Vectorcardiography

The vectorcardiogram ( VCG ) is a spatial representation of the time course of the potential difference generated by the heart, as they project themselves onto the body surface.

In contrast to the electrocardiogram ( ECG), which represents the temporal voltage profile of empirically defined derivations, Einthoven, Goldberger, Wilson and Nehb derivations as scalar voltage-time curve, the vectorcardiogram are in addition to the spatial variation of the voltage changes at the time of atrial and ventricular depolarization and ventricular repolarization vectorially, ie in the form of so-called vector loops again. The VKG therefore requires the use of certain derivative systems that adjust for the voltage distortion of the stored between heart and body surface organs. In the clinical context are usually the orthogonal Frank -lead, rarely uses the McPhee leads.

P and R- loop representing the spatial variation of the voltage vectors of the atrial (P- loop ) or ventricular (R- loop ) depolarization, while the T- loop represents the voltage developing during ventricular repolarization.

Shows the vector with its arrowhead at each time point of the electrical zero point of the heart in a particular direction in space. The magnitude of the vector ( sum of the potential ), the magnitude is represented by the length of the arrow. The angle, which forms the sum vector with the frontal plane (elevation) and the horizontal plane ( azimuth), its spatial orientation is clearly defined. Commonly used in clinical Vectorcardiography magnitude ( mV), Elevation (°) and azimuth (°) of the P, R and T vector loop as measures of comparison or follow-up examinations.

In contrast to the ECG diagnostics based on a lexicon of empirical findings allows the VCG in principle an automated analysis parameters and diagnosis of stress phenomena. The vectorcardiogram is also suitable as a complement to the teaching ECG. It allows the different ECG patterns to interpret vectorial and three-dimensional images.

Since the repolarization physiologically represents a metabolic process, the shape and position of the T- loop is particularly important for an under-supply of the heart affected by lack of oxygen. Diagnosis the vectorcardiogram may be important in the future because of the spatial profile of the T- loop can be parameterized for ischemia diagnosis. Thus, the early detection of coronary heart disease ( CHD) could be facilitated by the easy to perform and non-invasive method VKG by the family doctor.

There are various criteria, such as a vectorcardiogram was created and interpreted by various researchers. Grygoriy Risman shows the various methods that have been developed over half a century, and introduces a further method called Raumvektorkardiometrie ( RVKM ). Originally written in Russian thesis is available in the Medical Academy Omsk.