The Extraction of Thallium-201 by the Myocardium

The concentration of thallium-201 in the myocardium immediately following injection of tracer is the result of both blood flow delivering tracer to the heart and extraction by the myocardium. In these studies, the extraction of thallium-201 by the canine myocardium was determined as a function of heart rate, coronary blood flow, hypoxia, changes in pH, and following administration of propranolol, insulin, and strophanthin. Under basal con- ditions, extraction fraction measured 88 ± 2.1%, following pacing to a rate of 195 beats/min extraction fraction remained unchanged at 88.5%. Similar results were found with changes in pH, propranolol, insulin, and strophanthin. Hypoxia caused a significant decrease in extraction fraction to 77.9%. When coronary blood flow was increased in excess of demands by drugs, extraction fraction fell logarithmically.

[1]  B. Pitt,et al.  Thallium‐201 Myocardial Perfusion Imaging at Rest and during Exercise: Comparative Sensitivity to Electrocardiography in Coronary Artery Disease , 1977, Circulation.

[2]  M L Goris,et al.  Interpolative background subtraction. , 1976, Journal of nuclear medicine : official publication, Society of Nuclear Medicine.

[3]  B. Pitt,et al.  Myocardial imaging in the noninvasive evaluation of patients with suspected ischemic heart disease. , 1976, The American journal of cardiology.

[4]  P. Hammond,et al.  The interrelationship between thallium and potassium in animals. , 1967, The Journal of pharmacology and experimental therapeutics.