P wave and the development of atrial fibrillation

Electrocardiographic P terminal force in lead V1, its components, and the association with stroke and atrial fibrillation or flutter

BACKGROUND

The electrocardiographic (ECG) marker P terminal force V1 (PTFV1) is generally perceived as a marker of left atrial pathology and has been associated with atrial fibrillation or flutter (AF).

OBJECTIVE

The purpose of this study was to determine the association between PTFV1 components (duration and amplitude) and incident AF and stroke/transient ischemic attack (TIA).

METHODS

The study included patients with an ECG recorded at the Copenhagen General Practitioners Laboratory in 2001 to 2011. PTFV1 ≥4 mV·ms was considered abnormal. Patients with abnormal PTFV1 were stratified into tertiles based on duration (PTDV1) and amplitude (PTAV1) values. Cox regressions adjusted for age, sex, and relevant comorbidities were used to investigate associations between abnormal PTFV1 components and AF and stroke/TIA.

RESULTS

Of 267,636 patients, 5803 had AF and 18,176 had stroke/TIA (follow-up 6.5 years). Abnormal PTFV1 was present in 44,549 subjects (16.7%) and was associated with an increased risk of AF and stroke/TIA. Among patients with abnormal PTFV1, the highest tertile of PTDV1 (78-97 ms) was associated with the highest risk of AF (hazard ratio [HR] 1.37; 95% confidence interval [CI] 1.23-1.52) and highest risk of stroke/TIA (HR 1.13; 95% CI 1.05 -1.20). For PTAV1, the highest tertile (78-126 μV) conferred the highest risk of AF and stroke/TIA (HR 1.20; 95% CI 1.09-1.32; and HR 1.21; 95% CI 1.14-1.25, respectively).

CONCLUSION

Abnormal PTFV1 was associated with an increased risk of AF and stroke/TIA. Increasing PTDV1 showed a dose-response relationship with the development of AF and stroke/TIA, whereas the association between PTAV1 and AF was less apparent.

The Atrium in Atrial Fibrillation - A Clinical Review on How to Manage Atrial Fibrotic Substrates

Atrial fibrillation (AF) is the most common sustained arrhythmia in the population and is associated with a significant clinical and economic burden. Rigorous assessment of the presence and degree of an atrial arrhythmic substrate is essential for determining treatment options, predicting long-term success after catheter ablation, and as a substrate critical in the pathophysiology of atrial thrombogenesis. Catheter ablation of AF has developed into an essential rhythm-control strategy. Nowadays is one of the most common cardiac ablation procedures performed worldwide, with its success inversely related to the extent of atrial structural disease. Although atrial substrate evaluation remains complex, several diagnostic resources allow for a more comprehensive assessment and quantification of the extent of left atrial structural remodeling and the presence of atrial fibrosis. In this review, we summarize the current knowledge on the pathophysiology, etiology, and electrophysiological aspects of atrial substrates promoting the development of AF. We also describe the risk factors for its development and how to diagnose its presence using imaging, electrocardiograms, and electroanatomic voltage mapping. Finally, we discuss recent data regarding fibrosis biomarkers that could help diagnose atrial fibrotic substrates.

Embolic Stroke of Undetermined Source: Approaches in Risk Stratification for Cardioembolism

Ischemic stroke is a leading cause of morbidity and mortality worldwide. Embolic stroke of undetermined source has been recently proposed to categorize nonlacunar ischemic strokes without confirmed etiology after adequate investigation with a likely embolic stroke mechanism. A strategy of empirical anticoagulation for embolic stroke of undetermined source patients is attractive but may only be beneficial in a select subset of patients. Strategies which would help identify the subset of embolic stroke of undetermined source patients most likely to have cardioembolic origin of stroke, and hence benefit from anticoagulation, are needed. This article will review current evidence which may be useful in the development of a risk stratification approach based on arrhythmia monitoring, cardiac imaging, and clinical risk stratification. This approach may be beneficial in clinical practice in improving patient outcomes and reducing stroke recurrence in this population; however, further work is required with active trials underway.

Long-Term Exposures to Air Pollution and the Risk of Atrial Fibrillation in the Women's Health Initiative Cohort

BACKGROUND

Atrial fibrillation (AF) is associated with substantial morbidity and mortality. Short-term exposures to air pollution have been associated with AF triggering; less is known regarding associations between long-term air pollution exposures and AF incidence.

OBJECTIVES

Our objective was to assess the association between long-term exposures to air pollution and distance to road on incidence of AF in a cohort of U.S. women.

METHODS

We assessed the association of high resolution spatiotemporal model predictions of long-term exposures to particulate matter (PM 10 and PM 2.5 ), sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), and distance to major roads with incidence of AF diagnosis, identified through Medicare linkage, among 83,117 women in the prospective Women's Health Initiative cohort, followed from enrollment in Medicare through December 2012, incidence of AF, or death. Using time-varying Cox proportional hazards models adjusted for age, race/ethnicity, study component, body mass index, physical activity, menopausal hormone therapy, smoking, diet quality, alcohol consumption, educational attainment, and neighborhood socioeconomic status, we estimated the relative risk of incident AF in association with each pollutant.

RESULTS

A total of 16,348 incident AF cases were observed over 660,236 person-years of follow-up. Most exposure-response associations were nonlinear. NO 2 was associated with risk of AF in multivariable adjusted models [Hazard Ratio  ( HR ) = 1.18 ; 95% confidence interval (CI): 1.13, 1.24, comparing the top to bottom quartile, p -for-trend = < 0.0001 ]. Women living closer to roadways were at higher risk of AF (e.g., HR = 1.07 ; 95% CI: 1.01, 1.13 for living within 50 m of A3 roads, compared with ≥ 1,000  m , p -for-trend = 0.02 ), but we did not observe adverse associations with exposures to PM 10 , PM 2.5 , or SO 2 . There were adverse associations with PM 10 (top quartile HR = 1.10 ; 95% CI: 1.05, 1.16, p -for-trend = < 0.0001 ) and PM 2.5 (top quartile HR = 1.09 ; 95% CI: 1.03, 1.14, p -for-trend = 0.002 ) in sensitivity models adjusting for census region.

DISCUSSION

In this study of postmenopausal women, NO 2 and distance to road were consistently associated with higher risk of AF. https://doi.org/10.1289/EHP7683.

Incremental value of P-wave indices for predicting left atrial dysfunction in patients with primary mitral regurgitation using speckle tracking echocardiography

The correlation of P wave indices on surface ECG and phasic LA dysfunction in patients with significant primary mitral regurgitation (MR) due to the adverse LA adaptive structural and functional changes needs to be more studied. This study aims to investigate the diagnostic value of P wave indices to predict LA function assessed both by volumetric analysis using 3-dimensional (3D)echocardiography, and by strain analysis using speckle tracking echocardiography. (STE). The study included 107 subjects, we measured maximum P-duration (Pmax), P dispersion (PD), and V1 negative terminal force (V1-NTF) (negative duration x negative amplitude) on surface ECG. Both Basic and Dynamic LA volumes (LAV) during reservoir, conduit, and contractile phases were measured. The global LA strain and strain rate parameters were calculated By STE. LA ejection fraction (LAEF) and ejection force were also calculated.V1-NTF showed a significant positive correlation while P-max a significant negative correlation with global peak atrial longitudinal strain (GPALS) (r = 0.75; P < 0.001 and r = - 0.72; P < 0.001 respectively). Using ROC curve analysis, Pmax > 110 ms, 1-NTF ≥ 4 ms.mV and P notching > 40 ms had a sensitivity of 90%, 95% and 50% and a specificity of 87.4%, 94.3% and 100% respectively in predicting GPALS ≤ 30%. P notching > 40 ms was associated with severe LA dysfunction. ECG P wave indices represent a simple bedside tool that could have an incremental role in predicting LA dysfunction as well as size in patients with significant primary MR.

Effectiveness of P-wave ECG index and left atrial appendage volume in predicting atrial fibrillation recurrence after first radiofrequency catheter ablation

BACKGROUND

The primary aim was to observe the predictive value of P-wave ECG index and left atrial appendage volume (LLAV) for atrial fibrillation recurrence after first radiofrequency catheter ablation.

METHODS

A total of 196 patients with paroxysmal atrial fibrillation were enrolled. The preoperative LLAV was measured by cardiac enhanced CT. The P-wave ECG index including minimum P-wave duration (P-min), maximum P-wave duration (P-max), mean P-wave duration (mPWD), P-wave dispersion (PWD), P-wave terminal force in lead V1 (PtfV1), PR interval prolongation, and interatrial block (IAB) were analyzed and recorded in 12-lead ECG of sinus rhythm.

RESULTS

According to the follow-up results, the patients were divided into two groups: the non-recurrence group and the recurrence group. P-min, PWD, P-max, PtfV1 ≥ 0.04 mV·s, PR interval prolongation, and the ratio of first and third-degree IAB in the recurrence group were higher than those in the non-recurrence group, with significant statistical differences (P < 0.05). Kaplan-Meier curve analysis was performed on time to atrial fibrillation recurrence after catheter ablation when PtfV1 ≥ 0.04 mv s by comparison between groups (Log Rank test: 2 = 4.739, P < 0.001). Kaplan-Meier curve analysis showed that the survival rate without recurrence of atrial fibrillation after catheter ablation was lower when the LLAV exceeded 8.0 mL (log-rank test P < 0.001).

CONCLUSION

PWD, P-max, PtfV1, PR interval prolongation, first and third-degree IAB, and LLAV can effectively predict atrial fibrillation recurrence after radiofrequency catheter ablation. The combination might be a valid and alternative independent predictor of recurrence.

Alterations in atrial electrogram amplitude as steady sinus rhythm transitions to paroxysmal atrial fibrillation during continuous monitoring in patients with implantable cardiac devices: Insights from the IMPACT study

OBJECTIVES

We aimed to evaluate whether device measured amplitudes of atrial electrogram (AEGM) would change when measured in sinus rhythm (SR) transitioning to paroxysmal atrial fibrillation (AF) from previous steady SR, and significance of such change.

METHODS

From the IMPACT trial's database we selected two groups; (A) those who developed AF (n = 164), and (B) propensity-matched control (n = 459) who stayed in SR during continuous Home Monitoring (HM) to compare AEGMs amplitudes at baseline SR and transition phase.

RESULTS

During 420.0 ± 349.2 days (mean ± SD) from first postenrollment HM transmission to AF event transmission in Group A, and corresponding 515.3 ± 407.0 days in Group B, baseline and transition AEGM amplitude were 2.88 ± 1.146 and 2.74 ± 1.186 mV, respectively, for Group A (p = .1), and 2.88 ± 1.155 and 2.79 ± 1.145, respectively, for Group B (p < .005). Comparison of differences of AEGM amplitude, 0.14 ± 1.072 mV in Group A and 0.09 ± 0.893 mV in Group B were insignificant (p = .3). Age, sex, and hypertension identified as confounders had no association to AEGM changes (p = NS).

CONCLUSIONS

Independent of age, sex, and hypertension, AEGMs amplitudes decline over a long period of time in patients with defibrillators and substrate for AF. The significance of such change remains unclear as it occurs whether patients develop AF or not, but raises a possibility of progressive atrial myopathy that patients with substrate for AF may be predisposed to.

Atrial Myopathy Underlying Atrial Fibrillation

While AF most often occurs in the setting of atrial disease, current assessment and treatment of patients with AF does not focus on the extent of the atrial myopathy that serves as the substrate for this arrhythmia. Atrial myopathy, in particular atrial fibrosis, may initiate a vicious cycle in which atrial myopathy leads to AF, which in turn leads to a worsening myopathy. Various techniques, including ECG, plasma biomarkers, electroanatomical voltage mapping, echocardiography, and cardiac MRI, can help to identify and quantify aspects of the atrial myopathy. Current therapies, such as catheter ablation, do not directly address the underlying atrial myopathy. There is emerging research showing that by targeting this myopathy we can help decrease the occurrence and burden of AF.

P-Wave Area Predicts New Onset Atrial Fibrillation in Mitral Stenosis: A Machine Learning Approach

Introduction: Mitral stenosis is associated with an atrial cardiomyopathic process, leading to abnormal atrial electrophysiology, manifesting as prolonged P-wave duration (PWD), larger P-wave area, increased P-wave dispersion (PWD_max—PWD_min), and/or higher P-wave terminal force on lead V1 (PTFV1) on the electrocardiogram.

Methods: This was a single-center retrospective study of Chinese patients, diagnosed with mitral stenosis in sinus rhythm at baseline, between November 2009 and October 2016. Automated ECG measurements from raw data were determined. The primary outcome was incident atrial fibrillation (AF).

Results: A total 59 mitral stenosis patients were included (age 59 [54–65] years, 13 (22%) males). New onset AF was observed in 27 patients. Age (odds ratio [OR]: 1.08 [1.01–1.16], P = 0.017), systolic blood pressure (OR: 1.03 [1.00–1.07]; P = 0.046), mean P-wave area in V3 (odds ratio: 3.97 [1.32–11.96], P = 0.014) were significant predictors of incident AF. On multivariate analysis, age (OR: 1.08 [1.00–1.16], P = 0.037) and P-wave area in V3 (OR: 3.64 [1.10–12.00], P = 0.034) remained significant predictors of AF. Receiver-operating characteristic (ROC) analysis showed that the optimum cut-off for P-wave area in V3 was 1.45 Ashman units (area under the curve: 0.65) for classification of new onset AF. A decision tree learning model with individual and non-linear interaction variables with age achieved the best performance for outcome prediction (accuracy = 0.84, precision = 0.84, recall = 0.83, F-measure = 0.84).

Conclusion: Atrial electrophysiological alterations in mitral stenosis can detected on the electrocardiogram. Age, systolic blood pressure, and P-wave area in V3 predicted new onset AF. A decision tree learning model significantly improved outcome prediction.

Predictive value of P wave terminal force in lead V1 for atrial fibrillation: A meta-analysis

Background

Several studies have explored the association between P wave terminal force in lead V1 (PTFV1) and risk of atrial fibrillation (AF) occurrence, but the results were controversial. This meta‐analysis aimed to examine whether abnormal PTFV1 could predict AF occurrence.

Methods

We searched PubMed, Embase, and Cochrane Library databases for articles published before August 25, 2018. Pooled odds ratios (ORs) of AF occurrence were calculated using random‐effects models to explore the significance of PTFV1.

Results

A total of 12 studies examining 51,372 participants were included, with 9 studies analyzing PTFV1 as a categorical variable and 4 studies analyzing PTFV1 as a continuous variable. As a categorical variable, abnormal PTFV1 (>0.04 mm s) was significantly associated with AF occurrence with a pooled OR of 1.39 (95% confidence interval [CI] 1.08–1.79, p = .01). Subgroup analysis found that ORs of studies in hemodialysis patients (OR = 4.89, 95% CI 2.54–9.90, p < .001) and acute ischemic stroke patients (OR = 1.60, 95% CI 1.14–2.25, p = .007) were higher than general population (OR = 1.15, 95% CI 1.03–1.29, p = .01). Studies from Europe (OR = 1.05, 95% CI 0.91–1.20, p = .51) yielded lower OR of endpoints compared with Asia (OR = 1.89, 95% CI 1.38–2.60, p < .001) and United States (OR = 1.43, 95% CI 1.19–1.72, p < .001). As a continuous variable, PTFV1 was also significantly associated with AF occurrence with a polled OR per 1 standard deviation (SD) change of 1.27 (95% CI 1.02–1.59, p = .03).

Conclusions

PTFV1 was significantly associated with the risk of AF and was considered to be a good predictor of AF occurrence in population with or without cardiovascular diseases.

Value of the Electrocardiographic (P Wave, T Wave, QRS) Axis as a Predictor of Mortality in 14 Years in a Population With a High Prevalence of Chagas Disease from the Bambuí Cohort Study of Aging

We sought to investigate the prognostic value of the electrocardiogram (ECG) electrical axes (P wave, T wave and QRS) as predictors of mortality in the 14-year follow-up of the prospective cohort of all residents ≥60 years living in the southeastern Brazilian city of Bambuí, a population with high prevalence of Chagas disease (ChD). Baseline ECG axes were automatically measured with normal values defined as follows: P-wave axis 0° to 75°, QRS axis -30° to 90°, and T axis 15° to 75°. Participants underwent annual follow-up visits and death was verified using death certificates. Cox proportional hazards regression was used to assess the prognostic value of ECG axes for all-cause mortality, after adjustment for potential confounders. From 1,742 qualifying residents, 1,462 were enrolled, of whom 557 (38.1%) had ChD. Mortality rate was 51.9%. In multivariable adjusted models, abnormal P-wave axis was associated with a 48% (hazard ratio [HR] = 1.48 [95% confidence interval (CI) 1.16-1.88]) increased mortality risk in patients with ChD and 43% (HR = 1.43 [CI 1.13-1.81]) in patients without ChD. Abnormal QRS axis was associated with a 34% (HR = 1.34 [CI 1.04-1.73]) increased mortality risk in patients with ChD, but not in individuals without ChD. Similarly, in the ChD group, abnormal T-wave axis was associated with a 35% (HR = 1.35 [CI 1.07-1.71]) increased mortality, but not in patients without ChD. In conclusion, abnormal P-wave, QRS, and T-wave axes were associated with increased all-cause mortality in patients with ChD. Abnormal P-wave axis was associated with mortality also among those without ChD, being the strongest predictor among ECG variables.

