Myocardial Blood Flow in Man: Effects of Coronary Collateral Circulation and Coronary Artery Bypass Surgery
AUTOR(ES)
Smith, Sidney C.
RESUMO
The effects of coronary artery bypass graft (CAB) and coronary collaterals (CC) on myocardial blood flow (MBF) were studied in 24 patients undergoing 29 CAB's. MBF after CAB was compared to preexisting MBF by intraoperatively injecting 133xenon via distal CAB with proximal CAB first occluded then open. Pressure gradients across bypassed obstructions were measured. The results were correlated with preoperative coronary arteriograms to determine the effects of CC on MBF and postobstructive perfusion pressures. Mean MBF was increased by CAB from 32±6 (se) ml/min per 100 g (CAB occluded) to 118±13 ml/min per 100 g (CAB open). The 133Xe clearance curves with CAB open were resolved into slow (19±2 ml/min per 100 g) and rapid (133±12 ml/min per 100 g) phases, suggesting that MBF remained heterogeneous after CAB. Vessels with less than 80% stenosis by angiography had pressure gradients less than 20 mm Hg across obstructions, high postobstructive perfusion pressures (75±7 mm Hg), and normal MBF (87±6 ml/min per 100 g) even with CAB occluded. Vessels with greater than 80% stenosis or total occlusion by angiography had significant pressure gradients with marked reduction of postobstructive MBF. No significant difference in postobstructive MBF was found when vessels with CC (21±4 ml/min per 100 g) were compared to those without CC (17±4 ml/min per 100 g) (P > 0.4).
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=332953Documentos Relacionados
- The Effects of Preoperative Coronary Collateral Circulation on Cardiac-Related Events after Coronary Artery Bypass Graft Surgery
- Effects of Nitroglycerin on Regional Myocardial Blood Flow in Coronary Artery Disease
- Cerebral blood flow during cardiopulmonary bypass in man: effect of arterial filtration.
- Effects of Previously Well-Developed Collateral Vessels on Left Internal Mammary Artery Graft Flow after Bypass Surgery
- Myocardial infarction related to coronary artery bypass graft surgery.