Association Between P-Wave Duration, Dispersion, and Interatrial Block and Atrial High-Rate Episodes in CIED Patients.

INTRODUCTION: Atrial high-rate episodes (AHRE) have been linked to increased thromboembolic risk and all-cause mortality in patients with cardiac implantable electronic devices (CIEDs). Various predictors of AHRE development have been identified, emphasizing the need for close monitoring and the potential transition to clinical atrial fibrillation (AF). However, the predictive value of P wave characteristics on AHRE development remains conflicting. This meta-analysis aims to summarize existing data to investigate this association. METHOD: We examined studies from MEDLINE and EMBASE databases up to May 2024 to investigate the association of baseline P-wave duration (PWD), P-wave dispersion (PWDIS), and interatrial block (IAB) with the risk of developing AHRE. We extracted the mean and standard deviations of PWD and PWDIS to calculate the pooled mean difference (MD). Risk ratios (RR) and 95% confidence intervals (CIs) were used to assess the association between IAB and AHRE risk, using the generic inverse variance method for combination. RESULTS: The meta-analysis included nine studies. Patients with AHRE had longer PWD and PWDIS compared to those without AHRE, with a pooled MD for PWD of 9.17 ms (95% CI: 4.74-13.60; I2 = 47%, p < 0.001) and a pooled MD for PWDIS of 20.56 ms (95% CI: 11.57-29.56; I2 = 57%, p < 0.001). Additionally, patients with IAB had a higher risk of developing AHRE, with a pooled RR of 3.33 (95% CI: 2.53-4.38; I2 = 0%, p < 0.001), compared to those without IAB. CONCLUSIONS: Our meta-analysis found that patients with AHRE had higher PWD and PWDIS than those without AHRE. Additionally, IAB was associated with a higher risk of developing AHRE. These findings emphasize the importance of close monitoring and risk stratification, particularly for patients with P wave abnormalities.

Morbid obesity influences the nocturnal electrocardiogram wave and interval durations among suspected sleep apnea patients.

BACKGROUND: Obesity is a global issue with a major impact on cardiovascular health. This study explores how obesity influences nocturnal cardiac electrophysiology in suspected obstructive sleep apnea (OSA) patients. METHODS: We randomly selected 12 patients from each of the five World Health Organization body mass index (BMI) classifications groups (ntotal = 60) while keeping the group's age and sex matched. We evaluated 1965 nocturnal electrocardiography (ECG) samples (10 s) using modified lead II recorded during normal saturation conditions. R-wave peaks were detected and confirmed using dedicated software, with the exclusion of ventricular extrasystoles and artifacts. The duration of waves and intervals was manually marked. The average electric potential graphs were computed for each segment. Thresholds for abnormal ECG waveforms were P-wave > 120 ms, PQ interval > 200 ms, QRS complex > 120 ms for, and QTc > 440 ms. RESULTS: Obesity was significantly (p < .05) associated with prolonged conduction times. Compared to the normal weight (18.5 ≤ BMI < 25) group, the morbidly obese patients (BMI ≥ 40) had a significantly longer P-wave duration (101.7 vs. 117.2 ms), PQ interval (175.8 vs. 198.0 ms), QRS interval (89.9 vs. 97.7 ms), and QTc interval (402.8 vs. 421.2 ms). We further examined ECG waveform prolongations related to BMI. Compared to other patient groups, the morbidly obese patients had the highest number of ECG segments with PQ interval (44% of the ECG samples), QRS duration (14%), and QTc duration (20%) above the normal limits. CONCLUSIONS: Morbid obesity predisposes patients to prolongation of cardiac conduction times. This might increase the risk of arrhythmias, stroke, and even sudden cardiac death.

Association between body mass index and electrocardiogram indices: A Mendelian randomization study.

INTRODUCTION: 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. METHODS: 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. RESULTS: Our MR analysis revealed a significant positive causal association between higher BMI and P wave duration (ß = 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. CONCLUSION: 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.

Prognostic significance of ratio of P-wave duration to P-wave vector magnitude for mortality in acute anterior myocardial infarction.

