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Cardiovascular diseases (CVDs) remain a global health concern, and body mass index (BMI) is known to be associated with an increased risk of CVD, but the exact mechanisms underlying this relationship remain unclear. This study employs Mendelian randomization (MR) to investigate the causal association between BMI and electrocardiogram (ECG) indices, providing insights into potential pathways linking obesity to CVD. We conducted a comprehensive MR study utilizing large-scale genetic and ECG data from diverse populations. Instrumental variables were selected from genome-wide association studies, ensuring their relevance to BMI. Causal relationships between BMI and ECG indices, including P wave duration, PR interval, QRS duration, and QT interval, were assessed using various MR methods, with inverse variance weighted (IVW) considered as the primary analysis. Our MR analysis revealed a significant positive causal association between higher BMI and P wave duration (β = 8.078, 95% CI: 5.322 to 10.833, p < 0.001), suggesting a potential mechanism through which higher BMI may contribute to arrhythmogenic risks. However, no significant causal associations were observed between BMI and PR interval, QRS duration, or QT interval (all p > 0.005). In addition, our study also found that there is no horizontal pleiotropy between BMI and P wave duration, PR interval, QRS duration, and QT interval, suggesting that the conclusions of this study are robust. This study supports a causal relationship between elevated BMI and prolonged P wave duration, a marker of increased atrial arrhythmogenic risk. Further investigations are still needed to elucidate the underlying mechanisms. • Investigating the association between body mass index and electrocardiogram indices through a MR study; • Large sample size for body mass index, P wave duration, PR interval, QRS duration and QT interval. • Our analysis revealed a significant positive causal association between higher BMI and P wave duration (β = 8.078, p < 0.001). • No significant causal associations were observed between body mass index and PR interval, QRS duration, or QT interval. [ABSTRACT FROM AUTHOR]

Background: Pulmonary vein isolation (PVI) is an effective management method for paroxysmal atrial fibrillation (PAF). The P wave in the 12-lead electrocardiogram (ECG) represents atrial depolarisation. This study aims to utilise the P wave to predict PVI outcomes for PAF. Methods: This single-centre retrospective study aimed to predict PVI outcomes using P wave parameters. It included 211 consecutive patients with first PVI for PAF between 2018 and 2019 and targeted the pulmonary veins (PVs). Procedure success was defined by freedom of ECG-documented AF at 12 months. Digital 12-lead ECGs with 1–50 hertz bandpass filters were monitored before the procedure. Corrected P wave duration (PWDc), P wave amplitude (PWV), P wave dispersion (PWDisp), intra-atrial block (IAB), P wave area (PWA), and P wave terminal force in V1 (PTFV1) were measured before ablation and correlated with the outcomes. Results: Successful PVI occurred in 154 patients (73%). Demographics were similar between both arms. P wave parameters correlated with PVI failure included increased PWDc in all leads except for lead III, aVR, and V3, decreased PWV in lead I (hazard ratio [HR]: 0.7, 95% confidence interval [CI]: 0.53–0.95), lead II (HR: 0.45, 95% CI: 0.22–0.65), aVL (HR: 0.58, 95% CI: 0.22–0.98), and aVF (HR: 0.67, 95% CI: 0.58–0.87), decreased PWA in lead I (HR: 0.55, 95% CI: 0.21–0.76), lead II (HR: 0.48, 95% CI: 0.34–0.87), aVL (HR: 0.65, 95% CI: 0.45–0.96), and aVF (HR: 0.61, 95% CI: 0.32–0.89), and the presence of IAB (HR: 2, 95% CI: 1.4–4.2, p = 0.02). PWDisp and PTFV1 were not correlated with PVI outcome. Conclusions: PWDc, PWA, PWV, and IAB are valuable predictors for PVI outcome for PAF at 12 months.

Abstract Objective Previous reports on the epidemiology, influencing factors, and the prognostic value of the components of PR interval in hospitalized heart failure patients were limited. Methods This study retrospectively enrolled 1182 patients hospitalized with heart failure from 2014 to 2017. Multiple linear regression analysis was used to explore the association between the components of PR interval and the baseline parameters. The primary outcome was all-cause death or heart transplantation. Multivariable-adjusted Cox proportional hazard regression models were constructed to explore the predictive value of the components of PR interval for the primary outcome. Results In multiple linear regression analysis, higher height (for every 10 cm increase in height: regression coefficient 4.83, P

