Electrocardiographic diagnosis of left ventricular hypertrophy: is the method obsolete or should the hypothesis be reconsidered?

The current ECG diagnosis of LVH is based on QRS voltage criteria and aims to estimate left ventricular mass. Its underlying hypothesis includes unstated assumptions about the non-spatial determinants of QRS voltage;that the electrical properties of hypertrophied myocardium do not differ from those healthy myocardium, and that they are not changed in the course of developing LVH. Since these two assumptions are not true, the performance of the voltage criteria is limited and is reflected in the high number of so-called false negative ECG results, as well as their low sensitivity. The reconsidered hypothesis is based on a more complex understanding of LVH and on the analysis of information provided by electrocardiography. It considers false negative results for LVH diagnosis as a relative voltage deficit, and introduces a new parameter for its quantification: the specific potential (the relative QRS voltage).The relative voltage deficit is related to changes of active and passive electrical properties (electrophysiological remodelling) of the hypertrophied myocardium. This new hypothesis also takes into account changes of the relative QRS voltage in different stages of LVH. The potential of this concept is its usefulness as a parameter in the frame of diagnostics of LVH, of diffuse changes of myocardium, in cardiovascular risk assessment, and well as for evaluation of the effects of therapy.