P-wave Indices Research Articles

P-wave beat-to-beat analysis to predict atrial fibrillation recurrence after catheter ablation

Abstract Introduction Identification of patients prone to atrial fibrillation (AF) relapse after catheter ablation is essential for better patient selection and risk stratification. Purpose The current prospective cohort study aims to validate a novel P-wave index based on beat-to-beat (B2B) P-wave morphological and wavelet analysis designed to detect patients with low burden AF, as a predictor of AF recurrence within a year after successful catheter ablation. Methods 12-lead ECG and 10-minute vectorcardiogram (VCG) recordings were obtained from 138 consecutive patients scheduled for AF ablation. Pre-ablation B2B P-wave index, along with standard P-wave indices, clinical scores and patients history and physical examination parameters were evaluated as AF recurrence predictors. Results Univariate analysis revealed that patients with higher B2B P-wave index had a two-fold risk for AF recurrence (HR: 2.35, 95% CI: 1.24–4.44, p: 0.010). Prolonged P-wave, interatrial block, early AF recurrence, female gender, heart failure history, previous stroke, and CHA2DS2-VASc score ≥2 were also found to be related to higher recurrence rate. Multivariate analysis of predictors that can be assessed before ablation revealed that B2B P-wave index, along with heart failure history and history of previous stroke or transient ischemic attack are independent predicting factors of AF relapse. Conclusion B2B P-wave morphology and wavelet analysis, is a promising, non-invasive technique, able to identify patients prone to AF recurrence after pulmonary veins ablation. Further studies are needed to assess the predictive value of B2B index with greater accuracy and evaluate a possible relationship with atrial substrate analysis. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): Hellenic Society of Cardiology

PO-625-05 ELECTROCARDIOGRAPHIC DEEP TERMINAL NEGATIVE OF THE P WAVE IN V1 AND ISCHEMIC STROKE:THE ATHEROSCLEROSIS RISK IN COMMUNITIES (ARIC) STUDY

Abnormal P-wave indices are associated with ischemic stroke independent of atrial fibrillation (AF). Deep terminal negative of the P wave in V1 (DTNPV1) is a simple ECG index that reflects underlying left atrial remodeling. However, it is unknown whether DTNPV1 is associated with ischemic stroke.

The characteristic of an abnormal p-wave axis in patients with atrial fibrillation

BackgroundsAn adverse increased risk of atrial fibrillation (AF) can be detected by measuring the p-wave indices, including prolonged p-wave duration, the PR interval, abnormal p-wave terminal force, and abnormal p-wave axis (aPWA). Our purpose was to characterize the AF patient population with an aPWA and to identify whether the aPWA was associated with recurrence after catheter ablation of AF. MethodsThis study retrospectively included 249 patients with AF who underwent catheter ablation in our hospital from October 2015 to May 2019. We measured the p-wave indices and left atrial cavity size (LAVI) before the catheter ablation. A logistic regression analysis was performed to analyze the concurrent effects of various factors on the prevalence of AF recurrence over 12 months after the ablation. ResultsAn aPWA was observed in 35 patients (14%). There were significantly more patients with an aPWA in the non-PAF than PAF patients (26% versus 7%, p < 0.001). The patients with an aPWA had a significantly larger LAVI values (37 ± 12 versus 45 ± 11 ml/m2, p = 0.016). In a multivariate analysis, an aPWA (odds ratio, 4.27; 95% confidence interval, 1.75–10.4; p = 0.001) and the LAVI (odds ratio, 1.04; 95% confidence interval, 1.00–1.08; p = 0.032) were independently associated with recurrence after catheter ablation. ConclusionsOur results demonstrated that measuring the aPWA in patients with atrial fibrillation before ablation was useful for identifying patients at a higher risk of recurrence after catheter ablation of AF.

P-Wave Beat-to-Beat Analysis to Predict Atrial Fibrillation Recurrence after Catheter Ablation.

