Mutual Information Analysis of Temporal Patterns of Occurrence of Ventricular Premature Beats

摘要

The importance of ventricular premature beats (VPB's) (results from their possible association with an increased risk for cardiac sudden death. However, little is known about patterns of VPB generation. We applied mutual information (MI) to quantify how VPB's are generated with mutual dependence over time, with larger numbers indicating more mutual relation, and examined its relationship with VPB's/day and Lown grading system. Twenty subjects (Lown grade3, n=1; 4A, n=9; 4B, n=10) were identified retrospectively as having more than 3000 of VPB's during 24-hour Holter monitoring. Ten of these patients had no apparent heart disease (N-group). The other ten had coronary heart disease (C-group). MI had no significant correlation with VPB's/day and showed no significant difference between Lown grades (4A, 2.1±1.4bits vs 4B, 2.3±1.4bits). We found that values of MI were variable among N-group (2.2±1.3bits) and C-group (2.4±1.5bits). The values of MI of time series of random numbers were all zeros. We thought that the mechanism of VPB's in patients with strong generalized dependence of VPB's might be different from that in patients with weak generalized dependence, particularly with random generation of VPB's. The absent relations with VPB's/day and Lown grades suggested that MI of VPB's could be an independent marker.