Interatrial Block Research Articles

Identifying Atypical Interatrial Block

Identifying Atypical Interatrial Block

Interatrial Block in the Presence of Lipomatous Atrial Septal Hypertrophy.

Interatrial Block in the Presence of Lipomatous Atrial Septal Hypertrophy.

Computed Tomography Confirms Increased Left Atrial Volume in Patients with Bayés Syndrome Referred for Catheter Ablation of Atrial Fibrillation

Background: Bayés syndrome is a recently identified condition that is defined by the presence of an interatrial block on a surface electrocardiogram, in addition to atrial arrhythmias such as atrial fibrillation, tachycardia, or left atrial flutter. This syndrome is linked to an increased risk of stroke, morbidity, and mortality. An interatrial block is a conduction delay between the right atrium and left atrium and can be recognized by a P wave duration >120 ms. It is known that P wave duration can estimate the size of the left atrium measured via echocardiography, which is a marker for stratifying cardiovascular risk. Our study aims to verify whether the duration of the P wave can estimate the volume of the left atrium measured by computed tomography in patients with an interatrial block. Methods: We included 105 patients with a sinus rhythm and a partial or advanced interatrial block (IAB) who underwent contrast-enhanced cardiac computed tomography (CT). The mean age was 62.2 ± 10.1 years, and 38% of the patients were women. Results: The mean P wave duration was 122.6 ± 11.4 ms in the partial IAB group and 150 ± 8.4 ms in the advanced IAB group (p < 0.01). The mean left atrial volume was 115 ± 39 mL in the partial IAB group and 142 ± 34 mL in the advanced IAB group (p = 0.001). P wave duration was longer in patients with an advanced as opposed to partial interatrial block. Left atrial volume and LAVI were higher in patients with an advanced as opposed to partial interatrial block. Conclusions: All the patients (100%) with an advanced IAB had a dilated left atrium. P wave duration can accurately estimate LA volume in patients with an IAB using the formula: LA volume = 0.6 × P wave + 46 mL.

A novel electrocardiogram-based model for prediction of dementia: the Atherosclerosis Risk in Communities (ARIC) study

Abstract Background Current dementia prediction models, such as the UK Biobank Dementia Risk Score (UKBDRS, 12 variables), are limited by having variables that are difficult to obtain, subjectively measured, and self-reported. Although individual ECG parameters are linked to higher dementia risk, no study has combined multiple ECG parameters to create an ECG model for dementia prediction. Purpose Using data from the ARIC study, a prospective community-based cohort of Black and White participants in the USA that started in 1987-89, we created an ECG model (based on 7 pre-defined ECG parameters linked to dementia) and compared its model discrimination with the UKBDRS. Methods Participants without prevalent dementia from 2 baselines were included: Visit 4 (V4, 1996-98) and V5 (2011-13). Seven ECG parameters were examined: heart rate, abnormal P-wave terminal force in lead V1 (PTFV1), prolonged P wave duration, abnormal P wave axis, advanced interatrial block, left ventricular hypertrophy (LVH, Cornell voltage criteria), and corrected QT interval (QTc). Dementia cases were identified through 2019 using in-person and phone cognitive assessments, hospitalisation codes, and death certificates. Using a backward selection method (keeping variables with P<0.10 and age, since it is an important dementia risk factor), parsimonious Cox regression models were constructed for prediction of dementia over the longest available follow-up (V4: 23 years, V5: 8 years). Model discrimination of the ECG models and UKBDRS variables was evaluated by the Harrell’s C-statistic (95% CI). Results At V4, 11,520 participants (mean age, 62.8 ± 5.7 years; 56% women; 22% Black) were included; 2,427 developed dementia. At V5, 5,667 participants (mean age, 75.4 ± 5.1 years; 59% women; 22% Black) were included; 830 developed dementia. Figures 1 and 2 show the C-statistic (95%) and area under the ROC curve for the ECG model and UKBDRS variables at V4 and V5, respectively. The C-statistic (95% CI) for both ECG models were >0.70 and comparable with the corresponding UKBDRS models. Conclusion For middle-aged and older adults, a dementia prediction model comprising age and 4 ECG variables has good discrimination for dementia that is comparable with the 12-variable UKBDRS model. Since ECG variables are easily obtainable and objectively measured, these ECG models will be easier to adopt than the UKBDRS model. Further work to validate this model in an external cohort and develop a risk score will facilitate clinical translation.

