Predictive value of the P wave at implantation for atrial fibrillation after VVI pacemaker implantation

P-wave duration and interatrial block as predictors of new-onset atrial fibrillation: A systematic review and meta-analysis

BACKGROUND

Early detection of atrial fibrillation (AF) could improve patient outcomes. P-wave duration (PWD) and interatrial block (IAB) are known predictors of new-onset AF and could improve selection for AF screening. This meta-analysis reviews the published evidence and offers practical implications.

METHODS

Publication databases were systematically searched, and studies reporting PWD and/or morphology at baseline and new-onset AF during follow-up were included. IAB was defined as partial (pIAB) if PWD≥120 ms or advanced (aIAB) if the P-wave was biphasic in the inferior leads. After quality assessment and data extraction, random-effects analysis calculated odds ratio (OR) and confidence intervals (CI). Subgroup analysis was performed for those with implantable devices (continuous monitoring).

RESULTS

Among 16,830 patients (13 studies, mean 66 years old), 2,521 (15%) had new-onset AF over a median of 44 months. New-onset AF was associated with a longer PWD (mean pooled difference: 11.5 ms, 13 studies, p < 0.001). The OR for new-onset AF was 2.05 (95% CI: 1.3-3.2) for pIAB (5 studies, p = 0.002) and 3.9 (95% CI: 2.6-5.8) for aIAB (7 studies, p < 0.001). Patients with pIAB and devices had higher AF-detection risk (OR: 2.33, p < 0.001) than those without devices (OR: 1.36, p = 0.56). Patients with aIAB had similarly high risk regardless of device presence. There was significant heterogeneity but no publication bias.

CONCLUSION

Interatrial block is an independent predictor of new-onset AF. The association is stronger for patients with implantable devices (close monitoring). Thus, PWD and IAB could be used as selection criteria for intensive screening, follow-up or interventions.

QT and P-wave dispersion during the manic phase of bipolar disorder

BACKGROUND AND AIM

Patients with bipolar disorder (BD) are at increased risk for cardiovascular diseases and complications. This increased risk is considered to be associated with the autonomic nervous system (ANS) abnormalities. However, there is little or no documentation of the relationship between this increased risk and the phases of BD. In this study, we aimed to compare the changes in the QT dispersion (QTd) and P-wave dispersion (Pd), which are predictors of sudden cardiac death and atrial fibrillation, between the patients with manic BD and healthy controls.

PARTICIPANTS AND METHODS

The study included a patient group of 44 patients (26 female and 18 male) that were hospitalized due to a diagnosis of manic BD and met the inclusion criteria, and a control group of 34 age- and gender-matched healthy individuals (21 female and 13 male) with no history of psychiatric and neurological disorders. The QTd and Pd values were determined in each participant by performing the standard 12-lead body surface electrocardiography (ECG).

RESULTS

The principal electrocardiographic indicators including corrected maximum QT interval, corrected QT dispersion, and minimum P-wave duration significantly increased in the patient group compared to the control group (t=2.815, p<0.01; t=4.935, p<0.001; t=3.337, p<0.001, respectively).

CONCLUSION

The results indicated that patients with manic BD are at increased risk for cardiovascular autonomic dysfunction. Therefore, clinicians should be more careful about ECG changes and related possible cardiac conduction problems such as cardiac arrthythmias in patients with manic BD. Further longitudinal studies are needed to investigate BD and its phases (depression, mania, and hypomania) with regard to ANS and cardiac abnormalities.

P wave dispersion in obsessive-compulsive disorder

BACKGROUND

P wave dispersion (Pd) is defined as the difference between the maximum and the minimum P wave duration. It has recently been associated with increased anxiety levels, thereby predisposing affected individuals to fatal heart disease. Despite of evidence of this autonomous nervous system (ANS) relationship, there are no electrocardiography (ECG) studies in the patients with obsessive-compulsive disorder (OCD). Thus, in this study, we aimed to evaluate the Pd in OCD patients.

MATERIALS AND METHODS

The study consisted of a total of 25 patients with OCD and same number of physically and mentally healthy age- and gender-matched controls. For psychological testing, Yale-Brown Obsession and Compulsion (Y-BOCS) was administered.

RESULTS

Pmax was found to be significantly higher in the patients compared to controls. Pmin did not differ between groups. Left atrium sizes were not different between groups. As for the main parameter investigated in the present study, it was found that Pd was significantly increased in the OCD patients than the controls. Y-BOCS scores for the patient group was positively correlated with Pd (r = 0.73, P < 0.01).

CONCLUSIONS

In conclusion, our results suggest that Pd may be associated with OCD though our sample is too small to allow us to obtain a clear conclusion. Future studies with larger sample evaluating the effects of treatment are required.

The relationship between the left atrial volume and the maximum P-wave and P-wave dispersion in patients with congestive heart failure

PURPOSE

A maximum P-wave duration (Pmax) of > or = 110 msec and a P-wave dispersion (PWD) > or = 40 msec are accepted indicators of a disturbance in interatrial conduction and an inhomogeneous propagation of the sinus impulse, respectively. The left atrial (LA) volume has been reported to be strongly associated with a systolic and diastolic dysfunction and is considered to be an index of atrial remodeling. We aimed to investigate the relationship between LA volume and Pmax or PWD in patients with congestive heart failure (CHF).

PATIENTS AND METHODS

Sixty-one patients with CHF were enrolled in this study. The study population was classified into four groups: two groups were divided according to the Pmax (> or = 110 msec or < 110 ms), and the other two groups were formed based on the PWD (> or = 40 msec or < 40 msec). The left atrial volume index (LAVi) was measured by three-dimensional (3-D) transthoracic echocardiography. The Pmax and PWD were measured from a 12-lead electrocardiogram.

RESULTS

There were significant differences in the ejection fraction (EF), diastolic function, and LAVi between patients with a Pmax > or = 110 ms or a PWD > or = 40 ms and those with a Pmax < 110 ms or a PWD < 40 ms. The LAVi was independently associated with a disturbance in interatrial conduction and an inhomogeneous propagation of the sinus impulse. The LAVi can be used to identify patients with a disturbance in interatrial conduction and an inhomogeneous propagation of the sinus impulse with reasonably good accuracy.

CONCLUSION

We concluded that a disturbance in interatrial conduction and an inhomogeneous propagation of the sinus impulse in patients with CHF is associated with an increase in the LA volume and a deleterious systolic and diastolic dysfunction.

Duration of P-Wave Is Associated with Atrial Fibrillation Hospitalizations in Patients with Atrial Fibrillation and Paced for Bradycardia

BACKGROUND

Atrial fibrillation (AF) is a common problem in pacemaker patients. We conducted a prospective observational study in patients paced for bradycardia with associated paroxysmal or persistent AF, to determine whether P-wave duration may stratify patients at higher risk for AF recurrences and AF-related hospitalizations. The patients were evaluated for the prevalence, cause, and predictors of hospitalization.

METHODS

We studied 660 consecutive patients (50% male, 72 +/- 9 years) who received a dual-chamber pacemaker. Median value of baseline P-wave duration was equal to 100 ms (25%-75% quartile range equal to 80-120 ms). We used this cut-off to divide the patients into group A (P < or = 100 ms), composed of 385 (58.3%) patients, and group B (P>100 ms), composed of 275 (41.7%) patients.

RESULTS

In a median follow-up of 19 months, 173 patients were hospitalized for all causes, 130 for cardiovascular causes, and 85 for AF-related hospitalizations. Multivariate logistic analysis showed that P-wave duration >100 ms identified patients at higher risk (OR = 1.6, 95% confidence interval (1.1-2.8), P = 0.044) for AF-related hospitalizations. Patients in group B (P > 100 ms) more frequently suffered AF-related hospitalizations (16.4% vs 10.4%, P = 0.02) and underwent more frequent cardioversions (14.5% vs 9.1%, P = 0.029) compared with group A (P < or = 100 ms).

CONCLUSIONS

P-wave duration may define the risk of persistent AF requiring cardioversion or AF-related hospitalization in patients with a pacemaker for bradycardia with associated paroxysmal or persistent AF.

P-wave dispersion in panic disorder

BACKGROUND

P-wave dispersion (PWD) is defined as the difference between the maximum and the minimum P-wave (Pmax and Pmin, respectively) duration. Significant variation in cardiac atrial PWD has been correlated with changes in systemic autonomic tone such as during periods of anxiety. It is also known that the degree of PWD seen on 12-lead electrocardiogram (ECG) may be a predictor of susceptibility of the atrial myocardium to future atrial fibrillation (AF). Therefore, we firstly aimed to show an association between PWD and panic disorder, a state of high sympathetic tone.

METHODS

PWD was measured in 40 outpatients with panic disorder and in 40 physically and mentally healthy age- and gender-matched controls. In addition, the Panic Agoraphobia Scale (PAS) and the Hamilton Depression Rating Scale (HDRS) were scored concomitantly.

RESULTS

Both Pmax and Pmin were significantly higher than those of healthy controls. PWD was significantly greater in the panic disorder group than in the controls. As expected, the mean score on PAS was significantly higher for the panic disorder group than for the controls and correlated significantly with PWD. Heart rate (measured as RR intervals in milliseconds on electrocardiogram) did not differ significantly between the groups.

CONCLUSIONS

The findings of the present study suggest that the disorder may be associated with an increase in PWD. This association may result from prolonged anxiety and increase in sympathetic modulation, which are main characteristics of panic disorder.

Relation between P-wave dispersion and left ventricular geometric patterns in newly diagnosed essential hypertension

AIM

P-wave durations and P-wave dispersion (PD) are considered to reflect the heterogeneous conduction in atria. The aim of this study was to investigate PD and P-wave duration in different left ventricle geometric patterns of hypertensive patients.

METHODS

One hundred forty-nine consecutive patients with newly diagnosed essential hypertension and 29 healthy control groups were included in the study. The maximum and minimum P-wave duration (Pmax and Pmin, respectively) and PD were measured from the 12-lead surface electrocardiogram. Echocardiographic examination was also performed in all subjects. Four different geometric patterns were identified in hypertensive patients according to left ventricular mass index (LVMI) and relative wall thickness.

RESULTS

P-wave dispersion was longer in concentric remodeling (CR), concentric hypertrophy (CH), and eccentric hypertrophy (EH) groups when compared with the control group (P = .009, P < .001, P < .001, respectively). P-wave dispersion of normal left ventricle (NLV) geometric pattern was not different from that of the control group. Patients with NLV geometric pattern had shorter PD than patients who had CH and EH (NLV vs CH, P < .001; NLV vs EH, P = .025). P-wave dispersion of the NLV group was not different from that of the CR group. Patients with CR had also shorter PD than patients who had CH (P = .002). In bivariate analysis, there was a significant correlation between PD with left ventricle geometry, body surface area, LVMI, and relative wall thickness. In multiple linear regression analysis, PD was independently correlated only with LVMI (beta = .425, P < .001).

CONCLUSIONS

P-wave dispersion is independently associated with LVMI rather than left ventricle geometry and relative wall thickness in hypertensive patients. Thus, it is increased particularly in patients with CH and EH.

P-wave dispersion in patients with stable coronary artery disease and its relationship with severity of the disease

AIM

P-wave dispersion (PD) has been reported to be associated with inhomogeneous and discontinuous propagation of sinus impulses. The purpose of this study was to investigate the PD in patients with stable coronary artery disease (CAD) and to determine its relationship with severity of the disease.

METHODS

We prospectively analyzed 66 subjects with normal coronary angiogram (group 1) and 68 patients with significant (> or =50%) coronary stenosis; 25 had 1-vessel disease (group 2), 27 had 2-vessel disease (group 3), and 16 had 3-vessel disease (group 4). The maximum and minimum P-wave duration (Pmax and Pmin) and PD were measured from the 12-lead surface electrocardiogram. Echocardiographic examination was also performed. Angiographic vessel score and Gensini score were used to evaluate the severity of CAD.

RESULTS

Pmax was longer in groups 3 and 4 compared with group 1 (P = .001 for both comparison). PD was greater in groups 2, 3, and 4 compared with group 1 ( P < .001 for all comparison), and also in group 4 compared with group 2 (P = .001). However, there was no statistically significant difference among the groups regarding Pmin. In bivariate correlation, increased PD was correlated with presence of hypertension (r = 0.278, P = .013), left ventricular ejection fraction (r = -0.231, P = .044), left atrial diameter (r = 0.223, P = .032), presence of moderate to severe mitral regurgitation (r = 0.284, P = .017), vessel score (r = 0.465, P < .001), and Gensini score (r = 0.338, P = .005). Multiple linear regression analysis showed that only vessel score was independently associated with PD (beta = .471, P = .01).

CONCLUSIONS

PD was found to be greater in patients with stable CAD than in controls and to be associated with severity of the disease.

Assessment of left ventricular function by Doppler tissue imaging in patients with atrial fibrillation following acute myocardial infarction

AIMS

We studied tissue Doppler parameters in patients with atrial fibrillation following acute myocardial infarction, and their relation to P wave durations and P dispersion.

METHODS

Echocardiographic examination was performed in 84 consecutive patients with first anterior acute myocardial infarction. In addition to other conventional echocardiographic parameters, the peak systolic (Sm), early diastolic (Em) and late diastolic (Am) velocities were obtained at the lateral corner of the mitral annulus by pulsed wave tissue Doppler. The Em/Am ratio and the ratio of early diastolic mitral inflow velocity to Em (E/Em), which is a marker of diastolic filling pressure, were calculated. Electrocardiogram was recorded from all patients on admission; P wave measurements were also performed.

RESULTS

Atrial fibrillation occurred in 20 (23.8%) of 84 patients. The patients with atrial fibrillation had significant reduction of Em (5.6+/-1.5 vs. 8.7+/-2.7 cm/s, p < 0.001), Em/Am (0.61+/-0.27 vs. 0.84+/-0.23, p = 0.001) and Sm (7.1+/-1.0 vs. 8.3+/-1.9 cm/s, p < 0.001) values compared with those without. The E/Em ratio (14.45+/-4.62 vs. 7.47+/-2.79, p < 0.001), P maximum (102+/-11 vs. 95+/-11 ms, p = 0.02) and P dispersion (35+/-7 vs. 26+/-7 ms, p < 0.001) were significantly higher in patients with atrial fibrillation than in those without. In all patients, P dispersion showed significant correlation with Em (r = -0.33, p = 0.002), Sm (r = -0.40, p < 0.001) and E/Em (r = 0.32, p = 0.003). When E/Em > or = 10 was used as cutpoint, atrial fibrillation could be predicted with a sensitivity of 90%, and a specificity of 84%.

CONCLUSIONS

The patients with atrial fibrillation following acute myocardial infarction have reduced systolic and diastolic mitral annular velocities and increased E/Em ratio, P maximum and P dispersion values compared to those without. P dispersion is correlated with systolic and diastolic left ventricular function after acute myocardial infarction. The E/Em ratio appears to be a useful parameter for assessing the risk of atrial fibrillation occurrence after anterior acute myocardial infarction.

Association of stage of left ventricular diastolic dysfunction with P wave dispersion and occurrence of atrial fibrillation after first acute anterior myocardial infarction

OBJECTIVES

The aim of this study was to investigate the association of stage of left ventricular diastolic dysfunction after acute myocardial infarction (AMI) with P maximum, P dispersion, and atrial fibrillation (AF) occurrence rate.

BACKGROUND

The occurrence of AF following AMI is frequently associated with a left ventricle restrictive filling pattern. Increased P dispersion is also associated with the occurrence of AF after AMI. But, the relation between the stage of left ventricular diastolic dysfunction and the P wave measurements after AMI has not yet been investigated.

METHODS

Electrocardiograms of 90 patients with first anterior AMI were recorded on admission, and P wave measurements were performed. The left ventricular diastolic functions were evaluated by transthoracic echocardiography. On the basis of mitral inflow, subjects were stratified into three left ventricular diastolic filling patterns. All patients were monitored continuously for the detection of AF in the Coronary Care Unit.

RESULTS

Thirty patients had a normal filling pattern (33.3%) (NF group), 37 had impaired relaxation (41.1%) (IR group), and 23 had pseudonormal/restrictive filling pattern (25.6%) (PN/R group). P maximum was longer in the PN/R group (103 +/- 12 ms) compared with the NF group (94 +/- 9 ms, P = 0.019), but no significant difference was found between PN/R and IR (96 +/- 13 ms, P > 0.05) groups, and between NF and IR groups (P > 0.05). There was no significant difference for P minimum among the groups (P > 0.05). P dispersion was longer in the PN/R group (35 +/- 6 ms) than in the NF (26 +/- 7 ms, P < 0.001) and IR groups (26 +/- 6 ms, P < 0.001), but not different between the NF and IR groups (P > 0.05). Occurrence of AF was significantly more frequent in the PN/R group (52.2%) than in the NF (16.7%, P = 0.007) and IR groups (10.8%, P = 0.001). Frequency of AF was not different between the NF and IR groups (P > 0.05). In multivariate analyses, the stage of diastolic dysfunction was independently associated with P maximum, P minimum, P dispersion, and the occurrence of AF (P < 0.001, P = 0.035, P < 0.001, and P = 0.002, respectively).

