Detection of coronary microvascular disease by means of cardiac scintigraphy.

A 76-year-old woman strictly defined as having cardiac syndrome X underwent cardiac scintigraphies. A reversible perfusion abnormality was identified by (201)thallium in the inferior segment of the left ventricle. (123)iodine meta-iodo-benzyl-guanigine uptake showed extremely diminished uptake in the inferior segment of the myocardium. (123)iodine labelled beta-methyl-iodophenyl pentadecanoic acid myocardial single photon emission computed tomography showed decreased uptake of the inferior segment in the early image, whereas the delayed images revealed significant fill-in of the tracer in the inferior segment of the myocardium. These findings suggest that coronary microvascular dysfunction causes regional myocardial ischemia, resulting in metabolic and sympathetic abnormality.