The identification of patients prone to atrial fibrillation (AF) relapse after catheter ablation is essential for better patient selection and risk stratification. The current prospective cohort study aims to validate a novel P-wave index based on beat-to-beat (B2B) P-wave morphological and wavelet analysis designed to detect patients with low burden AF as a predictor of AF recurrence within a year after successful catheter ablation. From a total of 138 consecutive patients scheduled for AF ablation, 12-lead ECG and 10 min vectorcardiogram (VCG) recordings were obtained. Univariate analysis revealed that patients with higher B2B P-wave index had a two-fold risk for AF recurrence (HR: 2.35, 95% CI: 1.24–4.44, p: 0.010), along with prolonged P-wave, interatrial block, early AF recurrence, female gender, heart failure history, previous stroke, and CHA2DS2-VASc score. Multivariate analysis of assessable predictors before ablation revealed that B2B P-wave index, along with heart failure history and a history of previous stroke or transient ischemic attack, are independent predicting factors of atrial fibrillation recurrence. Further studies are needed to assess the predictive value of the B2B index with greater accuracy and evaluate a possible relationship with atrial substrate analysis.

Beat-to-beat P-wave analysis outperforms conventional P-wave indices in identifying patients with a history of paroxysmal atrial fibrillation, during sinus rhythm

Abstract Introduction Atrial fibrillation (AF) is the most common arrhythmia and is associated with high risk of morbidity and mortality. In many patients, AF is of episodic character (paroxysmal AF – PAF), which makes the identification of these patients during sinus rhythm (SR) challenging. Purpose The aim of the present study is to compare the performance of beat-to-beat P-wave analysis with P-wave indices used as predictors of PAF, such as P-wave duration, area, voltage, axis, terminal force in V1, inter-atrial block or orthogonal type, in identifying patients with history of PAF during sinus rhythm. Methods Standard 12-lead ECG and 10-minute orthogonal ECG recordings were obtained from 40 consecutive patients with short history of PAF under no antiarrhythmic medication and 60 age- and sex- matched healthy controls. The P-waves on the 10-minute recordings were analyzed on a beat-to-beat basis and classified as belonging to a primary or secondary morphology according to previous study. Wavelet transform used to further analyze P-wave orthogonal signals of main morphology on a beat-to-beat basis. Results 38 out of 327 studied features were found to differ significantly among the two groups. These features were tested for their diagnostic ability and receiver operating characteristic curves were ploted. Only 3 of them performed adequetly, with an area under curve (AUC) above 0.65; Two of them came from morphology analysis (percentage of beats following main morphology in axis X and Y) and one from wavelet analysis (max energy in high frequency zone -Y axis). Among standard P-wave indices, P-wave area in lead II was the one with the highest AUC (0.64). Conclusion Novel indices derived from beat-to-beat analysis outperform stadard P-wave markers in identifying patients with PAF history during sinus rhythm. Funding Acknowledgement Type of funding sources: None. ROC curves of most significant featuresAUC characteristics of P-wave indices

Beat-to-Beat P-Wave Analysis Outperforms Conventional P-Wave Indices in Identifying Patients with a History of Paroxysmal Atrial Fibrillation during Sinus Rhythm.

Early identification of patients at risk for paroxysmal atrial fibrillation (PAF) is essential to attain optimal treatment and a favorable prognosis. We compared the performance of a beat-to-beat (B2B) P-wave analysis with that of standard P-wave indices (SPWIs) in identifying patients prone to PAF. To this end, 12-lead ECG and 10 min vectorcardiogram (VCG) recordings were obtained from 33 consecutive, antiarrhythmic therapy naïve patients, with a short history of low burden PAF, and from 56 age- and sex-matched individuals with no AF history. For both groups, SPWIs were calculated, while the VCG recordings were analyzed on a B2B basis, and the P-waves were classified to a primary or secondary morphology. Wavelet transform was used to further analyze P-wave signals of main morphology. Univariate analysis revealed that none of the SPWIs performed acceptably in PAF detection, while five B2B features reached an AUC above 0.7. Moreover, multivariate logistic regression analysis was used to develop two classifiers—one based on B2B analysis derived features and one using only SPWIs. The B2B classifier was found to be superior to SPWIs classifier; B2B AUC: 0.849 (0.754–0.917) vs. SPWIs AUC: 0.721 (0.613–0.813), p value: 0.041. Therefore, in the studied population, the proposed B2B P-wave analysis outperforms SPWIs in detecting patients with PAF while in sinus rhythm. This can be used in further clinical trials regarding the prognosis of such patients.

