Malkowski M J, Kramer C M, Parvizi S T, Dianzumba S, Marquez J, Reichek N, Magovern J A
Department of Anesthesia, Allegheny General Hospital, Allegheny University of the Health Sciences, MCP-Hahnemann School of Medicine, Pittsburgh, Pennsylvania 15212-4772, USA.
J Am Coll Cardiol. 1998 Apr;31(5):1035-9. doi: 10.1016/s0735-1097(98)00023-0.
This study sought to assess the effects of sequential coronary artery occlusion during minimally invasive coronary artery bypass graft surgery (CABG) on hemodynamic variables and left ventricular systolic function by means of transesophageal echocardiography (TEE).
Clinical and experimental studies suggest a protective effect of ischemic preconditioning in patients with acute coronary syndromes. However, the effect of repetitive myocardial ischemia on myocardial mechanical function in humans is not completely understood.
Seventeen patients with left anterior descending coronary artery (LAD) stenosis > or =70% and normal rest left ventricular systolic function referred for minimally invasive CABG underwent intraoperative TEE for assessment of regional left ventricular wall motion and measurement of hemodynamic variables at baseline (baseline 1), during a 5-min coronary occlusion (occlusion 1), after a 5-min reperfusion period (baseline 2) and a during a second coronary occlusion during bypass anastomosis (occlusion 2).
Left ventricular wall motion score (LVWMS) increased significantly from baseline (16.0) to occlusion 1 (21.4+/-3.1 [mean +/- SD], p < 0.05) and occlusion 2 (21.8+/-3.1, p < 0.05). No difference in LVWMS was noted between occlusions 1 and 2. Pulmonary artery systolic pressure increased significantly from baseline (25+/-6 mm Hg) to occlusion 1 (32+/-7 mm Hg, p < 0.05) and occlusion 2 (33+/-6 mm Hg, p < 0.05). Pulmonary artery diastolic pressure also increased significantly from baseline (12+/-4 mm Hg) to occlusion 1 (16+/-4 mm Hg, p < 0.05) and occlusion 2 (16+/-4 mm Hg, p < 0.05). No significant differences in pulmonary artery pressures were noted between occlusions 1 and 2.
Ischemic dysfunction was precipitated by the 5-min LAD occlusion, as shown by the increase in LVWMS and pulmonary artery pressure. However, a 5-min coronary occlusion and the resulting ischemia do not alter regional left ventricular systolic function during subsequent ischemia in humans.
本研究旨在通过经食管超声心动图（TEE）评估微创冠状动脉旁路移植术（CABG）期间序贯性冠状动脉闭塞对血流动力学变量和左心室收缩功能的影响。
临床和实验研究提示缺血预处理对急性冠状动脉综合征患者具有保护作用。然而，重复性心肌缺血对人体心肌机械功能的影响尚未完全明确。
17例左前降支冠状动脉（LAD）狭窄≥70%且静息时左心室收缩功能正常、拟行微创CABG的患者，术中接受TEE检查，以评估左心室壁节段运动，并在基线（基线1）、5分钟冠状动脉闭塞期间（闭塞1）、5分钟再灌注期后（基线2）以及旁路吻合期间第二次冠状动脉闭塞期间（闭塞2）测量血流动力学变量。
左心室壁运动评分（LVWMS）从基线时的16.0显著增加至闭塞1时的21.4±3.1[均值±标准差，p<0.05]以及闭塞2时的21.8±3.1（p<0.05）。闭塞1和闭塞2之间的LVWMS无差异。肺动脉收缩压从基线时的25±6 mmHg显著增加至闭塞1时的32±7 mmHg（p<0.05）以及闭塞2时的33±6 mmHg（p<0.05）。肺动脉舒张压也从基线时的12±4 mmHg显著增加至闭塞1时的16±4 mmHg（p<0.05）以及闭塞2时的16±4 mmHg（p<0.05）。闭塞1和闭塞2之间的肺动脉压力无显著差异。
如LVWMS和肺动脉压力升高所示，5分钟的LAD闭塞引发了缺血性功能障碍。然而，5分钟的冠状动脉闭塞及由此产生的缺血并未改变人体后续缺血期间的左心室节段收缩功能。
