Fractal dimension analysis for the detection of ventricular late potentials in the time domain

The presence of ventricular late potential (LP) activity in patients with post-myocardial infarction has been correlated with their susceptibility to develop ventricular tachycardia and may be used as a risk criterion. A reliable novel approach for characterising and detecting abnormal LP activity is presented. It consists of analyzing the degree of complexity of LP activity by quantifying their fractal dimension (/spl delta/). Fractal dimensional analysis was applied to the LP's attractor traced in the microvoltage, 3-dimensional space. The /spl delta/ parameter may be interpreted as an index for the chaotic behaviour of the terminal activity of the ventricular depolarisation process which could trigger a catastrophic arrhythmic episode. Results of a clinical study indicated that the value of /spl delta/ was significantly higher in at risk patients than in healthy subjects (p<0.001), and suggested that a value of /spl delta/>1.30 can be a risk criterion.<
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