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 > 110ms, 1-NTF ≥ 4ms.mV and P notching > 40ms 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 > 40ms 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.

Effects of oral colchicine administration as first-lineadjuncttherapyin myopericarditis.

Although current guidelines recommend routine use of oral colchicine as afirst-lineadjunct therapy to aspirin/nonsteroidal anti-inflammatory drugs (NSAIDs) for acute and recurrent pericarditis, there are insufficient data to recommend routine use of colchicine for the initial management of myopericarditis. The records of 194patients who were admitted for myopericarditis were investigated retrospectively. Patients receiving oral colchicine (n = 33) as an adjunctto aspirin/NSAIDs comprised the study group and patients who received conventional therapy (n = 31) formed the control group. Plasma C‑reactive protein (CRP) levels, cardiac biomarkers, and several electrocardiographic parameters of atrial activation were evaluated before the start of treatment and at the 6‑month follow-up. Assessments before and after treatment with regard to cardiac biomarkers and plasma CRP levels showed improvements in both groups (p > 0.05). There were statistically significant improvements in Pwave indices including Pwave duration, PR interval length, Pwave dispersion, Pterminal force, and isoelectric interval in the colchicine therapy group compared with the control group (p < 0.01). Routine use of colchicine for the initial management of myopericarditis as afirst-line adjunct therapy to aspirin/NSAIDs in patients with myopericarditis has favorable effects on electrocardiographic indices of atrial activation parameters.

The immediate trends in atrial electrical remodeling for paroxysmal atrial fibrillation across different modes of catheter ablation.

BackgroundCatheter ablation has emerged as a major strategy for paroxysmal atrial fibrillation (PAF). Atrial electrical remodeling (AER) plays a critical role in the recurrence of PAF after ablation.HypothesisTo characterize the immediate trends of AER during ablations in patients with PAF, and assess the relationship between immediate trends and recurrence.MethodsWe performed this prospective observational study of 135 patients to investigate AER following three ablation modes: radiofrequency ablation (RFA), cryoablation (CA) and 3D mapping‐guided cryoablation (3D‐CA). The atrial effective refractory period (AERP) and atrial conduction time (ACT) were measured via electrophysiology before and immediately after ablation, and P‐wave indices were measured via electrocardiography before and within 24 h after ablation. Follow‐up visits were conducted for at least 1 year or until relapse.ResultsDifferent approaches of ablation caused a fairly significant increase in the shortest P‐wave duration and AERP in both the proximal coronary sinus (PCS) and distal coronary sinus (DCS) but caused a shortened P‐wave dispersion. No different effect was found at the AERP among the three modes. Compared to patients who received CA, among patients who received RFA, a significant reduction in total ACT and right ACT was seen. Statistically, there was a weakly positive association between changes in total ACT and early recurrence.ConclusionsInjury during ablation for PAF was associated with an increase in the AERP but not in the ACT. Total ACT and right ACT were shorter after RFA than after CA. The increase in total ACT were slightly predictive of early recurrence.

P-wave beat-to-beat morphology analysis outperforms conventional P-wave indices in detecting patients with paroxysmal atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background Atrial fibrillation (AF) - the most common sustained cardiac arrhythmia - while not a life-threatening condition itself, leads to an increased risk of stroke and high rates of mortality. Early detection and diagnosis of AF is a critical issue for all health stakeholders. Purpose The aim of this study is to compare the performance of standard P-wave indices with beat-to-beat P-wave morphological variability parameters in identifying patients with history of Paroxysmal Atrial Fibrillation (PAF). Methods Three-dimensional 1000Hz ECG digital recordings of 10 minutes duration were obtained from a total of 39 PAF patients and 60 healthy individuals. Following artifacts and ectopic beats removal, P‑wave morphology analysis was performed based on the dynamic application of the k‑means clustering process and main and secondary P-wave morphologies were identified. The percentage of P-waves following the main or the secondary morphology in each lead was calculated, as well as established indices such as Advanced Interatrial Block, P-wave duration, axis and area, P-wave Terminal Force in lead V1 and Orthogonal Leads Type 1, 2 or 3. Results 9 out of 24 parameters studied, were found to be significantly different between the two groups. 7 of these indices were derived from morphology analysis and 2 from P-wave area. Logistic regression revealed that the percentage of P-waves allocated to main morphology in X axis performed better than all other indices in identifying patients with PAF history from healthy volunteers in terms of total accuracy and F1 measure. Conclusion P-wave beat-to-beat morphology analysis can identify PAF patients during normal sinus rhythm more efficiently than standard P-wave indices. Abstract Figure.

Impact of P-wave indices in prediction of atrial fibrillation-Insight from loop recorder analysis.

BackgroundSeveral P‐wave indices are associated with the development of atrial fibrillation (AF). However, previous studies have been limited in their ability to reliably diagnose episodes of AF. Implantable loop recorders allow long‐term, continuous, and therefore more reliable detection of AF.HypothesisThe aim of this study is to identify and evaluate ECG parameters for predicting AF by analyzing patients with loop recorders.MethodsThis study included 366 patients (mean age 62 ± 16 years, mean LVEF 61 ± 6%, 175 women) without AF who underwent loop recorder implantation between 2010–2020. Patients were followed up on a 3 monthly outpatient interval.ResultsDuring a follow‐up of 627 ± 409 days, 75 patients (20%) reached the primary study end point (first detection of AF). Independent predictors of AF were as follows: age ≥68 years (hazard risk [HR], 2.66; 95% confidence interval [CI], 1.668–4.235; p < .001), P‐wave amplitude in II <0.1 mV (HR, 2.11; 95% CI, 1.298–3.441; p = .003), P‐wave terminal force in V1 ≤ −4000 µV × ms (HR, 5.3; 95% CI, 3.249–8.636; p < .001, and advanced interatrial block (HR, 5.01; 95% CI, 2.638–9.528; p < .001). Our risk stratification model based on these independent predictors separated patients into 4 groups with high (70%), intermediate high (41%), intermediate low (18%), and low (4%) rates of AF.ConclusionsOur study indicated that P‐wave indices are suitable for predicting AF episodes. Furthermore, it is possible to stratify patients into risk groups for AF using simple ECG parameters, which is particularly important for patients with cryptogenic stroke.

Evolution of P-wave indices during long-term follow-up as markers of atrial substrate progression in arrhythmogenic right ventricular cardiomyopathy.

Patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) have increased prevalence of atrial arrhythmias indicating atrial involvement in the disease. We aimed to assess the long-term evolution of P-wave indices as electrocardiographic (ECG) markers of atrial substrate during ARVC progression. We included 100 patients with a definite ARVC diagnosis according to 2010 Task Force criteria [34% females, median age 41 (inter-quartile range 30-55) years]. All available sinus rhythm ECGs (n = 1504) were extracted from the regional electronic ECG databases and automatically processed using Glasgow algorithm. P-wave duration, P-wave area, P-wave frontal axis, and prevalence of abnormal P terminal force in lead V1 (aPTF-V1) were assessed and compared at ARVC diagnosis, 10 years before and up to 15 years after diagnosis.Prior to ARVC diagnosis, none of the P-wave indices differed significantly from the data at ARVC diagnosis. After ascertainment of ARVC diagnosis, P-wave area in lead V1 decreased from -1 to -30 µV ms at 5 years (P = 0.002). P-wave area in lead V2 decreased from 82 µV ms at ARVC diagnosis to 42 µV ms 10 years after ARVC diagnosis (P = 0.006). The prevalence of aPTF-V1 increased from 5% at ARVC diagnosis to 18% by the 15th year of follow-up (P = 0.004). P-wave duration and frontal axis did not change during disease progression. Initial ARVC progression was associated with P-wave flattening in right precordial leads and in later disease stages an increased prevalence of aPTF-V1 was seen.

