Association of the interatrial block and left atrial fibrosis in the patients without history of atrial fibrillation.

Presence of left atrial (LA) fibrosis reflects underlying atrial cardiomyopathy. Interatrial block (IAB) is associated with LA fibrosis in patients with atrial fibrillation (AF). The association of IAB and LA fibrosis in the patients without history of AF is unknown. We examined association of IAB and LA fibrosis in the patients without AF history. This is a retrospective analysis of 229 patients undergoing cardiac magnetic resonance imaging (CMR). LA fibrosis was reported from spatial extent of late gadolinium enhancement of CMR. IAB was measured from 12-lead electrocardiography using digital caliper. Of 229 patients undergoing CMR, prevalence of IAB was 50.2%. Patients with IAB were older (56.9±13.9 years vs. 45.9±19.2 years, p<0.001) and had higher prevalence of co-morbidities. Left ventricular ejection fraction was lower in IAB group. LA volume index (LAVI) was greater in IAB group (54.6±24.9 ml/m2 vs. 43.0±21.1 ml/m2, p<0.001). Patients with IAB had higher prevalence of LA fibrosis than those without IAB (70.4% vs. 21.2%; p<0.001). After multivariable analysis, only IAB and LAVI were independent factors that predict LA fibrosis. Prevalence of IAB in patients undergoing CMR was high. IAB was highly associated with LA fibrosis and larger LA size in patients without AF history.

Left atrial strain associated with interatrial block in patients with ST-segment elevation myocardial infarction.

Both interatrial block (IAB) and left atrium (LA) strain are associated with atrial arrhythmias in ST-segment elevation myocardial infarction (STEMI) patients, but the relationship between IAB and LA strain has not yet been reported. This study was to investigate the correlation between LA strain and IAB in STEMI patients. This is a single-center retrospective clinical observational study. The STEMI patients with primary percutaneous coronary intervention (pPCI) were enrolled, and all patients completed cardiac magnetic resonance (CMR). A standard 12-lead electrocardiogram (ECG) was recorded on the same day as CMR. IAB was measured by p duration on ECG at follow-up. 302 patients were enrolled, including 91 (30.1%) with IAB. The reservoir strain, conduit strain and booster strain were included in model 1, model 2 and model 3, respectively. In model 1, age (OR 1.025; 95%CI 1.003-1.047; p = 0.026), hypertension (OR 2.188; 95%CI 1.288-3.719; p = 0.004), and reservoir strain (OR 0.947; 95%CI 0.920-0.974; p < 0.001) were independent factors for IAB. In model 2, age (OR 1.031; 95%CI 1.009-1.053; p = 0.006), hypertension (OR 2.058; 95%CI 1.202-3.522; p = 0.008), RCA lesions (OR 1.797; 95%CI 1.036-3.113; p = 0.037), and conduit strain (OR 0.910; 95%CI 0.868-0.953; p < 0.001) were independent factors for IAB. In model 3, age (OR 1.022; 95%CI 1.001-1.045; p = 0.044), hypertension (OR 2.239; 95%CI 1.329-3.773; p = 0.002), and booster strain (OR 0.948; 95%CI 0.908-0.991; p = 0.019) were independent factors for IAB. With the lowest AIC and BIC values, model 2 was the best-fit model. LA strain associated with IAB in STEMI patients. The model including conduit strain was the best-fit one.

New pattern of atypical advanced interatrial block.

INTRODUCTION: Interatrial block (IAB) is defined as prolonged P-wave duration (≥ 120 ms) due to delayed conduction in the Bachmann bundle. This is readily identifiable using surface electrocardiogram (ECG). Advanced IAB can be classified as typical and atypical. Atypical IAB can be further categorized by (i) duration or (ii) morphology. In this report, we have identified a new pattern of atypical IAB with triphasic morphology of the P-wave in the inferior leads. METHODS: Two clinical cases were evaluated including surface ECGs. P-wave durations and amplitudes were measured with digital calipers using ECG analysis software (MUSE, GE HealthCare). Comparisons were made using prior data to evaluate IAB and P-wave duration and morphology. RESULTS: A new pattern of atypical advanced IAB shows prolonged P-wave duration (P wave >160 ms) and triphasic morphology in all inferior leads with P +/+/- and P +/-/+, respectively. We speculate that triphasic P-waves in the inferior leads represent three moments of atrial depolarization; from right to left. CONCLUSION: This study describes a novel pattern of atypical advanced IAB. Further investigation regarding the increased risk of atrial fibrillation and stroke associated with this new pattern is warranted in the future.

