The influence of glucose on the myocardial time-activity curve during 17-iodo-123 heptadecanoic acid scintigraphy

The lipid pools of the heart (i.e. the triglyceride and phospholipid pool) participate in the free fatty acid metabolism. The degree of involvement, for instance will be determined by the available substrate in the blood. Scintigraphy with 17-iodo-123 heptadecanoic acid was performed to study free fatty acid kinetics in the normal human myocardium during control and glucose infusion (n = 9). In both situations the derived time-activity curves, measured during a period of 75 min, obeyed a monoexponential plus a constant curve fitting [A(t) = A(o)exp(-tln2/T1/2)+C]. During glucose infusion the half-time values did not change but the lipid storage increased in favour of the oxidation pool. In the three protocols used, hypoglycaemic responses were observed, therefore these protocols cannot be advocated.