Thallium-201 myocardial scintigraphy: fractional uptake by the myocardium at rest and during exercise in patients with coronary artery disease and hypertrophic cardiomyopathy.

Fractional myocardial uptake of thallium-201 was estimated by routine scintigraphic evaluation at rest and during exercise in 10 control subjects, 15 patients with coronary artery disease (CAD) and 12 patients with hypertrophic cardiomyopathy (HCM). Fractional myocardial uptake of the total dose administered at rest was 3.59 +/- 0.98% in the controls, 4.43 +/- 1.17% in patients with CAD and 5.68 +/- 1.29% in patients with HCM, and uptake during exercise was 5.07 +/- 1.23% in the controls, 4.67 +/- 1.04% in the CAD group and 7.50 +/- 1.68% in the HCM group. The value in the HCM group was significantly higher than in the controls (P < 0.001 at rest) or in the CAD group (P < 0.02 at rest). A percentage increment of fractional uptake during exercise was significantly smaller in the CAD group than in the controls or the HCM group (P < 0.01). Thus, assessment of the fractional uptake appears to be a valuable adjunct to myocardial imaging when attempting a clinical assessment of CAD or HCM.