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Paper doi:10.1016/j.jelectrocard.2012.07.009

Pubmed ID 22960164

abstract

An increased QRS voltage is considered to be specific for the ECG diagnosis of left ventricular hypertrophy (LVH). However, the QRS-complex patterns in patients with left ventricular hypertrophy cover a broader spectrum: increased QRS voltage, prolonged QRS duration, left axis deviation, and LAFB- and LBBB-like patterns, as well as pseudo-normal QRS patterns.

The classical interpretation of the QRS patterns in LVH relates these changes to increased left ventricular mass (LVM) per se, while tending to neglect the modified active and passive electrical properties of the myocardium. However, it has been well documented that both active and passive electrical properties in LVH are altered.

Using computer simulations, we have shown that an increased LVM is not the only determinant of QRS complex changes in LVH, since these changes also could be produced without changing the left ventricular mass, implying that these QRS patterns can be present in patients before their LVM exceeds the arbitrary upper normal limits.

Our results link the experimental evidence on electrical remodeling with clinical interpretation of ECG changes in patients with LVH, and stress the necessity of a complex interpretation of the QRS patterns considering both spatial and non-spatial determinants in terms of the spatial angle theory. We assume that hypertrophic electrical remodeling in combination with changes in left ventricular size and shape explains the variety of ECG patterns as well as the discrepancies between ECG and left ventricular mass.