Abstract
The post-ischemic distribution of Thallium 201 was studied in 30 patients with coronary artery disease and in 10 healthy subjects at rest and following ergometric exercise. This was achieved by performing serial myocardial Thallium images in 5 views immediately following exercise and at one and two hourly intervals thereafter. In 3 patients Thallium 201 blood clearance was simultaneously determined to estimate the biological halflive of the tracer in the blood. The images were taken by an Anger-Camera (ON 100) and processed by a computer system (ON 150), which allowed to produce comparable images by selecting a constant countrate in the region of maximal myocardial tracer uptake. The biexponential clearance of Thallium 201 showed a rapid initial disappearance from blood, with a halflive of 150 secnds. Equilibrium phase is reached 20 minutes after injection. All patients with CAD showed a significant regional defect of tracer uptake immediately after exercise. 20 patients revealed a significant (p<0.01) paradoxical increase of Thallium 201 concentration in the late scans, representing delayed filling of previously underperfused zones. From the washout of regions with a normal tracer uptake a biological halflive for Thallium-201 of 4-7 (5.6) hr could be calculated. In contrast 10 patients with resting defects due to myocardial scar tissue failed to show this late uptake of Thallium 201. Thus postischemic distribution ('redistribution') of Thallium 201 studied by serial myocardial imaging after a single tracer injection allows a differentiation between postinfarction scar and exercise induced ischemia.
| Translated title of the contribution | Serial myocardial scintigraphy in the evaluation of post-ischemic left ventricular Thallium-201 uptake |
|---|---|
| Original language | German |
| Pages (from-to) | 1-9 |
| Number of pages | 9 |
| Journal | Zeitschrift fur Kardiologie |
| Volume | 68 |
| Issue number | 1 |
| State | Published - 1979 |