P3799Experimental model of interatrial block by Bachmann bundle conduction block

Abstract Background The recognition of advanced IAB is becoming an important clinical landmark due to its association with atrial fibrillation, the so-called Bayes' syndrome. The electrocardiographic (ECG) criteria of interatrial block (IAB) have been established. A P-wave duration ≥120 ms is considered partial IAB and if there is a biphasic P-wave in the inferior leads advanced IAB. The pathophysiology of this ECG finding has been largely discussed. IAB has been explained as the result of the retrograde activation of left atrium due to complete block in the Bachmann bundle (BB). Purpose To assess the ECG changes resulting of blocking BB conduction in an experimental healthy animal model. Additionally, to compare the pattern of activation of the left atrium before and after the block. Methods Six open-chest anesthetized healthy adult swine were studied. A twelve-lead ECG was continuously recorded. The BB was epicardially accessed at the traversus sinus of the pericardium. At that level, monopolar electrosurgical energy (3 animals) and radiofrequency energy (3 animals) (Boston Scientific Blazer™ II XP, 8 mm tip) was applied until extensive tissue disruption was present and permanent P-wave changes observed. An electroanatomical map CARTO® XP (Biosense Webster Inc) of the right and left atrium was performed in two animals before and after energy deployment. Finally, animals were sacrificed, and tissue samples collected for anatomopathological examination. Results After energy application, all animals showed a significant prolongation of P-wave duration from 59±11 msec to 115±13 msec (p<0.001) with appearance of a biphasic P-wave pattern in the inferior leads. The CARTO® maps showed a change in left atrial activation, cranio-caudal at baseline and caudo-cranial at the end of the procedure. (Figure) The histological analysis showed transmural lesions at the level of the BB in all the specimens. ECG/CARTO maps: Baseline and after block Conclusion IAB ECG pattern, accompanied by a marked change in the activation of the left atrium, develops after blocking the conduction at the level of the BB in an experimental healthy animal model. These results confirm the association of IAB and BB conduction block and suggest that IAB represents an independent entity. Acknowledgement/Funding Fundaciό Privada Daniel Bravo Andreu

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Second-Degree Interatrial Block in Hemodialysis Patients

Case Reports in Cardiology ◽

10.1155/2015/468493 ◽

2015 ◽

Vol 2015 ◽

pp. 1-4 ◽

Cited By ~ 5

Author(s):

Andres Enriquez ◽

Marco Marano ◽

Anna D’Amato ◽

Antoni Bayes de Luna ◽

Adrian Baranchuk

Keyword(s):

Conduction Block ◽

Hemodialysis Patients ◽

Chronic Hemodialysis ◽

P Wave ◽

Wave Duration ◽

P Wave Duration ◽

Surface Ecg ◽

Interatrial Block ◽

Bachmann Bundle ◽

Interatrial Conduction

Interatrial conduction delays manifest as a prolonged P-wave duration on surface ECG and the term interatrial block (IAB) has been coined. They are usually fixed, but cases of intermittent IAB have been described, suggesting functional conduction block at the Bachmann bundle region. We report 2 cases of patients on chronic hemodialysis therapy presenting with intermittent IAB.

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P855Electrocardiographic p-wave duration in interatrial block and left atrium anatomo-functional alterations determined by speckle-tracking echocardiography

European Heart Journal ◽

10.1093/eurheartj/ehy564.p855 ◽

2018 ◽

Vol 39 (suppl_1) ◽

Author(s):

J Miranda-Bacallado ◽

M M Izquierdo-Gomez ◽

J Garcia-Niebla ◽

C Belleyo-Belkasem ◽

P Barrio-Martinez ◽

...

Keyword(s):

Left Atrium ◽

Speckle Tracking ◽

Speckle Tracking Echocardiography ◽

P Wave ◽

Wave Duration ◽

P Wave Duration ◽

Interatrial Block

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Advanced interatrial block precedes atrial fibrillation and stroke. The prospective interatrial Block And Yearly EventS (BAYES) registry

European Heart Journal ◽

10.1093/ehjci/ehaa946.0485 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

M Martinez-Selles ◽

R Elosua ◽

M Ibarrola ◽

M De Andres ◽

P Diez-Villanueva ◽

...

Keyword(s):

