Wiggers diagram

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)

A Wiggers diagram modified from ^[1]

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

Events

	Phase	EKG	Heart sounds	Semilunar valves	Atrioventricular valves
A	Atrial systole	P	S4*	closed	open
B	Ventricular systole – Isovolumetric/isovolumic contraction	QRS	S1 ("lub")	closed	closed
C1	Ventricular systole – Ejection 1	ST		open	closed
C2	Ventricular systole – Ejection 2	T		open	closed
D	Ventricular diastole – Isovolumetric/isovolumic relaxation	–	S2 ("dub")	closed	closed
E1	Ventricular diastole – Ventricular filling 1	–	S3*	closed	open
E2	Ventricular diastole – Ventricular filling 2	–		closed	open

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.

Additional images

• 
  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]

See also

• Pressure volume diagram