Association Between P-Wave Duration, Dispersion, and Interatrial Block and Atrial High-Rate Episodes in CIED Patients.

Atrial high-rate episodes (AHRE) have been linked to increased thromboembolic risk and all-cause mortality in patients with cardiac implantable electronic devices (CIEDs). Various predictors of AHRE development have been identified, emphasizing the need for close monitoring and the potential transition to clinical atrial fibrillation (AF). However, the predictive value of P wave characteristics on AHRE development remains conflicting. This meta-analysis aims to summarize existing data to investigate this association. We examined studies from MEDLINE and EMBASE databases up to May 2024 to investigate the association of baseline P-wave duration (PWD), P-wave dispersion (PWDIS), and interatrial block (IAB) with the risk of developing AHRE. We extracted the mean and standard deviations of PWD and PWDIS to calculate the pooled mean difference (MD). Risk ratios (RR) and 95% confidence intervals (CIs) were used to assess the association between IAB and AHRE risk, using the generic inverse variance method for combination. The meta-analysis included nine studies. Patients with AHRE had longer PWD and PWDIS compared to those without AHRE, with a pooled MD for PWD of 9.17ms (95% CI: 4.74-13.60; I2 = 47%, p < 0.001) and a pooled MD for PWDIS of 20.56ms (95% CI: 11.57-29.56; I2 = 57%, p < 0.001). Additionally, patients with IAB had a higher risk of developing AHRE, with a pooled RR of 3.33 (95% CI: 2.53-4.38; I2 = 0%, p < 0.001), compared to those without IAB. Our meta-analysis found that patients with AHRE had higher PWD and PWDIS than those without AHRE. Additionally, IAB was associated with a higher risk of developing AHRE. These findings emphasize the importance of close monitoring and risk stratification, particularly for patients with P wave abnormalities.

Role of interatrial block in modulating cryptogenic stroke risk in patients with patent foramen ovale: a retrospective study

BackgroundThe patent foramen ovale (PFO) and interatrial block (IAB) are associated with cryptogenic stroke (CS). However, the role of the interaction between PFO and IAB in CS remains unclear.MethodsThis case–control study enrolled 256 patients with CS and 156 individuals without a history of stroke or transient ischemic attack. IAB was defined as P wave duration > 120 ms. PFO was evaluated by contrast transesophageal echocardiography, and classified as no-PFO, low-risk PFO and high-risk PFO. Multiplicative and additive interaction analysis were used to assess the interaction between PFO and IAB in CS.ResultsMultiplicative interaction analysis unveiled a significant interaction between IAB and low-risk PFO in CS (OR for interaction = 3.653, 95% CI, 1.115–12.506; P = 0.037). Additive interaction analysis indicated that 68.4% (95% CI, 0.333–1.050; P < 0.001) of the increased risk of CS related to low-risk PFO was attributed to the interaction with IAB. The results were robust in multivariate analysis. However, but no significant multiplicative or additive interaction was observed between IAB and high-risk PFO. When stratified by IAB, high-risk PFO was associated with CS in both patients with IAB (OR, 4.186; 95% CI, 1.617–10.839; P = 0.003) and without IAB (OR, 3.476; 95% CI, 1.790–6.750; P < 0.001). However, low-risk PFO was only associated with CS in patients with IAB (OR, 2.684; 95% CI, 1.007–7.149; P = 0.048) but not in those without IAB (OR, 0.753; 95% CI, 0.343–1.651; P = 0.479).ConclusionThe interaction between IAB and PFO might play an important role in CS, particularly in cases with low-risk PFO.

