Reverse 201Tl myocardial redistribution induced by coronary artery spasm / 中华核医学杂志

Objective To investigate the mechanism of reverse redistribution (RR) on dipyridamole 201Tl myocardial perfusion studies in the patients with coronary artery spasm. Methods Twenty-six patients with coronary artery spasm and presented as RR on dipyridamole 201Tl myocardial perfusion studies were enlisted as RR group, while other 16 patients with no coronary artery stenosis nor RR were enlisted as control group. Dipyridamole test was repeated during coronary angiography. Corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC) and TIMI myocardial perfusion grade (TMPG) were measured at RR related and non-RR related coronary arteries before and after dipyridamole infusion respectively.All of the data were analyzed by Student's t-test orχ2-test and correlation analysis. Results Coronary artery angiography showed slower blood flow and lower myocardial perfusion in RR related vessels when compared with non-RR related vessels in RR group, but there was no significant difference among the main coronary arteries in control group. The perfusion defects of RR area at rest were positively related to slowerblood velocity at corresponding coronary arteries ( r = 0.79, t = 10.18, P ＜ 0.001 ). In RR related vessels,CTFC were (36 ±6) frames and (26 ±7) frames (t =4.15, P ＜0.01 ), while TMPG were (2.02 ±0.39)grades and (2.92 ± 0.12) grades ( t = 2.25, P ＜ 0.05 ) before and after dipyridamole infusion, respectively.In non-RR related vessels, CTFC were (29 ±7) frames and (25 ±5) frames (t =2.31, P ＜0.05), while TMPG were (2.56 ± 0.31 ) grades and (2.96 ± 0.06) grades ( t = 2.17, P ＜ 0.05 ) before and after dipyridamole infusion, respectively. However, there were no significant changes of CTFC and TMPG before and after dipyridamole infusion in control group ( t = 0.932, 0.867, respectively, both P ＞ 0.05 ). Conclusion RR is related to the decreased blood flow and myocardial perfusion induced by coronary artery spasm at rest,which may be improved by stress test such as intravenous dipyridamole infusion.

Clinical features of coronary artery spasm patients with or without myocardial bridge / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the clinical features of coronary artery spasm patients with or without myocardial bridge and explore the roles of endothelial dysfunction in these patients.</p><p><b>METHODS</b>One hundred eighteen patients undergone acetylcholine provoking test were divided into myocardial bridge (MB) group (n = 26) and non-myocardial bridge (NMB) group (n = 92). The results of acetylcholine test, treadmill exercise electrocardiography, stress myocardial perfusion scintigraphy, plasma level of endothelin-1 and nitric oxide were compared between MB group and NMB group.</p><p><b>RESULTS</b>Coronary artery spasm was induced in 21 patients in MB group (81%) and 52 patients in NMB group (57%, P < 0.05). Positive treadmill electrocardiography was obtained in 19 patients in MB group (73%) and 7 patients in NMB group (8%, P < 0.001). Ischemic perfusion defect in 20 (77%) and 9 patients (10%, P < 0.001) and reverse redistribution in 23 (88%) and 68 patients (74%, P > 0.05). Patients showed different clinical features in MB group and NMB group (more short-duration exertional angina and could not be readily released by nitroglycerine in MB group while more patients experienced long-lasting variant angina and symptoms could be readily released by nitroglycerine). Plasma endothelin-1 level was significantly higher [(132.1 +/- 6.5) ng/L vs. (108.5 +/- 8.2) ng/L, P < 0.01] while nitric oxide was significant lower [(84.7 +/- 17.5) ng/L vs. (99.8 +/- 18.2) ng/L, P < 0.05] in MB group compared to NMB group.</p><p><b>CONCLUSION</b>MB patients were prone to coronary artery spasm partly due to endothelial dysfunction. Patients with MB and coronary artery spasm also showed classic clinical symptoms and positive stress tests for ischemia.</p>

Clinical features of patients with atypical coronary artery spasm / 中华心血管病杂志

<p><b>OBJECTIVE</b>This study is aimed to compare the clinical characteristics of patients with typical and atypical coronary artery spasm.</p><p><b>METHODS</b>Out of 64 patients with chest pain at rest and without significant coronary artery stenosis, coronary artery spasm was provoked by intracoronary injection of acetylcholine in 46 patients, including 12 with ST segment elevation (typical coronary artery spasm group) and 34 without ST segment elevation (atypical coronary artery spasm group). The demographic data, coronary angiographic findings, treadmill electrocardiogram, dipyridamole and rest thallium-201 myocardial perfusion computed tomography, and the follow-up clinical data of the two groups were compared.</p><p><b>RESULTS</b>The patients with typical coronary artery spasm were younger (47 +/- 6 vs. 58 +/- 12, P < 0.05) than patients with atypical coronary artery spasm group. Hyperlipidemia were more common in atypical coronary artery spasm group (74% vs. 33%, P < 0.05) and myocardial bridging was more common in patients with typical coronary artery spasm group (67% vs. 32%, P < 0.01). Focal coronary spasm during acetylcholine provocation was seen in 92% patients with typical coronary spasm and in 32% patients with a atypical coronary artery spasm (P < 0.01) while diffuse coronary spasm was seen in 8% patients with typical coronary spasm and in 68% patients with a atypical coronary artery spasm (P < 0.01). All patients with coronary artery spasm were treated with aspirin, calcium channel blockers, long-acting nitroglycerine, with or without lipid-lowering drugs, 2 patients with typical coronary spasm and 4 patients with atypical coronary spasm were rehospitalized due to chest pain and rest of the patients remained free of chest pain during the median follow-up period of 18 +/- 14 months.</p><p><b>CONCLUSION</b>Atypical coronary artery spasm is common in patients with rest angina and diffuse coronary microvascular spasm might be the cause of chest pain in these patients.</p>