Radionuclide analysis of pulmonary blood volume: the response to spontaneous angina pectoris and sublingual nitroglycerin in patients with coronary artery disease.

By manually assigning pulmonary regions of interest and deriving pulmonary time-activity (volume) curves, we were able to make count estimates of pulmonary blood volume (PBV) from gated cardiac blood pool scans. Five patients with coronary heart disease developed angina spontaneously while under a gamma camera. This produced an increase in cardiac volumes (p less than 0.05), a reduction in left ventricular ejection fraction (p less than 0.01), along with a marked increase in PBV (0.010 +/- 0.003 to 0.015 +/- 0.002 units, p less than 0.05). Nitroglycerin was then administered and reduced PBV in association with a return to normal in cardiac systolic function and size. In patients with stable chronic ischemic heart disease, sublingual nitroglycerin also reduced PBV (p less than 0.05), although not as much as when administered during an anginal episode. We conclude that gated imaging of the chest can be utilized to follow changes in PBV serially. These changes can be utilized to evaluate clinically important changes in hemodynamic status and the response to pharmacologic interventions.