Flow-induced vasomotor response to tachycardia of the human internal mammary artery and saphenous vein grafts late following bypass surgery.

摘要: Increasing blood flow results in endothelium-dependent vasodilation of angiographically normal epicardial coronary arteries humans. To compare the ability internal mammary artery (IMA) and saphenous vein (SV) used as bypass grafts to adapt their vasomotor tone an increase myocardial demand induced by tachycardia, 10 IMA seven SV were studied quantitative angiography more than 6 months (range, 6-82 months) after surgery 17 patients. All smooth implanted large nonakinetic perfusion zones. Angiograms obtained basal sinus rhythm (71 +/- beats/min), during atrial pacing (129 9 intragraft infusion 1 mg isosorbide dinitrate (ISDN). In rhythm, cross-sectional area was superior that (10.7 3.6 versus 5.4 1.7 mm2; p < 0.01). dilated (+14.8 11.5%; 0.005) a further occurred ISDN (+27.4 20.1% basal; 0.005). contrast, failed dilate (+0.3 5.4%; = NS) (+0.7 6.0% NS). Thus, tachycardia dilation but not grafted on vessels. The endothelium modulate response changes could contribute excellent long-term functional surgery.