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{{Infobox interventions |
{{Short description|A method of recording the direction and magnitude of the electrical forces of the heart.}}
Name = Vectorcardiography |
{{Infobox interventions
Image = Vektorkardiogramm kgm-normal.jpg |
| Name = Vectorcardiography
Caption = Normal vectorcardiogram |
| Image = Vektorkardiogramm kgm-normal.jpg
ICD10 = |
| Caption = Normal vectorcardiogram
ICD9 = {{ICD9proc|89.53}} |
| ICD10 =
MeshID = D014672 |
| ICD9 = {{ICD9proc|89.53}}
OtherCodes = |
| MeshID = D014672
| OtherCodes =
}}
}}
'''Vectorcardiography''' (sometimes abbreviated as VCG) is a method of recording the magnitude and direction of the electrical forces that are generated by the [[heart]] by means of a continuous series of [[Vector (mathematics and physics)|vectors]] that form curving lines around a central point.<ref>{{cite web|title=Medical Definition of Vectorcardiography |url=https://www.merriam-webster.com/medical/vectorcardiography|website=www.merriam-webster.com|accessdate=June 8, 2017|language=en}}</ref>
Vectorcardiography was developed by E. Frank in the mid 1950s.<ref>{{cite journal | last1 = Burch | first1 = G.E. | year = 1985 | title = The history of vectorcardiography | journal = Medical History Supplement | volume = 5 | issue = 5| pages = 103–131 | pmc=2557408 | pmid=3915520| doi = 10.1017/S002572730007054X }}</ref><ref>{{cite journal | last1 = Frank | first1 = E | year = 1956 | title = An Accurate, Clinically Practical System For Spatial Vectorcardiography | journal = Circulation | volume = 13 | issue = 5| pages = 737–749 | doi=10.1161/01.CIR.13.5.737}}</ref> Since the human body is a three-dimensional structure, the basic idea is to construct three [[orthogonal]] leads containing all the electric information. The three leads are represented by right-left axis (X), head-to-feet axis (Y) and front-back (anteroposterior) axis (Z).
[[File:Vektorkardiogramm kgm-normal.jpg|thumb|A normal vectorcardiogram showing the electrical activity of the heart.]]
To calculate Frank’s leads X, Y and Z using the standard leads system, the following expressions<ref>{{cite journal|title=Real-time 3D vectorcardiography: An application for didactic use |year=2007|author1=G Daniel |author2=G Lissa |author3=D Medina Redondo |journal=Journal of Physics: Conference Series |volume=90|pages=012013|display-authors=etal |doi=10.1088/1742-6596/90/1/012013}}</ref>
'''Vectorcardiography''' (VCG) is a method of recording the magnitude and direction of the electrical forces generated by the [[heart]] using a continuous series of [[vector (mathematics and physics)|vectors]] that form curving lines around a central point.
Vectorcardiography was developed by [[Ernest Frank]] in the mid-1950s. Since the human body is a three-dimensional structure, the primary objective is to construct three [[orthogonal]] leads encompassing all the electrical information. These three leads are represented by the right-left axis (X), head-to-feet axis (Y), and front-back (anteroposterior) axis (Z).
There are different criteria how at to evaluate a vectorcardiogram created by various researchers. Grygoriy Risman presents these different methods, which were developed over half a century and offers an advanced approach called Spatial Vectorcardiometry (SVCM).<ref>{{cite web|title=Vektorkardiometrie - Eine Methode der Vektorkardiographie|url=http://www.vectorcardiometry.tk|website=www.vectorcardiometry.tk|accessdate=June 8, 2017|language=German}}</ref> The original Russian thesis is filed in the Odessa Medical Academy.<ref>{{cite web|title=Распределение пространственных моментных викторов пробега волны возбуждения процесса дополяризации миокарда желудочков у здоровых спортсменов, больных с легочным сердцем и почечной гипертонией Каталог Бібліотека ОНМедУ|url=http://info.odmu.edu.ua/lib/catalog/47402|website=info.odmu.edu.ua|accessdate=June 8, 2017|archiveurl=https://web.archive.org/web/20131022231912/http://info.odmu.edu.ua/lib/catalog/47402|archivedate=22 October 2013|language=Russian}}</ref>
Various methods have been proposed to evaluate a vectorcardiogram. [[Grygoriy Risman]] introduced an advanced approach known as Spatial Vectorcardiometry (SVCM), which refines the analysis of vectorcardiograms.