Objective: Previous reports on the epidemiology, influencing factors, and the prognostic value of the components of PR interval in hospitalized heart failure patients were limited. Methods: This study retrospectively enrolled 1182 patients hospitalized with heart failure from 2014 to 2017. Multiple linear regression analysis was used to explore the association between the components of PR interval and the baseline parameters. The primary outcome was all-cause death or heart transplantation. Multivariable-adjusted Cox proportional hazard regression models were constructed to explore the predictive value of the components of PR interval for the primary outcome. Results: In multiple linear regression analysis, higher height (for every 10 cm increase in height: regression coefficient 4.83, P < 0.001) as well as larger atrial and ventricular size were associated with larger P wave duration but not with PR segment. The primary outcome occurred in 310 patients after an average follow-up of 2.39 years. Cox regression analyses revealed that the increase in PR segment was an independent predictor of the primary outcome (every 10 ms increase: hazard ratio 1.041, 95% confidence interval [CI] 1.010–1.083, P = 0.023), whereas the P wave duration did not show significant correlation. When adding the PR segment to an initial prognostic prediction model, the likelihood ratio test and categorical net reclassification index (NRI) showed a significant improvement, but the increase in C-index was not significant. In subgroup analysis, increased PR segment was an independent predictor of the primary endpoint in patients taller than 170 cm (each 10 ms increase: hazard ratio 1.153, 95% CI 1.085–1.225, P < 0.001) but not the shorter group (P for interaction = 0.006). Conclusions: In hospitalized patients with heart failure, longer PR segment was an independent predictor of the composite endpoint of all-cause death and heart transplantation, especially in the taller group, but it had limited significance in improving the prognostic risk stratification of this population. [ABSTRACT FROM AUTHOR]

The electrophysiological activity of the heart is recorded and presented in form of electrocardiogram (ECG). In 1998 the concept of P wave dispersion as the risk factor for atrial fibrillation (AF) recurrence was introduced. It was calculated as the difference between the longest and the shortest P wave. The aim of our study is to prove that the P wave dispersion is an artifact of low accuracy in P wave measurement. The study included 186 patients (78M 108F) aged 59.7 ± 12.9 years, undergoing various electrophysiological procedures. The P wave was measured twice: first, at the paper speed of 50 mm/s, enhancement 8× (standard – imprecise) and the second time at 200 mm/s, 64–256× (precise). The imprecise measurement method resulted in different duration of all P wave parameters in comparison with precise measurement. The difference between Δ P max and Δ P min indicated a higher value for the latter parameter. It was indicated that the imprecise P wave dispersion value correlated most significantly with the maximal P wave duration, which was measured in a similar way. In contrast with the imprecise measurement method, the minimal and maximal durations of the P waves, being measured accurately, were almost identical. Using precise methodology, the P wave dispersion reaches negligible values and tends to zero. The measurements of the P wave have to be precise to assure the highest scientific and medical sincerity. The highest clinical value is related to the P wave duration.

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Background: Pulmonary vein isolation (PVI) is an effective management method for paroxysmal atrial fibrillation (PAF). The P wave in the 12-lead electrocardiogram (ECG) represents atrial depolarisation. This study aims to utilise the P wave to predict PVI outcomes for PAF., Methods: This single-centre retrospective study aimed to predict PVI outcomes using P wave parameters. It included 211 consecutive patients with first PVI for PAF between 2018 and 2019 and targeted the pulmonary veins (PVs). Procedure success was defined by freedom of ECG-documented AF at 12 months. Digital 12-lead ECGs with 1-50 hertz bandpass filters were monitored before the procedure. Corrected P wave duration (PWDc), P wave amplitude (PWV), P wave dispersion (PWDisp), intra-atrial block (IAB), P wave area (PWA), and P wave terminal force in V1 (PTFV1) were measured before ablation and correlated with the outcomes., Results: Successful PVI occurred in 154 patients (73%). Demographics were similar between both arms. P wave parameters correlated with PVI failure included increased PWDc in all leads except for lead III, aVR, and V3, decreased PWV in lead I (hazard ratio [HR]: 0.7, 95% confidence interval [CI]: 0.53-0.95), lead II (HR: 0.45, 95% CI: 0.22-0.65), aVL (HR: 0.58, 95% CI: 0.22-0.98), and aVF (HR: 0.67, 95% CI: 0.58-0.87), decreased PWA in lead I (HR: 0.55, 95% CI: 0.21-0.76), lead II (HR: 0.48, 95% CI: 0.34-0.87), aVL (HR: 0.65, 95% CI: 0.45-0.96), and aVF (HR: 0.61, 95% CI: 0.32-0.89), and the presence of IAB (HR: 2, 95% CI: 1.4-4.2, p = 0.02). PWDisp and PTFV1 were not correlated with PVI outcome., Conclusions: PWDc, PWA, PWV, and IAB are valuable predictors for PVI outcome for PAF at 12 months.

In the present study, we aimed to explore the association between P wave duration, as the measured time from the start point of the P wave to the end point, and atrial fibrillation recurrence after transcatheter radiofrequency ablation in patients with early persistent atrial fibrillation. Patients with early persistent atrial fibrillation who underwent the first radiofrequency ablation procedure were retrospectively analyzed. The electrocardiographic, echocardiographic and clinical data of the enrolled patients before and after operation were collected and recorded. After adjusting confounding factors and performing stratified analysis, the association between the P wave duration and the atrial fibrillation recurrence of patients with early persistent atrial fibrillation after radiofrequency ablation was explored. The proportions of atrial fibrillation recurrence of the low, medium, and high P wave duration groups were 6.4%, 19.7%, and 47.0%, respectively. After potential confounding factors were adjusted, the risk of atrial fibrillation recurrence gradually increased with the increase of P wave duration (odds ratio: 1.093, 95% confidence interval: 1.063–1.124, p < 0.001). This trend was statistically significant (odds ratio: 1.099, 95% confidence interval: 1.052–1.149, p < 0.001), especially in comparison of high vs. low (odds ratio: 16.99, 95% confidence interval: 4.75–60.78, p < 0.001). Curve fitting showed that there was a linear and positive association between the P wave duration and the risk of atrial fibrillation recurrence. This association was consistent in different subgroups based on gender, drinking, history of smoking, hypertension, diabetes mellitus, peripheral artery disease, stroke or transient ischemia attack, hyperlipidemia, heart failure, and heart rate, suggesting that there was no significant interaction between different grouping parameters and the association (p for interaction range = 0.217–0.965). In patients with early persistent atrial fibrillation who underwent radiofrequency ablation procedure for the first time and converted to sinus rhythm, the P wave duration within 72 h after the procedure was independently associated with the risk of atrial fibrillation recurrence, and such association was linear and positive. • Prolonged P wave duration (PWD) is known to be associated with delayed intra-atrial and inter-atrial conduction. • PWD was the time manually measured from the onset to the offset of the P wave and its accuracy was set to 1 ms. • An approximately linear and positive association between the PWD and the recurrence of atrial fibrillation has been found. [ABSTRACT FROM AUTHOR]

The electrophysiological activity of the heart is recorded and presented in form of electrocardiogram (ECG). In 1998 the concept of P wave dispersion as the risk factor for atrial fibrillation (AF) recurrence was introduced. It was calculated as the difference between the longest and the shortest P wave. The aim of our study is to prove that the P wave dispersion is an artifact of low accuracy in P wave measurement. The study included 186 patients (78M 108F) aged 59.7 ± 12.9 years, undergoing various electrophysiological procedures. The P wave was measured twice: first, at the paper speed of 50 mm/s, enhancement 8× (standard - imprecise) and the second time at 200 mm/s, 64-256× (precise). The imprecise measurement method resulted in different duration of all P wave parameters in comparison with precise measurement. The difference between Δ P max and Δ P min indicated a higher value for the latter parameter. It was indicated that the imprecise P wave dispersion value correlated most significantly with the maximal P wave duration, which was measured in a similar way. In contrast with the imprecise measurement method, the minimal and maximal durations of the P waves, being measured accurately, were almost identical. Using precise methodology, the P wave dispersion reaches negligible values and tends to zero. The measurements of the P wave have to be precise to assure the highest scientific and medical sincerity. The highest clinical value is related to the P wave duration. [ABSTRACT FROM AUTHOR]

Background: It remains unknown whether P wave duration (PWD) ≥ 150 ms measured after extensive radiofrequency catheter ablation (RFCA) can identify non-paroxysmal atrial fibrillation (non-PAF) patients at increased risk of atrial tachyarrhythmia recurrence. We investigated the predicting power of PWD and its association with left atrial (LA) reverse remodeling in patients with non-PAF undergoing pulmonary vein isolation with LA linear ablation.Methods: We retrospectively evaluated 136 patients who underwent RFCA for drug-refractory non-PAF. Electroanatomic mapping was acquired during AF. Low-voltage area (LVA) was defined as an area with bipolar voltage ≤0.5 mV. Electrocardiography and echocardiography were performed during sinus rhythm 1 day and 3 months after RFCA. PWD was measured using amplified 12‑lead electrocardiography. Prolonged PWD was defined as maximum PWD ≥ 150 ms.Results: Over a mean follow-up duration of 48 ± 35 months, 28 patients experienced atrial tachyarrhythmia recurrence. PWD was positively correlated with LVA (r = 0.527, p < 0.001) and inversely correlated with LA emptying fraction (r = -0.399, p < 0.001). PWD was shortened and LA emptying fraction (LAEF) was increased in patients without atrial tachyarrhythmia recurrence during follow-up. Atrial tachyarrhythmia-free survival was significantly more likely in patients without a prolonged PWD (83.5% vs 60.7%, p = 0.002). Multivariate analysis showed that LAEF and PWD were independent predictors of atrial tachyarrhythmia recurrence.Conclusions: PWD ≥ 150 ms measured after RFCA can identify patients with non-PAF at increased risk of atrial tachyarrhythmia recurrence. PWD is correlated with LVA and LAEF and reflects LA reverse remodeling. [ABSTRACT FROM AUTHOR]

