Open AccessDipyridamole‐Induced reversible Thallium‐201 defect in patients with vasospastic angina and nearly normal coronary arteries
Author(s) -
Fujita Hideki,
Yamabe Hiroshi,
Yokoyama Mitsuhiro
Publication year - 2000
Publication title -
clinical cardiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.263
H-Index - 72
eISSN - 1932-8737
pISSN - 0160-9289
DOI - 10.1002/clc.4960230106
Subject(s) - medicine , dipyridamole , isosorbide dinitrate , coronary arteries , cardiology , scintigraphy , angina , coronary vasospasm , vasodilation , vasospasm , vasoconstriction , artery , myocardial infarction , subarachnoid hemorrhage
Background : Dipyridamole is a vasodilator of resistance vessels and has no vasoconstrictive effect on large coronary arteries. Hypothesis : The present study used dipyridamole thallium‐201 ( 201 Tl) scintigraphy to clarify the role of microvasculature in coronary flow limitation in patients with vasospastic angina and normal coronary arteries. Methods : Sixteen patients underwent dipyridamole and exercise 201 Tl scintigraphy and provocative coronary angiography with acetylcholine. All patients showed coronary spasm (>90% vasoconstriction concomitant with ST change) in at least one vessel. Results : Dipyridamole or exercise caused only ST depression despite the ST elevation observed at spontaneous attack. Dipyridamole 201 Tl scintigraphy demonstrated the reversible defects (11 cases), as did exercise 201 Tl scintigraphy (13 cases). The region of 201 Tl defect was not always consistent with the territories of angiographically depicted vasospastic arteries. Basal coronary tone, assessed by percentage of diameter change of epicardial arteries from baseline to isosorbide dinitrate administration, did not differ between the positive and the negative defect regions. Conclusion : These results support the hypothesis that, in addition to epicardial coronary spasm, the dysfunction of microvasculature is responsible for abnormal coronary perfusion in the subgroup of patients with vasospastic angina and normal coronary arteries.