Abstract： Objective To explore the application value and advantages of combining electrocardiographic waterfall plot with scatter plot in diagnosing atrial arrhythmias. Methods The characteristics of changes in the electrocardiographic waterfall plot and scatter plot of typical atrial arrhythmias in ambulatory electrocardiography (AECG) were analyzed, and their application advantages were summarized. Results The electrocardiographic waterfall and scatter plots of different types of atrial arrhythmias were manifested by different characteristics. (ⅰ) Frequent atrial premature beats. The waterfall plot was characterized by intermittent P-peak band breaks while R- and T-peak bands remained unchanged; the scatter plot was featured by premature beat points located in the fast acceleration zone. (ⅱ) Atrial autonomic rhythm. The waterfall plot was characterized by a break in the P-peak band and changes of PR interval; the scatter plot feature was that this rhythm could be integrated into sinus rhythm cluster which was difficult to be distinguished from sinus rhythm. (ⅲ) Intermittent short paroxysmal atrial tachycardia. The waterfall plot was characterized by a P-peak band rupture and appearance of two or more R-peak bands; the feature of the scatter plot was that the cluster point could be located in the fast acceleration zone or on the 45° line, and its heart rate range could be distinguished from sinus heart rate, but the onset time can not be determined. (ⅳ) Persistent atrial fibrillation. The waterfall plot was characterized by the disappearance and disorder of P-peak band while R- and T-peak bands remained unchanged; the scatter plot was featured by a fan shape. (ⅴ) Atrial flutter. The waterfall plot was characterized by a P-peak band fault, with the appearance of two or more P-peak bands and corresponding PR intervals; the scatter plot was featured by a grid-like pattern. Conclusion The type of atrial arrhythmias could be accurately and quickly determined by selecting the leads with significant changes of P-QRS-T complex in AECG, and observing the characteristics of P-, QRS- and T-peak band changes in the electrocardiographic waterfall plot combined with changes of ECG scatter plot.
