[Biphasic 201thallium scintigraphy after dipyridamole in mitral valve diseases (author's transl)].

The results of biphasic 201thallium scintigraphy after dipyridamole i.v. could neither prove nor exclude the presence of small focal lesions in the myocardium of 17 patients with mitral valve diseases. The frequent finding of a decrease in activity in the anterolateral myocardium is probably due to a relative increase in activity in the region of the inferior wall with superimposed areas of the papillary muscle and right ventricular myocardium. If the right ventricle is visualized in stress- or redistribution images, an increase in mean pulmonary artery pressure can be accepted. According to Cohen's criteria, a grade 2 or 3 virtually proves the existence of pulmonary hypertension, a grade 1 makes this finding rather probable. The possibility of pulmonary hypertension can not be excluded if the right ventricular myocardium is not visualized.