Atrial Vectorcardiogram in Mitral Valve Disease

Abstract

Atrial vectorcardiograms (P sSPACE-loops) were recorded at high gain from 19 adult patients with mitral valve disease and enlargement of the left atrium using the equilateral tetrahedral reference frame. The P sSPACE-loops of the patients with mitral valve disease differed from P sSPACE-loops of 39 normal subjects in that (1) they were more distorted and contained a large number of high frequency components, (2) in the transverse plane projection they were more ‘open’ in appearance and enclosed a larger area when they were not of figure-of-eight configuration, and (3) those with a figure-of-eight configuration had maximal mean instantaneous vectors (MMIV) which were definitely abnormal. Catheterization data from seven patients failed to show a significant relationship with configuration of the P sSPACE-loops.