Electrocardiogram (ECG) for the Prediction of Incident Atrial Fibrillation: An Overview

Electrocardiograms (ECGs) have been employed to medically evaluate participants in population-based studies, and ECG-derived predictors have been reported for incident atrial fibrillation (AF). Here, we reviewed the status of ECG in predicting new-onset AF. We surveyed population-based studies and revealed ECG variables to be risk factors for incident AF. When available, the predictive values of each ECG risk marker were calculated. Both the atrium-related and ventricle-related ECG variables were risk factors for incident AF, with significant hazard risks (HRs) even after multivariate adjustments. The risk factors included P-wave indices (maximum P-wave duration, its dispersion or variation and P-wave morphology) and premature atrial contractions (PACs) or runs. In addition, left ventricular hypertrophy (LVH), ST-T abnormalities, intraventricular conduction delay, QTc interval and premature ventricular contractions (PVCs) or runs were a risk of incident AF. An HR of greater than 2.0 was observed in the upper 5th percentile of the P-wave durations, P-wave durations greater than 130 ms, P-wave morpholyg, PACs (PVCs) or runs, LVH, QTc and left anterior fascicular blocks. The sensitivity , specificity and the positive and negative predictive values were 3.6-53.8%, 61.7-97.9%, 2.9-61.7% and 77.4-97.7%, respectively. ECG variables are risk factors for incident AF. The correlation between the ECG-derived AF predictors, especially P-wave indices, and underlying diseases and the effects of the reversal of the ECG-derived predictors on incident AF by treatment of comorbidities require further study.

Association of Oral Lichen Planus and Electrocardiographic P-Wave Dispersion - An Original Research

Lichen planus (LP) is considered to be a T-cell-mediated inflammatory disorder. Inflammation is considered to produce disturbances of lipid metabolism which may affect the myocardium. Increased P-Wave Dispersion (PWD) is demonstrated as an independent risk factor for developing atrial fibrillation (AF). Hence the present study has been conducted to explore the possible relationship of oral lichen planus (OLP) with AF by the evaluation of PWD. Twelve-lead electrocardiographs (ECG) were obtained from 45 OLP patients and 45 age and gender-matched healthy controls. The P-wave durations (Pmax and Pmin) were calculated in all 12 leads. The difference between Pmax and Pmin was defined as P-Wave Dispersion (PWD). After the PWD was recorded, the results were statistically analyzed. The study showed that PWD increased on surface ECG measurements in OLP patients who were otherwise asymptomatic in relation to cardiac conditions. The p value obtained was <0.001 which was highly significant. The present study suggests a highly statistically significant association of OLP with increased P-wave dispersion. Hence the patients with OLP should undergo cardiac evaluation and follow up for early detection of atrial fibrillation.

Biphasic P wave in inferior leads and the development of atrial fibrillation

Background

Anisotropic and slow conduction in the atrium underlie the development of atrial fibrillation (AF). This study aimed to investigate the P wave characteristics associated with the development of AF in patients with a biphasic P wave in the inferior leads.

Methods

Digital analysis of retrospectively recorded 12-lead electrocardiograms was performed to select patients with a biphasic P wave (positive/negative) in lead II from a database of 114,334 patients. Characteristics of the P wave in the inferior leads associated with incidence of AF were determined. Receiver operating characteristic curves dichotomized P wave variables were measured in each lead.

