Peripheral Hemodynamic Responses Induced during Dipyridamole Infusion and the Relationships to the Coronary Artery Disease

ABSTRACT

BACKGROUND: Perfusion scintigraphy with dipyridamole have been reported to be useful for diagnosis of coronary artery disease and the assessment of the presence and extent of myocardium at ischemic risk, especially in patients who can not undergo dynamic exercise testing. Dipyridamole, pharmacologic coronary vasodilator, also induces fall in blood pressure and rise in heart rate. The purpose of this study was to answer the question if dipyridamole induced peripheral hemodynamic responses were related to chest pain, ST changes on EKG, scintigraphic defect or extent of coronary stenosis. METHODS: Dipyridamole 99mTc-MIBI myocardial scintigraphy and coronary angiography on 43 subjects who were suspected to have coronary artery disease. The peripheral hemodynamic response was graded as absent(group 0) if there was a 10 but 10 but 20mm fall in SBP and/or >20 beats/min rise in HR. RESULTS: The overall diagnostic sensitivity and specificity for coronary artery disease of dipyridamole perfusion scintigraphy were 68%, 83% while per vessel sensitivity and specificity for coronary artery disease were 66%, 97%. The numbers of induced chest pain and ischemic ST changes among hemodynamic subgroups, were 40%, 40% in group 0, 33%, 27% in group 1 and 50%, 40% in group 2 without significant difference in each hemodynamic subgroups. Either the numbers of diseased coronary arteries or the numbers of patients demonstrationg reversible scintigraphic defects were not statically different among each subgroups. CONCLUSION: Although the peripheral hemodynamic response dose not always correlate with its central coronary effect but dipyridamlole 99mTc-MIBI myocardial perfusion scintigraphy is an useful test for diagnosis of coronary artery disease.