Relationship between clinical and echocardiography-derived parameters and atrial activation as measured by the P-wave signal-averaged electrocardiogram.

UNLABELLED: P-wave signal averaging is used in an attempt to detect patients at risk of atrial arrhythmias, particularly atrial fibrillation. Although many studies utilized this method, data on the relationship between clinical and echocardiographic variables and signal averaged P-wave parameters are sparse. Thus, we performed a prospective study to evaluate the influence of important clinical and echocardiographic variables on P-wave parameters. The study included 100 probands without demonstrable cardiac disease. P-wave signal averaging was performed after echocardiographic examination in all subjects. Overall P-wave duration averaged 122 +/- 16 ms and correlated significantly with age, left atrial and left ventricular end-diastolic diameter on univariate analysis (r = 0.287, 0.393 and 0.375; p = 0.004, < 0.0001 and < 0.0001, respectively). On multivariate analysis, however, age was the only independent factor affecting signal averaged P-wave duration (p = 0.02). There were statistically significant differences in left atrial size and P-wave duration if probands were grouped according to their age.
CONCLUSION: There is a significant relationship between signal averaged P-wave duration and age. This may be due to increased atrial fibrosis in elderly subjects. These data should be considered when signal-averaged P wave duration is used as a risk stratifier in patients prone to atrial fibrillation.