Analysis of non-invasively recorded His-Purkinje signals from patients with myotonic muscular dystrophy

This study presents several new approaches to analyze the non-invasively recorded His-Purkinje system (HPS) signals from patients with myotonic muscular dystrophy. A high resolution electrocardiogram based on signal averaging to improve the signal-to-noise ratio(SNR) is a well established means to record HPS potentials. These new approaches used methods to temporally and spectrally separate the HPS potentials from the P wave potentials. These included both physiologically based and signal processing based schemes. Separating or shifting the P wave from the HPS potentials using heart rate dependent averaging and the addition of several highpass filtering methods proved somewhat, but not totally successful. In the group of patients with sequential recordings over a period of two years the progression of their muscular dystrophy may also be seen in the heart as well. This may then produce noticeable progressive trends or changes in their HPS waveforms over time. The most noticeable changes found in this study were temporal changes and morphological changes of the HPS activity of these patients over time.