Myocardial perfusion with rubidium-82. II. Effects of metabolic and pharmacologic interventions.
In order to validate a new method for quantifying coronary blood flow, we injected intravenously a bolus of rubidium-82 (Rb-82) into 28 open-chested dogs under a wide range of flow and physiologic conditions, using beta probes to monitor myocardial radioactivity. Extraction fraction and perfusion were measured using a functional model that separates the data into the free and trapped myocardial rubidium. Extraction and uptake of rubidium were lower during acidosis than during alkalosis and were unchanged by glucose-insulin, digoxin, or propranolol. Myocardial flow, as indicated by rubidium, correlated linearly with simultaneous measurements of flow by microspheres in the same sample volume over a wide range of flow (r = 0.97, n = 106, range 0.02-7.76 ml/min/g). Regional myocardial blood flow can be accurately determined using generator-produced Rb-82. Studies using current state-of-the-art, fast positron-emission tomographic cameras are required to determine the utility of this approach in man.
D000818:Animals; D003326:Coronary Circulation; D004077:Digoxin / Q000494:pharmacology; D004285:Dogs; D006321:Heart / Q000000981:diagnostic imaging* / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D006943:Hyperglycemia / Q000378:metabolism; D008722:Methods; D008863:Microspheres; D009206:Myocardium / Q000378:metabolism; D011433:Propranolol / Q000494:pharmacology; D011868:Radioisotopes / Q000378:metabolism; D011877:Radionuclide Imaging; D012413:Rubidium / Q000378:metabolism
D011868:Radioisotopes; D004077:Digoxin; D011433:Propranolol; D012413:Rubidium