Gli autori ringraziano la signora Maggie Wallner (Atritech Inc. / Boston Scientific) per la revisione critica di questo articolo. Gli autori vogliono ringraziare Mr. Mahesh Deshpanade (Boston Scientific) per il suo supporto amministrativo e le autorizzazioni di copyright organizzazione. Il video è stato finanziato da una sovvenzione illimitata di Boston Scientific.

<ol>
	<li>Miyasaka, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Time+trends+of+ischemic+stroke+incidence+and+mortality+in+patients+diagnosed+with+first+atrial+fibrillation+in+1980+to+2000:+report+of+a+community-based+study.">Time trends of ischemic stroke incidence and mortality in patients diagnosed with first atrial fibrillation in 1980 to 2000: report of a community-based study.</a> Stroke. 36, 2362-2366 (2005).</li><li>Holmes, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Percutaneous+closure+of+the+left+atrial+appendage+versus+warfarin+therapy+for+prevention+of+stroke+in+patients+with+atrial+fibrillation:+a+randomised+non-inferiority+trial.">Percutaneous closure of the left atrial appendage versus warfarin therapy for prevention of stroke in patients with atrial fibrillation: a randomised non-inferiority trial.</a> Lancet. 374, 534-542 (2009).</li><li>Schweizer, P. A., Becker, R., Katus, H. A., Thomas, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dronedarone:+current+evidence+for+its+safety+and+efficacy+in+the+management+of+atrial+fibrillation.">Dronedarone: current evidence for its safety and efficacy in the management of atrial fibrillation.</a> Drug. 5, 27-39 (2011).</li><li>Wyse, D. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+comparison+of+rate+control+and+rhythm+control+in+patients+with+atrial+fibrillation.">A comparison of rate control and rhythm control in patients with atrial fibrillation.</a> N. Engl. J. Med. 347, 1825-1833 (2002).</li><li>Carlsson, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Randomized+trial+of+rate-control+versus+rhythm-control+in+persistent+atrial+fibrillation:+the+Strategies+of+Treatment+of+Atrial+Fibrillation+(STAF)+study.">Randomized trial of rate-control versus rhythm-control in persistent atrial fibrillation: the Strategies of Treatment of Atrial Fibrillation (STAF) study.</a> J. Am. Coll. Cardiol. 41, 1690-1696 (2003).</li><li>Van Gelder, I. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+comparison+of+rate+control+and+rhythm+control+in+patients+with+recurrent+persistent+atrial+fibrillation.">A comparison of rate control and rhythm control in patients with recurrent persistent atrial fibrillation.</a> N. Engl. J. Med. 347, 1834-1840 (2002).</li><li>Echt, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mortality+and+morbidity+in+patients+receiving+encainide,+flecainide,+or+placebo.+The+Cardiac+Arrhythmia+Suppression+Trial.">Mortality and morbidity in patients receiving encainide, flecainide, or placebo. The Cardiac Arrhythmia Suppression Trial.</a> N. Engl. J. Med. 324, 781-788 (1991).</li><li>Ames, A., Stevenson, W. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiology+patient+page.+Catheter+ablation+of+atrial+fibrillation.">Cardiology patient page. Catheter ablation of atrial fibrillation.</a> Circulation. 113, e666-e668 (2006).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stroke+Prevention+in+Atrial+Fibrillation+Study.+Final+results.">Stroke Prevention in Atrial Fibrillation Study. Final results.</a> Circulation. 84, 527-539 (1991).</li><li>Singer, D. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antithrombotic+therapy+in+atrial+fibrillation:+American+College+of+Chest+Physicians+Evidence-Based+Clinical+Practice+Guidelines+(8th+Edition).">Antithrombotic therapy in atrial fibrillation: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition).</a> Chest. 133, 546S-592S (2008).</li><li>Connolly, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dabigatran+versus+warfarin+in+patients+with+atrial+fibrillation.">Dabigatran versus warfarin in patients with atrial fibrillation.</a> N. Engl. J. Med. 361, 1139-1151 (2009).</li><li>Patel, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rivaroxaban+versus+warfarin+in+nonvalvular+atrial+fibrillation.">Rivaroxaban versus warfarin in nonvalvular atrial fibrillation.</a> N. Engl. J. Med. 365, 883-891 (2011).</li><li>Albers, G. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ximelagatran+vs+warfarin+for+stroke+prevention+in+patients+with+nonvalvular+atrial+fibrillation:+a+randomized+trial.">Ximelagatran vs warfarin for stroke prevention in patients with nonvalvular atrial fibrillation: a randomized trial.</a> JAMA. 293, 690-698 (2005).</li><li>Fiessinger, J. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ximelagatran+vs+low-molecular-weight+heparin+and+warfarin+for+the+treatment+of+deep+vein+thrombosis:+a+randomized+trial.">Ximelagatran vs low-molecular-weight heparin and warfarin for the treatment of deep vein thrombosis: a randomized trial.</a> JAMA. 293, 681-689 (2005).</li><li>Schulman, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dabigatran+versus+warfarin+in+the+treatment+of+acute+venous+thromboembolism.">Dabigatran versus warfarin in the treatment of acute venous thromboembolism.</a> N. Engl. J. Med. 361, 2342-2352 (2009).</li><li>Sick, P. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Initial+worldwide+experience+with+the+WATCHMAN+left+atrial+appendage+system+for+stroke+prevention+in+atrial+fibrillation.">Initial worldwide experience with the WATCHMAN left atrial appendage system for stroke prevention in atrial fibrillation.</a> J. Am. Coll. Cardiol. 49, 1490-1495 (2007).</li><li>Reddy, V. Y., Holmes, D., Doshi, S. K., Neuzil, P., Kar, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Safety+of+percutaneous+left+atrial+appendage+closure:+results+from+the+Watchman+Left+Atrial+Appendage+System+for+Embolic+Protection+in+Patients+with+AF+(PROTECT+AF)+clinical+trial+and+the+Continued+Access+Registry.">Safety of percutaneous left atrial appendage closure: results from the Watchman Left Atrial Appendage System for Embolic Protection in Patients with AF (PROTECT AF) clinical trial and the Continued Access Registry.</a> Circulation. 123, 417-424 (2011).</li></ol>