Results

A total of 141 patients (77 men; mean age, 64±19 years) were enrolled in this study. Twenty-nine (20.6%) patients developed AF (AF group) vs. 112 (79.6%) who did not (non-AF group) during a follow-up period of 50±62 months. The amplitude of the initial P wave portion in lead II was significantly larger in the AF group when compared with the non-AF group (77.3±77.0 µV vs. 51.0±30.1 µV, p=0.003), while the amplitude of the terminal P wave portion in lead III was significantly decreased in the AF group when compared with the non-AF group (−70.6±41.3 µV vs. −89.1±38.1 µV, p=0.024). The duration of the initial P wave portion in lead III was significantly longer in the AF group when compared with the non-AF group (52.7±34.6 ms vs. 35.8±30.4 ms, p=0.011). Multivariate Cox proportional-hazards analysis confirmed that the increased duration of the initial P wave portion in lead III (≥71 ms) was independently associated with AF development (hazard ratio 2.90, 95% confidence interval 1.16–7.11, p=0.02).

Conclusion

The analyses of the biphasic P wave in the inferior leads suggest that the development of AF could be attributed to increased atrial slow conduction.

Blockade of brain angiotensin II type 1 receptor inhibits the development of atrial fibrillation in hypertensive rats

BACKGROUND

Hypertension is a powerful risk factor of atrial fibrillation (AF). The pathophysiology of AF with hypertension is associated with sympathoexcitation or the renin-angiotensin system; however, current therapies cannot sufficiently prevent its development. We previously revealed that brain angiotensin II type 1 receptor (AT1R) blockade causes a depressor response via sympathoinhibition. Herein, we evaluated whether brain AT1R contributes to AF development in hypertensive rats.

METHODS

We divided the stroke-prone spontaneously hypertensive rats (SHRSP) treated with intracerebroventricular (ICV) infusion of vehicle, ICV infusion of losartan (S-LOS), or oral administration of hydralazine (S-HYD); and Wistar Kyoto rats treated with ICV S-VEH.

RESULTS

Two weeks later, systolic blood pressure was significantly lower in the S-LOS group than in the S-VEH group and was even lower in the S-HYD group. Urinary norepinephrine excretion for 24h, an indirect marker of sympathoexcitation, significantly reduced in the S-LOS group but increased in the S-HYD group despite depressor response. AF was induced by transesophageal burst pacing. AF duration was significantly shorter in the S-LOS group than in the S-VEH group (5.0±0.4 vs. 15.2±3.7 s; n = 8 each; P < 0.05). However, it was significantly longer in the S-HYD group than in the S-VEH group. Interstitial atrial fibrosis and echocardiographic parameters did not differ between the SHRSP groups.

CONCLUSIONS

Brain AT1R blockade suppresses AF inducibility and maintenance independent of depressor response in hypertensive rats.

Gaussian modeling of the P-wave morphology time course applied to anticipate paroxysmal atrial fibrillation

This paper introduces a new algorithm to quantify the P-wave morphology time course with the aim of anticipating as much as possible the onset of paroxysmal atrial fibrillation (PAF). The method is based on modeling each P-wave with a single Gaussian function and analyzing the extracted parameters variability over time. The selected Gaussian approaches are associated with the amplitude, peak timing, and width of the P-wave. In order to validate the algorithm, electrocardiogram segments 2 h preceding the onset of PAF episodes from 46 different patients were assessed. According to the expected intermittently disturbed atrial conduction before the onset of PAF, all the analyzed Gaussian metrics showed an increasing variability trend as the PAF onset approximated. Moreover, the Gaussian P-wave width reported a diagnostic accuracy around 80% to discern between healthy subjects, patients far from PAF, and patients less than 1 h close to a PAF episode. This discriminant power was similar to those provided by the most classical time-domain approach, i.e., the P-wave duration. However, this newly proposed parameter presents the advantage of being less sensitive to a precise delineation of the P-wave boundaries. Furthermore, the linear combination of both metrics improved the diagnostic accuracy up to 86.69%. In conclusion, morphological P-wave characterization provides additional information to the metrics based on P-wave timing.

P-pulmonale and the development of atrial fibrillation

BACKGROUND

P wave ≥0.25mV in inferior leads (P pulmonale) occurs in chronic lung diseases that underlie atrial fibrillation (AF). The purpose of this study was to elucidate the prognostic value of P pulmonale for development of AF.