P-wave indices in Japanese patients with ischemic stroke: Implication of atrial myopathy in subtype of ischemic stroke

BackgroundP-wave indices have been not fully studied in subtypes of ischemic stroke. We compared P-wave indices among embolic stroke, lacunar stroke and the control. MethodsP-wave duration, advanced interatrial block (aIAB) defined as P-wave duration ≥120 ms and biphasic (positive negative) morphology in inferior leads, and P-terminal force in lead V1 (PTFV1) were measured at the time of the first episode of cardioembolic stroke in 81 patients with paroxysmal atrial fibrillation (PAF), and in 64 patients with lacunar stroke, and compared with 100 control subjects. The latter two groups had no episode of PAF. ResultsThe age of participants was 76 ± 11 years. Age, sex distribution, body mass index and CHADS2 score were comparable among three groups. Maximum P-wave duration, the longest across 12 leads, was significantly prolonged in cardioembolic and lacuna stroke compared to the control; 118 ± 12 ms and 118 ± 11 ms vs. 110 ± 11 ms, respectively (P < 0.0001). P-wave duration ≥120 ms and aIAB were more prevalent in ischemic stroke groups than the control, and associated with a higher Odds ratio for stroke, more so in cardioembolic stroke. However, PTFV1 value and the prevalence of PTFV1 ≥ 4.0 ms·mV were significantly not different among the three groups.Abnormal P-wave duration and aIAB indicating the presence of atrial myopathy were present in cardioembolic and lacuna stroke. ConclusionAtrial myopathy was present in cardioembolic and lacunar stroke, but it can't be the direct cause of small vessel occlusion in lacunar stroke. Roles of atrial myopathy in each subtype of ischemic stroke should be studied.

Abstract P667: Clinical Variables, Electrocardiogram Parameters and Blood Biomarkers Associated With Atrial Fibrillation Detection in the First Year After Ischaemic Stroke - A Systematic Review and Meta-Analysis

Introduction: Cardiac monitoring is performed to detect atrial fibrillation (AF) after stroke. Identifying patients at high or low risk of AF may allow cardiac monitoring approaches to be tailored on a more personalised basis. We performed a systematic review and meta-analysis to identify variables associated with AF detection after ischaemic stroke. Methods: We followed the Cochrane Collaboration Guidelines and retrieved 8503 studies. After screening, 35 studies were selected and 68 variables were assessed. We assessed 41 clinical variables, 20 ECG parameters and 7 blood biomarkers associated with AF detection &gt;30 seconds duration in the first year after stroke. Comprehensive Meta-analysis software was used to generate an odds ratio and Forest plot for each variable. Studies were assessed for quality using the Quality in Prognostic Studies (QUIPS) tool. Results: The 35 studies included 12010 patients and AF was detected in 1551 patients (13%). Of the 68 variables assessed, 20 were associated with increased odds of AF, 5 were associated with reduced odds of AF and 43 were not associated with AF (Figure 1). The variables most strongly associated with AF detection (odds ratio &gt;3.00) were older age, patients who received IV thrombolytic therapy, maximum P-wave duration, premature atrial complexes, P-wave dispersion, P-wave index, QTc interval and brain natriuretic peptide. Risk of bias was low in 3 studies, moderate in 24 studies and high in 8 studies. Conclusions: We have identified clinically applicable variables that can stratify the probability of AF detection after stroke. Our results will help guide more personalised approaches to cardiac monitoring for AF detection after stroke.

