P wave duration in paroxysmal and persistent atrial fibrillation

Background. Functional and structural changes in the atrial muscle constitute a substrate for atrial fibrillation (AF). The pathological changes in the left atrium decrease the conduction velocity and result in prolongation of the P wave duration. Objectives. To assess the duration of the P wave in patients with AF in different clinical presentations of arrhythmia. Material and methods. The study group consisted of 119 patients diagnosed with AF: 57 women and 62 men, aged 65.3 +/- 9.4 years. There were 65 patients with paroxysmal AF and 54 with persistent AF. In this group, electrical cardioversion was performed. The P wave duration was measured using an electrophysiological system in all leads at a paper speed of 200 mm/s. Results. The patients did not differ in terms of age, gender or comorbidities. The patients with persistent AF had longer P wave duration (159.9 +/- 22.3 ms compared to 144.6 +/- 17.2 ms; p < 0.001) and higher glucose concentration (119.4 +/- 33.4 mg/dL compared to 108.0 +/- 24.6 mg/dL; p = 0.015). These results were not influenced by the anti-arrhythmic treatment. Conclusions. Persistent AF shows a longer P wave duration than the paroxysmal AF, independent of age, gender and anti-arrhythmic medication. The prolongation of the P wave related to persistent arrhythmia should force physicians to restore the sinus rhythm earlier in order to more successfully maintain it in the long term.