Electrogram-guided Bachmann bundle area pacing to correct interatrial block: Initial experience, safety, and feasibility

BackgroundA lack of standard Bachman Bundle(BB) capture criteria has affected the clinical impact of Bachmann Bundle Area Pacing(BBAP) in patients with inter-atrial block(IAB). ObjectiveWe evaluated the feasibility and safety of electrogram guided BBP using sheath assisted, stylet-driven atrial lead implantation. MethodsPatients with a baseline IAB undergoing dual chamber PPI or ICD implantation were enrolled in a single center,prospective study. BBAP was attempted in all patients with the aid of a Selectra 3D S-40 delivery sheath and Solia S-60 pacing lead. BB capture was confirmed using a combination of fluoroscopy,P wave morphology,and electrophysiological criteria. These included the recording of a high frequency BB potential and a transition between non-selective(NS) to selective(S) BB capture during threshold testing. Procedure-related complications,lead parameters,and P wave morphology were assessed at implantation and follow up. ResultsPermanent BBAP was successful in 32 of the 36(88.9%) enrolled patients. Baseline P wave duration was 148.5+16.1ms. Among patients who underwent successful BBP, the final paced P wave duration was 117.8+19.6ms. There was a correction of the partial or complete interatrial block in 22(91.7%) and 6(75.0%) patients, respectively. BB potentials were recorded in 83.3% of all study patients.A transition from NS to S-BB capture could be demonstrated during threshold testing in 22(87.5%) patients. The only major complications were 2 BBAP lead dislodgements within 24 hours and a rise in pacing impedance at 3 weeks in 1 patient. ConclusionBBAP is feasible in a high percentage of patients and is associated with stable capture thresholds during follow up.

Advanced Interatrial Block across the Spectrum of Renal Function

Background and Objective: Interatrial block (IAB) is defined as a conduction delay between the right and left atria. No data are available about the prevalence of both partial IAB and advanced IAB among the different stages of chronic kidney disease. The aim of this study was to describe the prevalence and type of advanced IAB across the spectrum of renal function, including patients on dialysis and the clinical characteristics associated with advanced IAB. Materials and Methods: Retrospective, single-center study of 151 patients consecutively admitted to the Nephrology and Ophthalmology Unit for 3 months. The study population was divided into three groups according to stages of chronic kidney disease. We evaluated the prevalence and pattern of IAB among the groups and the clinical characteristics associated with advanced IAB. Results: The prevalence of partial IAB was significantly lower in end-stage kidney disease (ESKD) group compared to control group (36.7% vs. 59.6%; p = 0.02); in contrast the prevalence of advanced IAB was significantly higher in both chronic kidney disease (CKD) (17.8% vs. 5.3%, p = 0.04) and ESKD group (24.5% vs. 5.3%, p = 0.005) compared to control group. The atypical pattern of advanced IAB was more frequent in both the ESKD and CKD group than in the control group (100% and 75% vs. 33.3%; p = 0.02). Overall, among patients that showed advanced IAB, 17 (73.9%) showed an atypical pattern by morphology and 2 (8.7%) showed an atypical pattern by duration of advanced IAB. The ESKD group was younger than the control group (65.7 ± 12.3 years vs. 71.3 ± 9.9 years; p = 0.01) and showed a higher prevalence of beta blockers (42.9% vs. 19.3%; p = 0.009), as in the CKD group (37.8% vs. 19.3%; p= 0.04). Conclusions: The progressive worsening of renal function was associated with an increasing prevalence of advanced IAB. Advanced IAB may be a sign of uremic cardiomyopathy and may suggest further evaluation with long-term follow-up to investigate its prognostic significance in chronic kidney disease.

Does a complete atrial block exist?

Terminological problems associated with the definition of intra- and interatrial conduction disorders, the possibility of forming complete interatrial block and criteria for its electrocardiographic diagnosis are discussed.

Interatrial block and abnormal P-wave electrocardiographic parameters as non-invasive predictors of atrial fibrillation

Aim. To identify noninvasive markers of atrial electrical dysfunction and risk of nonvalvular atrial fibrillation (AF) and to develop a predictive mathematical model to estimate the AF risk based on electrocardiographic (ECG) P-wave parameters during sinus rhythm.Methods. The study included 211 patients with cardiovascular pathology (aged median 62 [52; 71] years, 67.8% male, NYHA heart failure class I-III). All patients (follow-up median 45 [26; 67] months) underwent a complex of studies: 12-lead ECG, echocardiography, 24-hour ECG monitoring. Based on surface ECG data during sinus rhythm, parameters of atrial electrical activation were assessed such as Morphology, Voltage and P waves duration (MVP) according to integral analysis by MVP score.Results. During 3.7-year period, 44 (20.8%) patients experienced new-onset sustained AF and 12 (5.69%) patients developed ischemic stroke. As a result of ROC analysis and univariate Cox regression, independent predictors of AF were identified: P-wave prolongation in the DII lead, 3rd degree or advanced interatrial block (aIAB), an increase P-wave terminal force in lead V1 (PTFV1), low-voltage P-wave in the DI lead and сalculated level of abnormal P-wave ≥3 points on the MVP score. Data from multivariate Cox proportional hazards regression analysis confirmed the prognostic significance for three independent predictors of AF: aIAB (hazard ratio (HR) 5.92; 95% confidence interval (CI) [2.48-4.12]; p=0.0001); PTFV1 (HR 1.14; 95% CI [1.04-1.24], p=0.003); low-voltage P-wave in lead DI &lt;0.1 mV (HR 1.03; 95% CI [1.02-1.05]; p=0.0001); and as a result a mathematical model was created to predict AF risk (-2LL =258; χ2=105; p=0.0001). Predictors such as PTFV1 (HR 1.41; 95% CI [1.17-1.72], p=0.0001) and MVP score of abnormal P-waves (HR 1.85; 95% CI [1.27-1.72] 2.70], p=0.001) were associated with a high risk of stroke according to Cox regression model (-2LL= 62.5; χ2=38.4; p &lt;0.001).Conclusion. Complex of ECG markers of atrial electrical dysfunction such as aIAB, PTFV1, level MVP score of abnormal P-wave and low P-wave voltage allows identifying patients at high risk of AF and ischemic stroke.

P-wave duration and interatrial block as predictors of ischemic stroke: a systematic review and meta-analysis

Abstract Introduction Ischemic stroke-risk has been associated with clinical characteristics, atrial remodeling and P- wave changes, like P-wave duration (PWD) or interatrial block (IAB). Despite the increasing evidence though, their use in risk-stratification remains limited. Purpose The aim of this review and meta-analysis was to examine the predictive value of PWD/IAB for stroke and offer practical implications. Methods Publication databases were systematically searched and studies reporting PWD and/or morphology at baseline and thromboembolic events (TEs) during follow-up (FUP) 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 to address heterogeneity. Results Among 180.997 patients (17 studies, mean 66 years old), including primary care patients (n=152.759), 15.578 (9%) had a new TE during 4 years of FUP. The pIAB was significant TE-risk predictor for non-primary care patients (OR:1.7; 95% CI:1.4-2.1) and those with prior TE (OR:1.8; 95% CI:1.4-2.2), but not for primary-care (OR:1.0) or those without prior TE (OR:1.3). The aIAB was significant TE-risk predictor both for primary (OR:1.6; 95% CI:1.4-1.9) and nonprimary care (OR:2.5; 95% CI:1.8-3.4) as well as those without (OR:2.2; 95% CI:1.1-4.4) or with prior TE (OR:2.6; 95% CI:1.4-4.7). There was heterogeneity but no publication bias in the subgroup-analysis. Conclusion Interatrial block is an independent predictor of TE-risk. The association is stronger for non-primary care patients or those with prior TE. Thus, PWD and IAB could be used as selection criteria for intensive screening, follow-up or interventions.

Machine learning for development of ECG-based prediction models for atrial fibrillation, thromboembolism and mortality in patients with heart failure

Abstract Background Heart failure (HF) is a worldwide epidemic affecting more than 64 million people. Given its massive burden both socially and economically, early identification of individuals at risk for complications is important. Purpose To test the predictive performance of non-invasive models from 12-lead digitalized electrocardiography (ECG) and cycle ergometer for adverse outcome in individuals with heart failure. Methods 598 Patients scheduled for right heart catheterization due to unexplained dyspnea were screened. All ECG recorded at admission were further analysed using the software "ECG-Precision-Analysis V-1-2023" to measure the duration of amplified p-wave (APWD at 175mm/sec, 80mm/mV) and to confirm the diagnosis of inter-atrial block. Ergometer was performed in a supine position with increasing intensity adapted to individual capacity (25 or 50W). The maximum physical capacity (Watt-max) was determined. Follow-up (FU) was scheduled at 12-,36-, 60- and 120-month after discharge with the primary endpoint as MACCE (a composite of new onset of AF, ischemic stroke and peripheral embolism) in at baseline event-free patients and the secondary endpoint as all-cause mortality in the total cohort. Three machine learning (ML) algorithms (COX regression, BSR and LASSO regression) were used to select candidate variables and establish predictive models for MACCE and all-cause mortality. Model evaluation was performed in terms of discriminatory power using C-statistics for each endpoint. Results Prediction models developed using machine learning (ML) algorithms (COX regression, BSR and LASSO regression) identified Watt-max and/or APWD as core components for MACCE and mortality prediction . APWD and Watt-max were key components of ML models for prediction of thromboembolic risk and AF (MACCE) and reached accurate diagnostic performances (C-statistics up to 0.74), moreover, another model consisted of APWD and aIAB (advanced inter-atrial block) was established to serve as a reference to ML models with moderate performance for MACCE (mean C-statistics &amp;lt;0.70). All ML models for prediction of all-cause mortality included Watt-max and achieved C-statistics &amp;gt; 0.75. Conclusions In patients with heart failure, the combination of APWD, aIAB and maximum excercice capacity allow to identify patients at risk for AF and stroke, whereas mortality is predominantly predicted by maximum exercise capacity but not APWD.Kaplan-Meier curves for MACCE/MortalitytimeROC curves for MACCE/Mortality

Comparison between Novel and Conventional Electrocardiographic Markers of Atrial Cardiomyopathy for identification of Persons at Risk for Ischemic Stroke

Abstract Background Atrial cardiomyopathy is associated with increased risk for future atrial fibrillation (AF) and ischemic stroke. Several ECG-derived parameters have been reported to assess the risk for future ischemic stroke. Purpose To predict risk of future ischemic stroke by comparison of the novel parameter duration of the amplified digital sinus-p-wave (APWD; 80mm/mV; 175mm/sec) vs previously described p-wave indices and clinical risk factors (cerebrovascular disease (CVD), CHADS-VASc-score). Methods P-wave-derived parameters were measured on digital 12-lead-sinus-ECGs (recorded +/- 6 months from the clinical stroke event) using the software "ECG-Precision-Analysis V-1-2023". and clinical CHA2DS2-VASc Score was assessed in 80 patients with ischemic stroke (no history of AF, no oral anticoagulation (OAC)) and compared to 80 control patients (without OAC, AF or ischemic stroke within the next five years). Results Patients with ischemic stroke vs control patients presented a higher CHA2DS2-VASc Score (3.7 vs 3.2, p=0.04), had more frequently heart failure (25% vs 13%, p=0.04) and cerebrovascular atherosclerotic disease with stenosis &amp;gt;40% ((22.5% vs 10%, p=0.032). P-wave indices were as follows in patients who developed ischemic stroke within the next 12 months versus patients without stroke within a follow-up period of five years, respectively: APWD (144 vs 128ms, p&amp;lt;0.0001), non-amplified SPWD (118 vs 116ms, p=0.081), A-PTF-V1 (-4660 vs -3860µV*ms, p=0.005), durations and amplitudes of terminal-p-wave in V1 (A-Duration-V1 (83 vs 79ms, p=0.119), A-Amplitude-V1 (-50µV vs -50µV, p=0.028), and advanced interatrial block (aIAB in 25% vs 3.8% of patients; p&amp;lt;0.0001. The novel ECG-derived parameter (duration of the amplified sinus-P-wave &amp;gt;140ms) was the best predictor for future ischemic stroke (accuracy: 74%, sensitivity and specificity: 61% and 86%, respectively; PPV: 82%; area under ROC: 0.776). Sensitivity and specificity of the SPWD, aPTFV1 and aIAB were significantly lower (SPWD&amp;gt;120ms: sensitivity 35% and specificity 78%, PPV: 61%; aPTFV1 ≤-5000µV*ms, accuracy: 61%, sensitivity 46%% and specificity 75%, PPV: 65%; aIAB: accuracy: 61%, sensitivity 25% and specificity 96%, PPV: 87%). Conclusions Among the currently identified ECG markers of atrial cardiomyopathy, the novel APWD and advanced interatrial block have the best predictive performances for diagnosis of persons at risk for ischemic stroke.Comparison between ECG ParametersPredictive Accuracy of Parameters

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.

Electrocardiogram prediction of atrial fibrillation risk after stroke: A protocol for systematic review and meta-analysis.

Atrial fibrillation (AF) is one of the most common clinical arrhythmias. This study aims to predict the risk of post-stroke AF through electrocardiographic changes in sinus rhythm. We searched the MEDLINE (PubMed) and EMBASE databases to identify relevant research articles published until August 2023. Prioritized items from systematic reviews and meta-analyses were screened, and data related to AF detection rate were extracted. A meta-analysis using a random-effects model was conducted for data synthesis and analysis. A total of 32 studies involving electrocardiograms (ECG) were included, with a total analysis population of 330,284 individuals. Among them, 16,662 individuals (ECG abnormal group) developed AF, while 313,622 individuals (ECG normal group) did not. ECG patterns included terminal P-wave terminal force V1, interatrial block (IAB), advanced interatrial block, abnormal P-wave axis, pulse rate prolongation, and atrial premature complexes. Overall, 15,762 patients experienced AF during the study period (4.77%). In the ECG abnormal group, the proportion was 14.21% (2367/16,662), while in the control group (ECG normal group), the proportion was 4.27% (13,395/313,622). The pooled risk ratio for developing AF was 2.45 (95% confidence interval [CI]: 2.02-2.98, P < .001), with heterogeneity (I2) of 95%. The risk ratio values of alAB, P-wave terminal force V1, interatrial block, abnormal P-wave axis, pulse rate prolongation and atrial premature complexes were 4.12 (95% CI, 2.99-5.66), 1.47 (95% CI, 1.19-1.82), 2.54 (95% CI, 1.83-3.52), 1.70 (95% CI, 0.98-2.97), 2.65 (95% CI, 1.88-3.72), 3.79 (95% CI, 2.12-6.76), respectively. There is a significant correlation between ECG patterns and the occurrence of AF. The alAB exhibited the highest level of predictability for the occurrence of AF. These indicators support their use as screening tools to identify high-risk individuals who may benefit from further examinations or empirical anticoagulation therapy following stroke.

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.

Atrial electrofunctional predictors of incident atrial fibrillation in cardiac amyloidosis

BackgroundAtrial fibrillation (AF) is common in patients with cardiac amyloidosis (CA) and is a significant risk factor for heart failure hospitalization and thromboembolic events. ObjectiveThis study was designed to investigate the atrial electrofunctional predictors of incident AF in CA. MethodsA multicenter, observational study was conducted in 4 CA referral centers including sinus rhythm patients with light-chain (AL) and transthyretin (ATTR) CA undergoing electrocardiography and cardiac magnetic resonance imaging. The primary end point was new-onset AF occurrence. ResultsOverall, 96 patients (AL-CA, n = 40; ATTR-CA, n = 56) were enrolled. During an 18-month median follow-up (Q1–Q3, 7–29 months), 30 patients (29%) had incident AF. Compared with those without AF, patients with AF were older (79 vs 73 years; P = .001). They more frequently had ATTR (87% vs 45%; P < .001); electrocardiographic interatrial block (IAB), either partial (47% vs 21%; P = .011) or advanced (17% vs 3%; P = .017); and lower left atrial ejection fraction (LAEF; 29% vs 41%; P = .004). Age (hazard ratio [HR], 1.059; 95% CI, 1.002–1.118; P = .042), any type of IAB (HR, 2.211; 95% CI, 1.03–4.75; P = .041), and LAEF (HR, 0.967; 95% CI, 0.936–0.998; P = .044) emerged as independent predictors of incident AF. Patients exhibiting any type of IAB, LAEF <40%, and age >78 years showed a cumulative incidence for AF of 40% at 12 months. This risk was significantly higher than that carried by 1 (8.5%) or none (7.6%) of these 3 risk factors. ConclusionIn patients with CA, older age, IAB on 12-lead electrocardiography, and reduced LAEF on cardiac magnetic resonance imaging are significant and independent predictors of incident AF. A closer screening for AF is advisable in CA patients carrying these features.

