Fedele F A, Capone R J, Most A S, Gewirtz H
Division of Cardiology, Rhode Island Hospital, Providence 02903.
Circulation. 1988 Jun;77(6):1403-13. doi: 10.1161/01.cir.77.6.1403.
This study tested the hypothesis that pressure-controlled intermittent coronary sinus occlusion (PICSO) would be useful in ameliorating myocardial ischemia under conditions characterized by preserved, but reduced (relative to demand), myocardial blood flow. Studies were conducted in closed-chest, sedated domestic swine prepared with an artificial stenosis that reduced luminal diameter of the animal's left anterior descending coronary artery by 80%. Measurements of hemodynamics, regional myocardial blood flow, and oxygen, lactate, and nucleoside metabolism were obtained in 10 animals (1) before placement of stenosis, (2) 30 min after insertion of stenosis, (3) after 30 and 60 min of PICSO, and (4) 30 min after discontinuation of PICSO. Two groups of control animals were studied to observe the natural history of metabolic markers of ischemia. Control group I consisted of four animals studied concurrently and subjected to the same protocol except for the fact that PICSO was not applied. Control group II consisted of eight additional animals studied as a group. A specially designed balloon-tipped catheter positioned in the proximal portion of the animal's great cardiac vein was used to provide PICSO. Heart rate was controlled by atrial pacing (rate, 145 beats/min) through the study. After placement of the stenosis, flow in endocardial and transmural layers distal to the stenosis declined significantly (p less than .01) vs control. Application of PICSO failed to increase arterial inflow distal to the stenosis in any myocardial layer. Myocardial aerobic metabolism was adversely affected by stenosis and changed from consumption of lactate, inosine, and hypoxanthine before stenosis to production at 30 min after stenosis. Although PICSO was associated with reduced production and a return toward consumption of lactate, inosine, and hypoxanthine, a similar pattern of changes in lactate, inosine, and hypoxanthine metabolism was observed in control animals over a comparable period of time. In addition, regional myocardial oxygen extraction and consumption were not changed vs poststenosis levels by PICSO. However, in comparison with controls, PICSO did accelerate the rate of resolution of myocardial ischemia as assessed by lactate metabolism. At 30 min of PICSO (or sham) the change vs poststenosis was +33.6 +/- 25.0 mumol/min/100 g in the PICSO but only +6.7 +/- 29.7 in the control group (p = .05). We conclude, therefore, that even though PICSO did not alter the final level of myocardial ischemia under conditions modeled in this study it did accelerate its rate of resolution, an effect that may be beneficial clinically.
在心肌血流保持但减少（相对于需求）的情况下，压力控制间歇性冠状静脉窦闭塞（PICSO）有助于改善心肌缺血。研究在闭胸、镇静的家猪身上进行，这些家猪通过人工狭窄使左前降支冠状动脉管腔直径减少80%。在10只动物中进行了血流动力学、局部心肌血流以及氧、乳酸和核苷代谢的测量：（1）在放置狭窄前；（2）插入狭窄后30分钟；（3）PICSO 30分钟和60分钟后；（4）停止PICSO后30分钟。研究了两组对照动物以观察缺血代谢标志物的自然病程。对照组I由4只同时进行研究的动物组成，除未应用PICSO外，接受相同方案。对照组II由另外8只作为一组进行研究的动物组成。使用专门设计的带球囊尖端的导管置于动物大心静脉近端以提供PICSO。在整个研究过程中，通过心房起搏（频率为145次/分钟）控制心率。放置狭窄后，狭窄远端的心内膜层和透壁层血流与对照组相比显著下降（p<0.01）。PICSO未能增加狭窄远端任何心肌层的动脉流入。狭窄对心肌有氧代谢产生不利影响，从狭窄前乳酸、肌苷和次黄嘌呤的消耗转变为狭窄后30分钟的生成。尽管PICSO与乳酸、肌苷和次黄嘌呤生成减少以及向消耗方向恢复有关，但在相当长的一段时间内，对照动物也观察到了乳酸、肌苷和次黄嘌呤代谢的类似变化模式。此外，与狭窄后水平相比，PICSO并未改变局部心肌氧摄取和消耗。然而，与对照组相比，通过乳酸代谢评估，PICSO确实加速了心肌缺血的缓解速度。在PICSO（或假手术）30分钟时，与狭窄后相比的变化在PICSO组为+3³³6±25.0 μmol/min/100 g，而对照组仅为+6.7±29.7（p = 0.05）。因此，我们得出结论，即使在本研究模拟的条件下，PICSO并未改变心肌缺血的最终水平，但它确实加速了其缓解速度，这一效应在临床上可能是有益的。
