Τίτλος:
Improved myocardial performance during repetitive exercise testing: The
role of extracellular superoxide dismutase activity in a model of
exercise-induced myocardial preconditioning
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
Background The aim of this study was to investigate whether endogenous
antioxidant defense is involved in adaptation to myocardial ischemia in
patients with coronary artery disease and severe exercise-induced
myocardial ischemia.
Methods Fifty patients, aged 50 to 72 years (mean, 58 6 years), with
positive exercise test results underwent 4 treadmill exercise tests.
Thallium-201 scintigraphy was performed during the first and the fourth
testing. The second, the third, and the fourth tests were performed the
next day. The time interval between the second and the third test was 15
minutes, and between the third and the fourth test, the interval was 45
minutes. Extracellular superoxide dismutase activity was measured just
before and at the peak of the first and the fourth exercise test.
Results The patients were divided in 2 groups according to the extent of
myocardial ischemia at peak exercise of the fourth test compared with
the first test. Most of the patients studied (37/50) showed improved
myocardial performance during the last of the sequential exercise tests,
as demonstrated with the studied exercise parameters and the extent of
myocardial ischemia in thallium-scintigraphy. Extracellular superoxide
dismutase activity before the lost exercise test was found to be
significantly increased only in the patients who had improved myocardial
performance at the last of the sequential exercise tests.
Conclusion The beneficial effects of sequential episodes of
exercise-induced myocardial ischemia seem to be strongly related to
extracellular superoxide dismutase activity. Although there is still
lack of direct evidence, our data support the theory that the favorable
adaptation to repetitive exercise may represent an aspect of the
clinical relevance of ischemic preconditioning in humans.
Συγγραφείς:
Michaelides, A
Andrikopoulos, GK
Oikonomou, EV
Psomadaki, ZD
and Richter, DJ
Dilaveris, PE
Exadaktylos, NI
Stefanadis, CI
and Toutouzas, PK
Περιοδικό:
American Heart Journal
Εκδότης:
Mosby Year Book Inc
DOI:
10.1016/S0002-8703(03)00115-7