ECG at the Bedside: Atrial Bigeminy with Alternating long and Short PR Interval

The admission electrocardiogram of an 88-year-old woman, showed sinus rhythm, biphasic P waves in leads II, III, with the terminal vector directed upward, P duration 130 msec, PR interval 200 msec, consistent with advanced inter-atrial block. Next, atrial bigeminy occurred originating in the left atrium and delaying the sinus P waves. With the ectopic P’ measuring 60 msec, the likely path of left atrial stimuli to delaying the sinus node was through Bachmann’s bundle, by retrograde conduction. This means that inter-atrial conduction via Bachmann bundle.

Interatrial Block and Electrocardiographic Markers of Repolarization in Patients Hospitalized with COVID-19: Classical and Bayesian Analysis.

Coronavirus disease-2019 (COVID-19) is associated with atrial fibrillation (AF) and ventricular arrhythmias. Several electrophysiological abnormalities on surface electrocardiography (ECG) are associated with AF and ventricular arrhythmias, either as markers of abnormal interatrial conduction or abnormal repolarization. The present study sought to understand whether such ECG markers are more common in patients hospitalized with COVID-19 infection during the pandemic. A total of 87 COVID-19 patients formed the study group, whereas 64 patients who were hospitalized for any reason other than COVID-19 infection served as controls. The frequency of partial and advanced interatrial block (IAB), QT and corrected QT (QTc) durations, QT dispersion (QTd), and T peak-to-end duration (Tpe) were measured from ECGs at admission. Both partial and advanced IAB were more common in patients with COVID-19, although statistical significance was only observed for advanced IAB (11.5% in COVID-19 patients vs. 0.0% in controls, p=0.005). There were no differences between the groups for QTc, QTd or Tpe. On Bayesian analyses, there was strong evidence favoring an association between COVID-19 and advanced IAB (BF10:16), whereas there was no evidence for an association for partial IAB, QTc, QTd, or Tpe (BF10<1 for all). Patients hospitalized with COVID-19 were more likely to have advanced IAB, which may explain why AF is more frequent in these patients.

P-wave characteristics as electrocardiographic markers of atrial abnormality in prediction of incident atrial fibrillation – The Malmö Preventive Project

BackgroundP-wave indices reflect atrial abnormalities contributing to atrial fibrillation (AF). We aimed to assess a comprehensive set of P-wave characteristics for prediction of incident AF in a population-based setting. MethodsMalmö Preventative Project (MPP) participants were reexamined in 2002–2006 with electrocardiographic (ECG) and echocardiographic examinations and followed for 5 years. AF-free subjects (n = 983, age 70 ± 5 years, 38% females) with sinus rhythm ECGs were included in the study. ECGs were digitally processed using the Glasgow algorithm. P-wave duration, axis, dispersion, P-terminal force in lead V1 and interatrial block (IAB) were evaluated. ECG risk score combining the morphology, voltage and length of P-wave (MVP score) was calculated. New-onset diagnoses of AF were obtained from nation-wide registers. ResultsDuring follow up, 66 patients (7%) developed AF. After adjustment for age and gender, the independent predictors of AF were abnormal P-wave axis > 75° (HR 1.63 CI95% 1.95–11.03) and MVP score 4 (HR 6.17 CI 95% 1.76–21.64), both correlated with LA area: Person r − 0.146, p < 0.001 and 0.192, p < 0.001 respectively. Advanced IAB (aIAB) with biphasic P-wave morphology in leads III and aVF was the most prevalent variant of aIAB and predicted AF in a univariate model (HR 2.59 CI 95% 1.02–6.58). ConclusionP-wave frontal axis and MVP score are ECG-based AF predictors in the population-based cohort. Our study provides estimates for prevalence and prognostic importance of different variants of aIAB, providing a support to use biphasic P-wave morphology in lead aVF as the basis for aIAB definition.