Interpolation of local activation times versus potentials to derive an activation map in infarcted myocardium

Cardiac mapping is a tool used in the analysis of activation wavefront patterns. The highly variable nature of infarcted myocardium may produce significant errors in activation mapping, using traditional mapping techniques. There are two aims to this study. The first aim is to compare activation time detection methods and the second aim is to compare potential and time interpolation. Unipolar electrograms recorded from epicardium of an infarct in the left ventricle of a canine were used to simulate activation patterns over an infarct region. Detected activation times, using (-dV/dt)/sub max/,, and the Laplacian, a spatial derivative, were compared. The Laplacian, unlike the (-dV/dt)/sub max/ could distinguish local from distant events. However, the Laplacian had an unexpected systematic error which was dependent on the direction a velocity of activation. Activation map generation was compared using two different sequences of analysis. Activation time interpolation and potential interpolation. Interpolated activation times could produced precise maps which were independent of propagation velocity. The accuracy of potential interpolation was limited as a function of decreasing conduction velocity.