CONCLUSIONS

P maximum and P dispersion are increased, and AF occurrence risk is higher in patients with pseudonormal/restrictive filling pattern after first anterior AMI. The stage of diastolic dysfunction is an independent predictor of P wave measurements and AF occurrence.

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.

Sinus and Paced P Wave Duration and Dispersion as Predictors of Atrial Fibrillation After Pacemaker Implantation in Patients with Isolated Sick Sinus Syndrome

The aim of this study was to prospectively evaluate the sinus and the paced P wave duration and dispersion as predictors of AF after pacemaker implantation in patients with isolated sick sinus syndrome (SSS). The study included 109 (69 women, mean age 72 +/- 11 years) patients with SSS, 59 with bradycardia-tachycardia syndrome (BTS). A 12-lead ECG was recorded before pacemaker implantation and during high right atrial and septal right atrial pacing at 70 and 100 beats/min. The ECGs were scanned into a computer and analyzed on screen. The patients were treated with AAIR (n = 52) or DDDR pacing. The P wave duration was measured in each lead and mean P wave duration and P wave dispersion were calculated for each ECG. AF during follow-up was defined as: AF in an ECG at or between follow-up visits; an atrial high rate episode with a rate of > or =220 beats/min for > or =5 minutes, atrial sensing with a rate of > or =170 beats/min in > or =5% of total counted beats, mode-switching in >/=5% of total time recorded, or a mode switching episode of > or =5 minutes recorded by the pacemaker telemetry. The ECG parameters were correlated to AF during follow-up. Mean follow-up was 1.5 +/- 0.9 years. None of the ECG parameters differed between patients with AF and patients without AF during follow-up, nor was there any difference between groups after correction for BTS and age. BTS was the strongest predictor of AF during follow-up (P < 0.001). P wave duration and dispersion measured before and during pacemaker implantation were not predictive of AF after pacemaker implantation in patients with isolated SSS.

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

BACKGROUND

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.

The effect of Valsalva maneuver on P wave in 12-lead surface electrocardiography in patients with paroxysmal atrial fibrillation

The previous studies relating to the effect of the Valsalva maneuver on P wave do not provide detailed information. In those studies, the parameters related to P wave duration during the release phase of the Valsalva maneuver were evaluated. The authors evaluated P wave amplitude as well as P wave duration during the strain phase of the Valsalva maneuver. Thirty-seven normal subjects and 36 patients with paroxysmal atrial fibrillation (PAF) were included in the study. Twelve-lead surface electrocardiography (ECG) was obtained from all the patients before and during the strain phase of the Valsalva maneuver. The authors evaluated the parameters related to both P wave duration and P wave amplitude. The highest P wave voltage was expressed as the P wave amplitude maximum (P amp max), the lowest P wave voltage as the P wave amplitude minimum (P amp min), and the P wave amplitude dispersion (P amp dispersion) as "the P amp max - the P amp min." Also, the maximum P wave duration was expressed as the P maximum (P max), the minimum P wave duration as the P minimum (P min), and the P wave dispersion as "the maximum P wave duration (P max) - the minimum P wave duration (P min)." All these parameters were measured before and during the strain phase of the Valsalva maneuver. P max, P dispersion, P amp max, and P amp dispersion were higher in patients with PAF compared to those of normal subjects before the Valsalva maneuver. In normal subjects, P max, P wave dispersion, P amp max, and P amp dispersion values were significantly higher in the strain phase of the Valsalva maneuver than before (p<0.01, p<0.01, p<0.05, and p<0.05, respectively). In the patients with PAF, P max, P wave dispersion, P amp max, and P amp dispersion values were significantly lower during the strain phase of the Valsalva maneuver than before. In conclusion, in the patients with PAF, P wave parameters were decreased during the strain phase of the Valsalva maneuver, approaching to the normal levels.

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 hypertension at risk of PAF can be identified while in sinus rhythm by measurements of P 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 of AF (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 ejection 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. However 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. Measurement of P wave dispersion in sinus rhythm may be a useful noninvasive clinical tool to identify patients with hypertension at risk of developing atrial electrical instability and atrial fibrillation.