Atrial Fibrillation ◽

Heart Disease ◽

Sinus Rhythm ◽

Structural Heart Disease ◽

P Wave ◽

Wave Duration ◽

P Wave Duration ◽

Previous Diagnosis ◽

Surface Ecg ◽

Interatrial Block

Abstract Background Advanced interatrial block (IAB), prolonged and bimodal P waves in surface ECG inferior leads, is an unrecognized surrogate of atrial dysfunction and a trigger of atrial dysrhythmias, mainly atrial fibrillation (AF). Our aim was to prospectively assess whether advanced IAB in sinus rhythm precedes AF and stroke in elderly outpatients with structural heart disease, a group not previously studied. Methods Prospective observational registry that included outpatients aged ≥70 years with structural heart disease and no previous diagnosis of AF. Patients were divided into three groups according to P-wave characteristics. Results Among 556 individuals, 223 had normal P-wave (40.1%), 196 partial IAB (35.3%), and 137 advanced IAB (24.6%). After a median follow-up of 694 days; 93 patients (16.7%) developed AF, 30 stroke (5.4%), and 34 died (6.1%). Advanced IAB was independently associated with AF (hazard ratio [HR] 2.9, 95% confidence interval [CI] 1.7–5.1, p<0.001), stroke (HR 3.8, 95% CI 1.4–10.7, p=0.010), and AF/stroke (HR 2.6, 95% CI 1.5–4.4, p=0.001). P-wave duration (ms) was independently associated with AF (HR 1.05, 95% CI 1.03–1.07, p<0.001), AF/stroke (HR 1.04, 95% CI 1.02–1.06, p<0.001), and mortality (HR 1.04, 95% CI 1.00–1.08, p=0.021). Conclusions The presence of advanced IAB in sinus rhythm is a risk factor for AF and stroke in an elderly population with structural heart disease and no previous diagnosis of AF. P-wave duration was also associated with all-cause mortality. Figure. Age- and sex-adjusted linear and non-linear association between P-wave duration (msec) and atrial fibrillation (A), stroke (B), and atrial fibrillation or stroke (C) risk. Results of a generalized additive model with spline smoothing functions and 4 degrees of freedom. Figure 1. Kaplan-Meyer curves of survival free of atrial fibrillation (A), stroke (B) and atrial fibrillation or stroke (C) in patients with normal P-wave, partial interatrial block (IAB) and advanced IAB. Funding Acknowledgement Type of funding source: None

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Abstract 2023: Effect Of Chronic Stretch Reversal On Atrial Remodeling In Humans: Implications For The Atrial Fibrillation Substrate

Circulation ◽

10.1161/circ.116.suppl_16.ii_438 ◽

2007 ◽

Vol 116 (suppl_16) ◽

Author(s):

Bobby John ◽

Martin K Stiles ◽

Sunil T Chandy ◽

Pawel K Kuklik ◽

Glenn D Young ◽

...

Keyword(s):

Atrial Fibrillation ◽

Important Determinant ◽

P Wave ◽

Atrial Remodeling ◽

Conduction Time ◽

Atrial Arrhythmias ◽

Wave Duration ◽

P Wave Duration ◽

Before And After ◽

Mitral Commissurotomy

Background : Chronic atrial stretch is an important determinant for atrial fibrillation (AF). Whether relief of stretch reverses the substrate predisposed to AF is unknown. Methods: Twenty one pts (31±9 years) with mitral stenosis (MS; MVA 0.89±0.1cm 2 ) undergoing mitral commissurotomy (MC) were studied by electrophysiological or electroanatomical mapping of both atria before and after MC. Multipolar catheters were placed in the lateral RA, Crista (CT), coronary sinus (CS), septal RA and LA. We measured: effective refractory period (ERP) at the LA appendage, septal/lateral LA roof, posterior LA, inferior LA, proximal/distal CS, low/high LRA and SRA at 600 and 450ms; P wave duration (PWD); double potentials (DP) or fractionated signals (FS) along CT; and conduction time along CS, LRA, inferior LA and LA roof. Activation and voltage maps were created to evaluate changes in conduction and voltage. In 14 pts, RA studies were repeated ≥6 months after MC. Results : Following MC, there was significant increase in MVA (2.1±0.3 cm 2, p<0.0001) with decrease in LA (23±8 to 10±4 mmHg, p<0.0001) and PA pressures (38±17 to 27±14mmHg, p<0.0001) and LA volume (75±12 to 52±13ml, p<0.0001). This was associated with no change in ERP and No. of DP/FS along the CT but with reduction in PWD (139±19 to 135±20ms, p=0.047), increase in conduction velocity (CV) in LA (1.3±0.3 to 1.7±0.2m/s, p=0.005) and RA (1.0±0.1 to 1.3±0.3 m/s, p=0.007) and increase in LA voltage (1.7±0.6 to 2.5±1.0 mV, p=0.05). Late after MC, there was a further decrease in PWD and RA ERP, with increase in RA CV (1.0±0.1 to 1.3±0.2 m/s, p=0.01) and voltage (1.7±0.7 to 2.8±0.6 mV, p=0.004) but with no change in other parameters. See table for details of pts studied late after MC. Conclusion: The electrophysiologic and electroanatomic abnormalities within the atria that result from MS are reversed after MC. These observations suggest that the substrate predisposing to atrial arrhythmias may be reversed. Results

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Correlation of Left Atrial Size With P-Wave Duration in Interatrial Block

CHEST Journal ◽

10.1378/chest.128.4.2615 ◽

2005 ◽

Vol 128 (4) ◽

pp. 2615-2618 ◽

Cited By ~ 46

Author(s):

Vignendra Ariyarajah ◽

Kristin Mercado ◽

Sirin Apiyasawat ◽

Puneet Puri ◽

David H Spodick

Keyword(s):

Left Atrial ◽

P Wave ◽

Left Atrial Size ◽

Wave Duration ◽

P Wave Duration ◽

Atrial Size ◽

Interatrial Block

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

Journal of the American Heart Association ◽

10.1161/jaha.120.017624 ◽

2020 ◽

Vol 9 (22) ◽

Author(s):

Lourdes Vicent ◽

Clara Fernández‐Cordón ◽

Luis Nombela‐Franco ◽

Luis Alberto Escobar‐Robledo ◽

Ana Ayesta ◽

...

Keyword(s):

Atrial Fibrillation ◽

Aortic Valve ◽

Transcatheter Aortic Valve Implantation ◽

P Wave ◽

Wave Duration ◽

Transcatheter Aortic Valve ◽

P Wave Duration ◽

Aortic Valve Implantation ◽

Interatrial Block ◽

Valve Implantation

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.

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