Increased P‐Wave Duration and P‐Wave Dispersion in Patients with Aortic Stenosis

Background: P‐wave dispersion (PWD), defined as the difference between the maximum and minimum P‐wave duration, has been proposed as being useful for the prediction of paroxysmal atrial fibrillation (AF). AF is the most common arrhythmia and an important prognostic indicator for clinical deterioration in patients with aortic stenosis (AS). The aim of the present study was to evaluate PWD in patients with AS. Methods: The study population consisted of two groups: Group I consisted of 98 patients with AS (76 men, 22 women; aged 63 ± 8 years) and group II consisted of 98 healthy subjects (same age and sex) without any cardiovascular disease. A 12‐lead electrocardiogram was recorded for each subject. The P‐wave duration was calculated in all leads of the surface electrocardiogram. The difference between the maximum and minimum P‐wave duration was calculated and was defined as the PWD. All patients and control subjects were also evaluated by echocardiography to measure the left atrial diameter, left ventricular ejection fraction, left ventricular wall thicknesses, and the maximum and mean aortic gradients. Patients were also evaluated for the presence of paroxysmal AF. Results: Maximum P‐wave duration and PWD of group I were found to be significantly higher than those of group II. In addition, patients with paroxysmal AF had significantly higher PWD than those without paroxysmal AF. There was no significant difference between the two groups regarding minimum P‐wave duration. In addition, there was no significant correlation between echocardiographic variables and PWD. Conclusion: PWD, indicating increased risk for paroxysmal AF, was found to be significantly higher in patients with AS than in those without it. Further assessment of the clinical utility of PWD for the prediction of paroxysmal AF in patients with severe AS will require longer prospective studies.     

P Wave Dispersion and P Wave Duration on SAECG in Predicting Atrial Fibrillation in Patients with Acute Myocardial Infarction

Background: Atrial fibrillation (AF) is a frequent complication of acute myocardial infarction (AMI), with reported incidence of 7% to 18%. The incidence of congestive heart failure, in‐hospital mortality, and long‐term mortality is higher in AMI patients with AF than in AMI patients without AF. P wave duration on signal‐averaged ECG (PWD) and P wave dispersion on standard ECG (Pd) are noninvasive markers of intra‐atrial conduction disturbances, which are believed to be the main electrophysiological cause of AF. Methods: In the present study we investigated prospectively whether P wave duration on SAECG and P wave dispersion on standard ECG can predict development of AF in a group of patients with AMI. One hundred and thirty patients (100 men and 30 women, aged 56.9 ± 12) with AMI were investigated. PWD, Pd, their clinical and hemodynamic characteristics were collected. Results: During the observation up to 14 days, 22 patients (16.9%) developed AF. Univariate analysis variables associated with development of AF: age > 65 years, Killip class III‐IV, PWD > 125 ms, and Pd > 25 ms. Stepwise logistic regression analysis showed that age > 65 years, PWD > 125 ms, and Pd > 25 ms were independently associated with AF. Conclusions: PWD and Pd both measured in a very early period of AMI are useful in predicting AF. A.N.E. 2002;7(4):363–368     

P Wave Dispersion: A Valuable Electrocardiographic Marker for the Prediction of Paroxysmal Lone Atrial Fibrillation

Background: The prolongation of atrial conduction time and the inhomogeneous propagation of sinus impulses are well known electrophysiological characteristics in patients with paroxysmal atrial fibrillation. Methods: The aim of this study was to test the ability of a new ECG marker to discriminate between patients with a prior history of paroxysmal lone atrial fibrillation and healthy controls. Maximum P wave duration (Pmax) and the difference between the maximum and the minimum P wave duration, which was defined as P-wave dispersion (Pdisp) were calculated from the 12-lead surface ECGs of 75 patients with a history of paroxysmal lone atrial fibrillation and 50 age-matched healthy controls. Results: Pmax was in patients 122 ± 17 ms and in controls 101 ± 10 ms (t = 7.935, P > 0.001). Pdisp was in patients 48 ± 16 ms and in controls 29 ± 8 ms (t = 7.616, P > 0.001). A Pmax value of 110 ms separated patients from controls with a sensitivity 85%, a specificity 72%, and a positive predictive accuracy of 82%. A Pdisp value of 40 ms separated patients from controls with a sensitivity of 81%, a specificity of 80%, and a positive predictive accuracy of 85%. Conclusions: (1) Pmax and Pdisp values were found to be significantly higher in patients with a prior history of paroxysmal lone atrial fibrillation than in age-matched healthy controls, and (2) Pdisp is a new simple ECG marker that could be possibly used for the identification of patients with a previous history of paroxysmal lone atrial fibrillation. A.N.E. 1999;4(1):39–45     

