A Wiggers diagram, named after its developer, Carl Wiggers, is a unique diagram that has been used in teaching cardiac physiology for more than a century.^[1][2] In the Wiggers diagram, the X-axis is used to plot time subdivided into the cardiac phases, while the Y-axis typically contains the following on a single grid:

• Blood pressure
  • Aortic pressure
  • Ventricular pressure
  • Atrial pressure
• Ventricular volume
• Electrocardiogram
• Arterial flow (optional)
• Heart sounds (optional)

The Wiggers diagram clearly illustrates the coordinated variation of these values as the heart beats, assisting one in understanding the entire cardiac cycle.^[1]

Note that during isovolumetric/isovolumic contraction and relaxation, all the heart valves are closed; at no time are all the heart valves open.^[1] *S3 and S4 heart sounds are associated with pathologies and are not routinely heard.

• Ventricular systole
• Cardiac diastole
• ECG
• The EKG complex. P=P wave, PR=PR interval, QRS=QRS complex, QT=QT interval, ST=ST segment, T=T wave
• Wiggers with jugular venous waveform
• Wiggers diagram with mechanical (echo), electrical (ECG), and aortic pressure (catheter) waveforms, together with an in-ear dynamic pressure waveform measured using a novel infrasonic hemodynography technology, for a patient with severe aortic stenosis. Modified from ^[3]

• Pressure volume diagram