Measurement of spontaneous morphologic variations in the electrocardiographic P-wave.

A real-time computer-oriented data acquisition and analysis system is described for measuring the spontaneous morphologic variations in the electrocardiographic P-wave. A waveform index is obtained by comparing each P-wave on a beat-by-beat basis with a reference P-wave. A graphic history of the P-wave morphology is produced by plotting this waveform index versus time. When structural changes in the P-wave are present the waveform index is further used to separate the P-waves into families and these families are averaged.