PMID: 45819Aug 1, 1975

Nonmechanical factors affecting aortocoronary vein graft flow

Circulation
G F TyersJ A Waldhausen

Abstract

To study aortocoronary vein graft flow, hemodynamic measurements were made in 17 patients with 22 grafts while on cardiopulmonary bypass during ventricular fibrillation and sinus rhythm and 15 minutes after termination of cardiopulmonary bypass. When compared with graft flow to the stable working heart, flow to the nonworking heart in sinus rhythm was reduced 50%. When fibrillating, the nonworking heart received 33% more flow than when in sinus rhythm but still significantly less flow than the working heart. All hemodynamic parameters measured, including flow in 12 grafts, remained stable between 15 minutes and 60 minutes following cardiopulmonary bypass. In contrast, heart rate and flow in 10 grafts fell within five minutes after 1 mg of propranolol was given intravenously. Although it was still reduced, heart rate had begun to rise 30 minutes after propranolol, but graft flow did not begin to return toward predrug control levels until over 60 minutes after drug administration. Further reduction in aortocoronary vein graft flow after heart rate had started to increase supports the possibility of a direct propranolol action reducing myocardial oxygen consumption in addition to its bradycardiac effect. This study shows the sensi...Continue Reading

Related Concepts

Coronary Artery Bypass Surgery
Blood Flow Velocity
Coronary Circulation
Heart Arrest, Induced
Pulse Rate
Rexigen
Transplantation, Autologous
Veins

Related Feeds

Arrhythmia

Arrhythmias are abnormalities in heart rhythms, which can be either too fast or too slow. They can result from abnormalities of the initiation of an impulse or impulse conduction or a combination of both. Here is the latest research on arrhythmias.

Allogenic & Autologous Therapies

Allogenic therapies are generated in large batches from unrelated donor tissues such as bone marrow. In contrast, autologous therapies are manufactures as a single lot from the patient being treated. Here is the latest research on allogenic and autologous therapies.

Cardiology Journals

Discover the latest cardiology research in this collection of the top cardiology journals.