Interatrial Block Association With Adverse Cardiovascular Outcomes in Patients Without a History of Atrial Fibrillation.

BACKGROUND: Interatrial block (IAB) is associated with thromboembolism and atrial arrhythmias. However, prior studies included small patient cohorts so it remains unclear whether IAB predicts adverse outcomes particularly in context of atrial fibrillation (AF)/atrial flutter (AFL). OBJECTIVES: This study sought to determine whether IAB portends increased stroke risk in a large cohort in the presence or absence of AFAF/AFL. METHODS: We performed a 5-center retrospective analysis of 4,837,989 electrocardiograms (ECGs) from 1,228,291 patients. IAB was defined as P-wave duration ≥120 ms in leads II, III, or aVF. Measurements were extracted as .XML files. After excluding patients with prior AF/AFL, 1,825,958 ECGs from 458,994 patients remained. Outcomes were analyzed using restricted mean survival time analysis and restricted mean time lost. RESULTS: There were 86,317 patients with IAB and 355,032 patients without IAB. IAB prevalence in the cohort was 19.6% and was most common in Black (26.1%), White (20.9%), and Hispanic (18.5%) patients and least prevalent in Native Americans (9.2%). IAB was independently associated with increased stroke probability (restricted mean time lost ratio coefficient [RMTLRC]: 1.43; 95% CI: 1.35-1.51; tau = 1,895), mortality (RMTLRC: 1.14; 95% CI: 1.07-1.21; tau = 1,924), heart failure (RMTLRC: 1.94; 95% CI: 1.83-2.04; tau = 1,921), systemic thromboembolism (RMTLRC: 1.62; 95% CI: 1.53-1.71; tau = 1,897), and incident AF/AFL (RMTLRC: 1.16; 95% CI: 1.10-1.22; tau = 1,888). IAB was not associated with stroke in patients with pre-existing AF/AFL. CONCLUSIONS: IAB is independently associated with stroke in patients with no history of AF/AFL even after adjustment for incident AF/AFL and CHA2DS2-VASc score. Patients are at increased risk of stroke even when AF/AFL is not identified.

P-wave duration and interatrial block as predictors of new-onset atrial fibrillation: A systematic review and meta-analysis.

BACKGROUND: Early detection of atrial fibrillation (AF) could improve patient outcomes. P-wave duration (PWD) and interatrial block (IAB) are known predictors of new-onset AF and could improve selection for AF screening. This meta-analysis reviews the published evidence and offers practical implications. METHODS: Publication databases were systematically searched, and studies reporting PWD and/or morphology at baseline and new-onset AF during follow-up were included. IAB was defined as partial (pIAB) if PWD≥120 ms or advanced (aIAB) if the P-wave was biphasic in the inferior leads. After quality assessment and data extraction, random-effects analysis calculated odds ratio (OR) and confidence intervals (CI). Subgroup analysis was performed for those with implantable devices (continuous monitoring). RESULTS: Among 16,830 patients (13 studies, mean 66 years old), 2,521 (15%) had new-onset AF over a median of 44 months. New-onset AF was associated with a longer PWD (mean pooled difference: 11.5 ms, 13 studies, p < 0.001). The OR for new-onset AF was 2.05 (95% CI: 1.3-3.2) for pIAB (5 studies, p = 0.002) and 3.9 (95% CI: 2.6-5.8) for aIAB (7 studies, p < 0.001). Patients with pIAB and devices had higher AF-detection risk (OR: 2.33, p < 0.001) than those without devices (OR: 1.36, p = 0.56). Patients with aIAB had similarly high risk regardless of device presence. There was significant heterogeneity but no publication bias. CONCLUSION: Interatrial block is an independent predictor of new-onset AF. The association is stronger for patients with implantable devices (close monitoring). Thus, PWD and IAB could be used as selection criteria for intensive screening, follow-up or interventions.

Evaluation of changes in atrial fibrillation predictors(P wave parameters and left atrial diameter) in morbidly obese patients undergoing bariatric surgery.

