Objective To investigate the correlation between P wave dispersion(Pd) and maximum time limit(Pmax) and paroxysmal atrial fibrillation(PAF) and atrial arrhythmia(AR). Methods 30 patients with PAF and 30 patients with AR who were all treated in our hospital in one stage were selected as subjects

and their Pd and Pmax were compared with those of 30 healthy people. Results the values of Pd and Pmax in group PAF were significantly higher than those in control group.; the values of Pd and Pmax in group AR were significantly higher than those in control group. There was no significant difference in Pd and Pmax between group PAF and group AR. The proportion of Pd ≥40 ms

Pd ≥110 ms

Pd ≥40 ms+Pmax≥110 ms in the PAF group was significantly higher than that in the control group; The proportion of Pd≥40 ms

Pd≥110 ms

Pd ≥40 ms+Pmax≥110 ms in AR group was significantly higher than that in control group; and there was no significant difference between the PAF group and the AR group.The highest specificity of PAF and AR were detected under Pd ≥40 ms+Pmax≥110 ms and the positive predictive value was the highest

but the difference between Pd≥40 ms and Pd≥110 ms was not significant. Conclusion Pd and Pmax can be used as physiological indexes to predict PAF and AR

and provide reliable basis for clinical diagnosis.The combination application of Pd and Pmax can further improve the positive predictive value of PAF and AR.