Introduction: P wave duration and dispersion are noninvasive markers for the prediction of atrial fibrillation risk in patients treated with hemodialysis. Objective: To determine P wave variations and dispersion in patients with stage 5 chronic kidney disease treated with periodic hemodialysis. Method: A longitudinal, observational, prospective study was carried out from October 2016 to April 2018. Results: Seventy-one patients (47 males) were included, averaging 56 years of age; P wave duration at the beginning of hemodialysis was 75.91 milliseconds and at the end was 81.2; p<0.001. Maximum P wave increased from 95.25 to 101.16 milliseconds; p<0.001. P wave dispersion did not show significant changes. In patients with more than one-year arteriovenous fistula, P wave dispersion increased from 35 milliseconds to 43.6 at the end of hemodialysis, with no significant differences. Increases in maximum P wave duration were significant regardless of smaller or larger left atrial size. P wave dispersion did not show significant differences when compared with left atrial size. Thrombolysis percentage in Group II was higher than 50% in most of the centers. Conclusions: P wave dispersion did not show significant changes during hemodialysis as has been observed in different international studies. Average/maximum P wave duration show significant increases that are probably the expression of changes in the heterogeneity of atrial conduction in the sample studied. [ABSTRACT FROM AUTHOR]

We present the electrocardiographic findings in a 36-year-old female with tricuspid atresia with double-outlet right ventricle and malposition of great arteries who underwent classical or "atriopulmonary" Fontan procedure in childhood. Her electrocardiograms have consistently shown marked intra-atrial delay with an initial positive P wave deflection and terminal negative P deflection in all leads with progressive increase in P wave duration with time. She has had frequent episodes of intra-atrial tachycardia, atrial fibrillation and sinus and post ectopic pauses over the past few years. The findings in our patient, which have not been reported before, illustrate the atrial pathology, which is unique to Fontan physiology, particularly those with classical or atriopulmonary Fontan. We hope that the specific electrocardiographic findings presented will allow for their recognition. [ABSTRACT FROM AUTHOR]

Background. The electrophysiological activity of the heart is recorded and presented in form of electrocardiography (ECG). In 1998, the concept of P wave dispersion as the risk factor for atrial fibrillation (AF) recurrence was introduced. It was calculated as the difference between the longest and the shortest P wave. Objectives. To prove that the P wave dispersion is an artifact of low accuracy in P wave measurement. Material and methods. The study included 104 patients (48 women, 56 men), aged 63 ±14 years, undergoing various electrophysiological procedures. The P wave was measured twice - firstly at the paper speed of 50 mm/s, enhancement x8 (standard - imprecise), and secondly at 200 mm/s, x64-256 (precise). Results. The imprecise measurement method resulted in different duration of all P wave parameters in comparison with precise measurement. The longest P wave duration (Pmax) measured imprecisely was 105.1 ±22.1, the Pmax measured precisely was 134.0 ±21.3 (p < 0.001). The P dispersion measured imprecisely was 44.1 ±16.8 and the P dispersion measured precisely was 2.8 ±3.4 (p < 0.0001). The correlation between imprecise Pmax and imprecise Pmin was r = 0.664 (p < 0.05). The correlation between imprecise Pmax and imprecise P wave dispersion was r = 0.612 (p < 0.05). The correlation between precise Pmax and Pmin was almost 1.0 (r = 0.987, p < 0.05). Conclusions. The P wave dispersion does not exist. The measurements of the P wave have to be precise to assure the highest scientific and medical sincerity. The highest clinical value is related to the P wave duration. [ABSTRACT FROM AUTHOR]

