Robertson J M, Buckberg G D, Vinten-Johansen J, Leaf J D
J Thorac Cardiovasc Surg. 1983 Jul;86(1):80-6.
In seven dogs on cardiopulmonary bypass, a critical stenosis (75% to 90%) of the left anterior descending coronary artery (LAD) was produced. Alternate 250 ml/min infusions of asanguineous and blood cardioplegic (4 degrees C) solutions were made for 3 to 5 minutes. Poststenotic flow (flowmeter), intramyocardial temperature, and aortic pressure were measured. During cardioplegic infusions of 250 ml/min, aortic pressure was 34 +/- 4 mm Hg higher with blood cardioplegia than with asanguineous cardioplegia (82 +/- 7 versus 48 +/- 8 mm Hg). Poststenotic cardioplegic flow was 39% +/- 9% higher (29 +/- 5 versus 18 +/- 5 ml/min) with blood cardioplegia. Consequently, blood cardioplegia resulted in more rapid arrest (20 +/- 2 versus 45 +/- 5 seconds) and lower myocardial temperature (6 degrees +/- 1 degree C) in the region of LAD blood supply; posterior ventricular myocardial cooling was similar (unobstructed vessels) with both solutions. These data show that the reduced viscosity of asanguineous cardioplegia compared to blood cardioplegia results in lower aortic pressure. Consequently, the higher aortic pressure with blood cardioplegia results in superior cardioplegic delivery beyond obstructed coronaries and better myocardial cooling. We conclude that the decreased viscosity of 4 degrees C asanguineous cardioplegia causes diversion of cardioplegic solution from the obstructed to the normal coronary bed.
在七只接受体外循环的犬身上，制造了左前降支冠状动脉（LAD）75%至90%的严重狭窄。以250毫升/分钟的速度交替输注无血和冷血心脏停搏液（4℃），持续3至5分钟。测量狭窄后血流（流量计）、心肌内温度和主动脉压力。在以250毫升/分钟的速度输注心脏停搏液期间，与无血心脏停搏液相比，冷血心脏停搏液使主动脉压力高34±4毫米汞柱（82±7对48±8毫米汞柱）。冷血心脏停搏液使狭窄后心脏停搏液流量高39%±9%（29±5对18±5毫升/分钟）。因此，冷血心脏停搏液导致LAD供血区域更快的心脏停搏（20±2对45±5秒）和更低的心肌温度（6℃±1℃）；两种溶液对心室后壁心肌的冷却效果相似（血管未阻塞）。这些数据表明，与冷血心脏停搏液相比，无血心脏停搏液粘度降低导致主动脉压力降低。因此，冷血心脏停搏液时较高的主动脉压力导致在阻塞冠状动脉远端有更好的心脏停搏液输送和更好的心肌冷却。我们得出结论，4℃无血心脏停搏液粘度降低导致心脏停搏液从阻塞冠状动脉床转移至正常冠状动脉床。
