Abstract
Diffusible radioactive tracers and nondiffusible microspheres have been used to estimate the distribution of left ventricular (LV) blood flow. These methods were directly compared in five open chested dogs 1.5 hr after ligation of branches of the anterior descending coronary artery. Strontium 85 labeled 15 micron diam microspheres (RM) were injected into the left atrium and 86RbCl was given intravenously; ninety sec later, the LV was excised and divided into multiple samples encompassing a wide range of flows. Tissue contents of RM and Rb, expressed relative to nonischemic posterior wall myocardium, were not significantly different at normal flows. However, in the peri ischemic region, where RM content exceeded posterior wall, there was relatively less Rb than RM, and where RM content fell below 20% in the ischemic region, there was more Rb than RM. At normal or hyperemic flows the ratio of tracer content in the inner half to that in the outer half of the LV (I/O) was 1.04 for RM and 1.02 for Rb, not significantly different. As flow fell below 0.60 cc/min/gm, I/O declined similarly for RM and Rb, except that below 0.10 cc/min/gm, I/O was significantly higher for Rb (0.30 versus 0.16, p < 0.005). The results suggest that the two methods are equally suitable for measuring blood flow distribution except at high or very low levels where microspheres may reflect blood flow more accurately. (25 references.)
Original language | English (US) |
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Pages (from-to) | 969-973 |
Number of pages | 5 |
Journal | Journal of Nuclear Medicine |
Volume | 15 |
Issue number | 11 |
State | Published - Jan 1 1974 |
Externally published | Yes |
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging