Ardehali A, Gates R N, Laks H, Drinkwater D C, Rudis E, Sorensen T J, Chang P, Aharon A
Department of Surgery, University of California, Los Angeles Medical Center 90024, USA.
J Thorac Cardiovasc Surg. 1995 May;109(5):935-9; discussion 939-40. doi: 10.1016/S0022-5223(95)70319-5.
Warm retrograde blood cardioplegia is frequently used for myocardial protection, despite experimental studies questioning the adequacy of capillary flow to the right ventricle and septum. The capillary distribution of retrograde blood cardioplegia in the human heart is unknown. Hearts from eight transplant recipients with the diagnosis of idiopathic or dilated cardiomyopathy were arrested in situ with cold blood cardioplegia and excised with the coronary sinus intact. Within 20 minutes of explanation, colored microspheres mixed in 37 degrees C blood cardioplegia were administered through the coronary sinus at a pressure of 30 to 40 mm Hg for 2 minutes. Twelve transmural myocardial samples were taken horizontally at the level of midventricle and apex to determine regional capillary flow rates. When retrograde warm blood cardioplegia was administered at a rate of 0.42 +/- 0.06 ml/gm/min, the left ventricle, the septum, the posterior wall of the right ventricle, and the apex consistently received capillary flow rates in excess of their metabolic requirements. The capillary perfusion of anterior and lateral walls of the right ventricle was marginally adequate to sustain aerobic metabolism. In explanted human hearts, retrograde blood cardioplegia provides adequate capillary flow to the left ventricle, the septum, the posterior wall of the right ventricle, and the apex; however, capillary flow to the anterior and lateral walls of the right ventricle is marginal. This study delineates the tenuous balance between supply and demand for right ventricular protection with warm continuous retrograde blood cardioplegia.
尽管有实验研究质疑逆行冷血停搏液对右心室和室间隔的毛细血管灌注是否充足，但温血逆行性心脏停搏液仍经常用于心肌保护。目前尚不清楚温血逆行性心脏停搏液在人体心脏中的毛细血管分布情况。对8例诊断为特发性或扩张型心肌病的心脏移植受者的心脏，先用冷血停搏液原位停搏，然后完整切除冠状动脉窦。在心脏切除后20分钟内，将混有彩色微球的37℃冷血停搏液以30至40mmHg的压力经冠状动脉窦注入2分钟。在心室中部和心尖水平水平取12个透壁心肌样本，以测定局部毛细血管流速。当以0.42±0.06ml/gm/min的速度给予逆行温血停搏液时，左心室、室间隔、右心室后壁和心尖持续获得超过其代谢需求的毛细血管流速。右心室前壁和侧壁的毛细血管灌注勉强足以维持有氧代谢。在离体人体心脏中，逆行性心脏停搏液能为左心室、室间隔、右心室后壁和心尖提供充足的毛细血管血流；然而，右心室前壁和侧壁的毛细血管血流处于临界状态。本研究描述了温血持续逆行性心脏停搏液在右心室保护中供需之间的脆弱平衡。
