Paradoxical regional myocardial uptake between 201Thallium and 123I-BMIPP SPECT in patients with cardiomyopathy.

The clinical significance of the paradoxical mismatched phenomenon between (201)Tl and (123)I-BMIPP is still unknown. We report two cases that revealed paradoxical regional myocardial uptake between two tracers in patients with cardiomyopathy. There may be abnormal myocardium in these patients where active transportation of (201)Tl is disturbed and passive transportation of (123)I-BMIPP is not disordered.

The incidence of discrepant regional myocardial uptake between 201 thallium and 123 I-BMIPP SPECT in patients with coronary heart disease.

Myocardial perfusion and fatty acid uptake at rest were assessed by SPECT with 201Tl (Tl) and 123I-BMIPP (BMIPP) in 50 consecutive patients with coronary heart disease. Discrepant regional myocardial uptake was observed in 19 patients and classified into the following two groups: mismatch (MM; Tl uptake > BMIPP uptake, n = 14, mean age, 66 years) and paradoxical mismatch (PM; Tl uptake < BMIPP uptake, n = 5, mean age, 68 years). In the MM group, 77% was single- or zero-vessel disease and the artery-perfused region in the mismatched area was almost always ischemia related.