title: The immediate effect of nitroglycerin on total body blood volume distribution in patients with congestive heart failure: a non-invasive study.
abstract: The effect of sublingually administered nitroglycerin (0.5 mg) on distribution of blood volume in 16 patients with congestive heart failure (NYHA class II and III), randomly assigned to placebo (N = 8) or nitroglycerin (N = 8) was studied 20 minutes after in vivo labelling of red blood cells with 99m-Tc pertechnetate. Count rates over thorax, abdomen and legs were collected with a large field gamma camera and expressed as percentage changes of baseline value. Changes in count rates, averaged for 5, 10 and 15 minutes after drug administration showed a significant decrease in the nitroglycerin group as compared to the placebo group over the thorax (mean 5%, P less than 0.01) and over the liver (mean 5%, P less than 0.05) and a significant increase over the abdomen (mean 4%, P less than 0.01) and the legs (mean 9%, P less than 0.01). After nitroglycerin, the changes in pulmonary activity were variable and did not differ from the placebo group. These results indicate that nitroglycerin causes a redistribution of blood volume in patients with congestive heart failure. An increase in the vascular capacitance in the abdomen and legs may be responsible for a decrease of blood volume of the thorax and the liver in these patients.
mesh_terms: D000005:Abdomen / Q000098:blood supply; D000368:Aged; D000369:Aged, 80 and over; D001810:Blood Volume / Q000187:drug effects*; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology; D006801:Humans; D007866:Leg / Q000098:blood supply; D008297:Male; D005996:Nitroglycerin / Q000494:pharmacology*; D011877:Radionuclide Imaging; D012039:Regional Blood Flow / Q000187:drug effects; D013909:Thorax / Q000098:blood supply
chemical_list: D005996:Nitroglycerin