Vector cardiogram

The vector cardiogram (VKG) is a spatial representation of the temporal progression of the potential differences generated by the heart as they are projected onto the body surface.

In contrast to the electrocardiogram (EKG), which shows the temporal voltage curve of empirically established leads, Einthoven , Goldberger , Wilson and Nehb leads as a scalar voltage-time curve, the vector cardiogram also shows the spatial course of the voltage changes at the time of atrial and ventricular depolarization as well as ventricular repolarization vectorial, d. H. in the form of so-called vector loops. The VKG therefore requires the use of certain derivation systems that compensate for the voltage distortions in the organs between the heart and the body surface. In the clinical context, the orthogonal Frank leads , less often the McPhee leads, are used.

Vector cardiogram, example with several cycles, gray = P-, ​​blue = R-, green = T-loop

The P and R loops represent the spatial course of the voltage vectors of the atrial (P loop) and ventricular (R loop) depolarization, while the T loop represents the voltage development during the ventricular repolarization.

With its arrowhead, the vector points at any point in time from the electrical zero point of the heart in a certain direction in space. The magnitude of the vector (total potential), the magnitude , is represented by the length of the arrow. Its spatial orientation is clearly defined by the angles that the sum vector forms with the frontal plane ( elevation ) and the horizontal plane ( azimuth ). Usually, in clinical vector cardiography, the magnitude (mV), elevation (°) and azimuth (°) of the P, R and T vector loops are used as measurement variables for comparative and progressive examinations.

In contrast to the ECG diagnosis, which is based on an empirical lexicon of findings, the VKG analysis in principle allows an automated parameterization and diagnosis of the voltage phenomena. The vector cardiogram is also suitable as a didactic supplement to the EKG. It allows the different EKG images to be interpreted vectorially and represented in three dimensions.

Since the repolarization is physiologically a metabolic process, the shape and position of the T-loop in particular is affected by a lack of oxygen in the heart. The vectorcardiogram may be diagnostically important in the future because the spatial course of the T-loop can be parameterized for ischemia diagnostics. This could facilitate the early detection of coronary heart disease (CHD) by the family doctor using the easy-to-use and non-invasive VKG method.

There are various criteria for how a vector cardiogram was created and interpreted by various researchers. Grygoriy Risman shows the various methods that have been developed over half a century and introduces a more advanced method called space vector cardiometry (RVKM). The dissertation, originally written in Russian, is available at the Omsk Medical Academy.

Individual evidence

1. ↑ Space vector cardiometry (Russian / English / German).
2. ↑ Odessa Medical Academy. ( Memento of the original from October 22, 2013 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. 

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !