Presence Of Interatrial Block Research Articles

INTERATRIAL BLOCK AS A FIRST CLINICAL PRESENTATION OF ATRIAL CARDIOMYOPATHY RELATED TO A NOVEL LMNA VARIANT: A CASE REPORT

Abstract Interatrial block (IAB) is a conduction delay in Bachmann’s bundle with a well–described association with structural heart disease, supraventricular arrhythmias, and cardiovascular events. We report the case of an asymptomatic 35–year–old man in whom the presence of IAB at electrocardiogram led to a comprehensive evaluation including speckle–tracking echocardiography, 24 h Holter monitoring, and genetic testing. Speckle–tracking echocardiography demonstrated a decrease in the longitudinal strain of interventricular septum, a typical feature of LMNA–related cardiomyopathy, and decreased indices of left atrial deformation. A diagnosis of cardiac laminopathy related to the frame shift variant c.1367 (p.Asn456Thrfs*24) of the LMNA gene was made. A dual–chamber implantable cardioverter defibrillator implantation was performed for the high risk of life–threatening ventricular tachyarrhythmias. This case demonstrates that IAB could be a rare presentation of a life–threatening laminopathy. Strain echocardiography is an essential tool to evaluate the deposition of fibrosis tissue in subclinical cardiomyopathies. Our report describes a novel variant of LMNA gene associated with a high risk of sudden cardiac death.

Inter-atrial block and atrial fibrillation predict cardiac adverse events in heart failure with preserved ejection fraction

Abstract Background Atrial fibrillation (AF) is a prognostic risk-factor in heart failure with preserved ejection fraction (HFpEF). Earlier stages of atrial dysfunction identified by the ECG, particularly inter-atrial block (IAB), may provide additional risk predictions in HFpEF patients in sinus rhythm. Purpose To assess the prevalence of IAB in patients diagnosed with HFpEF compared to non-HFpEF, and to evaluate the prognostic association of IAB and AF in patients diagnosed with HFpEF. Methods Consecutive symptomatic patients referred for a systematic diagnostic work-up to rule-in or rule-out HFpEF were included. The diagnosis of HFpEF was based on current guidelines (including HFA-PEFF and H2FPEF algorithms) and confirmed by consensus of multiple experienced HF specialists. Patients in whom HFpEF was ruled-out were included as non-HFpEF. We excluded patients with cardiac valve interventions before or up to 1 year after baseline, or with paced rhythm during IAB assessment. ECGs at baseline were assessed in detail for P-wave duration, morphology, and presence of IAB using digital calipers by investigators blinded to clinical data. IAB was defined based on a P-wave duration of >120ms. Patients with HFpEF and non-HFpEF were grouped into either i) AF based on ECG or medical history, ii) IAB based on ECG, or iii) no IAB or AF based on ECG. Adverse events were evaluated only in HFpEF patients and included HF hospitalization, cardiac or sudden death, and a composite of both. Results 372 patients with HFpEF and 68 non-HFpEF were included (females: 67.7% vs. 64.7%, p = 0.726; mean age: 75±7 vs. 67±10 years, p<0.001). AF was more common in HFpEF than non-HFpEF (64.8% vs. 23.5%, p<0.001). In sinus rhythm, presence of IAB was comparable between HFpEF and non-HFpEF (87.0% vs. 80.8%). During a mean follow-up of 3.2±1.6 years in HFpEF patients, more adverse cardiac events were observed when AF was present (23.7%, HR 10.6 [95%CI 1.5-1334.4]) compared to IAB (10.5%, HR 4.2 [95%CI 0.56-542.6]) and no IAB (0%), p = 0.0004 (Figure 1). Pairwise comparisons confirmed these observations: AF vs. IAB p = 0.006, AF vs. no IAB p = 0.031. In HFpEF patients with sinus rhythm, a trend was found for more adverse events when IAB was present versus no IAB (p = 0.06). Conclusion Patients with HFpEF have a higher prevalence of AF and similar prevalence of IAB compared to symptomatic patients ruled-out for HFpEF. Presence of IAB or AF in HFpEF may predispose to adverse cardiac events in patients without severe valve disease. IAB may enrich cardiac risk stratification in addition to AF in HFpEF.Survival curves for no IAB, IAB, and AF

Electro-Mechanical Alterations in Atrial Fibrillation: Structural, Electrical, and Functional Correlates.