P wave dispersion on 12-lead electrocardiography in patients with paroxysmal atrial fibrillation

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.

Increased variance of P wave duration on the electrocardiogram distinguishes patients with idiopathic paroxysmal atrial fibrillation

We hypothesized that the variance of P wave duration (P variance) in the 12-lead ECG could reflect the spatial dispersion of P wave duration due to inhomogeneous and delayed propagation of sinus impulses in the atria, and moreover could present better reproducibility than maximum P wave duration and P wave dispersion that have already been used for the prediction of idiopathic paroxysmal AF. We also tested a semiautomated PC-based method to improve the accuracy and reproducibility of P wave measurements. A 12-lead ECG was obtained from 60 patients with idiopathic paroxysmal AF and from 50 healthy controls. All ECGs were analyzed manually using magnifying lens and calipers, while 20 randomly selected ones were scanned and analyzed on screen using common commercial software. P maximum, P dispersion, and P variance were all significantly higher in patients with paroxysmal AF than in controls. A P maximum value of 110 ms, a P dispersion value of 40 ms, and a P variance value of 120 ms2 separated patients from controls with a sensitivity of 88%, 83%, and 80%, respectively and a specificity of 75%, 85%, and 74%, respectively. The reproducibility of P variance was higher compared to P dispersion and P maximum. Finally, the PC-based method significantly increased accuracy and reproducibility of P wave measurements. Thus, the variance of P wave duration could be a useful ECG marker for the prediction of paroxysmal idiopathic AF and the use of PC-based methods may enhance the accurate measuring of P wave duration on the ECG.

Simple electrocardiographic markers for the prediction of paroxysmal idiopathic atrial fibrillation

BACKGROUND

The prolongation of intraatrial and interatrial conduction time and the inhomogeneous propagation of sinus impulses are well known electrophysiologic characteristics in patients with paroxysmal atrial fibrillation (PAF).

METHODS

To search for possible electrocardiographic markers that could serve as predictors of idiopathic PAF, we measured the maximum P-wave duration (P maximum) and the difference between the maximum and the minimum P-wave duration (P dispersion) from the 12-lead surface electrocardiogram of 60 patients with a history of idiopathic PAF and 40 age-matched healthy control subjects.

RESULTS

P maximum and P dispersion were found to be significantly higher in patients with idiopathic PAF than in control subjects. A P maximum value of 110 msec and a P dispersion value of 40 msec separated patients from control subjects, with a sensitivity of 88% and 83% and a specificity of 75% and 85%, respectively.

CONCLUSIONS

P maximum and P dispersion are simple electrocardiographic markers that could be used for the prediction of idiopathic PAF.

Atrial fibrillation in patients with permanent VVI pacemakers: risk factors for atrial fibrillation

OBJECTIVES

Atrial fibrillation (AF) does not only deteriorate the cardiac function and increases the thromboembolic risk but also triggers rapid and irregular ventricular rhythm in patients with atrial synchronous pacing. However, the risk factors for the development of AF in patients with pacemakers are not clearly determined yet. The present study was designed to determine the risk factors for AF in patients with VVI pacemakers.

METHODS

This study included 80 patients (41 sick sinus syndrome, 39 AV block) who were followed for more than 6 months or developed AF regardless of the duration of follow-up after implantation of VVI pacemakers. Patients were divided into two groups according to whether or not AF developed during follow-up (mean: 25.7 +/- 2.5 months): group A developed AF and group B did not. The underlying arrhythmias, cardiovascular risk factors, left atrial size, characteristics of P wave were compared between the two groups.

RESULTS

The mean age of the patients was 58.9 +/- 11.4 years and 28 (35%) were male. AF developed in 13 (16.3%) of 80 patients with VVI pacemakers. Sick sinus syndrome (SSS) as an underlying arrhythmia was significantly more frequent in group A than group B (84.6% vs. 44.8%, p < 0.01). P wave width was greater in group A (127.6 +/- 24.8 ms) than in group B (110.7 +/- 17 ms) (p < 0.05). There was, however, no significant difference in cardiovascular risk factors, left atrial size, P wave axis and amplitude between the two groups.

CONCLUSION

These results suggest that sinus node dysfunction and intra-atrial conduction delay may be the risk factors for AF in patients with VVI pacemakers. Further studies are needed to determine how sick sinus syndrome and intra-atrial conduction delay increase the risk for AF in patients with VVI pacemakers.