Rationale and design of the rigorous atrial analysis in advanced interatrial block (ARABIA) prospective study.

BACKGROUND: Advanced interatrial block (IAB) is present in 10% of subjects ≥75 years and is associated with the risk of clinical events. METHODS AND RESULTS: Prospective multicenter study that will include subjects ≥75 years without exclusion criteria (indication for anticoagulation, cardiac devices, severe valve disease, systolic dysfunction, moderate or severe cognitive impairment, poor echocardiographic window, non-sinus rhythm or partial IAB, stroke, and life expectancy <2 years). A total of 356 subjects, 178 patients with advanced IAB (exposed) and 178 matched individuals with normal P-wave (non-exposed) will be included. Electrocardiogram and advanced transthoracic echocardiography will be performed. Two substudies will include magnetic resonance imaging: cardiac (86 subjects, 43 exposed, and 43 non-exposed) and brain (86 subjects, 43 exposed, and 43 non-exposed). The follow-up will be 2 years. Our main objective is to determine the association of advanced IAB, P-wave duration, and atrial imaging parameters (I] atrial global longitudinal strain, II] maximal left atrial volume index, III] left atrial ejection fraction, IV] left atrial fibrosis - % total left atrial area V] inter- and intra-atrial asynchrony/dyssynchrony) with clinical events (atrial fibrillation, stroke, cognitive impairment, and mortality). The secondary objective is to assess the association of the P-wave duration with atrial imaging parameters and of both with cerebral microemboli in magnetic resonance imaging. CONCLUSION: Our study will provide data regarding the association of advanced IAB, P-wave duration, and atrial imaging parameters with clinical events. We will also assess the association P-wave duration-atrial imaging parameters-cerebral microemboli.

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.

Comparison of clinical features and conventional echocardiographic characteristics of patients with heart failure with mid-range ejection fraction with and without interatrial block.

OBJECTIVE: Heart failure with mid-range ejection fraction (HFmrEF) has been proposed as a distinct heart failure (HF) phenotype. Interatrial block (IAB) is a conduction delay between the atria and is associated with cardiovascular disease. Although there are several studies examining the effect of IAB in patients with HF with reduced ejection fraction and HF with preserved ejection fraction, a literature review did not reveal any study investigating the clinical importance of the presence of IAB in patients with HFmrEF. Thus, the aim of this research was to evaluate clinical characteristics of HFmrEF with and without IAB. METHODS: A total of 520 consecutive patients with HFmrEF in sinus rhythm who were examined at outpatient clinics were enrolled in the study (244 patients with IAB and 276 patients without IAB). Surface 12-lead standard electrocardiograms (ECGs) were recorded. Clinical characteristics, echocardiographic examination results, and laboratory values of the patients were recorded. RESULTS: The mean age of the patients was 67.4±11.1 years, and 76.1% were male. The patients with IAB had more comorbidities, including hypertension, diabetes mellitus, and stroke/transient ischemic attack. A statistically significant, strong, positive linear correlation was observed between P-wave duration and age, systolic blood pressure, and left atrial volume index (r=0.718, p<0.001; r=0.704, p<0.001; and r=0.725, p<0.001, respectively). CONCLUSION: To the best of our knowledge, the present study is the first to evaluate the clinical relevance of IAB in HFmrEF. Adding this simple ECG marker to the clinical evaluation could add significantly to the management of HFmrEF. IAB can be used to identify high-risk HFmrEF patients, as well as to guide follow-up and appropriate treatment.

Interatrial block and cognitive impairment in the BAYES prospective registry.

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 ±â€¯6.5 vs. 76.8 ±â€¯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.

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.

Association between interatrial block, left atrial fibrosis, and mechanical dyssynchrony: Electrocardiography-magnetic resonance imaging correlation.

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/m2 , 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 (ß = .33; P = .049) and LA mechanical dyssynchrony (ß = 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.

Echocardiographic predictors of interatrial block in patients with severe chronic kidney disease.

