The Relationship between P Wave Dispersion and Diastolic Dysfunction in Patients with Significant and Insignificant Coronary Artery Disease

We investigated the relationship between P wave dispersion, which is easily measured on the surface electrocardiogram and left ventricular end diastolic pressure and echocardiographic markers of diastolic dysfunction in patients with coronary artery disease (CAD). Methods: We studied 50 patients with CAD: 8 patients with non significant CAD (16%) and 42 patients with significant CAD (84%). P wave dispersions were calculated by measuring minimum and maximum P wave duration values on the surface electrocardiogram. The relationships between P wave dispersion and the left ventricle end diastolic pressure (LVEDP), Left atrial volume (LAV), left atrial diameter (LAD) and echocardiographic measurements of diastolic dysfunction were investigated. Results: P wave dispersion was 65.7 ± 18.8 ms. The magnitude of P wave dispersion was higher in group of LVEDP > 15 than those who had their LVEDP < 15 mmHg, (70.6 ± 15.2 vs. 60 ± 20.4 respectively and p value 0.04). There was a significant positive correlation between the values of p wave dispersion and LVEDP, LAD and LAV as the correlation factor was (0.3, 0.5, 0.6, respectively and the p values were significant) . Also P wave dispersion was found to be higher in the group of significant CAD than insignificant CAD (68.7 ± 18.5 vs. 50 ± 10.35 respectively and p value 0.008). When patients with LVDD were staged, PD was 49 ± 9 ms in stage 1(9 pts.), 55 ± 10 ms in stage 2 (26 pts), and 58 ± 7 ms in stage 3 (15 pts.). As the severity of diastolic dysfunction increased, P wave dispersion increased but the difference did not reach statistical significance (P 0.07). Conclusion: We conclude that P wave dispersion is a non invasive marker for LVEDP and highly correlated to LA volume. P wave dispersion is another alternative for assessment of LV diastolic Dysfunction in CAD. P wave dispersion did not show a significant change in the 3 stages of diastolic dysfunction in our small studied groups so larger studies might be of help to elucidate that difference. [Journal of American Science. 2011;7(1):108-115]. (ISSN: 1545-1003).