Hess O M, Schneider J, Nonogi H, Carroll J D, Schneider K, Turina M, Krayenbuehl H P
Department of Internal Medicine, University Hospital, Zürich, Switzerland.
Circulation. 1988 May;77(5):967-77. doi: 10.1161/01.cir.77.5.967.
Myocardial structure of left ventricular segments with recurrent myocardial ischemia was evaluated by morphometry and compared with that of segments with normal blood supply in 15 patients with exercise-induced myocardial ischemia. Left ventricular high-fidelity pressure measurements and simultaneous biplane angiocardiography were performed in patients at rest and during supine bicycle exercise. Left ventricular transmural biopsy samples were obtained during open heart surgery in a normally contracting region and in a region with exercise-induced de novo wall motion abnormalities. Transmural and endocardial and epicardial left ventricular muscle fiber diameter and interstitial nonmuscular tissue were determined by morphometry. Eight patients were restudied 8 months after successful bypass grafting. Heart rate and left ventricular end-diastolic pressure increased significantly preoperatively and postoperatively during exercise. However, left ventricular end-diastolic pressure was significantly higher preoperatively (33 mm Hg) during exercise than postoperatively (19 mm Hg; p less than .01). Left ventricular ejection fraction dropped significantly during exercise (63% vs 54%; p less than .001) before surgery but remained unchanged (64% vs 66%; NS) after revascularization. Regional axis shortening of the normokinetic region increased slightly during exercise pre- and postoperatively, but decreased in the hypokinetic region from 42% at rest to 25% during exercise (p less than .001) before surgery and from 47% at rest to 41% during exercise (p less than .05) after revascularization. Transmural muscle fiber diameter (normal less than or equal to 23 microns) was significantly larger in regions with exercise-induced ischemia (29.3 microns, p less than .025) than in normally contracting regions (27.3 microns). Interstitial nonmuscular tissue (normal less than or equal to 10%) was significantly increased in regions with exercise-induced wall motion abnormalities (19.8%) compared with normally contracting regions (15.5%; p less than .05). In the endocardial half of left ventricular segments with recurrent myocardial ischemia interstitial tissue was significantly increased (23.7%; p less than .01) compared with that in the epicardial half of the same segment (17.5%). It is concluded that structural alterations of the myocardium (muscle fiber hypertrophy and increased interstitial nonmuscular tissue) develop especially in the endocardial layers of the transiently ischemic myocardium with normal function at rest.(ABSTRACT TRUNCATED AT 400 WORDS)
对15例运动诱发心肌缺血患者，采用形态计量学方法评估左心室节段反复心肌缺血的心肌结构，并与血供正常节段进行比较。在患者静息和仰卧位自行车运动时进行左心室高保真压力测量及同步双平面心血管造影。在心脏直视手术中，于正常收缩区域和运动诱发的新出现室壁运动异常区域获取左心室透壁活检样本。通过形态计量学测定透壁、心内膜和心外膜的左心室肌纤维直径以及间质非肌肉组织。8例患者在成功进行搭桥手术后8个月接受复查。运动期间术前和术后心率及左心室舒张末期压力显著升高。然而，运动期间术前左心室舒张末期压力（33mmHg）显著高于术后（19mmHg；p<0.01）。手术前运动期间左心室射血分数显著下降（63%对54%；p<0.001），但血运重建后保持不变（64%对66%；无显著性差异）。术前和术后运动期间，正常运动区域的节段性轴缩短略有增加，但运动减弱区域术前从静息时的42%降至运动时的25%（p<0.001），血运重建后从静息时的47%降至运动时的41%（p<0.05）。运动诱发缺血区域的透壁肌纤维直径（正常≤23微米）显著大于正常收缩区域（29.3微米，p<0.025）（27.3微米）。与正常收缩区域（15.5%）相比，运动诱发室壁运动异常区域的间质非肌肉组织（正常≤10%）显著增加（19.8%；p<0.05）。在反复心肌缺血的左心室节段的心内膜侧，间质组织较同一节段的心外膜侧显著增加（23.7%；p<0.01）（17.5%）。结论是，心肌结构改变（肌纤维肥大和间质非肌肉组织增加）尤其在静息功能正常的短暂缺血心肌的心内膜层发生。（摘要截选至400字）
