Abstract：Objective To explore the advantages of the joint use of three kinds of ECG scatter plots in rapidly analyzing special complex arrhythmias , and to accumulate experience of complex arrhythmia analysis. Methods Taking special atrial parasystolic rhythm as an example, its time scatter plot, Lorenz scatter plot and difference scatter plot were separately observed. Based on a combination of reversal technique and mathematical model of scatter plot, the characteristics of cardiac cycle, and features and formation principle of ECG scatter plot were analyzed. The electrophysiological significance reflected by ECG scatter plot was analyzed and summarized which helps to identify the nature of arrhythmias. ResultsThe three kinds of ECG scatter plots have their own characteristics. Time scatter plot: it is sometimes divided into two layers and sometimes divided into three layers. Within the time period corresponding to two layers, the scatter plot is presented as atrial bigeminy(the bottom layer is NS, and the top layer is SN) while atrial rhythm dominates the time period corresponding to three layers(layer SS is basically located in the middle of layer NS and SN). It implies that the compensatory interval added to coupling interval is equal to twice of the atrial rhythm cycle, that is, SN+NS=2SS. Lorenz scatter plot: the pink point set shows to be dominant(accounting for 2/3 of the total heart beats), and distributes neighboring to the shortlong period zone and constant velocity line. The blue point set is disadvantaged(accounting for 1/3 of the total heart beats), and distributes neighboring to the longshort period zone and constant velocity line. Mathematical model reveals that the pink point set embraces three overlapping components and no other obvious characteristic is found. Difference scatter plot: it is similar to make a 180° clockwise rotation of the difference scatter plot of bigeminy and trigeminy of frequent premature ventricular contraction with distinctive features. From a macroscopic view of scatter plot, atrial rhythm occupies a predominant position since its self-discipline reaches or is slightly over that of sinus rhythm. In the occurrence of intermittent efferent block, sinus rhythm appears in the form of escape beats without disrupting the rhythm. It suggests that there is protective afferent block in atrial rhythm of this example, and it is atrial parasystolic rhythm with increased self-discipline. Conclusion The joint use of three kinds of ECG scatter plots provides a macroscopic view for analyzing special complex cases. The electrophysiological significance revealed by scatter plot serves as references for defining the nature of arrhythmia. The joint use of three kinds of ECG scatter plots has obvious advantages in the rapid analysis of complex arrhythmia.