Variation of P-wave indices in paroxysmal atrial fibrillation patients before and after catheter ablation

The effects of pulmonary vein isolation in the surface electrocardiogram of patients with paroxysmal atrial fibrillation are analyzed in this paper using non-invasive markers for early detection of the arrhythmia recurrences.Several features have been extracted on P-waves of V1 lead for paroxysmal atrial fibrillation patients who underwent catheter ablation of pulmonary veins for restoring sinus rhythm permanently. Surface ECG was simultaneously recorded along with intracardiac recordings starting from the beginning of the intervention until half an hour after the catheter ablation successfully ended. Significant difference between the means before and after catheter ablation have been observed for the cross-correlation index, kurtosis and amplitude dispersion of P-waves.A logistic regression has been applied to all the descriptors and pointed to the amplitude dispersion index, as well as the minimum gradient joint with kurtosis of P-waves prior to catheter ablation as good predictors of recurrence of atrial fibrillation (78% accuracy). It is important to note how using a few descriptors good classification results are achieved. This study opens a door to early detection of atrial fibrillation recurrences using markers obtained by non-invasive methods.

Association of P-Wave Abnormalities With Sudden Cardiac and Cardiovascular Death: The ARIC Study.

Association of P-Wave Abnormalities With Sudden Cardiac and Cardiovascular Death: The ARIC Study.

Atrial Conduction Disorders.

Atrial conduction disorders result from impaired propagation of cardiac impulses from the sinoatrial node through the atrial conduction pathways. Disorders affecting interatrial conduction alter P-wave characteristics on the surface electrocardiogram. A variety of P-wave indices reflecting derangements in atrial conduction have been described and have been associated with an increased risk of atrial fibrillation (AF) and stroke. Interatrial block (IAB) is the most well-known of the different P-wave indices and is important clinically due to its ability to predict patients who are at risk of the development of AF and other supraventricular tachycardias. P-Wave Axis is a measure of the net direction of atrial depolarization and is determined by calculating the net vector of the P-wave electrical activation in the six limb-leads using the hexaxial reference system. It has been associated with stroke and it has been proposed that this variable be added to the existing CHA2DS2-VASc score to create a P2-CHA2DS2-VASc score to improve stroke prediction. P-Terminal Force in V1 is thought to be an epiphenomenon of advanced atrial fibrotic disease and has been shown to be associated with a higher risk of death, cardiac death, and congestive heart failure as well as an increased risk of AF. P-wave Dispersion is defined as the difference between the shortest and longest P-wave duration recorded on multiple concurrent surface ECG leads on a standard 12-lead ECG and has also been associated with the development of AF and AF recurrence. P-wave voltage in lead I (PVL1) is thought to be an electrocardiographic representation of cardiac conductive properties and, therefore, the extent of atrial fibrosis relative to myocardial mass. Reduced PVL1 has been demonstrated to be associated with new-onset AF in patients with coronary artery disease and may be useful for predicting AF. Recently a risk score (the MVP risk score) has been developed using IAB and PVL1 to predict atrial fibrillation and has shown a good predictive ability to determine patients at high risk of developing atrial fibrillation. The MVP risk score is currently undergoing validation in other populations. This section reviews the different P-wave indices in-depth, reflecting atrial conduction abnormalities.

Association of Electrocardiographic P-Wave Markers and Atrial Fibrillation in Embolic Stroke of Undetermined Source

Background: Several P-wave indices are thought to represent underlying atrial remodeling and have been associated with ischaemic stroke even in the absence of atrial fibrillation (AF). However, the utility of these P-wave indices in predicting outcomes in patients with embolic stroke of undetermined source (ESUS) has not been studied. The aim of this study is to examine these different P-wave indices towards predicting new-onset AF and stroke recurrence in a cohort of patients with ESUS, thereby demonstrating the value of these electrocardiographic markers for stroke risk stratification. Methods: Between October 2014 and October 2017, consecutive patients diagnosed with ESUS were followed for new-onset AF and ischaemic stroke recurrence. The various P-wave indices, namely, the P-terminal force in the precordial lead V1 (PTFV1), P-wave duration, P-wave dispersion, interatrial blocks, and P-wave axis, were assessed on the initial electrocardiogram on presentation and studied for their relation to eventual AF detection and recurrent stroke. Results: 181 ischaemic stroke patients with ESUS were recruited and followed up for a median duration of 2.1 years. An abnormal PTFV1 was associated with occult AF detection but not with recurrent ischaemic strokes. No significant association was observed between the other P-wave indices with either occult AF or stroke recurrence. Conclusion: PTFV1 is associated with AF detection but not recurrent strokes in ESUS patients and can be a useful electrocardiographic marker for further risk stratification in ESUS patients.

