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In this article, we will comment on new aspects of P-wave morphology that help us to better diagnose atrial blocks and atrial enlargement, and their clinical implications. These include: (1) Atypical ECG patterns of advanced interatrial block; (2) The ECG diagnosis of left atrial enlargement versus interatrial block; (3) Atrial fibrillation and advanced interatrial block: The two sides of the same coin; and (4) P-wave parameters: Clinical implications., (© 2023 The Authors. Annals of Noninvasive Electrocardiology published by Wiley Periodicals LLC.)

Introduction: Data regarding atrial electrocardiographic parameters in patients with atrial myxomas are scarce., Methods: We aimed to study atrial electrocardiographic features in patients with atrial myxomas, before and after surgery. We also analyze the incidence of atrial fibrillation during follow-up and its correlation with different P-wave indexes. In total 32 patients in sinus rhythm that underwent atrial myxoma surgery were included., Results: Mean age was 55.0 ± 12.6 years and 18 (56.3%) were women. Ten patients had left atrial enlargement (31.3%). Only one myxoma was located in the right atrium. At baseline seven cases of partial interatrial block (IAB) were detected (21.9%), two in the absence of left atrial enlargement. There were significant differences in atrial electrocardiographic indexes before and after surgery, including P-wave duration (108.9 ± 17.9 ms vs. 93.0 ± 12.4 ms; p < .001), partial IAB (21.9% vs. 3.1%; p = .012) and duration of P-wave terminal force in lead V1 negativity (-0.6 ± 0.3 vs. -0.5 ± 0.3 mm; p = .034). At a mean follow-up of 10.0 ± 5.5 years, 10 patients (31.3%) had experienced at least one episode of atrial fibrillation. Post-operative P-wave duration was associated with atrial fibrillation occurrence during follow-up (Hazard ratio: 0.90, 95% confidence interval: 0.83-0.98; p = .020)., Conclusions: Abnormalities in atrial electrocardiographic indexes are common in atrial myxomas and frequently improve after surgery. Post-operative P-wave duration is associated with atrial fibrillation occurrence during follow-up., (© 2022 Wiley Periodicals LLC.)

Background Interatrial block (IAB) has been associated with supraventricular arrhythmias and stroke, and even with sudden cardiac death in the general population. Whether IAB is associated with life-threatening arrhythmias (LTA) and sudden cardiac death in dilated cardiomyopathy (DCM) remains unknown. This study aimed to determine the association between IAB and LTA in ambulant patients with DCM. Methods and Results A derivation cohort (Maastricht Dilated Cardiomyopathy Registry; N=469) and an external validation cohort (Utrecht Cardiomyopathy Cohort; N=321) were used for this study. The presence of IAB (P-wave duration>120 milliseconds) or atrial fibrillation (AF) was determined using digital calipers by physicians blinded to the study data. In the derivation cohort, IAB and AF were present in 291 (62%) and 70 (15%) patients with DCM, respectively. LTA (defined as sudden cardiac death, justified shock from implantable cardioverter-defibrillator or anti-tachypacing, or hemodynamic unstable ventricular fibrillation/tachycardia) occurred in 49 patients (3 with no IAB, 35 with IAB, and 11 patients with AF, respectively; median follow-up, 4.4 years [2.1; 7.4]). The LTA-free survival distribution significantly differed between IAB or AF versus no IAB (both P <0.01), but not between IAB versus AF ( P =0.999). This association remained statistically significant in the multivariable model (IAB: HR, 4.8 (1.4-16.1), P =0.013; AF: HR, 6.4 (1.7-24.0), P =0.007). In the external validation cohort, the survival distribution was also significantly worse for IAB or AF versus no IAB ( P =0.037; P =0.005), but not for IAB versus AF ( P =0.836). Conclusions IAB is an easy to assess, widely applicable marker associated with LTA in DCM. IAB and AF seem to confer similar risk of LTA. Further research on IAB in DCM, and on the management of IAB in DCM is warranted.

Introduction and Objectives: There are scarce data on left atrial (LA) enlargement and electrophysiological features in athletes., Methods: Multicenter observational study in competitive athletes and controls. LA enlargement was defined as LA volume indexed to body surface area ≥ 34mL/m 2 . We analyzed its relationship with atrial electrocardiography parameters., Results: We included 356 participants, 308 athletes (mean age: 36.4±11.6 years) and 48 controls (mean age: 49.3±16.1 years). Compared with controls, athletes had a higher mean LA volume index (29.8±8.6 vs 25.6±8.0mL/m 2 , P=.006) and a higher prevalence of LA enlargement (113 [36.7%] vs 5 [10.4%], P <.001), but there were no relevant differences in P-wave duration (106.3±12.5ms vs 108.2±7.7ms; P=.31), the prevalence of interatrial block (40 [13.0%] vs 4 [8.3%]; P=.36), or morphology-voltage-P-wave duration score (1.8±0.84 vs 1.5±0.8; P=.71). Competitive training was independently associated with LA enlargement (OR, 14.7; 95%CI, 4.7-44.0; P <.001) but not with P-wave duration (OR, 1.02; 95%CI, 0.99-1.04), IAB (OR, 1.4; 95%CI, 0.7-3.1), or with morphology-voltage-P-wave duration score (OR, 1.4; 95%CI, 0.9-2.2)., Conclusions: LA enlargement is common in adult competitive athletes but is not accompanied by a significant modification in electrocardiographic parameters., (Copyright © 2021 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.)

