ABSTRACT
Lorenz plot (LP) method which gives a global view of long-time electrocardiogram signals, is an efficient simple visualization tool to analyze cardiac arrhythmias, and the morphologies and positions of the extracted attractors may reveal the underlying mechanisms of the onset and termination of arrhythmias. But automatic diagnosis is still impossible because it is lack of the method of extracting attractors by now. We presented here a methodology of attractor extraction and recognition based upon homogeneously statistical properties of the location parameters of scatter points in three dimensional LP (3DLP), which was constructed by three successive RR intervals as , and axis in Cartesian coordinate system. Validation experiments were tested in a group of RR-interval time series and tags data with frequent unifocal premature complexes exported from a 24-hour Holter system. The results showed that this method had excellent effective not only on extraction of attractors, but also on automatic recognition of attractors by the location parameters such as the azimuth of the points peak frequency ( ) of eccentric attractors once stereographic projection of 3DLP along the space diagonal. Besides, was still a powerful index of differential diagnosis of atrial and ventricular extrasystole. Additional experiments proved that this method was also available on several other arrhythmias. Moreover, there were extremely relevant relationships between 3DLP and two dimensional LPs which indicate any conventional achievement of LPs could be implanted into 3DLP. It would have a broad application prospect to integrate this method into conventional long-time electrocardiogram monitoring and analysis system.
ABSTRACT
Objective: To explore the advantage of RR-Lorenz plot (RR-LP) in analyzing the patients of sinus rhythm with long RR interval. Methods: A total of 308 RR-LP patients with long RR interval were retrospectively studied. The patients were divided into 7 groups according to the type of long RR intervals. ① Sinus bradycardia with arrhythmia group, n=63,②Repeated transient sinus arrest group, n=16, ③Ⅱ° sino-atrial block group, n=14, ④Ⅱ° atrial ventricular block (Ⅱ° AVB) group, n=47, ⑤ Un-passed atrial premature beats (APB) group, n=28, ⑥ Atrial premature beats group, n=72 and ⑦ Premature ventricular beats group, n=68. We analyzed the patients of RR interval greater than 1500 ms with ambulatory electrocardiogram record. Results: ①RR-LP of sinus bradycardia with arrhythmia group showed a single distributing area with 1500 ms for the origin of transverse and longitudinal axis with B line slope at 1, tilt angle of 45°.②RR-LP of repeated transient sinus arrest,Ⅱ° sino-atrial block,Ⅱ° AVB and APB groups showed special four distributing areas with B line slope at (0.51 ± 0.01), tilt angle of (23.04 ± 0.50) °, B line slope at 0.6, tilt angle of (27°), B line slope at (0.57 ± 0.21), tilt angle of (25.69 ± 9.59)° and B line slope at (0.50 ± 0.01), tilt angle of (22.59 ± 0.54) ° respectively.③RR-LP of premature beats groups showed special four regional distributing areas, B line slope for atrial premature beats was at (0.38 ± 0.12), tilt angle of (17.06 ± 5.22) ° and B line slope for ventricular premature beats was at (0.07 ± 0.05), tilt angle of (3.02 ± 2.39) °. Conclusion: RR-LP in patients of sinus rhythm with long RR interval had speciifc morphology and distribution features, the local abnormality could be found in a plane via all RR intervals which provided a differential diagnosis for repeated occurrence of short RR interval.