On-line analysis of cardiac near field signals during electrophysiological experiments with heart preparations

Two signal processing algorithms for the on-line analysis of local propagation of activation during electrophysiological in-vitro experiments with heart preparations are presented. The first algorithm computes local velocity and direction of the propagating activation wave. Along with the values, their uncertainties due to noise are given. The second algorithm determines the fractionation index, a quantitative measure to characterize fractionated electrograms. These parameters are expected to provide valuable information for the characterization of the microstructure of the tissue under examination. The implementation of these algorithms in a measurement system allows the on-line monitoring of the resulting parameters in a beat-to-beat manner for heart rates up to 1800 beats per minute. This enables the examination of tachycardia even in fast beating preparations like the mouse heart.