Dr. Möbius-Winkler, e il Prof. Dr. Dähnert Schuler ha partecipato alla Trial protect AF. Dr. Möbius-Winkler lavora come sorvegliante per l&#39;impianto sentinella per Atritech Inc. e Boston Scientific.

La procedura di impianto percutanea del METRONOTTE atriale sinistra dispositivo di chiusura appendice qui descritta, è stato dimostrato in studi clinici sia realizzabile 16, non inferiore a warfarin terapia 2, e cassaforte 17. Anche se in tutti gli studi vi era un tasso più elevato di complicanze nel gruppo trattato con l&#39;impianto 2,16,17, i dati dello studio PROTECT AF e il registro di studio della PAC, che ha valutato la sicurezza, suggerisce che le complicazioni connesse con l&#39;impianto del guardiano può essere in gran parte attribuito alla inesperienza dell&#39;operatore. La frequenza dei tassi di eventi di sicurezza era inizialmente alto, ma è diminuito nel corso del tempo 17. Il metodo qui presentato mette in luce alcuni punti critici nella prevenzione delle complicanze procedurali. Durante lo studio pilota, tre eventi di sicurezza si è verificato come risultato di guasto del dispositivo. In due soggetti il ​​dispositivo embolizzato, e in un soggetto il filo si è rotto durante la Implantazione procedura. Anche se questi eventi si sono verificati in dispositivi di prima generazione, e non si è verificato nella seconda generazione del dispositivo, il sistema METRONOTTE deve essere sempre accuratamente esaminato prima dell&#39;uso 16. Le complicazioni più comuni associati con la procedura di versamento pericardico sono che necessitano di intervento e di embolia gassosa. Analisi dei dati di imaging suggerisce che i versamenti pericardici gravi nello studio PROTECT AF sono stati causati da errori dell&#39;operatore durante la puntura transettali, dalla manipolazione del dispositivo METRONOTTE o dalla manipolazione all&#39;interno della LAA con la guaina di raggiungere un ottimale procedura di impianto. Utilizzando un catetere pigtail il rischio di perforazione della LAA dalla punta della guaina può essere fortemente ridotto. Un versamento pericardico molto probabilmente il risultato di una vigorosa &quot;test rimorchiatore&quot; eseguito per verificare la stabilità del dispositivo della LAA. Per questo motivo, è fondamentale utilizzare TEE e fluoroscopia durante la procedura per sorvegliare implantation processo. Durante il controllo di stabilità, il contrasto deve essere iniettato nel LAA per visualizzare la camera, o il processo deve essere continuamente monitorato con TEE. Con l&#39;osservazione, senza ulteriori tiro relativi versamenti sono stati osservati. Procedura correlata corsa in 3 casi si è verificato come risultato di embolia di aria dal grande guaina 12F accesso transettale. Pertanto, è fondamentale essere diligente in correttamente lavaggio guaina assicurare che l&#39;aria non è intrappolato all&#39;interno della guaina 17. Inoltre, digiuno prima della procedura può portare a disidratazione con conseguente bassa pressione atriale sinistra durante la procedura di impianto, che può causare embolia di aria. Pertanto, prima di distribuire il dispositivo, salina dovrebbe essere infuso per aumentare la pressione atriale sinistra del paziente di circa 10 mmHg. Nonostante il più alto tasso di sicurezza di eventi con LAA occlusione rispetto al trattamento con warfarin, il risultato complessivo per quanto riguarda la morbilità / mortalità con LAA occlusione è stata imdimostrato 17. Chiusura della atriale sinistra è pertanto una promettente alternativa alla terapia efficace warfarin continuo in pazienti con non-valvolare fibrillazione atriale.

