Ascah K J, Gillam L D, Davidoff R, Franklin T D, Newell J B, Hogan R D, Weyman A E
Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Boston 02114.
J Am Coll Cardiol. 1989 Mar 1;13(3):730-6. doi: 10.1016/0735-1097(89)90618-9.
The effect of infarct maturation on the temporal sequence of contraction within infarct zones has not previously been described. Accordingly, the time-varying pattern of contraction within ischemic/infarct zones was studied with use of cross-sectional echocardiography in 17 dogs at 10 min to 6 weeks after acute experimental myocardial infarction. Left ventricular short-axis images were digitized from end-diastole to end-systole and endocardial fractional radial change along 36 evenly spaced rays was calculated. The circumferential extent of dyskinesia and the number of rays that exhibited maximal dyskinesia were determined for each decile of the normalized contraction sequence. Between 10 min and 1 week after infarction, the greatest circumferential extent of dyskinesia occurred between the 3rd and 4th deciles of the normalized contraction sequence. However, as the infarct matured, the greatest spatial expanse of dyskinesia was noted to occur progressively earlier in the contraction sequence (second decile at 6 weeks), and the extent of mid- to late-systolic dyskinesia decreased markedly. Whereas end-systolic dyskinesia was present in 30% to 50% of ischemic/infarct zone rays from 10 min to 48 h, end-systolic dyskinesia was no longer observed at 6 weeks. Similarly, the maximal amplitude of dyskinesia was most commonly observed during midsystole from 10 min to 48 h, but occurred progressively earlier as the infarct matured, falling during the first decile at 6 weeks after infarction. These data suggest that maximal circumferential extent and amplitude of dyskinesia occur progressively earlier in the systolic contraction sequence as the infarct matures.(ABSTRACT TRUNCATED AT 250 WORDS)
梗死灶成熟对梗死区内收缩时间顺序的影响此前尚未见报道。因此，在17只犬急性实验性心肌梗死后10分钟至6周，采用横断面超声心动图研究了缺血/梗死区内收缩的时变模式。从舒张末期到收缩末期对左心室短轴图像进行数字化处理，并计算沿36条等间距射线的内膜径向分数变化。对于标准化收缩序列的每个十分位数，确定运动障碍的圆周范围和表现出最大运动障碍的射线数量。梗死发生后10分钟至1周内，运动障碍的最大圆周范围出现在标准化收缩序列的第3和第4十分位数之间。然而，随着梗死灶成熟，运动障碍的最大空间范围在收缩序列中出现得越来越早（6周时为第二十分位数），且收缩中期至晚期运动障碍的程度明显降低。从10分钟至48小时，30%至50%的缺血/梗死区射线存在收缩末期运动障碍，但在6周时不再观察到收缩末期运动障碍。同样，运动障碍的最大幅度最常见于10分钟至48小时的收缩中期，但随着梗死灶成熟，其出现得越来越早，在梗死后6周的第一个十分位数期间下降。这些数据表明，随着梗死灶成熟，运动障碍的最大圆周范围和幅度在收缩期收缩序列中出现得越来越早。（摘要截选至250词）