Background: Since low voltage area (LVA) impairs not only intra atrial conduction velocity but also intra atrial propagate direction, these alternates may reflect the P wave duration (PWD) and morphology. We examined the relationship between the PWD, morphology and LVA.Methods: Consecutive 127 AF patients were divided into 2 groups depending on the presence of LVA (35 subjects LVA positive group, 92 subjects LVA negative group). P wave morphologies were divided into 3 categories, normal: P-wave duration<120 ms, partial interatrial block (IAB): P wave duration≥120 ms, advanced IAB: PWD ≥ 120 ms with biphasic P waves in inferior leads. LVA was defined as a voltage amplitude<0.5 mV, and qualitatively assessed to be categorized into three grades (mild<10%, 10% ≤ moderate<30%, 30% ≤ extensive).Results: LVA was significantly highly detected in patients of advanced age, female, comorbidities of hypertension, prior brain infarction, LA enlargement. PWD was correlated with LA volume in the LVA negative group, but not in the LVA positive group. Advanced IAB was significantly accumulated in the LVA positive group while partial IAB was found in both LVA positive and negative groups. Receiver-operating characteristics curve revealed that a combination of IAB and biphasic P wave in any inferior lead identified the presence of LVA with 83% sensitivity and 98% specificity. PWD and the presence of advanced IAB were independent predictors of LVA as determined by multivariate logistic regression analysis.Conclusion: Advanced IAB is a favorable parameter for the presence of LVA. [ABSTRACT FROM AUTHOR]

Background. Functional and structural changes in the atrial muscle constitute a substrate for atrial fibrillation (AF). The pathological changes in the left atrium decrease the conduction velocity and result in prolongation of the P wave duration. Objectives. To assess the duration of the P wave in patients with AF in different clinical presentations of arrhythmia. Material and methods. The study group consisted of 119 patients diagnosed with AF: 57 women and 62 men, aged 65.3 ±9.4 years. There were 65 patients with paroxysmal AF and 54 with persistent AF. In this group, electrical cardioversion was performed. The P wave duration was measured using an electrophysiological system in all leads at a paper speed of 200 mm/s. Results. The patients did not differ in terms of age, gender or comorbidities. The patients with persistent AF had longer P wave duration (159.9 ±22.3 ms compared to 144.6 ±17.2 ms; p < 0.001) and higher glucose concentration (119.4 ±33.4 mg/dL compared to 108.0 ±24.6 mg/dL; p = 0.015). These results were not influenced by the anti-arrhythmic treatment. Conclusions. Persistent AF shows a longer P wave duration than the paroxysmal AF, independent of age, gender and anti-arrhythmic medication. The prolongation of the P wave related to persistent arrhythmia should force physicians to restore the sinus rhythm earlier in order to more successfully maintain it in the long term. [ABSTRACT FROM AUTHOR]

Introduction: Although some studies relate P wave parameters to different atrial conduction times, they do not consider each electrocardiogram lead separately. Objectives: To determine the duration of P wave (Pdur) in the 12 leads of the electrocardiogram and relate it to the interatrial conduction time. Methods: We conducted a cross-sectional study in 153 adult patients with confirmed diagnosis of atrioventricular nodal reentry tachycardia (AVNRT) or accessory pathways by invasive electrophysiological study. Results: When comparing the Pdur between arrhythmic substrates by each lead, no significant differences were found, except for V6. In leads II, III, aVR, aVF, V1 and V3-V6, Pdur was correlated with the interatrial conduction time in both arrhythmic substrates. In our multivariate analysis, the Pdur was an independent predictor of interatrial conduction times ≥ 95 percentile in inferior wall leads and in V3, V5 and V6. High values of the area under the receiver operating characteristic curve were observed in II (0.950; p<0.001), III (0.850; p<0.001) and V5 (0.891; p<0.001) leads. Conclusions: The Pdur showed no difference by leads when comparing cases with AVNRT and accessory pathways, except for V6. Most of the leads were correlated with the interatrial conduction time; Pdur was an independent predictor of interatrial conduction times ≥ 95 percentile. Lead II has the greatest discriminatory ability to find prolonged values of interatrial conduction time. [ABSTRACT FROM AUTHOR]

Background: Functional and structural atrial changes contribute to AF. It decreases conduction velocity and forms intra atrial blocks. In the ECG those changes are manifested by the duration and morphology of the P wave. Material and methods: The study group consisted of 50 patients with atrial fibrillation. There were 27 women and 23 men, aged 65.3 +/- 9.8 years. 22 patients had paroxysmal AF and 28 had persistent AF, in the latter direct current cardio version was performed. Results: In patients with a prolonged episodes of atrial fibrillation the P wave duration was longer in comparison to patients with sinus rhythm (187.1 +/- 31.5 vs 161.1 +/- 18.8 ms; p = 0.006). There were significant differences in P wave duration among the patients with normal and abnormal interatrial conduction, with the longest duration in complete Bachmann's bundle block group (152.7 +/- 17.5 vs 165.3 +/- 15.3 vs 207.9 +/- 27.5 ms; p < 0.001). Conclusions: In patients with persistent atrial fibrillation the duration of the P wave is prolonged in comparison to paroxysmal. In the majority of patients prolongation of the P wave duration is dependent on different forms of conduction block. The morphological changes of P waves are caused by the arrhythmia rather than left atrial hypertrophy. [ABSTRACT FROM AUTHOR]