甲状腺功能亢进并发阵发性心房纤颤P波离散度测定的意义研究

目的 探讨P波离散度（Pd）对甲状腺功能亢进症患者发生阵发性心房纤颤的预测价值.方法 62例甲状腺功能亢进症患者按是否伴有阵发性心房纤颤分为心房纤颤组（n=30）和无心房纤颤组（n=32）,分别测量两组患者的心电图P波最大时限、P波最小时限并计算P波离散度.结果 心房纤颤组与无心房纤颤组患者P波离散度和P波最大时限明显高于正常对照组;心房纤颤组又高于无心房纤颤组;心房纤颤组P波离散度＞40ms者23例（73.3%）,而无心房纤颤组4例（12.5%）,两组比较差异有显著性.结论 P波离散度可作为预测甲状腺功能亢进患者是否发生阵发性心房纤颤的一个有效指标.     

Effect of balloon-induced acute ischaemia on P wave dispersion during percutaneous transluminal coronary angioplasty.

AIMS: P wave dispersion is a recent ECG marker that reflects discontinuous and inhomogeneous conduction of sinus impulses, which has been studied in a limited number of cardiac conditions. The aim of our study was to investigate the effects of angioplasty induced-ischaemia on atrial conduction abnormalities as estimated by P maximum and P dispersion. METHODS AND RESULTS: The study consisted of 67 consecutive patients (41 men, mean age 58 +/- 11 years) with 1-vessel coronary artery disease who underwent elective single vessel coronary angioplasty (left anterior descending (LAD) coronary artery in 28 patients, the right coronary artery (RCA) in 22 patients and the left circumflex coronary artery (LCx) in 17 patients. All patients underwent 12-lead surface ECG before the first inflation (baseline) and then 60 s after intra-coronary balloon inflation. The maximum P wave duration, the minimum P wave duration, and P wave dispersion (Pd=Pmax - Pmin) were calculated from 12-lead surface ECGs. Baseline P wave duration measurements were not significantly different among the patients with LAD, RCA and LCx coronary artery disease (P>0.05). P dispersion and P maximum were significantly higher during balloon occlusion compared with the baseline condition in all three types of coronary dilatation procedures. However, P minimum was not found to differ between baseline and during balloon occlusion (P>0.05). CONCLUSION: The prolongation of P wave dispersion may be a useful and simple additional marker for myocardial ischaemia.     

Maximum P Wave Duration and P Wave Dispersion in Adult Patients with Secundum Atrial Septal Defect: The Impact of Surgical Repair

