I.   Introduction toThe HeartFlow Program

                        By     Daniel Burkhoff, M. D. 
                                                     and     Marc Dickstein, M. D. 
                                                   Programming     Paul Ferber                  
Exercises for Heart Mechanics

This Heart Simulator is continually being developed and modified to be used
as a tool for teaching cardiovascular physiology and pathophysiology to
students of all levels. The program simulates many aspects of ventricular
properties; because of this, however, the full program may at first seem
complex and confusing. Therefore, we have created a series of initial
exercises to familiarize you with the simulator, how you change
parameters, and how to view the resultant changes in cardiovascular

The approach we present is based largely on the work of numerous
cardiovascular physiologists, and most notably on the works of Suga,
Sagawa, Sunagawa and Maughan. Most of the concepts are difficult to
appreciate by static graphs and text descriptions. Our goal is to provide
students with a resource with which they can explore the dynamic
interactions that comprise the cardiovascular system. Our hope is that
this approach will facilitate the development of a system of understanding
the determinants of cardiac function in health and disease.

The Browser

    On the PC use Netscape 4.75 or 4.77 or 4.79

    On the Macintosh use OS 9.1 with Internet Explorer 5.0


    All pressures are given in mmHg.
    All volumes are given in milliliters, except Cardiac Output which is in liters per minute.
    Time is shown in milliseconds.

Graphs and Displays

    Click on any point on the graph to display its coordinates in the upper left.

    The axes of the graphs can be scaled by clicking on the small dot at the end of
an axis, and dragging it to give a new upper value (either direction.)

Use F1 for Help

Place the cursor over any item and press F1 for information.

Be sure that Java is enabled in your browser.
On Macintosh use Internet Explorer 5.0
Filling Pressure Threshold for Elastance/MAP effect is off. Was set to 50.0