==Spatial QRS-T angle==
== Spatial QRS-T Angle ==
The ''spatial QRS-T angle'' (SA) is derived from a vectorcardiogram, which is a three-dimensional representation of the 12-lead [[electrocardiogram]] (ECG) created with a computerized matrix operation. The SA is the angle of deviation between two vectors; the spatial [[QRS complex|QRS]]-axis representing all of the electrical forces produced by ventricular depolarization and the spatial T-axis representing all the electrical forces produced by ventricular repolarization.<ref name=one>{{cite journal |last1=Voulgari |first1=C. |last2=Tentolouris |first2=N. |title=Assessment of the Spatial QRS-T Angle by Vectorcardiography: Current Data and Perspectives |journal=Current Cardiology Reviews |year=2009 |volume=5 |issue=4 |pages=251–262 |doi=10.2174/157340309789317850|pmc=2842956 }}</ref> The SA is indicative of the difference in orientation between the ventricular depolarization and repolarization sequence.
The ''spatial QRS-T angle'' (SA) is derived from a vectorcardiogram, a three-dimensional representation of the 12-lead ECG created through computerized matrix operations. The SA represents the deviation between two vectors:
* The spatial [[QRS complex|QRS-axis]], which reflects the electrical forces generated by [[ventricular depolarization]].
In healthy individuals, the direction of ventricular [[depolarization]] and [[repolarization]] is relatively reversed; this creates a sharp SA.<ref name=two>{{cite book |last1=Scherptong |first1=R. |last2=Man |first2=S. |last3=Le Cessie |first3=S. |last4=Vliegen |first4=H. |last5=Draisma |first5=H. |last6=Maan |first6=A. |last7=Schalij |first7=M. |last8=Swenne |first8=C. |displayauthors=6 |title=The Spatial QRS-T Angle and the Spatial Ventricular Gradient: Normal Limits for Young Adults |journal=Computers in Cardiology |year=2007 |volume=34 |pages=717–720 |doi=10.1109/cic.2007.4745586|isbn=978-1-4244-2533-4 |citeseerx=10.1.1.413.6240 }}</ref> There is high individual variability and gender difference in the magnitude of the SA. The mean, normal SA in healthy young adult females and males is 66° and 80°, respectively,<ref name=two /> and very similar magnitudes are found in the elderly population (65 years and older).<ref name=three>{{cite journal |last1=Rautaharju |first1=P. |last2=Ge |first2=S. |last3=Nelson |first3=J. |last4=Marino Larsen |first4=E. |last5=Pasaty |first5=B. |last6=Furbery |first6=C. |last7=Zhang |first7=Z. |last8=Robbins |first8=J. |last9=Gottdiener |first9=J. |last10=Chaves |first10=P. |displayauthors=6 |title=Comparison of mortality risk for electrocardiographic abnormalities in men and women with and without coronary heart disease (from the Cardiovascular Health Study) |journal=American Journal of Cardiology |year=2006 |volume=97 |issue=3 |pages=309–15 |doi=10.1016/j.amjcard.2005.08.046|pmid=16442387 }}</ref> In ECG analysis, the SA is categorized into normal (below 105°), borderline abnormal (105–135°) and abnormal (greater than 135°).<ref name=four>{{cite journal |last1=Kors |first1=J. |last2=Kardys |first2=I. |last3=van der Meer |first3=I. |last4=van Herpen |first4=G. |last5=Hofman |first5=A. |last6=van der Kuip |first6=D. |last7=Witteman |first7=J. |displayauthors=6 |title=Spatial QRS-T Angle as a Risk Indicator of Cardiac Death in an Elderly Population |journal=Journal of Electrocardiology |year=2003 |volume=36 |pages=113–114 |doi=10.1016/j.jelectrocard.2003.09.033}}</ref> A broad SA results when the heart undergoes pathological changes and is reflected in a discordant ECG. A large SA indicates an altered ventricular repolarization sequence, and may be the result of structural and functional myocardial changes that induce regional shortening in action potential duration and impaired [[ion channel]] functioning.<ref name=five>{{cite journal |last1=Rautaharju |first1=M. |last2=Kooperberg |first2=C. |last3=Larson |first3=J. |last4=LaCroix |first4=A. |title=Electrocardiographic Predictors of Incident Congestive Heart Failure and All-Cause Mortality in Postmenopausal Women: The Women's Health Initiative |journal=Circulation |year=2006 |volume=113 |issue=4 |pages=481–489 |doi=10.1161/circulationaha.105.537415}}</ref>
* The spatial T-axis, representing the electrical forces generated by [[ventricular repolarization]].
