The prolongation of intraatrial and interatrial conduction time and the inhomogeneous propagation of sinus impulses have been shown in patients with atrial fibrillation. Recently P wave dispersion (PWD), which is believed to reflect inhomogeneous atrial conduction, has been proposed as being useful for the prediction of paroxysmal atrial fibrillation (PAF). Ninety consecutive patients (46 men, 44 women; aged 55 +/- 13 years) with a history of idiopathic PAF and 70 healthy subjects (42 men, 28 women; mean age 53 +/- 14 years) were studied. The P wave duration was calculated in all 12 leads of the surface ECG. The difference between the maximum and minimum P wave duration was calculated and this difference was defined as P wave dispersion (PWD = Pmax-Pmin). All patients and controls were also evaluated by echocardiography to measure the left atrial diameter and left ventricular ejection fraction (LVEF). There was no difference between patients and controls in gender (P = 0.26), age (P = 0.12), LVEF (66 +/- 4% vs 67 +/- 5%, P = 0.8) and left atrial diameter (36 +/- 4 mm vs 34 +/- 6 mm, P = 0.13). P maximum duration was found to be significantly higher in patients with a history of PAF (116 +/- 17 ms) than controls (101 +/- 11 ms, P < 0.001). P wave dispersion was also significantly higher in patients than in controls (44 +/- 15 ms vs 27 +/- 10 ms, P < 0.001). There was a weak correlation between age and P wave dispersion (r = 0.27, P < 0.001). A P maximum value of 106 ms separated patients with PAF from control subjects with a sensitivity of 83%, a specificity of 72%, and a positive predictive accuracy of 79%. A P wave dispersion value of 36 ms separated patients from control subjects with a sensitivity of 77%, a specificity of 82%, and a positive predictive accuracy of 85%. In conclusion, P maximum duration and P wave dispersion calculated on a standard surface ECG are simple ECG markers that could be used to identify the patients with idiopathic paroxysmal atrial fibrillation.

No abstract

P Wave Dispersion in Hypertensive Patients with Paroxysmal Atrial Fibrillation. It is important to assess the risk of developing paroxysmal atrial fibrillation (PAF) in hypertensive patients since hypertension is a common disorder predisposing to PAF. We sought to determine if patients with hy pertension at risk of PAF can be identified while in sinus rhythm by measurements ofP wave dispersion. Twelve-lead surface electrocardiograms were recorded in 44 hypertensive patients with history of PAF (group I, mean age = 60) and in 50 hypertensive patients without history ofAF (group II, mean age = 57). The maximum P wave duration, the minimum P wave duration, and P wave dispersion (Pd = Pmax -Pmin) were calculated from 12-lead surface ECGs. Left atrial dimension (LAD) and left ventricular ejec tion fraction (LVEF) were measured by echocardiography. P wave dispersion was significantly greater in group I than group II (50 ± 12 vs 38 ± 8 ms, P = 0.001). P minimum (75 ± 13 vs 87 ± 11 ms, P = 0.001) and LVEF (0.63 ± 0.05 vs 0.67 ± 0.04, P = 0.03) were significantly lower in group I than group II. How ever P maximum and LAD were not significantly different in group I than group II (P > 0.05). In univariate analysis, P minimum, P wave dispersion, and LVEF were significant predictors of PAF, whereas only P wave dispersion remained a significant independent predictor of PAF in a multivariate analysis. Mea surement of P wave dispersion in sinus rhythm may be a useful noninvasive clinical tool to identify pa tients with hypertension at risk of developing atrial electrical instability and atrial fibrillation. (PACE 2000; 23[Pt. II]'-.1859-1862 hypertension, paroxysmal atrial fibrillation, P wave dispersionAddress for reprints: Necia Özer, M.D., ZiraatMah, 14.sok, 8/6,

SUMMARYPseudoexfoliation syndrome (PEX) is the most common clinical precursor of openangle glaucoma. Recent studies have shown that pseudoexfoliative material is widely distributed throughout the body, including blood vessels. The aim of our study was to evaluate endothelial function in the brachial artery of patients with pseudoexfoliation syndrome.We prospectively examined 23 patients with PEX (mean age, 70 ± 8 years) and 20 healthy age-and sex-matched individuals (mean age, 68 ± 9 years) as a control group. Brachial artery endothelial function was assessed by vascular response to reactive hyperemia (flow-mediated dilation (FMD) and sublingual nitroglycerin (NTG-mediated dilation) using high-resolution ultrasound. Flow-mediated and NTG-induced dilation were expressed as the percent change in diameter after reactive hyperemia and after NTG administration relative to the baseline value, respectively. Patients with cardiovascular disease and other conditions associated with endothelial dysfunction were excluded.When compared with controls, patients with PEX had significantly lower flow-mediated dilation (4.5 ± 2.8 versus 8.2 ± 3.7, P = 0.01) and NTG-mediated dilation (10.9 ± 3.1 versus 15.8 ± 3.8, P = 0.0001). Flow-mediated dilation and NTG-mediated dilation were similar in PEX patients with glaucoma (n = 11) and without glaucoma (n = 12). Flow-mediated and NTG-mediated dilation did not correlate with any measured parameter in any patient or control subject.The findings indicate that systemic endothelial function is impaired in PEX syndrome patients. (Int Heart J 2006; 47: 77-84)

SummaryBackground: Paroxysmal atrial fibrillation (PAF) in hypertrophic cardiomyopathy (HCM) is associated with poor prognosis. Previous studies have shown good correlation between P-wave dispersion (Pd) and occurrence of PAF. However, Pd in patients with HCM for predicting PAF has not been studied.Hypothesis: The aim of the study was to determine whether Pd could identify patients with HCM who are likely to suffer from PAF.Methods: Twenty-two patients with HCM with a history of PAF (Group 1) and 26 patients with HCM without a history of PAF (Group 2) were studied. Maximum (Pmax) and minimum (Pmin) P-wave durations, as well as P-wave dispersion (Pd = Pmax ϪPmin) were calculated from 12-lead surface electrocardiograms (ECG).Results: P-wave dispersion was significantly different between the groups (Group 1: 55 ± 6 ms vs. Group 2: 37 ± 8 ms; p < 0.001), while Pmax (Group 1: 134 ± 11 ms vs. Group 2: 128 ± 13 ms; p = 0.06) and Pmin (Group 1: 78 ± 9 ms vs. Group 2: 81 ± 7 ms; p = 0.07) was not significantly different. Patients with a history of PAF had higher left atrial diameter than the patients without PAF (Group 1: 52 ± 8 mm vs. Group 2: 48 ± 10 mm; p = 0.02). A cut-off value of 46 ms for Pd had a sensitivity of 76% and a specificity of 82% in discriminating between patients with and without PAF.Conclusion: This study suggests that P-wave dispersion could identify patients with HCM who are likely to develop PAF.