BACKGROUND: Bariatric surgery has been associated with reduced cardiovascular event in obese patients.In this study, we aimed to investigate the changes between pre-operation and post-operation atrial fibrillation predictors(p-wave parameters and left atrial diameter)in morbidly obese patients who underwent bariatric surgery. METHODS: 176 obese patients undergoing bariatric surgery were enrolled. Heart rate, PR, P-wave max, P-wave min,P-wave dispersion (PWdis), average P-axis, P-wave peak time (PWPT) of lead II and lead V1, terminal force of lead V1 (PWTF V1), partial interatrial block (p-IAB), advanced interatrial block(a-IAB), and left atrial diamete were measured both before operation and 8 months post-operation. RESULTS: Heart rate, PR, PW max, PW min, PWdis, mean P-axis, PWPT II, PWPT V1, and PWTF V1 were near their upper limits before operation. Left atrial diameter was larger than the upper limit before operation. All parameters showed statistically significant decrease at 8 months post-operation. The most significant changes were observed in PWPT II (55.69 ± 6.87 ms vs 50.43 ± 7.48 ms, p < 0.001), PWPT V1(54.21 ± 7.01 ms vs 48.02 ± 7.13 ms, p < 0.001), PWTF V1(74 [42.0%] vs 41 [23.3%], p < 0.001),p-IAB(41[23.2%]vs11[6.2%],p < 0.001),a-IAB(6[3.4%]vs2[1.1%], p < 0.001), and left atrial diameter(43.25 ± 9.23 mm vs 34.27 ± 6.21 mm,p < 0.001). CONCLUSIONS: The results of our study showed that bariatric surgery had a positive effect on the regression of P wave parameters and left atrial diameter which are predictors of atrial fibrillation.

Predictive value of interatrial block on electrocardiogram among obese patients undergoing atrial fibrillation ablation.

BACKGROUND: Determine a predictive value of interatrial block (IAB) on atrial fibrillation (AF) ablation outcomes in obese patients. METHODS: Medical records were retrospectively reviewed for 205 consecutive patients with body mass indices (BMI) ≥ 30 kg/m2 who underwent initial AF ablation. Evidence of partial IAB defined as P-wave duration (PWD) ≥ 120 ms and advanced IAB with PWD ≥ 120 ms and biphasic or negative P-wave in inferior leads was examined from sinus electrocardiograms (ECGs) within 1-year pre-ablation. The primary outcome was recurrent atrial arrhythmia after 3-month blanking period post-ablation. RESULTS: The mean BMI was 36.9 ± 5.7 kg/m2. Partial IAB and advanced IAB were observed in 155 (75.61%) and 42 (20.49%) patients, respectively. During the median follow-up of 1.35 (interquartile range 0.74, 2.74) years, 115 (56.1%) patients had recurrent atrial arrhythmias. In multivariable analysis adjusting for age, gender, persistent AF, use of antiarrhythmic drugs (AADs), left atrial volume index (LAVI), partial IAB, and advanced IAB were independent predictors of recurrent arrhythmia with hazard ratio (HR) of 2.80 (95% confidence interval [CI] 1.47-6.05; p = 0.001) and HR 1.79 (95% CI 1.11-2.82; p = 0.017), respectively. The results were similar in a subgroup analysis of patients who had no severe left atrial enlargement and a subgroup analysis of patients who were not on AADs. CONCLUSIONS: IAB is highly prevalent in patients with obesity and AF. Partial IAB, defined as PWD ≥ 120 ms, and advanced IAB with evidence of biphasic P-wave in inferior leads were independently associated with increased risk of recurrent arrhythmia after AF ablation. Its predictive value is independent of other traditional risk factors, LAVI, or use of AADs.

