Περίληψη:
Study objectives: To examine the effects of low arterial BP (ABP) during
reperfusion on the extent of myocardial infarction and on coronary blood
flow (CBF) in an occlusion/reperfusion experimental model.
Design: Prospective, randomized animal study.
Setting: University hospital.
Participants: Normal pigs that were anesthetized, intubated, and
mechanically ventilated.
Interventions: Twenty-seven open-chest pigs underwent occlusion of the
mid left anterior descending (LAD) coronary artery for I h followed by
reperfusion for 2 h. During reperfusion, the animals were randomly
assigned to either continuous infusion of nitroglycerin in therapeutic
doses and fluid infusion at rates to maintain a mean ABP greater than or
equal to 80 mm Hg (group 1, n = 13), or continuous nitroglycerin
infusion at rates to maintain a mean ABP between 60 mm Hg and 75 mm Hg
(group 2, n = 14).
Measurements and results: The hemodynamics and the coronary ABP distal
to the occlusion were recorded throughout the experiment. In addition,
the LAD CBF and peak hyperemia CBF before occlusion and during
reperfusion periods were measured by transit-time flowmetry. At the end
of the experiment, the infareted left ventricular myocardial size was
measured. There were no significant hemodynamic differences, including
the distal coronary arterial pressure, between the two groups before or
during the LAD artery occlusion period. During reperfusion, mean ABP was
90 +/- 3 min Hg in group 1 vs 69 +/- 3 mm Hg in group 2 (p < 0.001). In
group 1, the infarcted myocardium represented 50.3 +/- 4.3% of the
myocardium at risk, vs 69.4 +/- 7.2% in group 2 (p < 0.001). During
reperfusion, CBF and peak hyperemia CBF were significantly higher in
group 1 than in group 2.
Conclusions: Low ABP during reperfusion increases the size of myocardial
infarction and decreases CBF.
Συγγραφείς:
Nanas, JN
Tsolakis, E
Terrovitis, JV
Eleftheriou, A and
Drakos, SG
Dalianis, A
Charitos, CE
