Wiggers diagram
{{Short description|Teaching aid in cardiac physiology}}
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.{{Cite book |last=Wiggers |first=Carl |title=Circulation in Health and Disease |publisher=Lea & Febiger |year=1915 |location=Philadelphia, PA}} 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.
Events
| class="wikitable" | |||||
| 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. *S3 and S4 heart sounds are associated with pathologies and are not routinely heard.
Additional images
File:Heart systole.svg|Ventricular systole
File:Heart diasystole.svg|Cardiac diastole
File:ECG Principle fast.gif|ECG
File:SinusRhythmLabels.svg|The EKG complex. P=P wave, PR=PR interval, QRS=QRS complex, QT=QT interval, ST=ST segment, T=T wave
File:Wiggers diagram with jugular venous waveform.png|Wiggers with jugular venous waveform
File:CathWiggers.png|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 {{Cite journal |last=Waldman |first=Carly E |last2=Patel |first2=Siddarth |title=Abstract 13654: Can a Novel Earbud Technology Detect Severe Aortic Stenosis? Modernizing the Wiggers Diagram Through Infrasonic Hemodynography Synchronized With Echocardiography and Cardiac Catheterization|url=https://www.ahajournals.org/doi/10.1161/circ.144.suppl_1.13654 |journal= Circulation | volume=144 | issue=Suppl_1 | pages=A13654–A13654 | publisher=American Heart Association | date=16 November 2021}}
See also
References
{{reflist}}
{{Cardiovascular physiology}}
Category:Cardiovascular physiology
Category:Diagnostic cardiology
{{cardiovascular-stub}}