Value of advanced interatrial block in the diagnosis of the ischemic stroke's aetiology: A cohort study

Introduction and objectives: Advanced interatrial block has been linked with atrial fibrillation (AF) (Bayes syndrome). On the other hand, the aetiology of the stroke remains unknown in approximately 20–25% of patients admitted due to ischaemic stroke. The aim of this study was to evaluate whether advanced interatrial block and CHADS2-VASC scale is linked to AF in patients admitted due to ischaemic stroke without previous AF history.MethodsA prospective analysis of consecutive in-hospital patients admitted with ischemic stroke between January/2018 and April/2019 in a stroke hospital was performed. Patients had to be in sinus rhythm at admission and without previous history of AF/atrial flutter. During follow up patients receive the usual care.ResultsA total of 236 patients were included. The median follow-up was 540 days (407–695). 19 patients (8.1%) had advanced interatrial block at admission. Advanced interatrial block was associated with the diagnosis of AF during follow up (5 (26.3%) Vs 21 (9.7%) p=0.027). A CHADS2-VASC score>4 at admission was also associated with AF diagnosis during follow up (23(14.6%) vs 3(3.9%) p=0.009).ConclusionThis study confirms the association of advanced interatrial block and CHADS2-VASC>4 at admission with the diagnosis of AF during follow up in patients with ischemic stroke. This association could have important implications in patients with ischemic stroke who present advanced interatrial block and without previous history of AF. (AU)

Introducción y objetivos: El bloqueo interauricular (BIA) completo se relaciona con el desarrollo de arritmias supraventriculares, especialmente de fibrilación auricular (FA) (síndrome de Bayés). En este trabajo evaluamos la utilidad de este fenómeno para discernir la etiología cardioembólica en los pacientes ingresados por ictus isquémico. También se estudió la relación entre la puntuación en la escala CHADS 2-VA 2 Sc y el desarrollo de FA durante el seguimiento.MétodosAnálisis prospectivo de pacientes consecutivos ingresados por ictus isquémico entre enero del 2018 y abril del 2019 en un hospital terciario centro de referencia de ictus. Los pacientes incluidos debían de estar en ritmo sinusal en el momento del ingreso y no tener historia previa de FA/flutter auricular. Se realizó el seguimiento mediante las consultas y estudios de rutina, sin intervenir en su manejo habitual.ResultadosSe incluyó a 236 pacientes. La mediana de seguimiento fue de 540 días (407-695); 19 pacientes (8,1%) presentaron BIA en el electrocardiograma al ingreso. El BIA completo al ingreso se relacionó con el desarrollo posterior de FA (5 [26,3%) vs. 21 [9,7%]; p=0,027). También se observó que un CHADS 2-VA 2 Sc>4 al ingreso se relacionaba con presentar FA durante el seguimiento (23 [14,6%] vs. 3 [3,9%]; p=0,009).ConclusiónCon este estudio se demuestra por primera vez en pacientes con ictus isquémico que tanto el BIA completo como un CHADS 2-VA 2 Sc>4 se asocian con el desarrollo de FA en el seguimiento. Esta asociación puede tener importantes implicaciones prácticas en el manejo de pacientes ingresados por ictus que presenten BIA completo. (AU)

Interatrial Block Predicts Life-Threatening Arrhythmias in Dilated Cardiomyopathy.

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.

Cardiovascular Complications of Interatrial Conduction Block: JACC State-of-the-Art Review.

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.

Value of advanced interatrial block in the diagnosis of the ischemic stroke's aetiology: A cohort study.

INTRODUCTION AND OBJECTIVES: Advanced interatrial block has been linked with atrial fibrillation (AF) (Bayes syndrome). On the other hand, the aetiology of the stroke remains unknown in approximately 20-25% of patients admitted due to ischaemic stroke. The aim of this study was to evaluate whether advanced interatrial block and CHADS2-VASC scale is linked to AF in patients admitted due to ischaemic stroke without previous AF history. METHODS: A prospective analysis of consecutive in-hospital patients admitted with ischemic stroke between January/2018 and April/2019 in a stroke hospital was performed. Patients had to be in sinus rhythm at admission and without previous history of AF/atrial flutter. During follow up patients receive the usual care. RESULTS: A total of 236 patients were included. The median follow-up was 540 days (407-695). 19 patients (8.1%) had advanced interatrial block at admission. Advanced interatrial block was associated with the diagnosis of AF during follow up (5 (26.3%) Vs 21 (9.7%) p=0.027). A CHADS2-VASC score>4 at admission was also associated with AF diagnosis during follow up (23(14.6%) vs 3(3.9%) p=0.009). CONCLUSION: This study confirms the association of advanced interatrial block and CHADS2-VASC>4 at admission with the diagnosis of AF during follow up in patients with ischemic stroke. This association could have important implications in patients with ischemic stroke who present advanced interatrial block and without previous history of AF.