METHODS AND RESULTS

Digital analysis of 12-lead electrocardiogram (ECG) was conducted to enroll patients with P pulmonale from among a database containing 308,391 ECGs. In a total of 591 patients (382 men; 56.4±14.8 years) with P pulmonale (follow-up, 46.7±65.6 months), AF occurred in 61 patients (AF group), but did not occur in 530 patients (non-AF group). Male gender was significantly more prevalent in the AF group than in the non-AF group (80.3% vs. 62.8%, P=0.0047). P-wave duration and PQ interval were significantly longer in the AF group than in the non-AF group (115.4±17.2ms vs. 107.0±17.2ms, P=0.0003 and 166.3±23.9ms vs. 153.2±25.4ms, P=0.0001, respectively). In the total patient group, multivariate Cox proportional-hazards analysis confirmed that male gender (hazard ratio [HR], 2.24; 95% confidence interval [CI]: 1.02-5.49; P=0.045), PQ interval >150ms (HR, 6.89; 95% CI: 2.39-29.15; P<0.0001), and P-wave axis <74° (HR, 2.55; 95% CI: 1.20-5.41; P=0.016) were associated with AF development. In medication-free patients (n=400), only PQ interval >150ms (HR, 9.26; 95% CI: 1.75-170.65; P=0.0055) was independently and significantly associated with AF development.

CONCLUSIONS

PQ interval is the strongest stratifier for AF development in P pulmonale.  

Short-term repeatability of electrocardiographic P wave indices and PR interval

BACKGROUND

P wave indices and PR interval from 12-lead electrocardiograms (ECGs) are predictors of cardiovascular morbidity and mortality, but their repeatability has not been examined.

OBJECTIVES

Determine the short-term repeatability of P wave indices (P axis, maximum P area and duration, P dispersion and P terminal force in V1) and PR interval.

METHODS

Participants (n=63) underwent two standard ECGs at each of two visits, two weeks apart. We calculated the intra-class correlation coefficient (ICC), weighted kappa, and minimal detectable change and difference.

RESULTS

ICCs were 0.93 for PR interval, 0.78 for P axis, 0.77 for maximum P area, and 0.58 for maximum P duration. Within- and between-visit Kappa were 0.30 and 0.11 for P dispersion, and 0.68 and 0.46 for P terminal force.

CONCLUSION

Repeatability of PR duration was excellent, that of P wave axis and maximum area was fair, and maximum P wave duration and terminal force was poor. Repeatability of P wave dispersion was fair within visit, yet poor between visits. These results illustrate potential biases when measurement error of some P wave indices is ignored in clinical and epidemiologic studies.

Electrocardiographic P wave changes after thoracoscopic pulmonary vein isolation for atrial fibrillation

BACKGROUND

Changes in P wave duration (PWD) and P wave area (PWA) have been described following catheter ablation for atrial fibrillation (AF). We hypothesize that video-assisted thoracoscopic pulmonary vein isolation (VATS-PVI) for AF results in decrease of PWD, PWA and P wave dispersion, which may resemble reverse electrical remodeling of the atrium after restoration of sinus rhythm.

METHODS

VATS-PVI consisted of PVI and ganglionic plexus ablation in 29 patients (mean age, 59 ± 7 years; 23 males; 17 paroxysmal AF) and additional left atrial lesions in patients with persistent AF. PWD and PWA were measured in ECG lead II, aVF and V2 of ECGs during sinus rhythm before, directly after, and 6 months postprocedure. P wave dispersion was derived from the 12 lead ECG.

RESULTS

Prior to VATS-PVI, PWD did not correlate with left atrial size and no difference in left atrial size was found between patients with paroxysmal or persistent AF (p = 0.27). Following VATS-PVI, PWD initially prolonged in all patients from 115 ± 4.6 ms to 131 ± 3.6 ms (p < 0.01) but shortened to 99 ± 3.2 ms after 6 months (p < 0.01). PWA was 5.60 ± 0.32 mV*ms at baseline, 6.44 ± 0.32 mV*ms post-VATS-PVI (P = NS), and 5.40 ± 0.28 mV*ms after 6 months (p = NS vs. baseline, p < 0.05 vs. post-VATS-PVI). P wave dispersion decreased in the persistent AF group from baseline 67 ± 3.3 to 64 ± 2.5 ms post-VATS-PVI (p = 0.30) and to 61 ± 3.4 ms after 6 months (p < 0.05).

