The significance of P wave duration and P wave dispersion for risk assessment of atrial tachyarrhythmias in patients with corrected tetralogy of Fallot.

BACKGROUND

The aim of the present study was to determine the potential role of P wave duration and P wave dispersion for risk assessment of atrial tachyarrhythmias in patients with corrected tetralogy of Fallot (ToF).

METHODS

The maximum P wave duration, minimum P wave duration, and the P wave dispersion from the 12-lead surface electrocardiogram of the patients and controls were measured. Electrophysiological study was performed only in the patient group.

RESULTS

The study group consisted of 25 patients with corrected ToF with a mean age of 16.4 +/- 4.25 years and 25 age-matched healthy control subjects. Patients underwent repair at a mean age of 4.6 +/- 3.41 years (range: 1-19), and the mean duration of follow-up of 11.8 +/- 1.7 years (range: 9-15) after surgery. On electrophysiological study sinus node dysfunction was detected in 3 patients (12%), atrial tachyarrythmias-atrial flutter or fibrillation-in 5 patients (20%), both sinus node dysfunction and atrial flutter in 1 patient (4%), and AV conduction delay in 1 patient (4%). P wave dispersion is significantly higher in patients with atrial tachyarrhythmia inducible by electrophysiological study than in other patients (P < 0.05). A P wave dispersion value of >35 ms has a high predictive accuracy (sensitivity = 83% and specificity = 89%) for inducible atrial tachyarrhythmia in patients with corrected tetralogy of Fallot.

CONCLUSION

P wave dispersion is an easily measured electrocardiographic marker with a good sensitivity and specificity for predicting atrial arrhythmias in patients after correction of ToF.