Roentgen densitometry for the detection of intracardiac shunts in 50 infants and children.
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Biomedical subjects
Publications and source records attributed to J D Cohn.
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An instrument has been developed to record contrast dilution curves by a noninvasive technique. Transthoracic roentgen density alterations are recorded by use of a solid state radiation detector array. A small amount of injected nonradioactive, radiopaque contrast material is distrubuted throughout the central circulation. The detector array positioned over the cardiopulmonary silhouette, records changes in density during the passage of the contrast material, and typical indicator dilution curves are transcribed. These curves reflect changes in blood flow distribution, vascular volume, cardiac function, and intrathoracic vascular shunts; and define the hemodynamic status of the circulatory system.
An automatic cardiac output analysis system is described in which indicator dilution studies are performed serially without operator assistance. Indicator dye injection, blood sampling, and monitoring for air entry into the system are performed automatically through a present program sequence. Sampled blood is returned to the subject through a venous cannula resulting in an absence of blood loss. This system may be used in performing cardiac output analyses on a serial basis and in infants and small animals where blood loss is critical.
A relatively simple and inexpensive data management system is described with which comprehensive physiologic and cardiovascular profiles are produced. The system is comprised of a desk-top programmable calculator interfaced with an acoustic digitizer input, and an X-Y plotter, with alphanumeric printing output capability. Numerical clinical data such as intracardiac pressures and blood gas values are entered into the calculator via the keyboard, and graphical data such as dye-dilution curves or ventricular contours are digitized with a pen stylus on the acoustic tablet. The data are processed in the calculator and the results charted in familiar and readily interpreted bar-graph format on preprinted charts on the X-Y plotter. The entire system is inexpensive and compact enough to be applicable to small- and medium-size community hospitals.
Measurements of hemodynamic, oxygen transport, and tissue utilization functions were incorporated into a physiologic profile assessment system in order to evaluate patients who are candidates for mechanical support of the failing heart. Circulatory function was assessed in patients with acute myocardial infarction associated with diminished peripheral perfusion and compared to an age-matched, normal patient group. Serial studies performed prior to and during intra-aortic balloon counterpulsation provide a means to assess circulatory status accurately and document the efficacy of therapeutic interventions.