Gurné O, Chenu P, Buche M, Louagie Y, Eucher P, Marchandise B, Rombaut E, Blommaert D, Schroeder E
Department of Cardiology, Mont-Godinne Hospital, Université Catholique de Louvain, 5530 Yvoir, Belgium.
Heart. 1999 Sep;82(3):336-42. doi: 10.1136/hrt.82.3.336.
To compare the mechanisms by which arterial and venous grafts increase their flow during pacing induced tachycardia, early and later after coronary bypass surgery.
43 grafts (13 epigastric artery, 15 mammary artery, 15 saphenous vein) evaluated early (9 (3) days (mean (SD)) after bypass surgery were compared with 41 other grafts (15 epigastric, 11 mammary, 15 saphenous vein) evaluated later after surgery (mean 23 months, range 6 to 168 months) by quantitative angiography and intravascular Doppler velocity analysis during atrial pacing. Controls were 17 normal coronary arteries.
Baseline graft flow tended to be lower later after surgery than early (41 (16) v 45 (21) ml/min, NS). Blood flow increased during pacing by 30 (16)% early after surgery, less than later after surgery (+46 (18)%, p < 0.001) and less than in normal coronary arteries (+54 (27)%, p < 0.001 v early grafts; NS v late grafts). There was no difference between venous and arterial grafts. No significant vasodilatation was observed during pacing early after surgery in arterial and venous grafts. Later after surgery, significant vasodilatation was observed only in arterial grafts (mammary and epigastric grafts), from 2.41 (0.37) to 2.53 (0. 41) mm (+5.1% v basal, p < 0.001). Early after surgery and in venous grafts later after surgery, the increase in flow was entirely due to an increase in velocity. In later arterial grafts, the relative contribution of the increase in velocity to the increase in flow during pacing was lower in arterial grafts (70 (22)%) than in venous grafts (102 (11)%, p < 0.001) and similar to normal coronary arteries (68 (28)%).
Early and later after surgery, arterial grafts and venous grafts both increase their flow similarly during pacing. Early arterial grafts and venous grafts increase their flow only through an increase in velocity. Later after surgery, arterial grafts act as more physiological conduits and increase their flow in the same way as normal coronary arteries, through an increase in velocity and calibre mediated by the endothelium.
比较冠状动脉搭桥手术后早期和晚期，动脉移植物和静脉移植物在起搏诱发心动过速时增加血流量的机制。
对43例搭桥手术后早期（9（3）天，平均（标准差））评估的移植物（13例腹壁动脉、15例乳内动脉、15例大隐静脉）与41例手术后晚期（平均23个月，范围6至168个月）评估的其他移植物（15例腹壁动脉、11例乳内动脉、15例大隐静脉）进行定量血管造影和心房起搏期间的血管内多普勒速度分析比较。对照组为17条正常冠状动脉。
术后晚期移植物的基线血流量往往低于早期（41（16）对45（21）ml/min，无显著性差异）。起搏期间血流量在术后早期增加30（16）%，低于术后晚期（+46（18）%，p<0.001）且低于正常冠状动脉（+54（27）%，与早期移植物相比p<0.001；与晚期移植物相比无显著性差异）。静脉移植物和动脉移植物之间无差异。术后早期在动脉和静脉移植物起搏期间未观察到明显的血管扩张。术后晚期，仅在动脉移植物（乳内动脉和腹壁动脉移植物）中观察到明显的血管扩张，从2.41（0.37）至2.53（0.41）mm（与基础值相比增加5.1%，p<0.001）。术后早期以及术后晚期的静脉移植物中，血流量的增加完全是由于速度的增加。在术后晚期的动脉移植物中，起搏期间速度增加对血流量增加的相对贡献在动脉移植物中（70（22）%）低于静脉移植物（102（11）%，p<0.001）且与正常冠状动脉（68（28）%）相似。
术后早期和晚期，动脉移植物和静脉移植物在起搏期间血流量增加情况相似。早期动脉移植物和静脉移植物仅通过速度增加来增加血流量。术后晚期，动脉移植物作为更具生理功能的管道，通过内皮介导的速度和管径增加，以与正常冠状动脉相同的方式增加血流量。