Background: Patients with atrial septal defect (ASD) have an increased risk for atrial fibrillation (AF). Previously it was shown that maximum P wave duration and P wave dispersion in 12‐lead surface electrocardiograms are significantly increased in individuals with a history of paroxysmal AF. We studied P maximum and P dispersion in adult patients with ASD during normal sinus rhythm. In addition, the impact of surgical closure of ASD on these variables within 1 year after surgery was evaluated. Methods: Thirty‐four patients (21 women, 13 men; mean age: 35 ± 11 years) operated on for ostium secundum type ASD and 24 age‐matched healthy subjects (13 women, 11 men; mean age: 37 ± 10 years) were investigated. P maximum, P minimum, and P dispersion (maximum – minimum P wave duration) were measured from the 12‐lead surface electrocardiography. Results: P maximum was found to be significantly longer in patients with ASD as compared to controls (115.2 ± 9 vs 99.3 ± 14 ms; P < 0.0001). In addition, P dispersion of the patients was significantly higher than controls (37 ± 9 vs 29.8 ± 10 ms; P = 0.003). P minimum was not different between the two groups (P = 0.074). After surgical repair of ASD, 10 patients (29%) experienced one or more episodes of paroxysmal AF. Patients with postoperative AF were older (45 ± 6 vs 30 ± 10 years; P = 0.001), and had a higher preoperative pulmonary artery peak systolic pressure as compared to those without postoperative AF (51 ± 11 vs 31 ± 9 mmHg; P < 0.0001). No significant difference in the pulmonary‐to‐systemic flow ratio was observed preoperatively between the two groups (P = 0.56). P maximum and P dispersion were significantly higher in patients with postoperative paroxysmal AF at baseline and at postoperative first month, sixth month, and first year as compared to those without it (for P maximum P = 0.027, P = 0.014, P = 0.001, P < 0.0001, respectively; for P dispersion P = 0.037, P = 0.026, P = 0.001, P < 0.0001, respectively). In addition, in patients with postoperative AF, no significant changes were detected in both of these P wave indices during postoperative follow‐up. However, in the other group, P maximum and P dispersion were found to be significantly decreased at postoperative 6 months and 1 year as compared to baseline. P minimum was similar throughout the postoperative follow‐up as compared to baseline in both groups. Conclusions: Mechanical and electrical changes in atrial myocardium may cause greater P maximum and P dispersion in patients with ASD. Surgical closure of the ASD can regress these pathological changes of atrial myocardium with a result in decreased P maximum and P dispersion. However, higher P maximum and P dispersion at baseline, which have not decreased after surgery, may be associated with postoperative paroxysmal AF, especially for older patients.     

Effects of P-wave dispersion on atrial fibrillation in patients with acute anterior wall myocardial infarction

Backround: P‐wave dispersion (P dispersion), defined as the difference between the maximum and the minimum P‐wave duration (P minimum), and maximum P‐wave duration (P maximum) have been used to evaluate the discontinuous propagation of sinus impulse and the prolongation of atrial conduction time respectively. The aim of this study was to investigate whether early assessment of P dispersion predicts paroxysmal atrial fibrillation (AF) in patients with acute anterior wall myocardial infarction (MI). Methods: We prospectively evaluated 147 consecutive patients (45 women, 102 men; aged 55 ± 9 years) with a first acute anterior wall MI. All patients were evaluated by echocardiography to measure the left atrial diameter and left ventricular ejection fraction (LVEF). Electrocardiography was recorded from all patients on admission and every day during hospitalization. Results: AF occurred in 25 patients. In 122 patients, AF did not occur. P maximum was found to be significantly higher in patients with AF than in patients without AF (115 ± 17.3 ms vs 101 ± 14.7 ms, P = 0.001 ). P dispersion also was significantly higher in patients with AF than in patients without AF (50 ± 12.5 ms vs 43 ± 10.1 ms, P = 0.01 ). There was no significant difference between the two groups in P minimum (64 ± 12.5 ms vs 59 ± 11.7 ms, P = 0.057 ). The echocardiographically left atrial diameters were not significantly higher in the patients with AF than those without (25 ± 3.38 mm and 23 ± 3.36 mm , respectively, P = 0.76 ). LVEF was found to be significantly different in the patients who developed AF and in those who did not (37.96 ± 6.18% vs 47.70 ± 6.01%, P = 0.0001 ). Conclusions: Although P maximum and P dispersion are significant predictive factors of AF in patients with acute anterior wall MI in the univariate analysis, on the basis of multivariate analysis, only age and LVEF were independent predictive parameters for AF.     

Factors Associated with the Development of Atrial Fibrillation in COPD Patients: The Role of P‐Wave Dispersion

Background: Supraventricular tachyarrhythmia is a common problem in chronic obstructive pulmonary disease (COPD) patients. The purpose of this study is to analyze the factors associated with paroxysmal atrial fibrillation (AF) in COPD patients. Methods: Forty COPD patients (38 male, 2 female, mean age 60 ± 9 years) and 33 healthy controls (29 male, 4 female, mean age: 58 ± 10 years) were included in this study. Echocardiography, 24‐hour ambulatory and 12‐lead ECG, pulmonary function tests, arterial blood gases, and serum electrolytes were measured. On ECG, maximum (P_max) and minimum (P_min) duration of P wave and its difference, P‐wave dispersion (PWd), were measured. Results: On echocardiography, diastolic dysfunction was found in 14 of the 40 (35%) COPD patients. Heart rate variability analysis revealed that COPD patients had decreased SDANN, SDNN, SDNNIDX in time‐domain, and decreased LF in frequency domain parameters. Fourteen of the 40 COPD patients (35%) had AF. Patients with AF were older (57 ± 10 vs 64 ± 5 years, P = 0.03) and had lower SDANN, SDNN, and LF/HF ratio as compared to patients without AF in univariate analysis. All P‐wave intervals (P_max P_min and PWd) were increased in COPD patients compared to controls. P‐wave dispersion was significantly increased in COPD patients with AF, as compared to patients without AF (57 ± 11 vs 44 ± 7 ms, P = 0.001). In logistic regression analysis PWd was found to be the only factor associated with the development of AF (P = 0.04). Conclusions: The presence of AF was significantly related to the prolongation of PWd, but not with pulmonary function, arterial blood gasses, and left and right atrial function. A.N.E. 2002;7(3):222–227     

Effects of Right Coronary Artery PTCA on Variables of P‐Wave Signal Averaged Electrocardiogram

Background: P‐wave signal averaged ECG has been used to detect atrial late potentials that were found in paroxysmal atrial fibrillation. Ischemia is supposed to trigger ventricular late potentials, which indicate an elevated risk for ventricular tachycardia. Preexistent ventricular late potentials measured by ventricular signal averaged ECG is supposed to be eliminated by successful PTCA. Methods: We examined the incidence of atrial late potentials in patients with a proximal stenosis of the right coronary artery and new onset of atrial fibrillation. Furthermore, we investigated the anti‐ischemic effect of a successful percutaneous transluminal coronary angioplasty.(PTCA) of the right coronary artery. P‐wave signal averaged ECG from 23 patients who had a PTCA of the right coronary artery (group A) were compared to age, sex, and disease‐matched control subjects (group B) one day before, one day after, and one month after PTCA. Results: A new appearance of paroxysmal atrial fibrillation was presented in eight patients before PTCA (group A1) of group A. Patients with a stenosis of the right coronary artery had a significantly higher incidence of supraventricular extrasystoles in a 24‐hour‐Holter ECG (131.1 ± 45.4 vs 17.1 ± 18.9, P < 0.0002 ). The duration of the filtered P wave was longer (124.8 ± 11.9 vs 118.5 ± 10.1 ms, P < 0.04 ) and the root mean square of the last 20 ms (RMS 20) was significantly lower in group A than in group B (2.87 ± 1.09 vs 3.97 ± 1.12 μV, P < 0.01 ). A successful PTCA caused an increase in RMS 20 (2.87 ± 1.11 vs 4.19 ± 1.19 μV, P < 0.02 ) and a decrease in filtered P‐wave duration (124.8 ± 11.9 vs 118.4 ± 10.4 ms, P < 0.04 ). Preexistent atrial late potentials were found among 15 patients before PTCA. After successful PTCA only 3 out of 15 patients were affected (P < 0.0004) after one day, as well as after one month. All patients with a history of atrial fibrillation did not suffer from an arrhythmic recurrence within the following six months after successful PTCA. Conclusion: A stenosis of the right coronary artery is associated with atrial late potentials. A successful PTCA of the right coronary artery eliminates preexistent atrial late potentials and may reduce the risk of atrial fibrillation.     

P wave dispersion and left atrial appendage function for predicting recurrence after conversion of atrial fibrillation and relation of p wave dispersion to appendage function

BACKGROUND: We investigated P wave dispersion and left atrial appendage (LAA) function for predicting atrial fibrillation (AF) relapse, and the relationship between P wave dispersion and LAA function. METHODS: Sixty-four consecutive patients with AF lasting /=5 days, LA size >/=45 mm, maximum P wave duration >/=112 ms, P wave dispersion >/=47 ms, spontaneous echo contrast, minimum LAA area >/=166 mm(2), and LAA emptying velocity <36 cm/sec were univariate predictors of recurrence (each P < 0.05). By multivariate analysis, LA size (P = 0.02), P wave dispersion (P < 0.001), and LAA emptying flow (P = 0.01) identified patients with recurrent AF. Their positive predictive values were 91, 97, and 72%, respectively. CONCLUSION: The increased P wave dispersion in addition to the dilated LA and the depressed LAA emptying flow can identify patients at risk of recurrent AF after cardioversion.     

