About one third of ischaemic strokes are classified as embolic strokes of undetermined source (ESUS). A silent atrial fibrillation (AF) may play a pathogenic role in these strokes and P wave dispersion (PWD), representing an electrocardiographic (ECG) predictor for paroxysmal AF, thereby a potential marker of covert cardioembolism, was found to be increased in cryptogenic stroke. Furthermore, current evidence links AF to inflammation: inflammatory markers, such as high-sensitive C-reactive protein (hsCRP), have been related to the development and persistence of AF, possibly by promoting atrial remodelling. The aim of this study was to evaluate whether a relationship between PWD and hsCRP in patients with ESUS exists, in order to highlight a possible role for inflammation in the atrial electric remodelling, that predisposes to AF.

We enrolled 174 patients (91 males, 83 females; mean age 69±13years) with ESUS. All patients underwent neuroimaging examination, arterial ultrasound examination, echocardiography and ECG. P wave dispersion and hsCRP were measured in all subjects.

A significant positive correlation was found between hsCRP and PWD (Spearman r: 0.35, p<0.0001). In patients with high PWD (>40 msec; n=102), hsCRP was three-fold higher than in patients with normal PWD (≤40 msec; n=72)(1.57±2.9 vs 0.42±0.4mg/dl, p=0.0005).

Our results show increased hsCRP levels in cryptogenic stroke patients with high PWD. These findings provide support for the hypothesis that systemic inflammation plays a role in a fraction of patients with ESUS, by increasing AF risk via atrial electric remodelling.