Conti V R, Bertranou E G, Blackstone E H, Kirklin J W, Digerness S B
J Thorac Cardiovasc Surg. 1978 Nov;76(5):577-89.
Seventeen of 34 consecutive patients undergoing coronary artery bypass grafting were randomly assigned to one of two methods of myocardial preservation. With the cold cardioplegic method (Group A), a 4 degrees C. asanguineous solution with 30 mEq. of potassium per liter was infused into the aortic root for about 2 minutes immediately after aortic cross-clamping and again after about 45 minutes or when myocardial temperature rose above 19 degrees C. External cardiac cooling was provided by constant infusion of 4 degrees C. Ringer's solution into the pericardium. Seventeen patients were assigned to simple cardiac cooling by hypothermic systemic perfusion before aortic cross-clamping plus external cardiac cooling (Group B). Electromechanical activity ceased within 1 to 2 minutes in Group A but continued throughout the ischemic period in 14 patients in Group B. Myocardial temperature (mean for all observations) during aortic cross-clamping was 17.2 +/- 0.44 degrees C. In Group A and 24.0 +/- 0.70 degrees C. in Group B. Operating conditions were better in Group A. Card-ac function early postoperatively was good in both groups clinically and according to measurements, but only in the cold cardioplegic group (A) was cardiac index not adversely affected by longer cross-clamp time. Myocardial necrosis occurred in both groups but was probably less in the cold cardioplegic group. Thirteen patients (76 percent) in Group A had no electrocardiographic evidence of myocardial injury, compared with eight (47 percent) in Group B (p = 0.08). Eleven (65 percent of Group A had no or short-lived appearance of ceatine phosphokinase isoenzyme (CK-MB), compared with six (35 percent) of Group B (p = 0.08). Time-related CK-MB and SGOT mean levels were consistently lower in Group A.
34例连续接受冠状动脉搭桥术的患者中，17例被随机分配至两种心肌保护方法之一。采用冷心脏停搏液法（A组），在主动脉阻断后立即向主动脉根部输注含30 mEq/L钾的4℃无血溶液约2分钟，约45分钟后或心肌温度升至19℃以上时再次输注。通过向心包持续输注4℃林格液进行心脏表面降温。17例患者在主动脉阻断前采用低温全身灌注加心脏表面降温进行单纯心脏降温（B组）。A组在1至2分钟内心电机械活动停止，但B组14例患者在整个缺血期心电机械活动持续存在。主动脉阻断期间心肌温度（所有观察值的平均值）A组为17.2±0.44℃，B组为24.0±0.70℃。A组手术条件更好。术后早期两组心功能在临床和测量方面均良好，但只有冷心脏停搏液组（A组）心脏指数未受较长阻断时间的不利影响。两组均发生心肌坏死，但冷心脏停搏液组可能较少。A组13例患者（76%）无心电图心肌损伤证据，B组为8例（47%）（p = 0.08）。A组11例（65%）肌酸磷酸激酶同工酶（CK-MB）无出现或短暂出现，B组为6例（35%）（p = 0.08）。A组与时间相关的CK-MB和SGOT平均水平持续较低。
