Christakis G T, Buth K J, Weisel R D, Rao V, Joy L, Fremes S E, Goldman B S
Division of Cardiovascular Surgery, Sunnybrook Health Science Centre, Toronto, Ontario, Canada.
Ann Thorac Surg. 1996 Jan;61(1):128-34. doi: 10.1016/0003-4975(95)00933-7.
Transient right ventricular dysfunction has been previously documented after bypass operations despite adequate myocardial protection with intermittent antegrade cold blood cardioplegia. Recently warm blood cardioplegia has been interrupted during construction of distal anastomoses to improve visualization. The effects of intermittent antegrade warm blood cardioplegia, and the resultant periods of right ventricular normothermic ischemia, on postoperative right ventricular function are unknown.
To assess the effects of cardioplegia on right ventricular protection, 52 patients undergoing isolated bypass grafting were randomized to intermittent warm or cold blood cardioplegia. The two groups were similar with respect to age, sex, ventricular function, and right coronary stenoses. Cross-clamp times were similar (warm, 64 +/- 22 minutes; cold, 63 +/- 15 minutes; not significant). The cumulative time of cardioplegia interruption was longer in the cold group (42 +/- 8 minutes) than in the warm group (31 +/- 14 minutes; p < 0.002). A rapid-response thermodilution catheter was employed to assess postoperative right ventricular ejection fraction and end-diastolic and end-systolic volume indices.
The right ventricular ejection fraction was greater in the warm group at 6 hours (warm, 0.46 +/- 0.06; cold, 0.37 +/- 0.08; p < 0.05) and 8 hours (warm, 0.43 +/- 0.08; cold, 0.37 +/- 0.08; p < 0.05) postoperatively. The right ventricular end-diastolic volume index was less in the warm group 8 hours postoperatively (warm, 83 +/- 11 mL/m2; cold, 94 +/- 16 mL/m2; p < 0.05). There were no differences in pulmonary arterial pressures or right ventricular stroke work index.
Despite intermittent normothermic ischemia of half the cross-clamp time, patients receiving warm cardioplegia maintained right ventricular hemodynamics after bypass grafting.
尽管采用间歇性顺行冷血心脏停搏液进行了充分的心肌保护，但在搭桥手术后仍有短暂性右心室功能障碍的记录。最近，在构建远端吻合口时中断了温血心脏停搏液以改善视野。间歇性顺行温血心脏停搏液以及由此产生的右心室常温缺血期对术后右心室功能的影响尚不清楚。
为评估心脏停搏液对右心室保护的作用，将52例行单纯搭桥手术的患者随机分为间歇性温血或冷血心脏停搏液组。两组在年龄、性别、心室功能和右冠状动脉狭窄方面相似。阻断时间相似（温血组，64±22分钟；冷血组，63±15分钟；无显著差异）。冷血组心脏停搏液中断的累计时间（42±8分钟）长于温血组（31±14分钟；p<0.002）。使用快速反应热稀释导管评估术后右心室射血分数以及舒张末期和收缩末期容积指数。
术后6小时（温血组，0.46±0.06；冷血组，0.37±0.08；p<0.05）和8小时（温血组，0.43±0.08；冷血组，0.37±0.08；p<0.05）温血组的右心室射血分数更高。术后8小时温血组的右心室舒张末期容积指数更低（温血组，83±11 mL/m²；冷血组，94±16 mL/m²；p<0.05）。肺动脉压或右心室每搏功指数无差异。
尽管有一半阻断时间的间歇性常温缺血，但接受温血心脏停搏液的患者在搭桥手术后维持了右心室血流动力学。