Abstract 13193: Association of Abnormal P-wave Indices With Brain MRI Infarcts: The Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS)

Introduction: We recently reported that abnormal P-wave indices (PWI)—ECG markers of atrial cardiomyopathy (AC)—are associated with an increased risk of dementia, independent of atrial fibrillation (AF) and clinical ischemic stroke. The mechanisms, however, remain unclear, but may include silent ischemia. Hypothesis: Abnormal PWI are associated with higher prevalence of cortical infarcts on MRI, suggesting cardioembolism as a potential mechanism. Methods: ARIC-NCS participants (mean age, 72.2±5.3 years; 60% women; 29% black) who underwent 3T brain MRI scans in 2011-2013 were included. Abnormal PWI included P-wave terminal force in lead V1 [(PTFV1) defined as ≥4000 μV*ms] and P-wave duration [(PWD) defined as &gt;120 ms], which were measured from standard 12-lead ECGs. Brain MRI outcomes included cortical infarcts, cerebral microbleeds (CMB), and markers of small vessel disease [white matter hyperintensities (WMH) and lacunar infarcts]. We used weighted multivariable logistic and linear regression analyses. Results: Of the 1,850 participants, 464 had abnormal PTFV1 and 415 had prolonged PWD. After multivariable adjustment including AF, abnormal PTFV1 and PWD were significantly associated with 26-44% increased odds of cortical and lacunar infarcts (Table) . Although PWD was associated with CMB in Model 1, the association was no longer significant after multivariable adjustment. Finally, abnormal PWIs were not associated with WMH after adjusting for stroke and AF (P &gt;0.5). Conclusions: Abnormal PWI are associated with higher prevalence of cortical infarcts, suggesting cardioembolism with silent ischemia as a possible mechanism underlying the association of AC with dementia. More research is needed to evaluate other mechanisms such as cerebral small vessel disease.

Interatrial Block Predicts Atrial Fibrillation and Total Mortality in Patients with Cardiac Resynchronization Therapy

Abstract Background Interatrial block (IAB) and abnormal P-wave terminal force in lead V1 (PTFV1) are electrocardiographic (ECG) abnormalities associated with new-onset atrial fibrillation (AF) and death. However, their prognostic importance has not been proven in CRT recipients with advanced heart failure (HF). Purpose To assess if IAB and abnormal PTFV1 are associated with new-onset AF or death in CRT recipients. Methods CRT recipients without AF history before CRT implantation were included (n=210, median age 67 years, 80% male, 55% ischemic heart disease, 70% NYHA Class III/IV, median LVEF 25%, 51% CRT-P). Automated analysis of P-wave duration (PWD) and morphology classified patients as having either No IAB (PWD &amp;lt;120ms), Partial IAB (pIAB: PWD ≥120 ms, positive P waves in leads II and aVF) or Advanced IAB (aIAB: PWD ≥120 ms and biphasic or negative P wave in leads II or aVF). PTFV1 &amp;gt;0.04 mm·s was considered abnormal. Cox regression analyses adjusted for age, NYHA Class, ischemic etiology of HF, LBBB, LVEF and CRT-P vs. CRT-D were performed to assess the impact of IAB and abnormal PTFV1 on the primary endpoint new-onset AF, death or heart transplant (HTx) and the secondary endpoint death or HTx at 5 years of follow up. Results IAB was found in 45% (34% pIAB and 11% aIAB) and was associated with both the primary (HR 1.9, 95% CI 1.2–2.9, p=0.004) and the secondary (HR 2.1, 95% CI 1.2–3.4, p=0.006) endpoints. Abnormal PTFV1 was not associated with outcome. See Forest plot for adjusted HRs for individual P-wave indices. Conclusions IAB is associated with new-onset AF and death in CRT recipients and may be helpful in risk stratification in the context of HF management. Abnormal PTFV1 did not demonstrate any prognostic value in the setting of CRT-treated patients with advanced HF. Forest plot Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Swedish Heart and Lung Foundation