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)

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]