Atrial cardiomyopathy, characterized by abnormalities in atrial structure and function, is associated with increased risk of adverse cardiovascular and neurocognitive outcomes, independent of atrial fibrillation. There exists a critical unmet need for a clinical tool that is cost-effective, easy to use, and that can diagnose atrial cardiomyopathy. P wave parameters (PWPs) reflect underlying atrial structure, size, and electrical activation; alterations in these factors manifest as abnormalities in PWPs that can be readily ascertained from a standard 12-lead ECG and potentially be used to aid clinical decision-making. PWPs include P wave duration, interatrial block, P wave terminal force in V 1 , P wave axis, P wave voltage, P wave area, and P wave dispersion. PWPs can be combined to yield an index (P wave index), such as the morphology-voltage-P-wave duration ECG risk score. Abnormal PWPs have been shown in population-based cohort studies to be independently associated with higher risks of atrial fibrillation, ischemic stroke, sudden cardiac death, and dementia. Additionally, PWPs, either individually or in combination (as a P wave index), have been reported to enhance prediction of atrial fibrillation or ischemic stroke. To facilitate translation of PWPs to routine clinical practice, additional work is needed to standardize measurement of PWPs (eg, via semiautomated or automated measurement), confirm their reliability and predictive value, leverage novel approaches (eg, wavelet analysis of P waves and machine learning algorithms), and finally, define the risk-benefit ratio of specific interventions in high-risk individuals. Our ultimate goal is to repurpose the ubiquitous 12-lead ECG to advance the study, diagnosis, and treatment of atrial cardiomyopathy, thus overcoming critical challenges in prevention of cardiovascular disease and dementia.

Interatrial block (IAB) is an electrocardiographic pattern describing the conduction delay between the right and left atria. IAB is classified into 3 degrees of block that correspond to decreasing conduction in the region of Bachmann's bundle. Although initially considered benign in nature, specific subsets of IAB have been associated with atrial arrhythmias, elevated thromboembolic stroke risk, cognitive impairment, and mortality. As the pathophysiologic relationships between IAB and stroke are reinforced, investigation has now turned to the potential benefit of early detection, atrial imaging, cardiovascular risk factor modification, antiarrhythmic pharmacotherapy, and stroke prevention with oral anticoagulation. This review provides a contemporary overview of the epidemiology, pathophysiology, diagnosis, and management of IAB, with a focus on future directions., Competing Interests: Funding Support and Author Disclosures The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2022 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

The two most common modes of death among chronic heart failure (CHF) patients are sudden cardiac death (SCD) and pump failure death (PFD). Periodic repolarization dynamics (PRD) quantifies low-frequency oscillations in the T wave vector of the electrocardiogram (ECG) and has been postulated to reflect sympathetic modulation of ventricular repolarization. This study aims to evaluate the prognostic value of PRD to predict SCD and PFD in a population of CHF patients. 20-min high-resolution (1000 Hz) ECG recordings from 569 CHF patients were analyzed. Patients were divided into two groups, [Formula: see text] and [Formula: see text], corresponding to PRD values above and below the optimum cutoff point of PRD in the study population. Univariate Cox regression analysis showed that SCD risk in the [Formula: see text] group was double the risk in the [Formula: see text] group [hazard ratio (95% CI) 2.001 (1.127-3.554), [Formula: see text]]. The combination of PRD with other Holter-based ECG indices, such as turbulence slope (TS) and index of average alternans (IAA), improved SCD prediction by identifying groups of patients at high SCD risk. PFD could be predicted by PRD only when combined with TS [hazard ratio 2.758 (1.572-4.838), [Formula: see text]]. In conclusion, the combination of PRD with IAA and TS can be used to stratify the risk for SCD and PFD, respectively, in CHF patients., (© 2021. The Author(s).)

Bayés's syndrome is a clinical entity based on the association between advanced interatrial block and the development of supraventricular tachyarrhythmia, being atrial fibrillation (AF) the most frequent. This association was discovered by Prof. Antoni Bayés de Luna in the '80s. Further studies by other groups found a strong relationship between Bayés's syndrome and thromboembolic phenomena, being stroke the most serious. Moreover, patients with this syndrome have an increased incidence of cognitive impairment and dementia. This observation triggered the question about whether the use of anticoagulation therapy prior to the documentation of AF could prevent A-IAB associated thromboembolic events. There are ongoing studies in different phases of development aiming to compare the efficacy of anticoagulation in patients with A-IAB with no prior documentation of AF. The outcomes of these studies will allow determining the efficacy of this early therapeutic intervention, and help deciding the role of anticoagulation in patients with A-IAB and no demonstrated AF., Competing Interests: Conflictos de interés: Los autores declaran no tener ningún conflicto de interés.