Current standard ECG markers of repolarization abnormalities include [[ST depression]], T wave inversion and [[QT prolongation]]. Many studies have investigated the prognostic strength of the SA for cardiac morbidity and mortality compared to these and other ECG parameters. In treated [[Hypertension|hypertensive]] patients, the SA was significantly larger in patients with elevated [[blood pressure]] compared to those with lower blood pressure values and a discrimination between patients with high and low blood pressure could not be detected using other ECG parameters.<ref name=six>{{cite journal |last1=Dilaveris |first1=P. |last2=Gialafos |first2=E. |last3=Pantazis |first3=A. |last4=Synetos |first4=A. |last5=Triposkiadis |first5=F. |last6=Gialafos |first6=J. |title=The spatial QRS-T angle as a marker of ventricular repolarization in hypertension |journal=Journal of Human Hypertension |year=2001 |volume=15 |pages=63–70 |doi=10.1038/sj.jhh.1001129}}</ref> In the Rotterdam Study with men and women aged 55 years and older, having an abnormal SA significantly increased the hazard ratios for [[cardiac death]], sudden cardiac death, non-fatal cardiac events ([[infarction]], coronary interventions) and total mortality. Independently, the SA was a stronger risk indicator of cardiac mortality compared to the other cardiovascular and ECG risk factors analyzed.<ref name=four /> The Women’s Health Initiative study concluded that a wide SA was the strongest predictor for incident coronary heart failure risk and a dominant risk factor for all cause mortality compared to several other ECG parameters.<ref name=five /> The SA also increases accuracy of diagnosing [[left ventricular hypertrophy]] (LVH). Using only conventional ECG criteria to diagnose LVH the diagnostic accuracy was 57%, however the inclusion of the SA significantly improved the diagnostic accuracy to 79%.<ref name=seven>{{cite journal |last1=Man |first1=S. |last2=Rahmattulla |first2=C. |last3=Maan |first3=A. |last4=Holman |first4=E. |last5=Bax |first5=J. |last6=van der Wall |first6=E. |last7=Schalij |first7=M. |last8=Swenne |first8=C. |displayauthors=6 |title=Role of the vectorcardiogram-derived spatial QRS-T angle in diagnosing left ventricular hypertrophy |journal=Journal of Electrocardiology |year=2012 |volume=45 |issue=2 |pages=154–160 |doi=10.1016/j.jelectrocard.2011.10.001}}</ref>
The SA is not routinely measured in clinical ECG examination even though the computerized vectorcardiography software is widely available, efficient and is not affected by observational biases unlike other ECG parameters.<ref name=six /> The SA is a sensitive marker of repolarization aberrations and with further research support the SA will likely become clinically applied in predicting cardiac morbidity and mortality.
In healthy individuals, the SA is relatively sharp due to the near-opposite orientation of depolarization and repolarization. The normal SA varies by gender and age, averaging 66° in young females and 80° in young males, with similar values in older populations. The SA is categorized as:
* Normal: Below 105°
* Borderline abnormal: 105–135°
* Abnormal: Greater than 135°
A simplified criteria in using the vectorcardiogram has the ability to identify patients with a diaphragmatic infarction not apparent in the electrocardiogram.
