[The criteria for the prediction of paroxysmal atrial fibrillation by time domain analysis of the P wave-triggered signal-averaged electrocardiogram].

In order to determine the criteria for definition of atrial late potentials in patients with paroxysmal atrial fibrillation (Paf), the P wave-triggered signal-averaged electrocardiogram (SAE) was recorded in 88 patients with Paf (Paf group) and in 216 normal subjects (Normal group). Three SAE variables, duration of the filtered P wave (FPD), root-mean-square voltage of the last 20 msec (V20) and duration of under 5 microV (D5) of the vector magnitude were measured. FPD and D5 were significantly longer in the Paf than in the Normal group (FPD; 137 +/- 13 vs. 115 +/- 7 msec, D5; 27 +/- 12 vs. 16 +/- 5 msec, p < 0.001, respectively). V20 was also significantly lower in the Paf than in the Normal group (2.5 +/- 1.1 vs. 3.9 +/- 1.1 microV, p < 0.001). The sensitivity and specificity for the prediction of Paf was computed (for all dichotomy points) and compared with various criteria for atrial late potentials based on the three SAE variables. Analysis showed that 1) FPD was a better predictor of Paf than the other two variables, 2) the criteria of [FPD > 125 msec and V20 = 3.0 microV or less] as defining "atrial late potentials" gave a sensitivity of 68%, a specificity of 99% and a predictive accuracy of 90%. These findings suggest that the SAE is useful to predict Paf. Additionally, prospective studies are needed with a larger number of patients to compare the different criteria of "atrial late potentials" by time domain analysis of the SAE.