A collection of Wiggers diagrams are available in this post to help you learn about the cardiac cycle. A Wiggers diagram is a standard diagram used in cardiac physiology named after Dr. Carl J. Wiggers who did important work in circulatory physiology in the early part of the 20th century. This diagram is a graphical representation of the cardiac cycle. Wiggers’ diagrams can vary in detail and number of variables presented. Regardless, all provide essential information on how the normal heart functions with a minimum description of pressure changes during phases of diastole and systole. Take a look at the first 101 Diagrams below.