CONCLUSIONS

PWD increases significantly directly after successful VATS-PVI in both groups. There was significant decrease in PWD after 6 months. Similarly, P wave dispersion decreased in the persistent group. These changes suggest an immediate procedure related effect, but the later changes may represent reverse electrical atrial remodeling following cessation of AF.

Brain natriuretic peptide: a relevant marker to rule out delayed atrial fibrillation in stroke patient

Detection of new atrial fibrillation (AF) after ischemic stroke is challenging. The aim of the TARGET-AF study was to identify relevant markers for ruling out delayed AF in stroke patients. Early and prolonged Holter electrocardiography (ECG) monitoring during hospitalization was performed systematically in consecutive acute stroke patients naive to AF (no history of AF or no AF on baseline ECG). All clinical and paraclinical data for routine etiologic assessment were collected. The diagnostic value of all parameters significantly associated with AF was assessed by comparison of area under the receiver operating characteristic curve (AUC). Of the 300 stroke patients enrolled (mean age, 62.5 ± 15.5 years; sex ratio: 1.7; mean National Institutes of Health Stroke Scale score, 7.1 ± 7.9, median duration of Holter ECG monitoring, 6.8 days), 52 (17.3%) had newly diagnosed AF. Parameters significantly associated with AF were classified by increasing AUC: anterior circulation localization (AUC, 0.604; 95% confidence interval [CI], 0.546-0.660), P-wave initial force (AUC, 0.608; 95% CI, 0.545-0.669), left atrial dilatation (AUC, 0.657; 95% CI, 0.600-0.711), National Institutes of Health Stroke Scale score (AUC, 0.667; 95% CI, 0.611-0.720), sex (AUC, 0.683; 95% CI, 0.627-0.736), age (AUC, 0.755; 95% CI, 0.707-0.797), CHA2DS2-VASc score (AUC, 0.796; 95% CI, 0.746-0.841), STAF (score for the targeting of AF) score (AUC, 0.842; 95% CI, 0.796-0.882), and plasma brain natriuretic peptide (BNP) level (AUC, 0.868; 95% CI, 0.825-0.904). The use of all parameters combined (AUC, 0.910; 95% CI, 0.872-0.940) was not significantly more efficient in diagnosing AF than BNP alone (P = .248). At the Youden plot, the diagnostic properties for BNP >131 pg/mL were sensitivity, 98.1% (95% CI, 89.7-99.7); specificity, 71.4% (95% CI, 65.3-76.9); and negative predictive value, 99.4% (95% CI, 96.9-99.9). Our data indicate that a BNP level ≤ 131 pg/mL might rule out delayed AF in stroke survivors and could be included in algorithms for AF detection.

P wave duration is associated with cardiovascular and all-cause mortality outcomes: the National Health and Nutrition Examination Survey

BACKGROUND

P wave indices are an intermediate phenotype modulated by atrial conduction and electrophysiology. Their clinical correlates and association with all-cause mortality have received limited scrutiny.

OBJECTIVE

To determine the relationship between P wave indices and cardiovascular and all-cause mortality in the National Health and Nutrition Examination Survey (NHANES), a highly representative United States sample.

METHODS

NHANES III (1988-1994) quantified PR interval and P wave duration and amplitude. Mortality data through 2006 were obtained from National Death Index (NDI) records.

RESULTS

Of 8,561 subjects with electrocardiograms (ECGs), 7,486 (mean age 60.0 ± 13.3 years., 51.9% women, 50.1% ethnic minorities) had ECGs in sinus rhythm, linked mortality data, and complete assessments. Over a median 8.6-year follow-up (range 0.1-12.2 years), there were 679 cardiovascular deaths and 1,559 all-cause mortality deaths. Older age, male sex, and higher body mass index were significantly associated with greater PR interval and P wave duration and with lower P wave amplitude. African Americans had higher mean values of all three P wave indices. In a multivariable model adjusting for cardiovascular risk factors, P wave duration was the only P wave index significantly associated with cardiovascular mortality (hazard ratio [HR] 1.13, per 1 standard deviation [SD], 95% confidence interval [CI] 1.04-1.23; P = .004) and all-cause mortality (HR 1.06 per 1 SD; 95% CI 1.00-1.13; P = .050).

CONCLUSIONS

In a highly representative U.S. sample, P wave duration was significantly associated with increased cardiovascular and all-cause mortality. P wave duration may reflect subclinical disease and merits elucidation as a marker of risk for adverse outcomes.