Atrial fibrillation (AF) is associated with an increased risk of ischemic stroke, heart failure, cognitive decline, dementia, myocardial infarction, sudden cardiac death (SCD), and all-cause death. Although these associations are firmly established, our understanding of the underlying mechanisms remains incomplete. Accumulating evidence suggests that left atrial (LA) abnormality or atrial cardiomyopathy may explain the relationship of AF to the aforementioned outcomes. P-wave indices (PWIs) reflect underlying atrial remodeling. In this mini review, we define representative PWIs, discuss state-of-the-art knowledge on the relationship between abnormal PWIs and AF-related cardiovascular outcomes (focusing on ischemic stroke and sudden cardiac death), and propose directions for future research. Our ultimate goal is to present a practical way forward to advance the emerging field of LA abnormality or atrial cardiomyopathy.

Background: We evaluated the association of P wave duration (PWD) with left atrial scar (LAS) in patients with paroxysmal atrial fibrillation (PAF). Methods: Consecutive patients with PAF undergoing their first catheter ablation were screened and only those in sinus rhythm at baseline were included in the analysis. A standard 12‐lead electrocardiogram (ECG) was performed in all and three‐dimensional voltage mapping of the left atrium was generated for identification of low‐voltage areas (≤0.2 mV) before the procedure. Results: In total, 411 patients with PAF were included in this study of which 181 had LASs (scar group), while 230 had no scar (nonscar group). In the scar group, patients were older (65.5 ± 8.8 vs 59.7 ± 11.7 years; P < .001), the proportion of female was higher (47.5% vs 37.4%; P = .04) and left atrial (LA) diameter (4.1 ± 0.6 vs 3.9 ± 0.6 cm; P < .001) was larger compared with the nonscar group. There was no significant difference in terms of hypertension, sleep apnea, and diabetes between the two groups. When comparing ECG characteristics between the two groups, PWD was significantly longer in the scar group (122.9 ± 18.5 and 116.9 ± 28.0 ms; P = .01). A multivariate analysis was performed, after adjustment of age, sex, LA diameter, PWD ≥ 120 ms was found to be an independent predictor of LA scarring (OR: 1.69, p‐value: 0.02). Conclusion: In the current series, prolonged PWD was found to be independently associated with LA scarring in PAF, even after adjustment for age, sex, and LA diameter. [ABSTRACT FROM AUTHOR]

Convergent atrial fibrillation ablation involves extensive epicardial as well as endocardial ablation of the left atrium. We examined whether it changes the morphology of the surface P wave. We reviewed electrocardiograms of 29 patients who underwent convergent ablation for atrial fibrillation. In leads V1, II and III, we measured P wave duration, area and amplitude before ablation, and at 1, 3 and 6 months from ablation. After ablation, there were no significant changes in P wave amplitude, area, or duration in leads II and III. There was a significant reduction in the area of the terminal negative deflection of the P wave in V1 from 0.38 mm2 to 0.13 mm2 (p = 0.03). There is also an acute increase in the amplitude and duration of the positive component of the P wave in V1 followed by a reduction in both by 6 months. Before ablation, 62.5% of the patients had biphasic P waves in V1. In 6 months, only 39.2% of them had biphasic P waves. Hybrid ablation causes a reduction of the terminal negative deflection of the P wave in V1 as well as temporal changes in the duration and amplitude of the positive component of the P wave in V1. This likely reflects the reduced electrical contribution of the posterior left atrium after ablation as well as anatomical and autonomic remodeling. Recognition of this altered sinus P wave morphology is useful in the diagnosis of atrial arrhythmias in this patient population.

Introduction: P-wave duration (PWD) is an electrocardiographic (ECG) marker reflecting atrial conduction, and studies have shown that its prolongation is associated with atrial fibrillation. Areas covered: This review addresses the relationship between PWD and atrial fibrillation, how anatomic and physiologic changes in the atria potentiate the risk for atrial fibrillation, and how these atrial anatomic and physiologic changes relate to PWD. Other P-wave related entities, such as P-wave terminal force in V1, PR interval, and P wave axis are also addressed. Expert commentary: Atrial fibrillation is a manifestation of the underlying atrial disease. Fibrotic collagen deposition interrupts the electrical flow and thus can potentiate the transition from sinus rhythm to atrial fibrillation. PWD is an ECG parameter that provides insight into the intricacies of the atria and could be a useful marker for assessing the risk for atrial fibrillation. The main obstacle for broad utilization of PWD is that it is not routinely reported on the printout of the electrocardiogram. [ABSTRACT FROM AUTHOR]

