title: Regional blood volume changes during acute pericardial tamponade.
abstract: Using radionuclide blood pool imaging, we evaluated sequential changes in heart, lung, liver, and spleen intravascular volumes were evaluated before and during acute pericardial tamponade in 9 anesthetized dogs. Tamponade resulted in an abrupt (less than 1 min) decline in mean right heart (-30 +/- 5%, p less than 0.001 vs control) and left heart volumes (-27 +/- 4%, p less than 0.001 vs control), with a concomitant reduction in pulmonary volume (-17 +/- 3%, p less than 0.01 vs control). Within this short time frame, both hepatic (+19 +/- 3%) and splenic (+16 +/- 4%, both p less than 0.01 vs control) volumes rose. Five min after the production of tamponade, right and left heart volumes were still significantly reduced (-28 +/- 4, p less than 0.005 vs control and -23 +/- 2%, p less than 0.005 vs control), though pulmonary (+2 +/- 5%, p = NS vs control), hepatic (+7 +/- 3%, p less than 0.05 vs control) and splenic (+9 +/- 3%, p less than 0.05 vs control) volumes had returned toward baseline values. These volume changes were similar at 20 min after tamponade. Thus, tamponade resulted in a sudden shunting of blood from the central to the peripheral circulation, initially from both the lungs and heart. After 5 min pulmonary volumes returned to baseline values, while splenic and hepatic volumes remained slightly, though significantly elevated.
mesh_terms: D000208:Acute Disease; D000818:Animals; D001810:Blood Volume; D002305:Cardiac Tamponade / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003326:Coronary Circulation; D004285:Dogs; D006439:Hemodynamics; D008102:Liver Circulation; D008176:Lung Volume Measurements; D011877:Radionuclide Imaging; D012039:Regional Blood Flow