Atrial fibrillation is the most common arrhythmia encountered in clinical practice affecting both patients' survival and well-being. Apart from aging, many cardiovascular risk factors may cause structural remodeling of the atrial myocardium leading to atrial fibrillation development. Structural remodelling refers to the development of atrial fibrosis, as well as to alterations in atrial size and cellular ultrastructure. The latter includes myolysis, the development of glycogen accumulation, altered Connexin expression, subcellular changes, and sinus rhythm alterations. The structural remodeling of the atrial myocardium is commonly associated with the presence of interatrial block. On the other hand, prolongation of the interatrial conduction time is encountered when atrial pressure is acutely increased. Electrical correlates of conduction disturbances include alterations in P wave parameters, such as partial or advanced interatrial block, alterations in P wave axis, voltage, area, morphology, or abnormal electrophysiological characteristics, such as alterations in bipolar or unipolar voltage mapping, electrogram fractionation, endo-epicardial asynchrony of the atrial wall, or slower cardiac conduction velocity. Functional correlates of conduction disturbances may incorporate alterations in left atrial diameter, volume, or strain. Echocardiography or cardiac magnetic resonance imaging (MRI) is commonly used to assess these parameters. Finally, the echocardiography-derived total atrial conduction time (PA-TDI duration) may reflect both atrial electrical and structural alterations.

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>120milliseconds) 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, 4.4years [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.

The prognostic role of interatrial block among COVID-19 patients hospitalized in medicine wards.

IntroductionSome abnormal electrocardiographic findings were independently associated with increased mortality in patients admitted for COVID‐19; however, no studies have focussed on the prognosis impact of the interatrial block (IAB) in this clinical setting. The aim of our study was to assess the prevalence and clinical implications of IAB, both partial and advanced, in hospitalized COVID‐19 patients.MaterialsWe retrospectively evaluated 300 consecutive COVID‐19 patients (63.22 ± 15.16 years; 70% males) admitted to eight Italian Hospitals from February 2020 to April 2020 who underwent twelve lead electrocardiographic recording at admission. The study population has been dichotomized into two groups according to the evidence of IAB at admission, both partial and advanced. The differences in terms of ARDS in need of intubation, in‐hospital mortality and thromboembolic events (a composite of myocardial infarction, stroke and transient ischaemic attack) have been evaluated.ResultsThe presence of IAB was noticed in 64 patients (21%). In the adjusted logistic regression model, the partial interatrial block was found to be an independent predictor of ARDS in need of intubation (HR: 1.92; p: .04) and in‐hospital mortality (HR: 2.65; p: .02); moreover, the advanced interatrial block was an independent predictor of thrombotic events (HR: 7.14; p < .001).ConclusionsAmong COVID‐19 patients hospitalized in medical wards, the presence of interatrial block is more frequent than in the general population and it might be useful as an early predictor for increased risk of incident thrombotic events, ARDS in need of intubation and in‐hospital mortality.

Advanced interatrial block predicts recurrence of embolic stroke of undetermined source

BackgroundAdvanced 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). Methods104 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. ResultsMedian 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). ConclusionsAdvanced IAB and age older than 50 years predict ESUS recurrence.

Correlation between atrial electrocardiographic indexes and left atrial enlargement in competitive athletes. From the ALMUDAINA case-control study