Background: An association between interatrial block (IAB) (P wave duration ≥120 ms) and dementia has been suggested. Our objective was to assess the association of IAB with cognitive impairment (CI)., Methods: The prospective BAYES registry included 552 patients ≥70 years with structural heart disease without documented atrial fibrillation. Cognitive ability was assessed at baseline and every 6 months with the Pfeiffer test. The median follow-up was 22 months., Results: Thirty patients (5.4%) had baseline CI, 20 patients with mild CI and 10 with moderate CI. Compared to patients without CI, patients with CI had higher mean age (80.4 ± 6.5 vs. 76.8 ± 5.4 years) and higher prevalence of advanced IAB (with biphasic P-wave ± in inferior leads) (14 [46.7%] vs. 122 [23.4%], p < .01). The prevalence of baseline CI was 2.7% in normal P-wave, 5.1% in partial IAB, and 10.3% in advanced IAB, p < .001. Advanced IAB was independently associated with baseline CI (odds ratio 4.9, 95% confidence interval 1.4-16.5), this was not the case with partial IAB (odds ratio 2.1, 95% confidence interval 0.5-7.4). The independent association with CI at follow-up existed both for partial IAB (hazard ratio 1.98, 95% confidence interval 1.18-3.33) and advanced IAB (hazard ratio 2.04, 95% confidence interval 1.19-3.51)., Conclusion: In patients aged 70 years or more with structural heart disease who are in sinus rhythm advanced IAB is associated with baseline CI. There is also an association of partial and advanced IAB with CI during follow-up., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The association between atrial fibrillation, stroke, and interatrial block (IAB) (P-wave duration ≥120 ms) is well recognized, particularly in the case of advanced IAB. We aimed to assess the association of IAB with mild cognitive impairment. Advanced Characterization of Cognitive Impairment in Elderly with Interatrial Block was a case-control multicenter study, conducted in subjects aged ≥70 years in sinus rhythm without significant structural heart disease. Diagnosis of mild cognitive impairment was performed by an expert geriatrician, internist, or neurologist in the presence of changes in cognitive function (Mini Mental State Examination score 20 to 25) without established dementia. A total of 265 subjects were included. Mean age was 79.6 ± 6.3 years and 174 (65.7%) were women; there were 143 cases with mild cognitive impairment and 122 controls with normal cognitive function. Compared with controls, cases had longer P-wave duration (116.2 ± 13.8 ms vs 112.5 ± 13.3 ms, p = 0.028), higher prevalence of IAB (73 [51.0%] vs 38 [31.1%], p = 0.001), higher prevalence of advanced IAB (28 [19.6%] vs 10 [8.2%], p = 0.002), and higher MVP ECG risk score (2.7 ± 1.4 vs 2.2 ± 1.3, p = 0.004). IAB was independently associated with mild cognitive impairment, both for partial (odds ratio 2.0, 95% CI: 1.1 to 3.9) and advanced IAB (odds ratio 2.8, 95% CI: 1.1 to 6.7). In conclusion, in subjects aged ≥70 years without significant structural heart disease, IAB is independently associated with mild cognitive impairment. This association is stronger in the case of advanced IAB., Competing Interests: Declaration of interests The authors declare that they have no known competing financial interests or personal relations that could have appeared to influence the work reported in this study., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background The clinical significance of conduction disturbances after transcatheter aortic valve implantation has been described; however, little is known about the influence of baseline ECGs in the prognosis of these patients. Our aim was to study the influence of baseline ECG parameters, including interatrial block (IAB), in the prognosis of patients treated with transcatheter aortic valve implantation. Methods and Results The BIT (Baseline Interatrial Block and Transcatheter Aortic Valve Implantation) registry included 2527 patients with aortic stenosis treated with transcatheter aortic valve implantation. A centralized analysis of baseline ECGs was performed. Patients were divided into 4 groups: normal P wave duration (<120 ms); partial IAB (P wave duration ≥120 ms, positive in the inferior leads); advanced IAB (P wave duration ≥120 ms, biphasic [+/-] morphology in the inferior leads); and nonsinus rhythm (atrial fibrillation/flutter and paced rhythm). The mean age of patients was 82.6±9.8 years and 1397 (55.3%) were women. A total of 960 patients (38.0%) had a normal P wave, 582 (23.0%) had partial IAB, 300 (11.9%) had advanced IAB, and 685 (27.1%) presented with nonsinus rhythm. Mean follow-up duration was 465±171 days. Advanced IAB was the only independent predictor of all-cause mortality (hazard ratio [HR], 1.48; 95% CI, 1.10-1.98 [ P =0.010]) and of the composite end point (death/stroke/new atrial fibrillation) (HR, 1.51; 95% CI, 1.17-1.94 [ P =0.001]). Conclusions Baseline ECG characteristics influence the prognosis of patients with aortic stenosis treated with transcatheter aortic valve implantation. Advanced IAB is present in about an eighth of patients and is associated with all-cause death and the composite end point of death, stroke, and new atrial fibrillation during follow-up.

Background: The criteria applied for diagnosis of left atrial (LA) abnormality using electrocardiogram (ECG) have high specificity but low sensitivity. In fact, some authors have suggested classifying P-wave anomalies associated with LA abnormality and interatrial block as "atrial abnormalities." The most widely known ECG criteria for LA abnormality include P-wave duration, morphology and voltage of P wave in inferior leads, presence of P-wave terminal force in V 1 (PtfV 1 ), and P-wave axis and area. PtfV 1 has also been reported to vary according to misplacement of the V 1 and V 2 electrodes., Methods: The objective of this observational cohort study is to determine the degree of correlation between ECG criteria for LA abnormality and left atrium volume and functionality, as determined by speckle tracking echocardiography. The study also aims to investigate the correlation between these echocardiographic parameters and PtfV 1 value by placing the V 1 and V 2 electrodes in the second, third, and fourth intercostal spaces., Results and Conclusions: Our results could help to clarify whether the decrease in left atrial deformity, which is currently considered a surrogate target of fibrosis, correlates better with ECG criteria for LA abnormality than atrial volumes., (© 2020 The Authors. Annals of Noninvasive Electrocardiology published by Wiley Periodicals LLC.)

Bayés syndrome is a new clinical entity, characterized by the association of advanced interatrial block (IAB) on surface electrocardiogram with atrial fibrillation (AF) and other atrial arrhythmias. This syndrome is associated with an increased risk of stroke, dementia, and mortality. Advanced IAB is diagnosed by the presence of a P-wave ≥ 120ms with biphasic morphology (±) in inferior leads. The cause of IAB is complete Bachmann bundle blockade, leading to retrograde depolarization of the left atrium from areas near the atrioventricular junction. The anatomic substrate of advanced IAB is fibrotic atrial cardiomyopathy. Dyssynchrony induced by advanced IAB is a trigger and maintenance mechanism of AF. This alteration of the atrial architecture produces atrial remodeling, blood stasis and hypercoagulability, triggering the thrombogenic cascade. The presence of advanced IAB, even in patients without documented atrial arrhythmias, has also been associated with AF, stroke, dementia, and mortality. However, in these patients, there is no evidence to support the use of anticoagulation. Therefore, in patients with advanced IAB, a proactive search for AF is recommended., (Copyright © 2020 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.)

Introduction: Advanced interatrial block (IAB) on a 12-lead electrocardiogram (ECG) is a predictor of stroke, incident atrial fibrillation (AF), and AF recurrence after catheter ablation. The objective of this study was to determine which features of IAB structural remodeling is associated with left atrium (LA) magnetic resonance imaging structure and function., Methods/results: We included 152 consecutive patients (23% nonparoxysmal AF) who underwent preprocedural ECG and cardiac magnetic resonance (CMR) in sinus rhythm before catheter ablation of AF. IAB was defined as P-wave duration ≥120 ms, and was considered partial if P-wave was positive and advanced if P-wave had a biphasic morphology in inferior leads. From cine CMR and late gadolinium enhancement, we derived LA maximum and minimum volume indices, strain, LA fibrosis, and LA dyssynchrony. A total of 77 patients (50.7% paroxysmal) had normal P-wave, 52 (34.2%) partial IAB, and 23 (15.1%) advanced IAB. Patients with advanced IAB had significantly higher LA minimum volume index (25.7 vs 19.9 mL/m 2 , P = .010), more LA fibrosis (21.9% vs 13.1%, P = .020), and lower LA maximum strain rate (0.99 vs 1.18, P = .007) than those without. Advanced IAB was independently associated with LA (minimum [P = .032] and fibrosis [P = .009]). P-wave duration was also independently associated with LA fibrosis (β = .33; P = .049) and LA mechanical dyssynchrony (β = 2.01; P = .007)., Conclusion: Advanced IAB is associated with larger LA volumes, lower emptying fraction, and more fibrosis. Longer P-wave duration is also associated with more LA fibrosis and higher LA mechanical dyssynchrony., (© 2020 Wiley Periodicals LLC.)

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., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

Advanced interatrial block (A-IAB) has been associated to atrial fibrillation (AF) and ischemic stroke, raising the question as to whether such patients, even when still in sinus rhythm without documented AF, could benefit from oral anticoagulation. AF and A-IAB are both markers of stroke. The anatomical substrate in both is fibrotic atrial cardiomyopathy, resulting in atrial electromechanical dyssynchrony, dysfunction, and left atrial remodelling, that favour blood stasis and hypercoagulation. Under these conditions thrombogenic cascade may be triggered, resulting in systemic embolization. Before proposing oral anticoagulation in the management of selected patients with A-IAB, as is currently recommended in patients with AF and high CHA 2 DS 2 -Vasc score, a randomized clinical trial will have to demonstrate efficacy and safety of anticoagulation in this setting. In the meantime, an individualized approach may be considered based on the recognition of those patients at a higher risk of stroke. These may be elderly patients with A-IAB and several risk factors and, thus, with a high CHA 2 DS 2 -Vasc score and the presence of environmental arrhythmias., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Introduction: Partial and advanced interatrial block (IAB) in the electrocardiographic (ECG) represents inter-atrial conduction delay. IAB is associated with atrial fibrillation (AF) and stroke in the general population. Material and methods: A representative sample of Finnish subjects ( n  = 6354) aged over 30 years (mean: 52.2 years, standard deviation: 14.6) underwent a health examination including a 12-lead ECG. Five different IAB groups based on automatic measurements were compared to normal P waves using multivariate-adjusted Cox proportional hazard model. Follow-up lasted up to 15 years. Results: The prevalence of advanced and partial IAB was 1.0% and 9.7%, respectively. In the multivariate model, both advanced (hazard ratio (HR): 1.63 (95% confidence interval (CI): 1.00-2.65)) and partial IAB (HR: 1.39 (1.09-1.77)) were associated with increased risk of AF. Advanced IAB was associated with increased risk of stroke or transient ischaemic attack (TIA) independently of associated AF (HR: 2.22 (1.20-4.13)). Partial IAB was also associated with increased risk of being diagnosed with coronary heart disease (HR: 1.26 (1.01-1.58)). Discussion: IAB is a rather frequent finding in the general population. IAB is a risk factor for AF and is associated with an increased risk of stroke or TIA independently of associated AF.Key messagesBoth partial and advanced interatrial block are associated with increased risk of atrial fibrillation in the general population.Advanced interatrial block is an independent risk factor for stroke and transient ischaemic attack.The clinical significance of interatrial block is dependent on the subtype classification.

We present the surface electrocardiogram of an open-chest anesthetized healthy adult swine after direct application of ice at the transversus sinus of the pericardium where the Bachmann's region is located. Gradual and transient interatrial block (IAB) in the absence of structural atrial disease is described. This new experimental model demonstrated that IAB is an independent entity from left atrial enlargement., (© 2020 Wiley Periodicals, Inc.)

Atrial dysfunction has been widely considered a marker or consequence of other cardiac conditions rather than the cause itself. Here, we propose the term atrial failure as a clinically relevant entity, defined as any atrial dysfunction causing impaired heart performance, symptoms, and worsening quality of life or life expectancy. Aspects of the etiology, mechanisms, and consequences of atrial failure are discussed. Recent advances in cardiac electrophysiology and imaging have improved our understanding of the highly complex atrial anatomy and function, underlying the paramount importance of the atria in optimal heart performance. It is time to reappraise the concept of the failing atrium as a primary cause or aggravating factor of the symptoms in many of our patients. The concept of atrial failure may foster basic and translational research to gain a better understanding of how to identify and manage atrial dysfunction., (Copyright © 2020 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Aims: One third of ischemic strokes are of unknown etiology. Interatrial block (IAB) is a marker of atrial electromechanical dysfunction that may predispose to the development of atrial fibrillation (AF). We hypothesized that IAB, especially in its advanced form, could be a marker of covert AF in patients with embolic stroke of undetermined source (ESUS)., Methods: We reviewed a single center cohort of ESUS patients with no prior history of AF. According to P-wave analysis of baseline ECG we distinguished 3 groups: normal P-wave duration (P-wave < 120 ms), partial IAB (P-IAB, P-wave ≥ 120 ms) and A-IAB (A-IAB, P-wave ≥ 120 ms with biphasic morphology in inferior leads). Follow-up was done 1, 6 and 12 months after discharge; then every 6 months. AF episodes, frequent premature atrial contractions (PACs) (>1%) and atrial tachyarrhythmias (runs of >3 consecutive PACs) were detected on 24 h Holter. The primary endpoint was new-onset AF detection on follow-up by any means., Results: A high prevalence of both P-IAB (n = 30, 40%) and A-IAB (n = 23, 31%) was found in 75 ESUS patients. After a 521 day mean follow-up, 14 patients (19%) were diagnosed of AF. A-IAB independently predicted AF diagnosis (p =0.042) on follow-up. 24 h Holter analysis showed greater frequency of PACs and atrial tachyarrhythmia episodes in patients with IAB (p = 0.0275)., Conclusions: In this hypothesis-generating study, A-IAB in the setting of ESUS is an independent risk predictor of covert AF. Although additional randomized clinical trials are warranted, A-IAB identifies ESUS patients with advanced atrial disease that could potentially benefit from early oral anticoagulation in secondary prevention., Competing Interests: Declaration of competing interest Dr. Lluis Mont has received research grants, support for fellowship program, and honoraria as consultant and lecturer from Abbott, Boston Scientific, Medtronic, Biotronik and Biosense. He is a Shareholder for Galgo Medical SL. The rest of authors have no conflicts of interest to declare., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Aortic stenosis (AS) is currently the most frequent heart valve disease. Symptomatic severe AS has a poor prognosis and transcatheter aortic valve implantation (TAVI) is becoming the therapy of choice in these patients. Changes in the conduction tissue after the procedure constitute one of the main limitations of TAVI, with a frequent need for a definitive pacemaker. Interatrial block (IAB) is defined as a prolonged P-wave duration and is related with atrial fibrosis. The presence of IAB could be a marker of conduction tissue abnormalities at other levels. No study has specifically analyzed the role of IAB as a predictor of the need for permanent pacemaker in patients with AS undergoing TAVI., Methods: The Baseline Interatrial block and Transcatheter aortic valve implantation (BIT) registry will be performed in approximately 3000 patients with severe AS treated with TAVI. A centralized analysis of baseline ECGs will study the presence and type of IAB and other ECG data (rhythm, P-wave duration, PR and QRS intervals/intraventricular conduction disorders). Clinical follow-up will be carried out by local researchers. The primary endpoint will be the requirement of permanent pacemaker during post-TAVI hospitalization. As secondary objectives, the incidence of new onset AF, stroke, or mortality during follow-up will be analyzed. Secondary endpoints will include the incidence of new onset AF, stroke, or mortality during follow-up., Conclusion: The BIT registry will study, for the first time, the influence of previous IAB in the need of permanent pacemaker after TAVI: This large registry will also provide information regarding the association of this and other ECG parameters with prognosis., (Copyright © 2019 Elsevier Inc. All rights reserved.)

As medical education evolves, some traditional teaching methods often get forgotten. For generations, the Lewis ladder diagram (LLD) has helped students understand the mechanisms of cardiac arrhythmias and conduction disorders. Similarly, clinicians have used LLDs to communicate their proposed mechanisms to their colleagues and trainees. In this article, we revisit this technique of constructing the LLD and demonstrate this process by describing the mechanisms of various bigeminal rhythms., (© 2019 Wiley Periodicals, Inc.)