Background: The relationship of epicardial fat and cardiac arrhythmias has been described in many studies. The association of the amounts of epicardial fat and the characteristics of electrocardiogram (ECG) remains unclear. The purpose of this study was to elucidate the association between the amounts of epicardial fat and the characteristics of ECG.Methods: A total of 100 consecutive patients who received multi-detector computer tomography (MDCT) were enrolled. The amounts of epicardial fat, including total heart, total atria, total ventricles, right atrium (RA), right ventricle (RV), left atrium (LA), and left ventricle (LV) regions, were measured. The PR interval in lead II, the P wave duration in lead I, the characteristics of inter-atrial conduction block manifested in ECG, the corrected QT interval (QTc) and the QT dispersion of a 12‑lead ECG were measured manually by a computer caliper.Results: The PR interval was correlated with the amounts of epicardial fat including total heart, total atria, total ventricles, RA, RV, LA, and LV (R = 0.295, p = 0.003; R = 0.379, p < 0.001; R = 0.284, p = 0.003; R = 0.415, p < 0.001; R = 0.287, p < 0.001; R = 0.33, p < 0.001; R = 0.244, p = 0.014). The P wave duration of lead I was also correlated with the amounts of epicardial fat (R = 0.202, p = 0.043; R = 0.283, p = 0.004; R = 0.225, p = 0.024; R = 0.365, p < 0.001; R = 0.256, p = 0.001; R = 0.20, p = 0.046; R = 0.199, p = 0.048) but the QTc interval and the QT dispersion were not. Inter-atrial conduction block was also associated with the amounts of epicardial fat, including total atria, RA and LA in univariate analysis (odds ratio (OR): 1.04, 95% of confidence interval (CI): 1.01-1.06, p = 0.015; OR: 1.08, 95% CI: 1.02-1.15, p = 0.011; OR: 1.05, 95% CI: 1.01-1.10, p = 0.031). In multivariate analysis of linear regression, the amounts of RA epicardial fat was most significantly associated with the PR interval, and the P wave duration (β value: 1.30, 95% CI: 0.59-2.02, p < 0.001; β value: 0.81, 95% CI: 0.34-1.28, p = 0.001). In multivariate analysis of logistic regression, inter-atrial conduction block was also significantly associated with the amounts of RA epicardial fat (odds ratio (OR): 1.08, 95% CI: 1.02-1.15, p = 0.011).Conclusions: The PR interval, P wave duration and inter-atrial conduction block were associated with the amounts of epicardial fat, which might imply an effect for arrhythmogenesis. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Aortic regurgitation, conduction disturbances, increased myocardial fibrosis and pericarditis could be seen in ankylosing spondylitis (AS). However, less attention has been paid to supraventricular arrhythmias (SVA) and atrial conduction system changes. We aimed to assess SVA and conduction system changes in patients with AS. PATIENTS AND METHODS: Twenty-eight patients (24 men; mean age, 28.7 ± 5.7 years) with AS and 30 healthy volunteers (26 men; mean age, 29.3 ± 5.8 years) were enrolled. All subjects were evaluated by 24-hour ambulatory electrocardiogram, 12 lead standard electrocardiogram (ECG) for P wave dispersion (Pd), and signal-averaged ECG (SAECG) for P wave duration (SAPWD). RESULTS: SVAs were detected in 9 patients with AS (32%) and 3 controls (10%; p = 0.02). Mean SAPWD (115.7 ± 28.6 ms vs. 100.2 ± 18.7 ms, p = 0.017) and mean Pd (11.9 ± 4.8 ms vs. 9.3±3.6 ms, 0.023) was longer in patients with AS than the control group. When patient with AS were divided into 2 subgroups as patients with or without SVA, the Pd (16.2 ± 5.0 vs. 9.9 ± 3.2, p = 0.001), SAPWD (151.4 ± 7.8 vs. 98.7 ± 16.1, p = 0.001) and Bath ankylosing spondylitis disease activity index (BASDAI) (5.1 ± 1.6 vs. 3.7 ± 1.0, p = 0.014) were significantly greater in the subgroup with arrhythmias compared to the subgroup without arrhythmias. There was a strong positive correlation between BASDAI and SAPWD (r = 0.622, p = 0.001). There was also a moderate positive correlation between BASDAI and Pd (r = 0.479, p = 0.01). CONCLUSIONS: SVA were detected more frequently in AS than control group. SAPWD and Pd were prolonged in patients with AS. Clinical severity assessed with BASDAI had a positive correlation with prolongation of SAPWD and Pd. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Myotonic dystrophy type 1 (MD1) is characterized by cardiac involvement, in about 80% of case, that predominantly affects the conduction system. Aim of our study was to evaluate the P-wave duration and dispersion (PD) in MD1 patients underwent pacemaker implantation with conserved systolic and diastolic function. PATIENTS AND METHODS: We enrolled 60 MD1 patients (age 51.3 ± 5 years; 11 females) underwent dual chamber pacemaker implantation for various grade of atrioventricular (AV) block. Sixty sex-and age matched non-MD1 subjects were recruited as controls. P-wave duration and dispersion were carefully measured using 12-lead electrocardiogram. RESULTS: Compared with healthy control group, MD1 patients presented increased maximum P wave duration (106.4 ± 20.9 vs 65.9 ± 8.2 ms, p = 0.03) and PD values (40.1 ± 11 vs 27.1 ± 4.2 ms, p = 0.003). No statistically significant difference was found in minimum P wave duration (69.7 ± 11.8 vs 65.4 ± 8.1 ms, p = 0.4). The MD1 patients with paroxysmal atrial fibrillation, compared with MD1 patients without evidence of atrial fibrillation, presented increased maximum P wave duration (108.1 ± 10.4 vs 78.1 ± 7.9 ms, p = 0.001) and PD values (41.1 ± 8.5 vs 33.2 ± 4.2 ms, p = 0.003). Minimum P wave duration (68.4 ± 8.2 vs 67.1 ± 4.9 ms, p = 0.5) didn't differ between the two groups. CONCLUSIONS: Our data showed a significantly increased P wave duration and dispersion in MD1 patients compared with age and sex-matched healthy controls. We showed a statistically significant increase in PD and P max in MD1 patients subgroup with AF compared to MD1 patients with no arrhythmias. [ABSTRACT FROM AUTHOR]