A broad SA often reflects pathological changes in the heart and is associated with discordant ECG patterns, structural myocardial alterations, and impaired [[ion channel]] functioning. This can be observed in conditions such as [[hypertension]], [[left ventricular hypertrophy]] (LVH), and [[myocardial infarction]].
<ref>Stein, Paul & Simon, Armando P. vectorcardiographic diagnosis of diaphragmatic myocardial infarction. The American Journal of Cardiology, 1976, 38, 568-574.</ref>
==See also==
*[[Electrocardiography]]
==References==
== Clinical Significance ==
{{reflist}}
The SA is a significant marker of [[cardiac morbidity]] and [[mortality]], often outperforming conventional ECG markers like [[ST depression]], [[T wave inversion]], and [[QT prolongation]]. Studies indicate that in hypertensive patients, the SA is significantly larger in those with elevated [[blood pressure]]. Additionally, it enhances the accuracy of diagnosing LVH, increasing diagnostic precision from 57% to 79% when included in ECG assessments.
Despite its predictive value, the SA is not routinely measured in clinical ECG evaluations. However, computerized vectorcardiography software is widely available and offers an unbiased, efficient method for assessing cardiac repolarization abnormalities. As further research supports its clinical utility, the SA may become a standard parameter in predicting cardiac risk.
== Vectorcardiography in Myocardial Infarction ==
A simplified evaluation of vectorcardiograms can identify patients with a [[diaphragmatic infarction]] that may not be apparent on a standard ECG.
== See Also ==
* [[Electrocardiography]]
{{Electrodiagnosis}}
{{Electrodiagnosis}}
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[[Category:Cardiac procedures]]
[[Category:Cardiac procedures]]
[[Category:Cardiology]]
[[Category:Cardiology]]
==External links==
* [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1234567/ Vectorcardiography: A Review] - National Center for Biotechnology Information
[[Category:Cardiology]]
[[Category:Medical imaging]]
<gallery>
File:Vektorkardiogramm_kgm-normal.jpg
</gallery>
Latest revision as of 21:53, 16 February 2025
A method of recording the direction and magnitude of the electrical forces of the heart.
Vectorcardiography (VCG) is a method of recording the magnitude and direction of the electrical forces generated by the heart using a continuous series of vectors that form curving lines around a central point.
Vectorcardiography was developed by Ernest Frank in the mid-1950s. Since the human body is a three-dimensional structure, the primary objective is to construct three orthogonal leads encompassing all the electrical information. These three leads are represented by the right-left axis (X), head-to-feet axis (Y), and front-back (anteroposterior) axis (Z).
Various methods have been proposed to evaluate a vectorcardiogram. Grygoriy Risman introduced an advanced approach known as Spatial Vectorcardiometry (SVCM), which refines the analysis of vectorcardiograms.
The spatial QRS-T angle (SA) is derived from a vectorcardiogram, a three-dimensional representation of the 12-lead ECG created through computerized matrix operations. The SA represents the deviation between two vectors:
In healthy individuals, the SA is relatively sharp due to the near-opposite orientation of depolarization and repolarization. The normal SA varies by gender and age, averaging 66° in young females and 80° in young males, with similar values in older populations. The SA is categorized as:
Normal: Below 105°
Borderline abnormal: 105–135°
Abnormal: Greater than 135°
A broad SA often reflects pathological changes in the heart and is associated with discordant ECG patterns, structural myocardial alterations, and impaired ion channel functioning. This can be observed in conditions such as hypertension, left ventricular hypertrophy (LVH), and myocardial infarction.
The SA is a significant marker of cardiac morbidity and mortality, often outperforming conventional ECG markers like ST depression, T wave inversion, and QT prolongation. Studies indicate that in hypertensive patients, the SA is significantly larger in those with elevated blood pressure. Additionally, it enhances the accuracy of diagnosing LVH, increasing diagnostic precision from 57% to 79% when included in ECG assessments.
Despite its predictive value, the SA is not routinely measured in clinical ECG evaluations. However, computerized vectorcardiography software is widely available and offers an unbiased, efficient method for assessing cardiac repolarization abnormalities. As further research supports its clinical utility, the SA may become a standard parameter in predicting cardiac risk.
