Analysis of the pulmonary circulation using digital intravenous angiography.

We evaluated pulmonary transit time in dogs and humans using digital intravenous angiography. Digital data were acquired in both the control state and after isoproterenol was administered to alter the inotropic state. When compared with the control value, transit time was shortened with isoproterenol in both dogs and humans. The inter- and intraobserver variabilities were small (less than 4%), as were the variabilities in data obtained from two sequential injections (less than 5%). Digital analysis of the pulmonary circulation time is a simple technique that requires little image manipulation. This information may be obtained during standard digital cardiac studies, and it can assist in the analysis of cardiopulmonary dynamics.