Advanced interatrial block predicts recurrence of embolic stroke of undetermined source.

BACKGROUND: Advanced interatrial block (IAB) is an independent risk factor for ischaemic stroke. This study aimed to analyse whether advanced IAB predicts recurrence of embolic stroke of undetermined source (ESUS). METHODS: 104 patients with a confirmed diagnosis of ESUS were followed up for a median period of 15 months (interquartile range, 10-48). We recorded data on clinical variables, P-wave characteristics, and presence of IAB on the electrocardiogram (ECG). ECG findings were interpreted by a blinded, centralised rater at (XXXX2). ESUS recurrence was the primary outcome variable. RESULTS: Median age was 47 years (range, 19-85); 50% of patients were women. IAB was detected in 36 patients (34.6%); IAB was partial in 29 cases (27.9%) and advanced in 7 (6.7%). Sixteen patients (15.4%) presented stroke recurrence; of these, 5 had partial and 4 had advanced IAB (P = .01; odds ratio [OR] = 9.44; 95% confidence interval [CI], 1.88-47.46; relative risk [RR] = 4.62; 95% CI, 2.01-10.61). Median P-wave duration was longer in patients with stroke recurrence (P = .009). The multivariate logistic regression analysis identified the following independent risk factors for stroke recurrence: advanced IAB (P < .001; OR = 10.86; 95% CI, 3.07-38.46), male sex (P = .028; OR = 4.6; 95% CI, 1.18-17.96), and age older than 50 years (P = .039; OR = 3.84; 95% CI, 1.06-13.88). In the Cox proportional hazards model, the risk variables identified were age older than 50 years (P = .002; hazard ratio, 7.04; 95% CI, 2.06-23.8) and P-wave duration (per ms) (P = .007; hazard ratio, 1.02; 95% CI, 1.01-1.04). CONCLUSIONS: Advanced IAB and age older than 50 years predict ESUS recurrence.

Ischemic stroke in a patient with interatrial block: Is it only a coincidence or a clear relationship?

Atrial fibrillation (AF) can be detected in nearly 25% of all patients with stroke by sequentially combining different electrocardiographic methods. Prediction of early cardio-embolic stroke remain a permanent challenge in everyday practice. The early identification of an increased risk for atrial fibrillation episodes (which are frequently asymptomatic) is essential for the prevention of cardioembolic events. One of the noninvasive modalities of atrial fibrillation prediction is represented by the electrocardiographic P-wave analysis. This includes study and diagnosis of interatrial conduction block. Our short case report presents a case with ischemic cortico-sottocortical stroke involving capsulo and caudo regions in a woman patient with interatrial block as realized by electrocardiographic P analysis.

Baseline ECG and Prognosis After Transcatheter Aortic Valve Implantation: The Role of Interatrial Block.

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.

Differential characteristics of the typical and atypical advanced interatrial block.

