Stoica Serban C, Satchithananda Duwarakan K, White Paul A, Sharples Linda, Parameshwar Jayan, Redington Andrew N, Large Stephen R
Papworth Hospital, Cambridge, United Kingdom.
J Thorac Cardiovasc Surg. 2006 Jul;132(1):116-23. doi: 10.1016/j.jtcvs.2005.12.061.
Experimental and clinical data suggest that brain death predominantly affects the right ventricle. We aimed to investigate right ventricle function after brain death and during clinical transplantation with load-independent methods.
Patients with and without brain death were enrolled. A total of 33 consecutive heart donors (5 live, "domino" donors) and 10 patients undergoing coronary surgery (coronary artery bypass graft controls) were studied with pressure-volume loops in the right ventricle. Contractile reserve was measured with dopamine stimulation.
Brain-dead donors had a higher mean cardiac index than coronary artery bypass graft controls (3.3 vs 2.8 L/min/m2), but impaired load-independent indices. Despite increased right ventricle stroke volume, the ejection fraction and slope of the end-systolic pressure-volume relationship were significantly reduced in brain-dead donors compared with controls. Diastolic abnormalities were also manifest as increased end-diastolic volume index and prolonged Tau (P < .05). Dopamine improved cardiac output, but without influencing end-systolic pressure-volume relationship, or Tau, and at the expense of further increased right ventricle end-diastolic volume. Before explantation, a significantly higher diastolic volume was also seen in hearts that developed postoperative dysfunction compared with organs without this complication (114.4 vs 77.2 mL/m2, P = .02).
Brain death leads to right ventricle dysfunction, which may go undetected with conventional techniques. Right ventricle dilatation could represent an early marker of failure. Refinement of selection criteria to include load-independent indices of performance may be desirable to help expand the donor pool.
实验和临床数据表明,脑死亡主要影响右心室。我们旨在采用负荷独立方法研究脑死亡后及临床移植期间的右心室功能。
纳入有和无脑死亡的患者。对33例连续的心脏供体(5例活体“多米诺”供体)和10例接受冠状动脉手术的患者(冠状动脉搭桥术对照组)进行右心室压力-容积环研究。用多巴胺刺激测量收缩储备。
脑死亡供体的平均心脏指数高于冠状动脉搭桥术对照组(3.3对2.8L/min/m²),但负荷独立指标受损。尽管右心室每搏输出量增加,但与对照组相比,脑死亡供体的射血分数和收缩末期压力-容积关系斜率显著降低。舒张功能异常还表现为舒张末期容积指数增加和Tau延长(P<.05)。多巴胺改善了心输出量,但未影响收缩末期压力-容积关系或Tau,且以进一步增加右心室舒张末期容积为代价。在植入前,与无此并发症的器官相比,术后发生功能障碍的心脏舒张容积也显著更高(114.4对77.2mL/m²,P=.02)。
脑死亡导致右心室功能障碍,传统技术可能无法检测到。右心室扩张可能是功能衰竭的早期标志。完善选择标准以纳入负荷独立的性能指标可能有助于扩大供体库。