High prevalence of the thallium-201 reverse redistribution phenomenon in patients with syndrome X

Abstract

Our study confirms that perfusion abnormalities are present in most syndrome X patients. Additionally, the data show that reverse redistribution (a perfusion defect that develops or becomes more evident on delayed imaging) is a common finding in these patients. The mechanisms of the phenomenon remain obscure: we suggest that it is due to inhomogeneous perfusion, and the hyperaemic response induced by exercise masks resting underperfusion of certain areas.

Association between anxiety disorder and the extent of ischemia observed in cardiac syndrome X

“…3,4 A subgroup of these patients has objective signs of ischemia, such as the classic downsloping ST-segment depression on exercise testing and/or a reversible defect detected by myocardial single-photon emission computed tomography (SPECT). [5][6][7][8][9] The pathogenesis of CSX remains uncertain. Two mechanisms have been proposed: ischemia caused by coronary microvascular dysfunction, and enhanced cardiac pain sensitivity (''sensitive heart'' syndrome).…”

“…Two mechanisms have been proposed: ischemia caused by coronary microvascular dysfunction, and enhanced cardiac pain sensitivity (''sensitive heart'' syndrome). 10 Several studies found abnormalities consistent with ischemia in patients with syndrome X using scintigraphic myocardial perfusion imaging, [5][6][7][8][9] thermodilution, 11 nuclear magnetic resonance spectroscopy, 12 intracoronary acetylcholine, 13,14 atrial pacing, 15 and cardiac magnetic resonance (CMR) imaging. 16,17 These CMR studies support the hypothesis of microvascular ischemia in CSX patients.…”

Coronary Vasospasm Produces Reversible Perfusion Defects Observed During Adenosine Triphosphate Stress Myocardial Single‐photon Emission Computed Tomography

“…It has been reported that abnormal findings on myocardial perfusion imaging are observed in patients with cardiac syndrome X. 20 It is possible that our non-VSA group included patients with cardiac syndrome X. In addition, it has been reported that several factors, such as the presence of hypercholesterolemia, diabetes mellitus, and left ventricular hypertrophy impair coronary flow reserve.…”

“…If coronary spasm was not induced by ACh, then incremental doses of methylergometrine maleate (EM) were infused into the left coronary artery (10,20, and 30 µg/min) for 1 min, with 1-min, intervals between consecutive doses. If coronary spasm was not induced by the infusion of EM, incremental doses of EM were infused into the right coronary artery (15 and 25 µg/min) using the same protocol as for the left coronary artery.…”

The light of inflammation in the darkness of the coronary slow flow phenomenon

“…In particular, it has been suggested that increased sympathetic outflow to the cardiovascular system may be responsible for both symptoms and inducible ischemia (9)(10)(11)(12)(13). Since the autonomic nervous system plays a central role in the regulation of coronary blood flow, increased sympathetic activity could be responsible for both primary reduction of coronary blood flow and reduced vasodilator reserve, which is observed in some patients with syndrome X (14,15). Previous studies have also shown that endothelial dysfunction (16)(17)(18) and inflammation (19) might play important roles in the pathogenesis of microvascular angina.…”