BACKGROUND: The impact of P-wave abnormality in acute anterior MI, where the culprit vessel is the left anterior descending artery, remains undetermined. This study aimed to elucidate the impact of P-wave morphology on clinical outcomes in acute anterior MI. METHODS: Patients undergoing emergent percutaneous coronary intervention for acute anterior MI were enrolled between September 2014 and April 2019 (derivation cohort) and May 2019 through July 2023 (validation cohort). P-wave duration (Pd) and P-wave vector magnitude (Pvm) were measured. The Pvm was calculated as the square root of the sum of the squared P-wave magnitudes in leads II and V6 and one-half of the P-wave amplitude in V2. The patients were categorized into high and low Pd/Pvm groups using a statistically derived cut-off value. The endpoint comprised the composite of heart failure (HF) hospitalization and all-cause death. RESULTS: Consecutive 426 patients were enrolled in this study (derivation cohort, 213 patients; validation cohort, 216 patients). The calculated cut-off value of Pd/Pvm for predicting the clinical endpoint, determined through receiver operating curve analysis, was 793.5 ms/mV (area under the curve [AUC] = 0.85, sensitivity of 73.8 %, and specificity of 94.0 %) in the derivation cohort. Kaplan-Meier analyses revealed a significantly higher risk of the endpoint in patients with high Pd/Pvm than those with low Pd/Pvm in derivation and validation cohorts (Log-rank p < 0.001 and p < 0.001, respectively). Multivariate Cox proportional hazards analysis identified advanced age, elevated Pd/Pvm, and reduced left ventricular ejection fraction as independent and significant factors associated with the endpoint in the validation cohort (p = 0.008, p < 0.001, and p < 0.001, respectively). CONCLUSION: High Pd/Pvm was significantly associated with the composite of HF hospitalization and all-cause death after acute anterior MI.

Left atrial epicardial adipose tissue exacerbates electrical conduction disturbance in normal-weight patients undergoing pulmonary vein isolation for atrial fibrillation.

INTRODUCTION: Epicardial adipose tissue (EAT) exacerbates both electrical and structural remodeling in obese atrial fibrillation (AF) patients, but the impacts of EAT on atrial arrhythmogenicity remain unclear in normal-weight AF patients. Therefore, we sought to investigate this issue using electroanatomic mapping. METHODS AND RESULTS: We enrolled drug-refractory 105 paroxysmal AF patients in the normal body mass index range (18.5-24.9 kg/m2 ), who had undergone electroanatomic mapping after pulmonary vein isolation (PVI). One day before PVI, we assessed P-wave duration in a 12-lead electrocardiogram and left atrial (LA)-EAT volumes using contrast-enhanced computed tomography. The patients were divided into two groups based on the median LA-EAT volume (16.0 ml); the high LA-EAT group (≥16.0 ml, n = 53) and low LA-EAT group (<16.0 ml, n = 52). We compared P-wave duration, LA conduction velocity and bipolar voltage, the presence of low-voltage zone (<0.5 mV), and LA volume index on echocardiography between the two groups. The LA bipolar voltage, low-voltage zone, and LA volume index were not different between the high and low LA-EAT groups. However, P-wave duration was significantly longer in the high group than in the low group (p < .001). Additionally, the LA conduction velocity was significantly more depressed in the high group than in the low group (p < .001). Multivariate linear regression analysis revealed that LA-EAT volume was correlated with P-wave duration (ß = .367, p < .001) and conduction velocity (ß = -.566, p < .001), respectively. CONCLUSIONS: Increased LA-EAT volumes were associated with electrical conduction disturbance after PVI in normal-weight patients with AF. P-wave duration may be a clinically useful predictor of LA-EAT.

The prognostic predictive value of the components of the PR interval in hospitalized patients with heart failure.

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.

Paced P-wave duration as a significant predictor for atrial high-rate episodes in patients with cardiac implantable electronic devices.