Aim: Hybrid procedure (HP) involves epicardial isolation of pulmonary vein and posterior wall of left atrium, and endocardial checking of lesions and touchups (if needed). We aimed at observing the effect of hybrid procedure on P wave duration (PWD), calculated automatically from surface ECG leads at start and end of HP, and also for relationship to atrial fibrillation (AF) recurrence at 9 months. Methods: Forty-one patients (32 male; mean age, 58.4 ± 9.5 years) underwent HP, as first ever ablation. A new automated method was used for P wave segmentation and PWD estimation from recognizable P waves in ECG lead I or II before and after HP, based on fitting of each P wave by means of two Gaussian functions. Results: Overall, PWD was significantly decreased after procedure (104.4 ± 25.1 ms vs. 84.7 ± 23.8 ms, p = 0.0151), especially in persistent AF patients (122.4 ± 32.2 ms vs. 85.6 ± 24.5 ms, p = 0.02). PWD preprocedure was significantly higher in persistent than in paroxysmal patients (122.4 ± 32.2 ms vs. 92.5 ± 17.9 ms, p = 0.0383). PWD was significantly decreased after procedure in prior electrical cardioverted patients (106.7 ± 30.5 ms vs. 84.7 ± 23.1 ms, p = 0.0353). After 9-month follow-up of 40 patients, HP-induced PWD decrease was significant for the 12 persistent patients without recurrence (122.4.1 ± 35.3 ms vs. 85.6 ± 22.0 ms, p = 0.0210). Conclusion: Preprocedure PWD was higher for persistent than paroxysmal patients. HP reduced PWD significantly. Nine-month follow-up suggests that HP is successful in restoring and maintaining sinus rhythm. To individualize AF therapy, AF type-based selection of patients may be possible before procedure. Automated analysis of PWD from surface ECG is possible. [ABSTRACT FROM AUTHOR]

Background Prolonged P wave duration is a marker of delayed inter-atrial conduction which may predict cardiovascular disease (CVD). Type 2 diabetes is a risk factor for all atherosclerotic manifestations including stroke. We evaluated the prognostic significance of prolonged P wave duration among middle-aged Finnish type 2 diabetes patients with and without prevalent non-major macrovascular disease (PNMMVD) with respect to total and stroke mortality. Methods We followed up for 18 years 739 type 2 diabetic patients without previous major CVD event at baseline. Participants were stratified according to P wave duration (<114 or ⩾114 ms) and PNMMVD (i.e. coronary heart disease defined as ischaemic ECG changes and typical symptoms of angina pectoris, or claudication; yes or no). The Cox proportional hazards model was used to estimate the joint association between P wave duration, PNMMVD and the mortality risk. Results During the follow-up, 509 patients died, and 59 of them died from stroke. Those who had prolonged P wave duration had 2.45 (95% confidence interval: 1.11-5.37) increased stroke mortality among PNMMVD patients. In patients without PNMMVD, there was no relationship between P wave duration and stroke mortality. Conclusions As an easily measurable factor P wave duration merits further studies with higher number of patients to evaluate its importance in the estimation of stroke risk in type 2 diabetic patients with PNMMVD. [ABSTRACT FROM AUTHOR]