Focal Atrial Fibrillation in Dextrocardia

A 49‐year‐old woman with dextrocardia and situs inversus underwent catheter ablation of paroxysmal atrial fibrillation (AF). During the electrophysiologic study, AF triggered by frequent premature atrial contractions (PACs) with a short coupling interval exhibiting a “P on T” pattern occurred. Pulmonary vein mapping revealed that those PACs originated from right‐sided (anatomic left) or left‐sided (anatomic right) pulmonary veins. In this case with mirror‐image dextrocardia, the P‐wave morphologies in leads I and aVL and the II/III ratio of the P‐wave amplitude were helpful for predicting a right‐ or left‐sided pulmonary vein origin.     

P‐Wave Morphology: Underlying Mechanisms and Clinical Implications

Increasing awareness of atrial fibrillation (AF) and its impact on public health revives interest in identification of noninvasive markers of predisposition to AF and ECG‐based risk stratification. P‐wave duration is generally accepted as the most reliable noninvasive marker of atrial conduction, and its prolongation has been associated with history of AF. However, patients with paroxysmal AF without structural heart disease may not have any impressive P‐wave prolongation, thus suggesting that global conduction slowing is not an obligatory requirement for development of AF. P‐wave morphology is therefore drawing increasing attention as it reflects the three‐dimensional course of atrial depolarization propagation and detects local conduction disturbances. The factors that determine P‐wave appearance include (1) the origin of the sinus rhythm that defines right atrial depolarization vector, (2) localization of left atrial breakthrough that defines left atrial depolarization vector, and (3) the shape and size of atrial chambers. However, it is often difficult to distinguish whether P‐wave abnormalities are caused by atrial enlargement or interatrial conduction delay. Recent advances in endocardial mapping technologies have linked certain P‐wave morphologies with interatrial conduction patterns and the function of major interatrial conduction routes. The value of P‐wave morphology extends beyond cardiac arrhythmias associated with atrial conduction delay and can be used for prediction of clinical outcome of a wide range of cardiovascular disorders, including ischemic heart disease and congestive heart failure.     

Analysis of P Wave and P Dispersion in Children with Secundum Atrial Septal Defect

Background: P maximum and P dispersion are evaluated as predictors of paroxysmal atrial fibrillation in adults. In this study, these variables are being investigated in children with secundum ASD in comparison with that of normal controls and in relation to size of ASD and the presence or absence of atrial dilation. Methods: Ninety‐four children with isolated secundum ASD (33 boys, 60 girls; mean ± SD age at diagnosis 2.9 ± 4.1 years) and 65 age‐matched controls (mean ± SD age 4.2 ± 4.2 years) were evaluated. Resting 12‐lead ECG was used to measure P waves from which P maximum and P dispersion (difference between maximum and minimum P‐wave duration) were derived. ASD children were arbitrarily subgrouped according to ASD sizes (small: 1–3 mm, moderate: 4–7 mm, large: 8 mm). The presence of right atrial dilation was noted from echocardiography. Results: Children with ASD had significantly longer mean P dispersion compared to controls (P dispersion: 30.2 ± 11.1 vs 26.4 ± 6.6 ms, P = 0.008). Mean P maximum and P dispersion were significantly prolonged with increasing ASD size (P < 0.001). Children with right atrial dilation had significantly longer P maximum (102.3 ± 15.2 vs 82.8 ‐13.4 ms, P < 0.001) and larger P dispersion (36.1 ± 12.5 vs 27.6 ± 9.4 ms, P = 0.003) compared to those without right atrial dilation. Conclusion: Prolonged atrial conduction time and inhomogeneity of atrial conduction may possibly be present in children with moderate to large sized ASD and in those with atrial dilation. A.N.E. 2001;6(4):305–309     

阵发性房颤患者心电图P波形态的分析

目的 探讨体表心电图P波形态与阵发性心房颤动(PAF)的关系.方法 选择52例非瓣膜性阵发性房颤患者及47例无PAF的对照组患者,测定窦性心律时12导联心电图P波离散度(Pd),最大P波时限( Pmax),V1导联P波终末电势(Ptfv1)及aVR导联P波面积和振幅,超声心动图测定左房内径(LAD)、左室舒张末期内径(...     

