Coronary circulation, myocardial metabolism and cardiac catecholamine flux in patients with syndrome X
Ishihara, T.; Seki, I.; Yamada, Y.; Tamoto, S.; Fukai, M.; Takada, K.; Fujiwara, M.; Ashida, H.; Shimada, T.; Ohsawa, N.
Journal of Cardiology 20(2): 267-274
1990
ISSN/ISBN: 0914-5087 PMID: 2104403 Document Number: 356517
To clarify the pathogenesis of syndrome X (Sx), hemodynamics, coronary circulation, myocardial lactate metabolism and cardiac catecholamine flux were studied before and during bicycle ergometry in 25 patients (pts) and these data were compared with those in 15 with effort angina (EA) and in eight controls. The results were as follows: 1. The cardiac index during exercise decreased in EA pts probably due to their coronary lesions, while those in the controls and Sx were well preserved. 2. An increase of coronary blood flow during exercise, both in Sx and EA pts, was significantly impaired and the myocardial extraction ratio of lactic acid was significantly lower compared with those in the controls. The cardiac norepinephrine release during exercise was markedly higher in Sx, compared with that in controls and in EA. These results suggested that in Sx, excessive sympathoadrenergic stimulation may play an important role in restricting coronary reserve and in accelerating myocardial anaerobic metabolism.