BACKGROUND: Atrial pacing (AP) can unmask or aggravate a preexisting interatrial block (IAB). The aim of our study was to determine whether AP is associated with the development of atrial high-rate episodes (AHRE) during follow-up. METHODS: Patients with dual-chamber cardiac implantable electronic devices (CIEDs), no previous documented atrial fibrillation, and with a 6-month minimum follow-up were included. In all patients, sinus and paced P-wave duration were measured. AHRE was defined as an episode of atrial rate ≥225 bpm with a minimum duration of 5 min, excluding those documented during the first 3 months after implantation. RESULTS: A total of 220 patients were included (75 ± 10 years, 61% male). After a mean follow-up of 59 ± 25 months, 46% of patients presented AHRE. Mean paced P-wave duration was significantly longer than the sinus P-wave duration (154 ± 27 vs. 115 ± 18 ms; p < .001). Sinus and paced P-waves were significantly longer in those who developed AHRE (sinus: 119 ± 20 vs. 112 ± 16; p = .006; paced: 161 ± 29 vs. 148 ± 23; p < .001). A paced P-wave ≥160 ms was the best predictor of AHRE, especially those lasting >24 h (odds ratio [OR] 4.2 [95% confidence interval (CI)] [1.6-11.4]; p = .004). CONCLUSIONS: AP significantly prolongs P-wave duration and is associated with further development of AHRE. A paced P-wave ≥160 ms is a strong predictor of AHRE and should be taken into consideration as a new definition of IAB in the presence of AP.

Long P-wave duration immediately after pulmonary vein isolation on radiofrequency catheter ablation for atrial fibrillation predicts clinical recurrence: correlation with atrial remodeling in persistent atrial fibrillation.

P-wave morphology reflects atrial remodeling and indicates prognosis after radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF). The impact of p-wave morphology after excluding the effect of pulmonary vein (PV) substrate on outcomes is unknown. We evaluated the p-wave morphology on electrocardiography immediately after PV isolation for clinical outcomes. Eighty-four consecutive patients (47 with paroxysmal AF and 37 with persistent AF) who underwent RFCA were included. P-wave duration (PWD) and amplitude in all leads were examined during sinus rhythm immediately after PV isolation. We evaluated the relationship between electrocardiogram parameters and AF recurrence, according to the type of AF and following ablation, and the correlation with left atrial (LA) volume, low voltage ratio, and fixed conduction time. During 12 months of follow-up, 20 patients experienced recurrence. The cut-off value of PWD > 120 ms in lead I showed a sensitivity of 75% and specificity of 69% for predicting recurrence. PWD was significantly correlated with LA volume, low voltage, and conduction velocity. Significantly higher recurrence rates were observed in patients with PWD > 120 ms than in those with PWD ≤ 120 ms (p < 0.001), and the difference was more pronounced in patients with persistent AF. Multivariate analysis demonstrated that PWD > 120 ms was independently associated with recurrence in the total population (hazard ratio 2.00; 95% confidence interval 1.27-3.22; p = 0.003) and in patients with persistent AF. In conclusion, long PWD after PV isolation predicts AF recurrence, which might be associated with the extent of the LA substrate in persistent AF.

Easily available ECG and echocardiographic parameters for prediction of left atrial remodeling and atrial fibrillation recurrence after pulmonary vein isolation: A multicenter study.

BACKGROUND: The assessment of noninvasive markers of left atrial (LA) low-voltage substrate (LVS) enables the identification of atrial fibrillation (AF) patients at risk for arrhythmia recurrence after pulmonary vein isolation (PVI). METHODS: In this prospective multicenter study, 292 consecutive AF patients (72% male, 62 ± 11 years, 65% persistent AF) underwent high-density LA voltage mapping in sinus rhythm. LA-LVS (<0.5 mV) was considered as significant at 2 cm2  or above. Preprocedural clinical electrocardiogram and echocardiographic data were assessed to identify predictors of LA-LVS. The role of the identified LA-LVS markers in predicting 1-year arrhythmia freedom after PVI was assessed in 245 patients. RESULTS: Significant LA-LVS was identified in 123 (42%) patients. The amplified sinus P-wave duration (APWD) best predicted LA-LVS, with a 148-ms value providing the best-balanced sensitivity (0.81) and specificity (0.88). An APWD over 160 ms was associated with LA-LVS in 96% of patients, whereas an APWD under 145 ms in 15%. Remaining gray zones improved their accuracy by introduction of systolic pulmonary artery pressure (sPAP) of 35 mmHg or above, age, and sex. According to COX regression, the risk of arrhythmia recurrence 12 months following PVI was twofold and threefold higher in patients with APWD 145-160 and over 160 ms, compared to APWD under 145 ms. Integration of pulmonary hypertension further improved the outcome prediction in the intermediate APWD group: Patients with APWD 145-160 ms and normal sPAP had similar outcome than patients with APWD under 145 ms (hazard ratio [HR] 1.62, p = .14), whereas high sPAP implied worse outcome (HR 2.56, p < .001). CONCLUSIONS: The APWD identifies LA-LVS and risk for arrhythmia recurrence after PVI. Our prediction model becomes optimized by means of integration of the pulmonary artery pressure.

The P wave dispersion-one pixel, one millisecond.

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.

Electrocardiographic predictors of early recurrence of atrial fibrillation.

BACKGROUND: Electrical cardioversion (ECV) is an effective method for restoring sinus rhythm after atrial fibrillation (AF). However, early recurrence of AF occurs in a significant number of patients after ECV. This study aimed to identify electrocardiographic (ECG) predictors of early AF recurrence after ECV. METHODS: A total of 272 patients with persistent AF undergoing successful ECV were consecutively enrolled in this study. We investigated clinical, echocardiographic, and ECG data. The 12-lead ECG parameters were measured during sinus rhythm right after ECV using a digital caliper. The early AF recurrence was defined as recurrence within 2 months. RESULTS: Of the 272 patients, 165 patients (60.7%) experienced an early AF recurrence. Maximum P-wave duration (PWD) in limb leads (OR: 1.086; 95% CI: 1.019-1.157; p = .012) and P-terminal force (PTF) in V1 (OR: 1.019; 95% CI: 1.004-1.033; p = .011) were independent predictors of early AF recurrence after ECV. The optimal cutoff value of the maximum PWD in limb leads for predicting early AF recurrence was 134 ms, characterized by 90.3% sensitivity and 72.0% specificity. Likewise, the optimal cutoff value of PTF in V1 was 50 ms × mm, characterized by 80.0% sensitivity and 64.5% specificity. CONCLUSION: A longer PWD (>134 ms) and a larger PTF (>50 ms × mm) were useful predictors of early recurrence of AF after successful ECV in clinical practice. A more effective rhythm control therapy such as catheter ablation or rate control strategy rather than a repeat ECV should be considered.

Effects of angiotensin receptor neprilysin inhibition on P-wave dispersion in heart failure with reduced ejection fraction.

BACKGROUND: Angiotensin receptor neprilysin inhibitors (ARNI; sacubitril/valsartan combination) decrease morbidity and mortality in heart failure with reduced ejection fraction (HFrEF). Increased P­wave duration and P­wave dispersion (Pd) reflect prolongation of atrial conduction and correlate with atrial fibrillation. Here, we aimed to assess the effects of switching from valsartan to ARNI treatment on the basis of P­wave indices. METHODS: A total of 28 patients with HFrEF (mean age, 64.8 ± 10.6 years; 18 males, 78.6% ischemic etiology) were included. All patients had New York Heart Association functional class II-III, left ventricular ejection fraction ≤35%, and had been switched from valsartan to ARNI treatment. Standard 12-lead electrocardiograms from patients on valsartan treatment and electrocardiograms 1 month after ARNI treatment were analyzed; heart rate, maximum P­wave duration (Pmax), minimum P­wave duration (Pmin), and Pd were calculated. Minnesota Living with Heart Failure Questionnaire (MLWHFQ) scores and N­terminal pro-brain natriuretic peptide (NT-proBNP) values were recorded. RESULTS: The Pmax (135.6 ± 32.1 ms vs. 116.1 ± 14.1 ms, p = 0.041) and Pd (33.6 ± 7.9 vs. 28.6 ± 5.3, p = 0.006) values were significantly reduced after ARNI treatment. Furthermore, ARNI treatment was associated with an improvement in MLWHFQ scores (31.2 ± 6.2 ms vs. 23.2 ± 7.0 ms, p < 0.001) and with a reduction in NT-proBNP values (1827.3 ± 1287.3 pg/ml vs. 1074.4 ± 692.3 pg/ml, p < 0.001). There were moderately positive correlations between the reduction in Pd and the improvement in MLWHFQ scores (r = 0.408, p = 0.031) and the reduction in NT-proBNP values (r = 0.499, p = 0.007) CONCLUSION: Switching to ARNI treatment alters Pd and Pmax favorably in patients with HFrEF. The reduction in atrial inhomogeneous conduction assessed by Pd was correlated with clinical improvement and reduced NT-proBNP levels in patients with HFrEF.