P‐Wave Duration and Dispersion in Obese Subjects

Background: Although previous studies have documented a variety of electrocardiogram (ECG) abnormalities in obesity, P‐wave alterations, which represent an increased risk for atrial arrhythmia, have not been studied very well in these patients. The aim of the present study was to evaluate P‐wave duration and P dispersion (Pd) in obese subjects, and to investigate the relationship between P‐wave measurements, and the clinical and echocardiographic variables. Methods: The study population consisted of 52 obese and 30 normal weight control subjects. P‐wave duration and P‐wave dispersion were calculated on the 12‐lead ECG. As echocardiographic variables, left atrial diameter (LAD), left ventricular end‐diastolic, and end‐systolic diameters (LVDD and LVSD), left ventricular ejection fraction (LVEF), interventricular septum thickness (IVST), left ventricular posterior wall thickness (LVPWT), and left ventricular mass (LVM) of the obese and the control subjects were measured by means of transthoracic echocardiography. Results: There were statistically significant differences between obese and controls as regards to Pmax (maximum P‐wave duration) and Pd (P dispersion) (P < 0.001 and P < 0.001, respectively). Pmin (minimum P wave duration) was similar in both groups. Correlation analysis showed that Pd in the obese patients was related to any the clinical and echocardiographic parameters including BMI, LAD, LVDD, IVST, LVPWT, and LVM. Conclusion: Our data suggest that obesity affects P‐wave dispersion and duration, and changes in P dispersion may be closely related to the clinical and the echocardiographic parameters such as BMI, LAD, IVST, LVPWT, and LVM.     

P波特征与冠状动脉旁路移植术后心房颤动关系的Meta分析

目的 通过Meta分析综合评价冠状动脉旁路移植术前12导联心电图P波时限、信号平均心电图P波时限及P波离散度与冠状动脉旁路移植术后心房颤动（房颤）的关系.方法 通过进行文献质量评价,应用RevMan 4.3软件进行敏感性和异质性分析后计算综合效应.结果 13篇文献符合纳入标准.Meta分析结果显示,冠状动脉旁路移植术后发生房颤患者的术前12导联心电图P波时限和信号平均心电图P波时限均比未发生房颤患者长.加权均数差（WMD）分别为3.69ms,95%CI 1.93～5.44 12.23ms,95%CI 4.82～19.63.术前P波离散度两组之间差异无统计学意义.术后P波离散度的增加是否是术后房颤的独立预测因子未获得综合效应.结论 术前12导联心电图P波时限和信号平均心电图P波时限延长与术后房颤高发有关,P波离散度的增加与术后房颤的关系有待进一步研究.     

Predictive Value of P‐Wave Signal‐Averaged Electrocardiogram for Atrial Fibrillation in Acute Myocardial Infarction

Background: Atrial fibrillation (AF) is a common complication of acute myocardial infarction (AMI) with a reported incidence of 7–18%. Recently, P‐wave signal‐averaged electrocardiogram (P‐SAECG) has been used to assess the risk of paroxysmal AF attacks in some diseases. The aim of this study was to determine prospectively whether patients with AMI at risk for paroxysmal AF would be identified by P‐SAECG and other clinical variables. Methods: A total of 100 patients (mean age: 59 ± 12 , 77 male, 23 female) with ST segment elevation AMI were enrolled in this study. Patients with chronic AF were excluded. At entry, all patients underwent standard 12‐lead ECG and in the first 24 hours, P‐SAECG was taken, and echocardiography and coronary angiography were performed on the patients. Patients are followed for a month in terms of paroxysmal AF attacks and mortality. Results: AF was determined in 19 patients (19%). In patients with AF, abnormal P‐SAECG more frequently occurred than in patients without AF (37% vs 15%, P < 0.05) . Patients with AF were older (70 ± 14 vs 56 ± 10, P < 0.001) and had lower left ventricular ejection fraction (42%± 8 vs 49%± 11, P < 0.05) . AF was less common in thrombolysis‐treated patients (47% vs 74%, P <0.05) . Thirty‐day mortality was higher in patients with AF (16% vs 2%, P = 0.05) . Conclusions: An abnormal P‐SAECG may be a predictor of paroxysmal AF in patients with AMI. Advanced age and systolic heart failure were detected as two important clinical risk factors for the development of AF.     