Background: Brugada phenocopies clinical entities that have indistinguishable electrocardiographic (ECG) patterns from true congenital Brugada syndrome. However, they are induced by other clinical circumstances such as myocardial ischemia. The purpose of our study was to examine the clinical features and pathogenesis of ischemia-induced Brugada phenocopy (BrP)., Methods: Data from 17 cases of ischemia-induced BrP were collected from the International Registry (www.brugadaphenocopy.com). Data were extracted from these publications and authors were contacted to provide further insight into each case., Results: Of the patients included in this study, 71% were male. Mean age was 59 ± 11 years (range: 38-76). Type-1 Brugada ECG pattern occurred in 15/17 (88%) of the cases, while a type-2 Brugada ECG pattern was observed in the other 2/17 (12%). In all cases, the Brugada ECG pattern resolved upon correction of the ischemia, indicating ischemia as the inducing circumstance. No arrhythmic events have been detected acutely or during the follow-up. Reported time to resolution ranged from 2 minutes to 5 hours. Provocative challenges using sodium channel blocking agents were performed in 7/17 cases (41%), and all failed to induce a Brugada ECG pattern (BrP Class A). The remaining 10/17 cases (59%) did not undergo provocative testing due to various clinical reasons., Conclusions: Myocardial ischemia is a commonly reported etiology of BrP. Importantly, this study found no association between BrP induced by myocardial ischemia and sudden cardiac death or malignant ventricular arrhythmias., (© 2019 Wiley Periodicals, Inc.)

Background: The influence of interatrial block (IAB) in the prognosis after an acute ST-segment elevation myocardial infarction (STEMI) is unknown., Objectives: To assess the prognostic impact of IAB after an acute STEMI regarding long-term mortality, development of atrial fibrillation, and stroke., Methods: Registry of 972 consecutive patients with STEMI and sinus rhythm at discharge, with a long-term follow-up (49.6 ± 24.9 months). P wave duration was analyzed using digital calipers, and patients were divided into three groups: normal P wave duration (<120 ms), partial IAB (pIAB) (P wave ≥120 ms and positive in inferior leads), and advanced IAB (aIAB) (P wave ≥120 ms plus biphasic [positive/negative] morphology in inferior leads)., Results: Mean age was 62.6 ± 13.5 years. A total of 708 patients had normal P wave (72.8%), 207 pIAB (21.3%), and 57 aIAB (5.9%). Patients with aIAB were older (mean age 73 years) than the rest (62 years in the other two groups, p < 0.001). They also had a higher rate of hypertension (70 vs. 55% in pIAB and 49% in normal P wave, p = 0.006) and higher all-cause mortality (26.3 vs. 12.6% in pIAB and 10.3% in normal P wave, p = 0.001). However, multivariable analysis did not show an independent association between IAB and prognosis., Conclusion: About a quarter of patients discharged in sinus rhythm after an acute STEMI have IAB. Patients with aIAB have a poor prognosis, although this is explained mainly by the association of aIAB with age and other variables., (© 2019 S. Karger AG, Basel.)

Aims: Advanced interatrial block (IAB) is characterized by a prolonged (≥120 ms) and bimodal P wave in the inferior leads. The association between advanced IAB and atrial fibrillation (AF) is known as "Bayes' Syndrome", and there is scarce information about it in heart failure (HF). We examined the prevalence of IAB and whether advanced IAB could predict new-onset AF and/or stroke in HF patients., Methods and Results: The prospective observational "Bayes' Syndrome-HF" study included consecutive outpatients with chronic HF. The primary endpoints were new-onset AF, ischemic stroke, and the composite of both. A secondary endpoint included all-cause death alone or in combination with the primary endpoint. Comprehensive multivariable Cox regression analyses were performed. Among 1050 consecutive patients, 536 (51.0%) were in sinus rhythm, 464 with a measurable P wave are the focus of this study. Two-hundred and sixty patients (56.0%) had normal atrial conduction, 95 (20.5%) partial IAB, and 109 (23.5%) advanced IAB. During a mean follow-up of 4.5 ± 2.1 years, 235 patients experienced all-cause death, new-onset AF, or stroke. In multivariable comprehensive Cox regression analyses, advanced IAB was associated with new-onset AF (HR 2.71 [1.61-4.56], P < 0.001), ischemic stroke (HR 3.02 [1.07-8.53], P = 0.04), and the composite of both (HR 2.42 [1.41-4.15], P < 0.001)., Conclusions: In patients with HF advanced IAB predicts new-onset AF and ischemic stroke. Future studies must assess whether anticoagulant treatment in Bayes' Syndrome leads to better outcomes in HF., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The advanced interatrial block (A-IAB) (P ≥ 120 ms plus ± pattern in II, III and aVF) corresponds at atrial level, to right or left advanced bundle branch block at ventricular level, and it is well known that these patterns may be seen transiently in relation to taquicardia or bradycardia (tachycardia or bradycardia dependent right or left bundle branch block). We present for the first time, the same phenomenon at atrial level. In one case, the A-IAB appears in relation to tachycardization and in the other disappears during a pause induced by ventricular premature complex., (© 2018 Wiley Periodicals, Inc.)

The diagnosis of advanced interatrial block (A-IAB) is done by surface ECG analysis when the P-wave ≥120 ms with biphasic (±) morphology in leads II, III and aVF. In this brief communication, we advance a new concept involving atypical patterns of A-IAB due to changes about the morphology or duration of the P-wave. It remains to be determined its real prevalence in different clinical scenarios, and whether these atypical ECG patterns should be considered as predictors of atrial fibrillation/stroke., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Arrhythmogenic right ventricular dysplasia or cardiomyopathy (ARVD/C) is a pathologic condition where the right ventricle is partially or totally replaced by fatty and fibrous tissue. The electrocardiogram (ECG) has a central role for diagnosis since it comprises two major and two minor criteria in the diagnostic criteria published by the Task 1 Force, although it is not 100% necessary to make a final diagnosis, because around 10% of patients with ARVD/C present with a normal ECG. In this article, we review the 12-lead electrocardiographic findings of patients with ARVD/C. ECG criteria observed during depolarization [prolonged terminal activation duration, epsilon wave, partial right bundle branch block (RBBB) and advanced RBBB of peripheral origin with characteristic ECG patterns] and repolarization abnormalities, (negative T waves) are reviewed in detail. More common ventricular arrhythmias and risk of sudden death, and how to use the surface ECG to stratify the risk, are part of our final comments.

