改善心肌顿抑的恢复情况。
