The broad goals of this program continue as perceived and are to extend knowledge concerning circulatory performance and prediction and through this improve diagnostic methods and therapy of patients with heart disease. These objectives will be accomplished through the collaborative efforts of individuals who are experienced investigators in a variety of areas and are members of a number of different departments. The research program is being approached through the cooperative efforts of 12 research units and 7 core support laboratories. Research will be conducted on many aspects of problems of circulatory performance: myocardial function, ventricular and atrial function, circulatory responses to stress, responses to altered venous return, circulatory reflexes, instrumentation and cardiovascular surgical problems. The descriptions of the progress report for each of the units and the functions of the core laboratories are detailed in the body of the application.