Background: To evaluate the possibility of left atrial (LA) remodeling using speckle tracking echocardiography (STE) in patients with interatrial block (IAB)., Methods: We performed a cross-sectional study with three groups of patients: 56 without IAB, 21 with partial IAB (pIAB), and 22 with advanced IAB (aIAB). Transthoracic echocardiographic (TTE) STE was performed and clinical and echocardiographic findings were analyzed., Results: TTE showed higher LA volume/body surface area in the patients with IAB. With STE, the absolute value of strain rate during atrial booster pump function (SRa) and early reservoir period (SRs) decreased in the pIAB group and even more in the aIAB group, compared to the group without IAB. The independent variables were the echocardiographic measures of LA size and function. After adjusting for confounders, both multiple linear regression and multivariate multinomial regression showed good correlation with dependent variables: longer P-wave duration on electrocardiography and with the type of IAB, respectively. SRa (p < 0.001), SRs (p < 0.001), and maximal peak LA longitudinal strain in the reservoir period (p = 0.009) were independently associated with P-wave duration. SRa was also associated with the presence of pIAB (OR = 11.5; 95% confidence interval (CI): 2.7-49.0; p = 0.001) and aIAB, (OR = 98.2; 95% CI: 16-120.4; p < 0.001) and SRs was associated with pIAB (OR: 0.03; CI: 0.003-0.29; p = 0.003) and with aIAB (OR: 0.008; CI: 0.001-0.12; p = 0.004)., Conclusions: IAB correlates directly with structural remodeling and a decrease in the absolute value of LA SRa and SRs determined using STE.

Most heart failure (HF) related mortality is due to sudden cardiac death (SCD) and worsening HF, particularly in the case of reduced ejection fraction. Predicting and preventing SCD is an important goal but most works include no or few patients with advanced age, and the prevention of SCD in elderly patients with HF is still controversial. A recent reduction in the annual rate of SCD has been recently described but it is not clear if this is also true in advanced age patients. Age is associated with SCD, although physicians frequently have the perception that elderly patients with HF die mainly of pump failure, underestimating the importance of SCD. Other clinical variables that have been associated to SCD are symptoms, New York Heart Association functional class, ischemic cause, and comorbidities (chronic obstructive pulmonary disease, renal dysfunction and diabetes). Some test results that should also be considered are left ventricular ejection fraction and diameters, natriuretic peptides, non-sustained ventricular tachycardias and autonomic abnormalities. The combination of all these markers is probably the best option to predict SCD. Different risk scores have been described and, although there are no specific ones for elderly populations, most include age as a risk predictor and some were developed in populations with mean age > 65 years. Finally, it is important to stress that these scores should be able to predict any type of SCD as, although most are due to tachyarrhythmias, bradyarrhythmias also play a role, particularly in the case of the elderly.

Background: Sudden cardiac death (SCD) and pump failure death (PFD) are common endpoints in chronic heart failure (CHF) patients, but prevention strategies are different. Currently used tools to specifically predict these endpoints are limited. We developed risk models to specifically assess SCD and PFD risk in CHF by combining ECG markers and clinical variables., Methods: The relation of clinical and ECG markers with SCD and PFD risk was assessed in 597 patients enrolled in the MUSIC (MUerte Súbita en Insuficiencia Cardiaca) study. ECG indices included: turbulence slope (TS), reflecting autonomic dysfunction; T-wave alternans (TWA), reflecting ventricular repolarization instability; and T-peak-to-end restitution (ΔαTpe) and T-wave morphology restitution (TMR), both reflecting changes in dispersion of repolarization due to heart rate changes. Standard clinical indices were also included., Results: The indices with the greatest SCD prognostic impact were gender, New York Heart Association (NYHA) class, left ventricular ejection fraction, TWA, ΔαTpe and TMR. For PFD, the indices were diabetes, NYHA class, ΔαTpe and TS. Using a model with only clinical variables, the hazard ratios (HRs) for SCD and PFD for patients in the high-risk group (fifth quintile of risk score) with respect to patients in the low-risk group (first and second quintiles of risk score) were both greater than 4. HRs for SCD and PFD increased to 9 and 11 when using a model including only ECG markers, and to 14 and 13, when combining clinical and ECG markers., Conclusion: The inclusion of ECG markers capturing complementary pro-arrhythmic and pump failure mechanisms into risk models based only on standard clinical variables substantially improves prediction of SCD and PFD in CHF patients.