Vectorial theory surpasses the local theory in explaining the origin of P-wave dispersion.

BACKGROUND: Local theory and the vectorial theory are used to explain the origin of P-wave dispersion (PWD). There are no previous studies that analyze both at the same time. OBJECTIVES: We set out to determine the implication of local and vectorial theories in the origin of PWD. METHODS: Cross-sectional study in 153 randomly selected patients aged 18-70 years, undergoing electrophysiological study. Inhomogeneous atrial conduction was evaluated by atrial electrogram dispersion in terms of duration (EGMdurdis) and morphology (EGMmorph dis). P-distal coronary sinus interval (P-DCS) was also measured. P-wave was measured twice, firstly at a calibration of 20 mm/mV and a sweep speed of 50 mm/s, enhancement 10× (basic measurement [BM]), and second time at sweep speed of 150 mm/s, enhancement 80-160× (high precision measurement [HPM]). RESULTS: PWD with BM was 48 ms [36-54 ms] while with HPM it was 4 ms [0-10 ms], p < 0.001. With BM, maximum and minimum P- wave duration presented a moderate correlation (r = 0.342; p < 0.001), using HPM it becomes strong (r = 0.750; p < 0.001). In cases with P-DCS < 80 ms (r = 0.965; p < 0.001), but not with P-DCS ≥ 80 ms (r = 0.649; p < 0.001), the previous correlation became almost perfect with HPM. EGMdurdis and EGMmorphdis were weak but significantly correlated with PWD. This correlation became moderate in patients with P-DCS ≥ 80 ms and disappeared in those with P-DCS, using BM and HPM. CONCLUSION: Vectorial theory explains almost entirely the PWD phenomenon. Inhomogeneous conduction could be an additional mechanism to explain PWD, but its contribution is small.

Temporal progression of P wave abnormality in a patient with classical or atriopulmonary Fontan.

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.

P wave duration ≥150 ms predicts poor left atrial function and ablation outcomes in non-paroxysmal atrial fibrillation.

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 12­lead 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.

Advanced interatrial block and P-wave duration are associated with atrial fibrillation and stroke in older adults with heart disease: the BAYES registry.

AIMS: Advanced interatrial block (IAB), is an unrecognized surrogate of atrial dysfunction and a trigger of atrial dysrhythmias, mainly atrial fibrillation (AF). Our aim was to prospectively assess whether advanced IAB in sinus rhythm is associated with AF and stroke in elderly outpatients with structural heart disease, a group not previously studied. METHODS AND RESULTS: Prospective observational registry that included outpatients aged ≥70 years with structural heart disease and no previous diagnosis of AF. Patients were divided into three groups: normal P-wave duration (<120 ms), partial IAB (P-wave duration ≥120 ms, positive in the inferior leads), and advanced IAB [P-wave duration ≥120 ms, biphasic (plus/minus) morphology in the inferior leads]. Among 556 individuals, 223 had normal P-wave (40.1%), 196 partial IAB (35.3%), and 137 advanced IAB (24.6%). After a median follow-up of 694 days, 93 patients (16.7%) developed AF, 30 stroke (5.4%), and 34 died (6.1%). Advanced IAB was independently associated with AF -[hazard ratio (HR) 2.9, 95% confidence interval (CI) 1.7-5.1; P < 0.001], stroke [HR 3.8, 95% CI 1.4-10.7; P = 0.010), and AF/stroke (HR 2.6, 95% CI 1.5-4.4; P = 0.001). P-wave duration (ms) was independently associated with AF (HR 1.05, 95% CI 1.03-1.07; P < 0.001), AF/stroke (HR 1.04, 95% CI 1.02-1.06; P < 0.001), and mortality (HR 1.04, 95% CI 1.00-1.08; P = 0.021). CONCLUSIONS: The presence of advanced IAB in sinus rhythm is independently associated with AF and stroke in an elderly population with structural heart disease and no previous diagnosis of AF. P-wave duration was also associated with all-cause mortality.