BACKGROUND: Interatrial block (IAB), defined as a conduction delay between the right and left atrium, is manifested on the electrocardiogram as a prolonged P-wave duration. Large number of studies recently have been published regarding the prevalence of IAB and its associations with the risk of atrial fibrillation and ischemic stroke. Cardiovascular diseases are the leading causes of mortality in chronic kidney disease (CKD). In this study, we aimed to investigate echocardiographic predictors of IAB in patients with severe CKD. METHODS: This study enrolled a total of 155 patients [male: 95 (61.3%), mean age: 56.3 ± 12.8 years] with severe CKD (glomerular filtration rate < 30 mL/min). All patients were evaluated by electrocardiography and transthoracic echocardiography. IAB was defined as P wave duration of ≥ 120 ms on electrocardiography. RESULTS: Electrocardiography revealed IAB in 54 patients. The baseline demographic characteristics of the patients were similar in both groups with and without IAB. Left atrial diameter (LAD), left ventricular end-systolic and end-diastolic diameters, interventricular septal thickness, posterior wall thickness, left ventricular mass, left ventricular mass index (LVMI), and the prevalence of left ventricular hypertrophy were found to be significantly increased in patients with IAB. Increased LAD (OR = 1.119; 95% CI 1.019-1.228; p = 0.019) and LVMI (OR = 1.036; 95% CI 1.003-1.070; p = 0.031) were found to be independent predictors of IAB. CONCLUSION: A significant association exists between the presence of IAB and echocardiographic parameters related to left ventricular hypertrophy and left atrial dilatation. Presence of IAB may be an additional and easy diagnostic marker for risk stratification of patients with severe CKD.

Agreement Between Electrophysiology Study and Tissue Doppler Imaging Regarding the Measurement of Total Atrial Conduction Time and Left Atrial Conduction Delay.

The aim of our study was to evaluate the agreement between tissue Doppler imaging (TDI) methods and electrophysiology study (EPS) concerning the measurement of total atrial conduction time (TACT) and left atrial conduction delay (LACD). Sixty-nine candidates for EPS were included. TACT and LACD were measured in the EPS. The TDI time intervals for each patient were measured using both pulsed-wave (PW) and 2-D color-coded (CC) methods, once from the beginning of the P wave to the beginning of the a' wave (Tb) and once again to the peak of the a' wave (Tp) at the mitral annulus. TACT and LACD measured by TDI were not in good agreement with those measured by EPS. There was moderate agreement between PW-Tb and CC-Tb and good agreement between PW-Tp and CC-Tp for the measurement of TACT; nevertheless, agreement was not good in the case of LACD.

Second-degree interatrial block: Brief review and concept.

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.

Advanced interatrial block is an electrocardiographic marker for recurrence of atrial fibrillation after electrical cardioversion.

BACKGROUND: Early recurrence of atrial fibrillation (AF) is common following a successful electrical cardioversion (ECV). The purpose of this study was to investigate the hypothesis that AF recurrence is related to atrial electrical inhomogeneity, which may influence the P wave characteristics. METHODS: Two hundred ninety-one consecutive persistent AF patients who underwent ECV were enrolled, and evaluated for AF recurrences one month after the ECV. Patients with open-heart surgery, a history of catheter ablation, and an unsuccessful ECV were excluded. The P wave duration, dispersion and P wave morphology were evaluated by 12­lead ECGs 30 min after the ECV. RESULTS: In total, 141 patients were investigated. One month after the ECV, 60 (43%) patients maintained sinus rhythm. The advanced interatrial block (aIAB; P wave duration >120 ms and biphasic P waves in the inferior leads) (Hazard ratio [HR], 4.51; 95% confidence interval [CI] 1.45-14.01, P = 0.009), P wave dispersion (HR, 1.06; 95%CI 1.02-1.09, P = 0.001), and duration of AF per month (HR, 1.03; 95%CI 1.01-1.04, P = 0.004) were independent predictors of AF recurrence. An aIAB was not associated with structural parameters such as the left atrial volume index or right atrial area. There were no differences in the serum BNP level and frequency of administering anti-arrhythmic drugs between the patients with and without recurrence. CONCLUSIONS: The risk of AF recurrence after the ECV can be predicted by the P wave characteristics. A longer P wave dispersion and the duration of AF also had a tendency for recurrence.

Interatrial block and atrial remodeling assessed using speckle tracking echocardiography.

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.

Surface ECG interatrial block-guided treatment for stroke prevention: rationale for an attractive hypothesis.

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 CHA2DS2VASc (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.