Abstract Background Left atrial (LA) remodelling and enlargement in athletes is a well-kown component of the athlete's heart. However, information about the correlation between of LA enlargement and atrial electrophysiological features in athletes is scarce. Purpose Our aim was to characterize LA enlargement, P-wave duration, and the prevalence of interatrial block (IAB) in competitive athletes (with and without LA enlargement) and in controls. Methods ALMUDAINA (Analysis of Left atrial Measurements of Ultrasound Dilation Among International and National Athletes) was a nationwide, cross-sectional study involving 9 hospitals and sport clinics across Spain. Cases fulfilled the international consensus definition of a competitive athlete and were currently engaged in skill, power, mixed or endurance disciplines at a national or international level. The following P-wave parameters were analysed: 1) duration 2) voltage in lead I and 3) the presence of interatrial block (IAB). LA enlargement was defined as an indexed volume by body surface area ≥34 ml/m2, measured by transthoracic echocardiography. A contemporary cohort of otherwise healthy and active controls was used as a comparison group. Results Baseline clinical and echocardiographic characteristics of both cohorts are summarised in table 1 whereas electrocardiographic characteristics are displayed in table 2, respectively. 356 subjects were included, 308 athletes (mean age: 36.4±11.6 years) and 48 controls (mean age: 49.3±16.1 years). Athletes showed a higher mean LA indexed volume (29.8±8.6 vs. 25.6±8.0 mL/m2, P=0.006) and higher prevalence of LA enlargement (113 [36.7%] vs. 5 [10.4%], P&amp;lt;0.001), but there were no relevant differences in P-wave duration (106.3±12.5 ms vs 108.2±7.7 ms; P=0.31), voltage in lead I (0.08±0.04 vs. 0.08±0,04 mV; P=0.79) and the prevalence of IAB (40 [13.0%] vs. 4 [8.3%], P=0.36). Only a case of advance IAB was detected, in an athlete without LA enlargement. Among athletes, those with LA enlargement (113, 36.7%) had higher P-wave duration (110.3±14.1 vs. 103.0±10.9 ms, P&amp;lt;0.001) and a higher prevalence of interatrial blockade (23 [20.4%] vs. 17 [8.8%], P=0.004), but similar voltage of P-wave in lead I (0.08±0.003 vs. 0.08±0.05 mV, P=0.689). In a multivariate analysis, competitive training was independently associated with LA enlargement (odds ratio [OR] 14.7, 95% confidence interval [CI] 4.7–44.0; P&amp;lt;0.001) but was not associated with P-wave duration (OR 1.02, 95% CI: 0.99–1.04; P=0.19) or IAB (OR 1.4, 95% CI 0.7–3.1; P=0.34). Conclusions LA enlargement is prevalent in adult competitive athletes. However, ECG indexes of atrial electrophysiology were not different from healthy controls. Our data suggest that LA enlargement and IAB are two different entities. Funding Acknowledgement Type of funding sources: None.

Evaluation of Electrocardiographic Parameters and the Presence of Interatrial Block in Patients with Mad Honey Intoxication.

Mad honey intoxication (MHI) is a food-induced clinical condition that usually presents with cardiovascular symptoms and can lead to life-threatening arrhythmias if not diagnosed and treated early. No data exist in the literature on the presence of interatrial block (IAB) after food intoxication. In our study, we sought to investigate atrioventricular electrocardiography (ECG) parameters and determine the frequency of IAB in patients with MHI. In total, 76 patients diagnosed with MHI were included in our retrospective study. Twelve-lead ECGs were performed and participants were divided into two groups according to the presence of IAB in the reference ECG. The P maximum (Pmax), P minimum (Pmin), P dispersion (Pdisp), T peak to T end (Tp-Te) interval and QT dispersion (QTdisp) values were compared between the two groups. IAB was detected in 28 (35.5%) of 76 MHI patients included in the final analysis. Pmax duration (122 ± 8; p < 0.001) and PD (69 ± 11; p < 0.001) were significantly higher in the IAB ( +) group. During regression analysis, Pmax [odds ratio (OR) 1.158, 95% confidence interval (CI) 1.036-1.294; p = 0.010] and Pd (OR 1.086, 95% CI 1.001-1.017; p = 0.046) were independently associated with IAB. Pmax and Pd area under the receiver operating characteristic curve values for IAB prediction were 0.926 (95% CI 0.841-1,000; p < 0.001) and 0.872 (95% CI 0.765-0.974; p < 0.001), respectively. ECG changes are common in patients presenting with MHI. These patients need to be followed up clinically in terms of progression to arrhythmic events that may occur in the future.

Impaired left atrial strain in the presence of interatrial block in patients with type 2 diabetes mellitus.

Type 2 diabetes mellitus (T2DM) is one of the most common chronic diseases, and is a risk factor for atrial cardiomyopathy. Interatrial block (IAB), as a predictor of AF, is correlated with the extent of LA fibrosis in the process of atrial cardiomyopathy. We have not encountered any study evaluating LA and LV functions with 3D-STE in the presence of IAB in the T2DM patients. The purpose of the present study was to compare the LA and LV myocardial functions in patients with T2DM with and without IAB by 3D-STE. A total of 175 consecutive patients with T2DM who were examined at outpatient clinics were enrolled in the study (85 patients with IAB and 90 patients without IAB). Surface 12-lead standard electrocardiograms (ECGs) were recorded. Clinical characteristics and laboratory values of the patients were obtained. Conventional 2D echocardiographic and 3D-STE analyses were performed. The mean age of the patients was 59 ± 8.7 years, and 112 (64%) of the patients were female. The LAS-r and LAS-active were significantly decreased in the IAB (+) group than in the IAB (-) group. Statistically significant strong negative linear correlations were observed between P-wave duration and 3D-LA strain values. Our results indicate that there is an impairment in LA myocardial dynamics in the presence of IAB in T2DM patients. According to these findings, we can say that it will be useful to evaluate the LA functions at the preclinical stage in the presence of IAB in patients with T2DM, when considering ischemic cardiovascular and cerebral events.

Diyastolik disfonksiyon ve interatrial blok arasındaki ilişkinin değerlendirilmesi

Background: The interatrial block is a condition that occurs due to the delay of conduction in the right atrium to the left atrium, and can be partial (pIAB) or advanced (aIAB), and also is associated with atrial arrhythmia. Diastolic dysfunction (DD) is an important condition frequently encountered in most healthy middle-aged individuals and plays a role in the development of many cardiovascular diseases. It is noteworthy that frequent paroxysmal AF (PAF) attacks are observed especially in individuals with DD in clinical life, and its relationship with the presence of interatrial block is still unclear in these patients. Our aim in this study was to evaluate the relationship between the presence of DD and the development of interatrial block and PAF.&#x0D; Methods: A total of 146; 92 patients with DD and 54 control (proven by echocardiography) were enrolled in this cross-sectional and prospectively study. The properties of the P wave were evaluated in leads D2-3 aVF and V1. Echocardiography and electrocardiography results of the two groups were compared. &#x0D; Results: The mean age of the DD and the control group was (62.3 ± 0.74 and 61.2 ± 0.61 years, p=0.481) respectively. The frequency of IAB was significantly higher in the DD than the control group (%37-%46.7-%16.3, %77.8-%18.5-%3.7, none-pİAB-aİAB, respectively). In the correlation analysis, there was a strong correlation between the presence of DD and IAB (r: 0.439, p

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

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. This study enrolled a total of 155 patients [male: 95 (61.3%), mean age: 56.3 ± 12.8years] with severe CKD (glomerular filtration rate < 30mL/min). All patients were evaluated by electrocardiography and transthoracic echocardiography. IAB was defined as P wave duration of ≥ 120ms on electrocardiography. 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. 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.

El bloqueo interatrial avanzado predice recurrencia de infarto cerebral embólico de origen no determinado

BackgroundAdvanced 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). Methods104 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. Electrocardiogram findings were interpreted by a blinded, centralised rater at (XXXX2). ESUS recurrence was the primary outcome variable. ResultsMedian 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). ConclusionsAdvanced IAB and age older than 50 years predict ESUS recurrence.

Coexistence of increased arterial stiffness and interatrial block in overweight subjects.

BackgroundInteratrial block (IAB) is an electrical conduction delay between the right and left atrium and is associated with some cardiovascular disorders. Arterial stiffness is a useful prognostic marker for cardiovascular events. In the present study, we aimed to investigate the coexistence of increased arterial stiffness and IAB in overweight subjects.MethodsA total of 110 overweight people were enrolled (56 subjects with IAB, and 54 age‐ and gender‐matched subjects without IAB) into the study. Surface 12‐lead standard ECGs were recorded. I.E.M. Mobil‐O‐Graph ambulatory blood pressure monitor device was used to assess the arterial stiffness.ResultsThe mean age of the patients was 54.1 ± 11.5 years, and 53.6% were male. PWV and Aix were significantly higher in IAB (+) group than IAB (−) group (9.34 ± 1.5 vs. 7.86 ± 1.3, p < .001; 29.18 ± 11.2 vs. 22.75 ± 10.4, p < .001, respectively), and also, positive linear correlation was observed between arterial stiffness parameters and P‐wave duration (r = .758 for PWV; r = .682 for Aix, respectively).ConclusionThe present study is the first to focus on evaluating the relationship between the presence of IAB and arterial stiffness in overweight subjects. If there is a coexistence of increased arterial stiffness and IAB in overweight subjects, it should be considered as requiring clinically closer follow‐up.

Rational and design of the Baseline Interatrial block and Transcatheter aortic valve implantation (BIT) registry

BackgroundAortic 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. MethodsThe 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. ConclusionThe 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.

Advanced interatrial block: An electrocardiographic marker for stroke recurrence

The presence of interatrial block (IAB) has been directly related to the appearance of various atrial tachyarrhythmias and therefore could be a risk factor for stroke. The objective of this study is to establish whether the presence of IAB could predict stroke recurrence in patients with a previous episode. MethodsWe included all patients discharged from our hospital in 2011 following treatment for stroke, excluding those of cardioembolic or lacunar etiology. For all patients we analyzed the ECG recordings, determined whether the patient presented cardiovascular risk factors, and determined the presence and type of IAB. An IAB was defined as partial if the P-wave duration was ≥120 ms, and advanced if the duration was ≥120 ms and presented biphasic morphology in the inferior leads. The primary endpoint was the recurrence of stroke and the secondary endpoint was the incidence of atrial tachyarrhythmias after the first episode. ResultsA total of 149 patients were identified (80 (71.5–86.0) years, 41% men). After a median follow-up of 3.96 (0.63–5.35) years, 54 deaths (36%) were observed, 27 patients (18%) had experienced stroke recurrence, and 20 (13%) had developed atrial tachyarrhythmias. On multivariate analysis, the presence of advanced IAB [HR: 2.3, 95% CI (1.0–5.5); p = 0.043] and diabetes [HR: 2.5, 95% CI (1.1–5.4); p = 0.018] were significantly associated with stroke recurrence. ConclusionThe presence of advanced IAB predicts the recurrence of stroke in patients with a previous episode. Further studies should be performed to investigate possible interventions.

P-waveand interatrial block: New predictor for atrial high rate episodes in patients with cardiac implantable electronic devices.

The presence of interatrial block (IAB) is associated with the development of atrial fibrillation (AF). The aim of this study was to determine whether P-wave duration and presence of IAB before the implantation of a cardiac implantable electronic device (CIED) are associated with the presence of atrial high rate episodes (AHRE), during long-term follow-up. 380 patients (57% men; 75 ± 10 years) were included. IAB was defined according to the International Consensus Criteria. AHRE was defined as an episode of atrial rate ≥225beats/min with a minimum duration of 5minutes. Documented paroxysmal AF before the implantation was present in 24% of the patients; 80% had hypertension and 32% structural heart disease. Mean P-wave duration was 123 ± 23ms, and 39% of the patients had IAB (32% partial, 7% advanced). After a mean follow-up of 18 ± 12 months, 33% of the patients presented AHRE. Patients with AHRE had a P-wave duration significantly longer (130 ± 24ms vs 119 ± 21ms; P<0.001) and a greater prevalence of IAB (53%vs 32%; P<0.001). In a multivariate analysis, predictors of AHRE were: IAB (odds ratio [OR] 2.1; 95% confidence interval [CI] [1.3-3.4], P<0.001) and previous paroxysmal AF (OR 2.6; 95% CI [1.5-4.3], P<0.001). In patients without previous AF, the presence of IAB was also a significant predictor of AHRE (OR 3.1; 95% CI [1.8-5.5], P<0.001). IAB is a strong predictor of AHRE in patients with CIED. This finding is independent of the presence of prior paroxysmal AF.