Objetivo: Se denomina bloqueo interauricular avanzado (BIA) a la existencia de una onda P ≥ 120 ms y bifásica +/- en las derivaciones inferiores (II-III-VF) del electrocardiograma (ECG) de superficie, el cual constituye un factor predictivo significativo del desarrollo de fibrilación auricular. En fecha reciente se han descrito cuatro patrones de BIA atípicos (BIA-At) con base en la morfología y la duración de la onda P, sin conocer si comparten patogenia y características clínicas similares. Método: Estudio observacional, descriptivo y retrospectivo de pacientes, visitados en el Servicio de Cardiología, en ritmo sinusal y con BIA. Las variables analizadas se obtuvieron de la historia clínica informatizada. El análisis de la onda P se efectuó al aumentar el tamaño del electrocardiograma y mediante calipers electrónicos. El análisis estadístico se realizó con SPSS 19.0, con nivel de significación de p < 0.05. Resultados: Se incluyó a 75 pacientes con media de edad de 74.4 ± 11.7 años, con 62.7% de varones. Se compararon los grupos de pacientes con BIA típico (BIA-T) y BIA-At. El primero se relacionó con la existencia de diabetes mellitus (p = 0.001), enfermedad renal crónica estadio ≥ 3 (p = 0.036), bloqueo auriculoventricular (p = 0.006) y una menor fracción de expulsión ventricular media (p = 0.025); no hubo diferencias respecto de la prevalencia de fibrilación auricular/flúter o accidente cerebrovascular. Sólo la diabetes se acompañó de riesgo de ser un BIA-T (OR: 6.4; p = 0.002; IC 95%: 2.0-21.1). Conclusiones: La diabetes mellitus constituye el único factor de riesgo de que un BIA sea típico. Los pacientes con BIA-T y BIA-At presentan similar prevalencia de fibrilación auricular y accidente cerebrovascular, por lo que son objeto de un mismo tratamiento clínico. Objective: It is called advanced interatrial block (IAB) to the existence of a P wave ≥ 120 ms and biphasic ± in the lower leads II-III-VF of the surface electrocardiogram (ECG), which constitutes a significant predictive factor for the development of atrial fibrillation. Recently, four patterns of atypical aIAB (At-IAB) have been described based on the morphology and duration of the P wave, but it's unknown if they share the same pathogenesis and clinical characteristics. Method: An observational, descriptive and retrospective study was performed with patients, visited in cardiology, who have a sinus rhythm and with aIAB. The analyzed variables were obtained from the computerized clinical history. The analysis of the P wave was made by increasing the size of the ECG and by electronic calipers. Statistical analysis was performed with SPSS 19.0; level of significance: p < 0.05. Results: A total of 75 patients with an average age of 74.4 ± 11.7 years and with a 62.7% males, were included. It was compared the group of patients with typical aIAB (T-aIAB) and with At-aIAB. The first one was associated with the existence of diabetes mellitus (p = 0.001), chronic kidney disease stage ≥ 3 (p = 0.036), atrioventricular block (p = 0.006) and a lower mean ventricular ejection fraction (p = 0.025); there were no differences regarding the prevalence of atrial fibrillation/flutter or stroke. Only diabetes was associated with the risk of T-aIAB (odds ratio: 6.4; p = 0.002; 95% confidence interval: 2.0-21.1). Conclusions: Diabetes mellitus is the only risk factor for an aIAB to be typical. Patients with T-aIAB and At-aIAB have a similar prevalence of atrial fibrillation and stroke, so they must follow the same clinical management.

Relation of Interatrial Block to Cognitive Impairment in Patients ≥ 70 Years of Age (From the CAMBIAD Case-control Study).

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.

Síndrome de Bayés. Lo que todo clínico debe conocer / What every clinician should know about Bayés syndrome

El síndrome de Bayés es una nueva entidad clínica, caracterizada por la combinación de bloqueo interauricular (BIA) avanzado en el electrocardiograma de superficie con fibrilación auricular (FA) y otras arritmias auriculares. Este síndrome se asocia con un riesgo incrementado de ictus, demencia y mortalidad. El BIA avanzado se diagnostica con la presencia de una onda P ≥ 120ms de morfología bifásica (±) en derivaciones de cara inferior. Se produce por un bloqueo completo del haz de Bachmann que causa una despolarización retrógrada de la aurícula izquierda desde zonas cercanas a la unión auriculoventricular. La miocardiopatía auricular fibrótica es el sustrato anatómico del BIA avanzado. La disincronía inducida por el BIA avanzado funciona como desencadenante y mecanismo de mantenimiento de la FA. Esta alteración de la arquitectura auricular produce remodelado auricular, estasis sanguínea e hipercoagulabilidad, lo cual desencadena la cascada trombogénica. El BIA avanzado, incluso sin arritmias auriculares documentadas, también se ha relacionado con FA, ictus, demencia y mortalidad. Sin embargo, todavía no se ha demostrado el beneficio de la anticoagulación para los pacientes sin FA documentada. Por lo tanto, es recomendable una búsqueda proactiva de FA en los pacientes con BIA avanzado

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

Características diferenciales del bloqueo interauricular avanzado típico y atípico / Differential characteristics of the typical and atypical advanced interatrial block

