Assessment of right atrial mapping and P wave-triggered signal-average in patients with paroxysmal atrial fibrillation

To assess right atrial mapping and P wave-triggered signal-averaged electrocardiogram (ECG) in patients with paroxysmal atrial fibrillation (PAF), this study examined right atrial electrograms using atrial mapping and parameters by P wave-triggered signal-averaged ECG in 39 patients without sick sinus syndrome. Subjects were divided into those with PAF (n = 13, 60 +/- 13 years old) and a control group (n = 26; 49 +/- 19 years old). The total number of abnormal right atrial electrograms per patient was significantly greater in the PAF group (3.2 +/- 1.9) than in the control group (1.1 +/- 0.9; P < .001). The longest duration of right atrial electrogram in the PAF group tended to be greater than that in the control group (P = .06). The filtered P wave duration was significantly longer in the PAF group than in the control group (144 +/- 21 vs 125 +/- 14 ms [P < .002]). The values of the root mean square of P wave-triggered signal-averaged ECG 15 ms from the onset (RMSi 15) and 20 ms from the offset (RMSe 20) were significantly lower in the PAF group (1.1 +/- 0.4 mu V, 1.4 +/- 0.5 mu V) than in the control group (1.9 +/- 1.1 mu V [P < .02], 2.1 +/- 0.9 mu V [P < .01]). The total number of right atrial electrograms in patients with RMSi 15 of less than or equal to 1.5 mu V was significantly greater than in patients with RMSi 15 of >1.5 mu V (2.2 +/- 1.8 vs 1.3 +/- 1.3 [P < .05]). Thus, the total number of abnormal right atrial electrograms per patient, the total filtered P wave duration, RMSi-15, and RMSe 20 may be good indices of PAF in patients without sick sinus syndrome. RMSi 15 may reflect the total number of the abnormal right atrial electrograms per patient.