Comparison of the Extent of Coronary Artery Disease in Patients With Versus Without Interatrial Block and Implications for New-Onset Atrial Fibrillation

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±11.9years, mean ejection fraction of 55.2 ± 12.7% and mean left atrial diameter of 38.7 ± 6mm. 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.

Interatrial block and interatrial septal thickness in patients with paroxysmal atrial fibrillation undergoing catheter ablation: Long-term follow-up study.

Interatrial block (IAB) is a strong predictor of recurrence of atrial fibrillation (AF). IAB is a conduction delay through the Bachman region, which is located in the upper region of the interatrial space. During IAB, the impulse travels from the right atrium to the interatrial septum (IAS) and coronary sinus to finally reach the left atrium in a caudocranial direction. No relation between the presence of IAB and IAS thickness has been established yet. To determine whether a correlation exists between the degree of IAB and the thickness of the IAS and to determine whether IAS thickness predicts AF recurrence. Sixty-two patients with diagnosis of paroxysmal AF undergoing catheter ablation were enrolled. IAB was defined as P-wave duration ≥120ms. IAS thickness was measured by cardiac computed tomography. Among 62 patients with paroxysmal AF, 45 patients (72%) were diagnosed with IAB. Advanced IAB was diagnosed in 24 patients (39%). Forty-seven patients were male. During a mean follow-up period of 49.8±22months (range 12-60months), 32 patients (51%) developed AF recurrence. IAS thickness was similar in patients with and without IAB (4.5±2.0mm vs. 4.0±1.4mm; p=.45) and did not predict AF. Left atrial size was significantly enlarged in patients with IAB (40.9±5.7mm vs. 37.2±4.0mm; p=.03). Advanced IAB predicted AF recurrence after the ablation (OR: 3.34, CI: 1.12-9.93; p=.03). IAS thickness was not significantly correlated to IAB and did not predict AF recurrence. IAB as previously demonstrated was an independent predictor of AF recurrence.

Effect of Obesity on P‐Wave Parameters in a Chinese Population

To study the association between obesity and P-wave duration and dispersion (P(d)) in order to evaluate the potential risk for atrial fibrillation development in Chinese subjects using the definitions applied for Asian populations. The study population consisted of 40 obese (body mass index (BMI) > or = 25 Kg/m(2), according to the World Health Organization classification for the Asian population) subjects and 20 age- and sex-matched normal weight controls. Maximum P-wave duration (P(max)), minimum P-wave duration (P(min)), and P(d) were carefully measured using a 12-lead electrocardiogram, while the presence of interatrial block (IAB; P > or = 110 ms) was assessed. There were no significant differences between the two groups regarding age, sex, history of hypertension or diabetes, and hyperlipidemia. Compared to controls, BMI, left atrial diameter (LAD), and interventricular septal thickness were increased, while P(max) (111.9 +/- 9.3 vs 101.1 +/- 6.0 ms, P < 0.01) and P(d) (47.9 +/- 9.3 vs 31.8 +/- 6.9 ms, P < 0.01) were significantly prolonged in the obese group. P(min) was similar between the two groups. The prevalence of IAB was significantly greater in the obese subjects. Pearson's correlation analysis showed that there were positive correlations between P(d) and BMI (r = 0.6, P < 0.001), as well as between P(d) and LAD (r = 0.366, P < 0.05). Our data suggest that obesity is associated with increased P(max) and P(d), and increased prevalence of IAB, parameters that have been associated with atrial fibrillation. The correlation of these electrocardiogram parameters with LAD indicates an association between increased BMI and atrial remodeling in Asian subjects.

Widely split P waves in the presence of interatrial block

Interatrial block (IAB; P wave ≥110 milliseconds), conduction delay between the atria, is highly prevalent and is associated with atrial tachyarrhythmias, left atrial electromechanical dysfunction, as well as a potential risk for systemic embolism. However, much is still yet to be known of IAB's exact pathophysiology and how it may manifest in relation to medical disease. We present an unusual case of widely split P waves in the presence of IAB in a severely ill patient.