Electrocardiogram characteristics of P wave associated with successful pulmonary vein isolation in patients with paroxysmal atrial fibrillation: Significance of changes in P-wave duration and notched P wave.

BACKGROUND: The mechanisms involved in changes in P wave following catheter ablation for atrial fibrillation (AF) are uncertain. This study aimed to assess the relationship between changes in P-wave morphology and pulmonary vein (PV) reconnection following ablation by the assessment of 12-lead surface electrocardiogram and signal-averaged electrocardiogram. METHODS: This retrospective study included 115 consecutive patients with paroxysmal AF that underwent repeat ablation for recurrence following initial ablation. We investigated changes in P-wave morphology between baseline and repeat procedure in patients with and without PV reconnection. The study also included as validation group without recurrence (n = 67) following initial ablation. RESULTS: The maximum P-wave duration (PWD) was significantly decreased from baseline to just after the procedure in all groups. However, for the PV reconnection group (n = 100), the maximum PWD was significantly increased again at the repeat procedure. In contrast, the maximum PWD was significantly reduced between baseline and repeat procedure in the non-PV reconnection group (n = 15). The signal-averaged PWD was significantly decreased from baseline to repeat procedure in the non-PV reconnection group, but, conversely, was increased in the PV reconnection group. In the non-PV reconnection group, the disappearance of notched P wave was detected in 8 of 15 patients (53%), which was significantly higher than in other groups (p = .001). A new or delayed notched P wave was identified in the PV reconnection group only. These results were confirmed in the validation group. CONCLUSIONS: The reverse dynamics of PWD after initial shortening directly following ablation were significantly associated with PV reconnection.

A specific combination of P wave duration and morphology accurately predicts the presence of left atrial low voltage area in patients with atrial fibrillation.

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.

Interatrial conduction times in paroxysmal atrial fibrillation patients with normal atrial volume and their correlation with areas of local prolonged bipolar electrograms.

BACKGROUND: Recent evidence has shown that the presence of abnormal substrate can be demonstrated also among patients with "lone" AF. OBJECTIVES: Interatrial conduction slowing is likely to characterize patients with paroxysmal atrial fibrillation (AF) and it could be correlated to the left atrium area of prolonged local bipolar endocardial electrograms. METHODS: P-wave duration (PWD), amplified PWD and endocavitary interatrial conduction time (IACT), were analyzed in 60 patients; 30 undergoing de novo ablation for paroxysmal AF with normal atrial volumes and without any other cardiac disease and 30 of similar age undergoing electrophysiological study for atrioventricular nodal reentrant tachycardia or atrioventricular re- entrant tachycardia. In patients with AF, voltage maps and local bipolar electrograms (LBE) duration map were evaluated. RESULTS: Although PWD was <120 ms in 28 patients with AF and in 29 controls, patients with AF exhibited longer PWD, amplified-PWD and IACT. Although low-voltage areas (<0.5 mV) were not found in the study population, 28 of them demonstrated areas with LBE longer than 60 ms. These LBE were found mainly in the roof of the left atrium and their extension was correlated to IACT (R = 0.51, p = 0.004). IACT >135.5 ms identified the subjects who experienced AF with 90% sensitivity and 97% specificity. CONCLUSION: A subclinical interatrial conduction disturbance is demonstrable in subjects with paroxysmal AF and normal left atrial volume. IACT has a good correlation to the areas of abnormal LBE in the left atrium. IACT >135 ms identified subjects who have experienced AF.

Association between prolonged P wave duration and left atrial scarring in patients with paroxysmal atrial fibrillation.

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.