Tian G, Shen J, Sun J, Xiang B, Oriaku G I, Zhezong L, Scarth G, Somorjai R, Saunders J K, Salerno T A, Deslauriers R
Institute for Biodiagnostics, National Research Council, Winnipeg, Manitoba, Canada.
J Thorac Cardiovasc Surg. 1998 Apr;115(4):913-24. doi: 10.1016/S0022-5223(98)70374-5.
This study was designed to determine whether simultaneous antegrade/retrograde cardioplegia improves myocardial perfusion in areas supplied by occluded vessels.
Isolated pig hearts placed in a Langendorff preparation were divided into two groups. The left anterior descending coronary artery was occluded at its origin. In group 1 (n = 7), simultaneous antegrade/retrograde cardioplegia was conducted with use of a single perfusion unit with tubing in a Y-shaped configuration at the end, joined to the aorta and the coronary sinus. In group 2 (n = 8) simultaneous antegrade/retrograde cardioplegia was performed with two separate units, one for antegrade delivery of cardioplegic solution and the other for retrograde cardioplegic solution delivery. Myocardial perfusion in the region supplied by the left anterior descending artery and the region not supplied by this artery was assessed by magnetic resonance imaging, with use of a magnetic resonance contrast agent. The contrast agent was introduced into the common perfusion line in group 1 and into the aortic line only in group 2.
Magnetic resonance images showed that the myocardium in the region supported by the left anterior descending artery could not be perfused with antegrade cardioplegic solution because of occlusion of the artery. During simultaneous antegrade/retrograde cardioplegia, however, the myocardium in the left anterior descending region was perfused by approximately 40% to 50% (group 1) or 20% to 30% (group 2) of the degree of perfusion in the region not perfused by the left anterior descending artery (100%). Almost no cardioplegic solution was delivered to the heart through the coronary sinus route during simultaneous antegrade/retrograde cardioplegia in both groups of hearts. Myocardial perfusion in the region supported by the left anterior descending artery was heterogeneous during simultaneous antegrade/retrograde cardioplegia.
Simultaneous antegrade/retrograde cardioplegia significantly improved myocardial perfusion in jeopardized areas of the myocardium. The jeopardized myocardium was mainly perfused by the solution drained from the adjacent normal tissue. Elevated pressure at the coronary sinus during simultaneous antegrade/retrograde cardioplegia is responsible for the redistribution of antegradely delivered cardioplegic solution.
本研究旨在确定顺行/逆行联合心脏停搏法能否改善闭塞血管供血区域的心肌灌注。
将置于Langendorff装置中的离体猪心分为两组。左冠状动脉前降支在其起始处被阻断。在第1组（n = 7）中，使用一个末端呈Y形配置的单一灌注单元进行顺行/逆行联合心脏停搏，该单元通过管道连接到主动脉和冠状窦。在第2组（n = 8）中，使用两个独立的单元进行顺行/逆行联合心脏停搏，一个用于顺行输送心脏停搏液，另一个用于逆行输送心脏停搏液。通过磁共振成像并使用磁共振造影剂评估左冠状动脉前降支供血区域和非该动脉供血区域的心肌灌注。在第1组中，造影剂被引入共同灌注管路，而在第2组中仅被引入主动脉管路。
磁共振图像显示，由于动脉闭塞，左冠状动脉前降支供血区域的心肌无法通过顺行心脏停搏液进行灌注。然而，在顺行/逆行联合心脏停搏期间，左冠状动脉前降支区域的心肌灌注程度约为未被左冠状动脉前降支灌注区域（100%）的40%至50%（第1组）或20%至30%（第2组）。在两组心脏的顺行/逆行联合心脏停搏期间，几乎没有心脏停搏液通过冠状窦途径输送到心脏。在顺行/逆行联合心脏停搏期间，左冠状动脉前降支供血区域的心肌灌注不均匀。
顺行/逆行联合心脏停搏显著改善了心肌濒危区域的心肌灌注。濒危心肌主要由相邻正常组织引流的液体灌注。顺行/逆行联合心脏停搏期间冠状窦压力升高导致顺行输送的心脏停搏液重新分布。