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.     

P Wave Dispersion Predicts Recurrence of Paroxysmal Atrial Fibrillation in Patients with Atrioventricular Nodal Reentrant Tachycardia Treated with Radiofrequency Catheter Ablation

Background: Paroxysmal atrial fibrillation (AF) recurs in up to one‐third of patients with atrioventricular nodal reentrant tachycardia (AVNRT) treated with slow pathway ablation. Therefore, identification of patients at risk for recurrence of AF after slow pathway ablation is important because of the necessity for additional therapies. The purpose of this study was to determine whether successful slow pathway ablation influences P wave parameters and whether these parameters predict the recurrence of paroxysmal AF in patients with both AVNRT and paroxysmal AF after ablation. Methods: Thirty‐six patients with AVNRT and documented paroxysmal AF (Group 1) were compared to 36 age‐matched controls with AVNRT only (Group 2). P wave durations and P dispersion were measured before and after ablation. Results: No significant differences were observed between P wave parameters observed before and after ablation. Maximum P wave durations (Pmax) and P dispersion (Pdisp) were significantly higher in Group 1 than in Group 2 (P < 0.001 for both) whereas minimum P wave durations did not differ between groups, both before and after ablation. Ten patients (28%) in Group‐1 had recurrence of AF during a mean follow‐up of 34 ± 11 months. Univariate predictors of AF recurrence were Pdisp ≥35.5 ms (P < 0.010), left atrial diameter >40 mm (P < 0.010), mitral or aortic calcification (P < 0.010), Pmax ≥112 ms (P < 0.050), valvular heart disease (P < 0.050), and atrial vulnerability (induction of AF lasting >30 second) after ablation (P < 0.050). However, only Pdisp ≥35.5 ms (P < 0.050) and left atrial diameter >40 mm (P < 0.010) were independent predictors of AF recurrences. Conclusion: This study suggests that P wave dispersion could identify patients with AVNRT susceptible to recurrence of AF after slow pathway ablation.     

The Effect of Exercise to P Wave Dispersion and Its Evaluation as a Predictor of Atrial Fibrillation

Aim: Prolongation of P wave time and increase of its dispersion as an independent predictor of atrial fibrillation. In patients with paroxysmal atrial fibrillation (PAF) as in healthy people, exercise augments sympathetic activity and therefore can cause the development of atrial fibrillation. The aim of this study is to evaluate the effect of exercise on P wave dispersion and to predict the development of atrial fibrillation. Methods: One hundred and ninety‐eight patients (93 women, 105 men, mean age: 59.05 ± 11.01 years ) having the diagnosis of PAF were included in the study. The left atrial diameter of all these patients was more than 4.0 cm. One hundred and fifty‐five patients (72 females, 83 males, mean age: 58.41 ± 10.79 years ), with left atrial diameter more than 4.0 cm and without PAF were taken as control group. Symptom limited exercise test with modified Bruce protocol was performed on all patients. Rest, maximum exercise and recovery, and first, third, and fifth‐minute 12‐derivation ECG was taken in all patients. The velocity of ECG was adjusted to 50 mm/s; shortest and largest P wave durations were measured and P wave dispersion was calculated. Results: The mean left atrial diameter was 4.41 ± 0.58 cm in PAF patients and 4.38 ± 0.48 cm in control group. No differences were found between PAF patients with the controls in exercise time (10.38 ± 2.93 vs 10.81 ± 2.75 minutes ); METs (6.98 ± 1.72 vs 7.28 ± 1.75 minutes ); resting heart rate (79.13 ± 14.86 vs 79.69 ± 10.43 bpm ); peak heart rate (146.83 ± 23.21 vs 146.94 ± 16.13 bpm ). Maximum exercise P wave duration and P wave dispersion were greater than the rest measurements in PAF group (respectively P < 0.0001 and P = 0.0004 ). Conclusion: In PAF patients, P wave dispersion is significantly longer at rest, maximum exercise and recovery time than in a control group without PAF.