99Tcm-Sestamibi Uptake in the Leg Muscles and in the Myocardium in Patients with Intermittent Claudication

⁹⁹Tc^m -Sestamibi has now replaced ²⁰¹Tl as a cardiac imaging agent. In addi tion to the myocardial uptake there is also a considerable uptake in the striated muscle, which may be used for analyzing the muscular perfusion. Sixteen pa tients with intermittent claudication were investigated with ⁹⁹Tc^m -Sestamibi- SPECT (single photon emission computerized tomography) in order to visualize coronary ischemic disease. After the registration of the myocardial perfusion they were also studied regarding their leg muscle perfusion. This was done at rest and during standardized stress test using a bicycle ergometer.

In 10 of the patients there was an increase in the isotope uptake in the myocardium from work to rest > 10% reflecting pronounced myocardial ische mia, which, however, was symptomatic in only 4 of the patients.

The muscular uptake in the myocardium of ⁹⁹Tc^m -Sestamibi in the thigh in creased significantly from rest to exercise (P < 0.01), while it remained un changed in the calf muscle.

There were no significant correlations at rest between the ratio of the right and left systolic blood pressure in the ankles and the ratio between the right and left isotope uptake in the calves, but the increase in the isotope uptake from rest to work correlated with the blood pressure ratio at r = 0.79, P< 0.01 (anterior projection) and r = 0.71, P< 0.01 (posterior projection).

This study demonstrates the possibility of using ⁹⁹Tc^m -Sestamibi to analyze myocardial and muscular perfusion impairment in intermittent claudication.