Resumen Objetivo: Se denomina bloqueo interauricular avanzado (BIA) a la existencia de una onda P ≥ 120 ms y bifásica +/- en las derivaciones inferiores (II-III-VF) del electrocardiograma (ECG) de superficie, el cual constituye un factor predictivo significativo del desarrollo de fibrilación auricular. En fecha reciente se han descrito cuatro patrones de BIA atípicos (BIA-At) con base en la morfología y la duración de la onda P, sin conocer si comparten patogenia y características clínicas similares. Método: Estudio observacional, descriptivo y retrospectivo de pacientes, visitados en el Servicio de Cardiología, en ritmo sinusal y con BIA. Las variables analizadas se obtuvieron de la historia clínica informatizada. El análisis de la onda P se efectuó al aumentar el tamaño del electrocardiograma y mediante calipers electrónicos. El análisis estadístico se realizó con SPSS 19.0, con nivel de significación de p < 0.05. Resultados: Se incluyó a 75 pacientes con media de edad de 74.4 ± 11.7 años, con 62.7% de varones. Se compararon los grupos de pacientes con BIA típico (BIA-T) y BIA-At. El primero se relacionó con la existencia de diabetes mellitus (p = 0.001), enfermedad renal crónica estadio ≥ 3 (p = 0.036), bloqueo auriculoventricular (p = 0.006) y una menor fracción de expulsión ventricular media (p = 0.025); no hubo diferencias respecto de la prevalencia de fibrilación auricular/flúter o accidente cerebrovascular. Sólo la diabetes se acompañó de riesgo de ser un BIA-T (OR: 6.4; p = 0.002; IC 95%: 2.0-21.1). Conclusiones: La diabetes mellitus constituye el único factor de riesgo de que un BIA sea típico. Los pacientes con BIA-T y BIA-At presentan similar prevalencia de fibrilación auricular y accidente cerebrovascular, por lo que son objeto de un mismo tratamiento clínico.

Abstract Objective: It is called advanced interatrial block (IAB) to the existence of a P wave ≥ 120 ms and biphasic ± in the lower leads II-III-VF of the surface electrocardiogram (ECG), which constitutes a significant predictive factor for the development of atrial fibrillation. Recently, four patterns of atypical aIAB (At-IAB) have been described based on the morphology and duration of the P wave, but it’s unknown if they share the same pathogenesis and clinical characteristics. Method: An observational, descriptive and retrospective study was performed with patients, visited in cardiology, who have a sinus rhythm and with aIAB. The analyzed variables were obtained from the computerized clinical history. The analysis of the P wave was made by increasing the size of the ECG and by electronic calipers. Statistical analysis was performed with SPSS 19.0; level of significance: p < 0.05. Results: A total of 75 patients with an average age of 74.4 ± 11.7 years and with a 62.7% males, were included. It was compared the group of patients with typical aIAB (T-aIAB) and with At-aIAB. The first one was associated with the existence of diabetes mellitus (p = 0.001), chronic kidney disease stage ≥ 3 (p = 0.036), atrioventricular block (p = 0.006) and a lower mean ventricular ejection fraction (p = 0.025); there were no differences regarding the prevalence of atrial fibrillation/flutter or stroke. Only diabetes was associated with the risk of T-aIAB (odds ratio: 6.4; p = 0.002; 95% confidence interval: 2.0-21.1). Conclusions: Diabetes mellitus is the only risk factor for an aIAB to be typical. Patients with T-aIAB and At-aIAB have a similar prevalence of atrial fibrillation and stroke, so they must follow the same clinical management.

Bayés' Syndrome-A Comprehensive Short Review.

Prediction and early detection of atrial fibrillation (AF) remain a permanent challenge in everyday practice. Timely identification of an increased risk for AF episodes (which are frequently asymptomatic) is essential in the primary and secondary prevention of cardioembolic events. One of the noninvasive modalities of AF prediction is represented by the electrocardiographic P-wave analysis. This includes the study and diagnosis of interatrial conduction block (Bachmann's bundle block). Bayés' Syndrome (named after its first descriptor) denotes the association between interatrial conduction defect and supraventricular arrhythmias (mainly AF) predisposing to cardioembolic events. Our short review presents an update of the most important data concerning this syndrome: brief history, main ECG features, pathophysiological background and clinical implications.

Relation of Advanced Interatrial Block to Risk of Atrial Fibrillation and Stroke.

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 CHA2DS2-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 CHA2DS2-Vasc score and the presence of environmental arrhythmias.