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Increased release of nitric oxide in ischemic hearts after exercise in patients with effort angina
1First Department of Medicine, Osaka University School of Medicine, Suita, Japan.
Objectives:
The aim of this study was to determine whether the release of nitric oxide (NO) from the ischemic heart increases during exercise in patients with effort angina.
Background:
Myocardial ischemia increases NO production in the canine heart, but no such increase has been demonstrated in the ischemic human heart.
Methods:
Fifteen patients with effort angina underwent supine ergometer exercise tests. All patients had severe proximal stenosis (>90%) in the left anterior descending coronary artery. The control group consisted of 17 subjects without coronary artery disease or systemic hemodynamic abnormalities.
Results:
Neither the lactate extraction ratio (LER) nor the difference in NO concentration between coronary venous and arterial blood (deltaVA[NO]) was affected by exercise in the control subjects. In patients with effort angina, neither variable differed from that in the control group at rest; however, exercise markedly decreased LER and significantly increased deltaVA(NO) (from 4.7 +/- 0.3 to 16.5 +/- 1.6 micromol/liter, p < 0.001) in the patient group. The extent of decrease in LER was significantly correlated with the extent of increase in deltaVA(NO) in the patients with effort angina (r2 = -0.837, p < 0.001).
Conclusions:
Provocation of myocardial ischemia by exercise stress increases NO production in the hearts of patients with effort angina.