Introduction and Objectives: Atrial fibrillation (AF) is the most common clinically significant cardiac arrhythmia. P-wave duration and interatrial blocks (IAB) have been reported to be associated with AF. Our aim was to determine the individual and combined association of P-wave duration and advanced IAB morphology with AF., Methods: We designed an age-, sex-, and survey-matched case-control study nested in a population-based cohort (REGICOR: REgistre GIroní del COR). Two different surveys recruited a total of 9380 participants from 1999 to 2005; all participants were invited to a second examination between 2009 and 2013. For the present study, we selected participants aged 25 to 79 years with follow-up through the end of the study. All electrocardiograms were analyzed by 2 observers to determine P-wave duration and morphology (normal, partial, or advanced IAB)., Results: The median follow-up was 7.12 years. Eighty participants presented with AF, had a legible baseline electrocardiogram, and were included in the study, along with 160 controls. P-wave duration and the presence of partial or advanced IAB were associated with AF. When P-wave duration and morphology were considered together, only P-wave duration (≥ 110 milliseconds) showed an independent and strong association with AF. The odds ratio for AF of P-wave duration between 110-119, 120-129 and ≥ 130 milliseconds vs < 110 milliseconds were 5.33; 95%CI, 1.74-16.33, 5.08; 95%CI, 1.73-14.90 and 5.44; 95%CI, 1.95-15.15, respectively., Conclusions: A P-wave longer than 110 milliseconds increases the risk of AF. Advanced IAB morphology did not seem to provide an additional AF risk beyond that of P-wave duration., (Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.)

Atrial fibrillation (AF) is the most common sustained arrhythmia and is associated with stroke, cognitive impairment, and cardiovascular death. Some predisposing factors - as aging, diabetes, hypertension - induce and maintain electrophysiological and ultrastructural remodeling that usually includes fibrosis. Interatrial conduction disturbances play a crucial role in the initiation of atrial fibrosis and in its associated complications. The diagnosis of interatrial blocks (IABs) is easy to perform using the surface ECG. IAB is classified as partial when the P wave duration is ≥120 ms, and advanced if the P wave also presents a biphasic pattern in II, III and aVF. IAB is very frequent in the elderly and, particularly in the case of the advanced type, is associated with AF, AF recurrences, stroke, and dementia. The anticoagulation in elderly patients at high risk of AF without documented arrhythmias is an open issue but recent data suggest that it might have a role, particularly in elderly patients with structural heart disease, high CHA 2 DS 2 VASc (Congestive heart failure/left ventricular dysfunction, Hypertension, Age ≥ 75 [doubled], Diabetes, Stroke [doubled] - Vascular disease, Age 65-74, and Sex category [female]), and advanced IAB. In this debate, we discuss the association of surface ECG IAB, a marker of atrial fibrosis, with AF and stroke. We also present the rationale that justifies further studies regarding anticoagulation in some of these patients.

Background: Patients with chronic heart failure are at high risk of sudden cardiac death (SCD). Increased dispersion of repolarization restitution has been associated with SCD, and we hypothesize that this should be reflected in the morphology of the T-wave and its variations with heart rate. The aim of this study is to propose an electrocardiogram (ECG)-based index characterizing T-wave morphology restitution (TMR), and to assess its association with SCD risk in a population of chronic heart failure patients., Methods and Results: Holter ECGs from 651 ambulatory patients with chronic heart failure from the MUSIC (MUerte Súbita en Insuficiencia Cardiaca) study were available for the analysis. TMR was quantified by measuring the morphological variation of the T-wave per RR increment using time-warping metrics, and its predictive power was compared to that of clinical variables such as the left ventricular ejection fraction and other ECG-derived indices, such as T-wave alternans and heart rate variability. TMR was significantly higher in SCD victims than in the rest of patients (median 0.046 versus 0.039, P <0.001). When TMR was dichotomized at TMR=0.040, the SCD rate was significantly higher in the TMR≥0.040 group ( P <0.001). Cox analysis revealed that TMR≥0.040 was strongly associated with SCD, with a hazard ratio of 3.27 ( P <0.001), independently of clinical and ECG-derived variables. No association was found between TMR and pump failure death., Conclusions: This study shows that TMR is specifically associated with SCD in a population of chronic heart failure patients, and it is a better predictor than clinical and ECG-derived variables., (© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Interatrial block (IAB) represents delay or block of conduction between the atria. IAB has been shown to predict the development or recurrence of atrial fibrillation (AF) in various clinical scenarios. Few studies have examined the correlation between coronary artery disease and the prevalence of IAB and its impact on AF. The aim of this study was to determine if specific coronary artery lesions (location and number) are associated with the presence of IAB and development of new-onset AF. Retrospective analysis of patients presenting with non-ST-segment elevation myocardial infarction (NSTEMI) to our institution. Data were recorded for clinical, echocardiographic, angiographic, electrocardiographic, and outcome variables. Semiautomatic calipers and scanned electrocardiograms at 300 DPI maximized × 8 were used to measure P-wave duration, with a follow-up for a minimum of 1 year. The chi-square and independent-sample t tests were done using IBM SPSS. A total of 322 patients were included in the analysis. Men 72.3%, mean age 65.4 ± 11.9 years, mean ejection fraction of 55.2 ± 12.7% and mean left atrial diameter of 38.7 ± 6 mm. The prevalence of partial IAB was 31.9%, and advanced IAB was 6.5%. Patients with IAB were significantly older (<0.001) and had a greater prevalence of hypertension (0.014). The presence of diffuse coronary artery disease defined as >1 significant coronary artery lesion was associated with IAB (0.026). No specific coronary artery lesion location was found to be associated with IAB nor increased P-wave duration. Patients who developed AF during the follow-up had a significantly higher prevalence of IAB (p = 0.021) and also higher prevalence of diffuse coronary artery disease (p = 0.001). IAB is significantly associated with diffuse coronary artery disease in patients with NSTEMI. IAB is significantly associated with the development of new-onset AF within 12 months after NSTEMI., (Copyright © 2017 Elsevier Inc. All rights reserved.)