BACKGROUND: It has been reported that vasodilator function in remote myocardial regions supplied by "angiographically normal" coronary arteries is impaired in patients after acute myocardial infarction (MI). The aim of this study was to determine whether coronary artery flow reserve and coronary artery resistance in remote, nonischemic areas are also altered in experimental MI. METHODS: Experiments were performed in anesthetized pigs. In group 1 infarction was induced by ligation of the left-anterior descending artery (LAD); group 2 consisted of sham-operated animals. Hemodynamic parameters, coronary artery resistance, and myocardial blood flow (MBF) were measured before and 4 hours after MI under rest and during infusion of adenosine. RESULTS: Coronary artery dilation by adenosine caused a similar increase in MBF before and 4 hours after coronary artery occlusion. Resting MBF after acute MI was not altered, although a significant reduction (15%; P < .04) in mean aortic pressure was observed compared with baseline. Coronary artery resistance was significantly reduced by adenosine (P < .04) before MI, as well as at 4 hours after MI (P < .03). Coronary artery flow reserve was not adversely affected. The sham-operated animals showed similar results without any significant differences between the two study groups. CONCLUSION: This study indicates that an acute MI in pigs did not increase coronary artery resistance in the remote area after MI and therefore did not adversely affect coronary artery flow reserve in the nonischemic vascular bed. Further studies are necessary to fully understand the exact mechanism of the alterations in remote flow reserve of patients after MI.
BACKGROUND: It has been reported that vasodilator function in remote myocardial regions supplied by "angiographically normal" coronary arteries is impaired in patients after acute myocardial infarction (MI). The aim of this study was to determine whether coronary artery flow reserve and coronary artery resistance in remote, nonischemic areas are also altered in experimental MI. METHODS: Experiments were performed in anesthetized pigs. In group 1 infarction was induced by ligation of the left-anterior descending artery (LAD); group 2 consisted of sham-operated animals. Hemodynamic parameters, coronary artery resistance, and myocardial blood flow (MBF) were measured before and 4 hours after MI under rest and during infusion of adenosine. RESULTS: Coronary artery dilation by adenosine caused a similar increase in MBF before and 4 hours after coronary artery occlusion. Resting MBF after acute MI was not altered, although a significant reduction (15%; P < .04) in mean aortic pressure was observed compared with baseline. Coronary artery resistance was significantly reduced by adenosine (P < .04) before MI, as well as at 4 hours after MI (P < .03). Coronary artery flow reserve was not adversely affected. The sham-operated animals showed similar results without any significant differences between the two study groups. CONCLUSION: This study indicates that an acute MI in pigs did not increase coronary artery resistance in the remote area after MI and therefore did not adversely affect coronary artery flow reserve in the nonischemic vascular bed. Further studies are necessary to fully understand the exact mechanism of the alterations in remote flow reserve of patients after MI.
Authors: Marta Regueiro-Purriños; Felipe Fernández-Vázquez; Armando Perez de Prado; Jose R Altónaga; Carlos Cuellas-Ramón; Jose M Ajenjo-Silverio; Asuncion Orden; Jose M Gonzalo-Orden Journal: J Am Assoc Lab Anim Sci Date: 2011-01 Impact factor: 1.232
Authors: P L Van Herck; S G Carlier; M J Claeys; S E Haine; P Gorissen; H Miljoen; J M Bosmans; C J Vrints Journal: Heart Date: 2007-03-29 Impact factor: 5.994