Electrical and structural remodeling in left ventricular hypertrophy-a substrate for a decrease in QRS voltage?

Abstract

Electrical remodeling in advanced stages of cardiovascular diseases creates a substrate for triggering and maintenance of arrhythmias. The electrical remodeling is a continuous process initiated already in the early stages of cardiological pathology. The aim of this opinion article was to discuss the changes in electrical properties of myocardium in left ventricular hypertrophy (LVH), with special focus on its early stage, as well as their possible reflection in the QRS amplitude of the electrocardiogram. It critically appraises the classical hypothesis related to the QRS voltage changes in LVH. The hypothesis of the relative voltage deficit is discussed in the context of supporting evidence from clinical studies, animal experiments, and simulation studies. The underlying determinants of electrical impulse propagation which may explain discrepancies between "normal" ECG findings and increased left ventricular size/mass in LVH are reviewed.

Figure 1

Mind map: Factors involved in the impulse propagation which have been reported to develop changes in the early stage of left ventricular hypertrophy.

Figure 2

Schematic presentation of interrelations among changes in structural and electrical characteristics in hypertrophied myocardium.