Weisel R D, Goldman B S, Lipton I H, Teasdale S, Mickle D, Baird R J
Surgery. 1978 Dec;84(6):812-21.
The low mortality and perioperative infarction rates for aortocoronary bypass (ACB) make them unsuitable for evaluating the adequacy of myocardial protection. Enzymatic and functional measurements were found to be sensitive and specific indicators of myocardial injury. A prospective concurrent study of 78 patients undergoing triple ACB was conducted to evaluate the effectiveness of three popular methods of myocardial protection. Group I (32 patients) had a single dose of cold (4 degrees C) potassium cardioplegic (CPC) solution infused inducing a mean myocardial temperature (MMT) of 31 +/- 4 degrees C/min. Group II (23 patients) had multiple doses of CPC solution 8nducing a MMT of 22 +/- 2 degrees C/min. Group III (23 patients) had intermittent anoxic arrest at a MMT of 28 +/- 1 degrees C. The groups were not randomized but had comparable clinical symptoms and catheterization findings. Serial measurements of cardiac specific creatine kinase (CK-MB) revealed a peak in enzymatic activity occurring 60 minutes following ACB. The highest CK-MB was significantly (P less than 0.01) lower in group II (25 +/- 8 IU/liter) than group I (50 +/- 8 IU/liter), or group III (68 +/- 14 IU/liter). Myocardial performance was evaluated after ACB by serially measuring left ventricular stroke work index (SW) and left atrial pressure (LAP) in response to volume loading. The rise in SW was significantly (P less than 0.01) greater in group II (3.0 +/- 0.7 gm.m/sq m/mm Hg) than in group I (1.4 +/- 0.7) or group III (1.8 +/- 0.9). The highest SW attained was higher (P less than .01) in group II (43 +/- 7 gm.m/sq m) than group I (19 +/- 6) or group III (34 +/- 8) at comparable LAP values (group I: 20 +/- 5 mm Hg; group II: 18 +/- 3; group III: 18 +/- 4). Post-operative clinical evaluation failed to differentiate among the three groups. The more sensitive indices, however, demonstrated the superiority of cold, multidose cardioplegia in providing optimal myocardial protection.
主动脉冠状动脉搭桥术（ACB）的低死亡率和围手术期梗死率使其不适用于评估心肌保护的充分性。酶学和功能测量被发现是心肌损伤的敏感和特异指标。对78例行三联ACB的患者进行了一项前瞻性同期研究，以评估三种常用心肌保护方法的有效性。第一组（32例患者）输注单剂量冷（4℃）钾停搏液（CPC），诱导平均心肌温度（MMT）为31±4℃/分钟。第二组（23例患者）输注多剂量CPC溶液，诱导MMT为22±2℃/分钟。第三组（23例患者）在MMT为28±1℃时进行间歇性缺氧停搏。各组未随机分组，但临床症状和导管检查结果具有可比性。连续测量心肌特异性肌酸激酶（CK-MB）显示，ACB后60分钟酶活性达到峰值。第二组（25±8 IU/升）的最高CK-MB显著低于第一组（50±8 IU/升）或第三组（68±14 IU/升）（P<0.01）。ACB后通过连续测量左心室每搏作功指数（SW）和左心房压力（LAP）对容量负荷的反应来评估心肌功能。第二组（3.0±0.7 gm.m/平方米/毫米汞柱）的SW升高显著高于第一组（1.4±0.7）或第三组（1.8±0.9）（P<0.01）。在可比的LAP值下（第一组：20±5毫米汞柱；第二组：18±3；第三组：18±4），第二组（43±7 gm.m/平方米）达到的最高SW高于第一组（19±6）或第三组（34±8）（P<0.01）。术后临床评估未能区分三组。然而，更敏感的指标显示了冷的多剂量心脏停搏在提供最佳心肌保护方面的优越性。