the watchman left atrial appendage closure device for atrial fibrillation

La fibrillazione atriale (AF) è la più comune aritmia cardiaca, che colpisce circa 6 milioni di persone negli Stati Uniti 1. Dal momento che AF colpisce le persone anziane soprattutto, la sua prevalenza aumenta parallelamente con l&#39;età. Come tale, si prevede che 15,9 milioni di americani saranno interessati entro il 2050 2. Ictus ischemico si verifica nel 5% dei non-anticoagulante pazienti con fibrillazione atriale ogni anno. Gli attuali trattamenti per AF includono il controllo della frequenza, il controllo del ritmo e la prevenzione di ictus 3. L&#39;American College of Cardiology, American Heart Association e della European Society of Cardiology attualmente il controllo della frequenza indicato come il primo corso di terapia per la AF 3. Il controllo della frequenza si ottiene con la somministrazione di agenti farmacologici, quali beta-bloccanti, che abbassano la frequenza cardiaca fino a raggiungere uno stato meno sintomatico 3. Il controllo del ritmo ha lo scopo di riportare il cuore al suo ritmo sinusale normale ed è tipicamenterealizzato attraverso la somministrazione di farmaci antiaritmici come amiodarone, cardioversione elettrica o terapia di ablazione. Metodi di controllo del ritmo, tuttavia, non hanno dimostrato di essere superiore al tasso di metodi di controllo 4-6. Infatti, alcuni farmaci antiaritmici hanno dimostrato di essere associata a tassi di ospedalizzazione più elevati, gravi effetti avversi 3, o addirittura incrementi di mortalità nei pazienti con difetti cardiaci strutturali 7. Pertanto, il trattamento con antiaritmici è più spesso utilizzato quando il tasso di controllo farmaci sono inefficaci o sono controindicati. Rate-controllo e gli agenti antiaritmici alleviare i sintomi della AF, tra cui palpitazioni, fiato corto e stanchezza 8, ma non in modo affidabile la prevenzione di episodi tromboembolici 6. Il trattamento con il farmaco anticoagulante warfarin riduce in modo significativo il tasso di ictus o embolia 9,10. Tuttavia, a causa dei problemi associati al suo impiego, meno del 50%pazienti vengono trattati con esso. La dose terapeutica è influenzata dal farmaco, dieta, e le interazioni metaboliche, e quindi richiede un attento monitoraggio. Inoltre, warfarin ha il potenziale di provocare gravi, talvolta letale, sanguinamento 2. In alternativa, aspirina è comunemente prescritta. Mentre l&#39;aspirina è in genere ben tollerato, è molto meno efficace nel prevenire l&#39;ictus 10. Altre alternative a warfarin, come dabigatran 11 o 12 rivaroxaban dimostrato la non inferiorità rispetto a warfarin rispetto a eventi tromboembolici (in realtà, dabigatran somministrato un alto dosaggio di 150 mg due volte al giorno ha dimostrato superiorità). Anche se questi farmaci hanno il vantaggio di eliminare le preoccupazioni alimentari ed eliminando la necessità di un monitoraggio regolare del sangue, sanguinamento maggiore e complicanze associate, mentre un po &#39;meno che con warfarin, restano un problema 13-15. Poiché il 90% di AF-associati colpi risultato di emboli che Arise dal auricola sinistra (LAA) 2, un approccio alternativo per terapia con warfarin è stato quello di escludere la LAA utilizzando un dispositivo impiantato per intrappolare i coaguli di sangue prima di uscire. Qui, dimostriamo una procedura per impiantare il METRONOTTE atriale sinistra dispositivo di chiusura Appendage. Una cannula transettale viene inserito attraverso la vena femorale, e sotto guida fluoroscopica, inter-setto atriale viene attraversato. Una volta accesso all&#39;atrio sinistro è stato raggiunto, un filo di guida viene inserito nella vena polmonare superiore e la guaina di accesso METRONOTTE dilatatore e vengono fatti avanzare sul filo nell&#39;atrio sinistro. Il filo guida viene rimosso, e la guaina di accesso viene accuratamente avanzare nella porzione distale della LAA su un catetere pigtail. Il sistema di rilascio METRONOTTE viene preparato, inserito nella guaina di accesso, e lentamente avanzato. Il dispositivo METRONOTTE viene quindi distribuito in LAA. I criteri di rilascio dei dispositivi vengono confermate tramite fluoroscopia e ecocardiogramma transesofageo (TEE) e il dispositivo is rilasciato.

Watch this Scientific Journal Video about The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation at JoVE.com

The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation

Il video di accompagnamento descrive una procedura per il posizionamento percutaneo del guardiano Appendage atriale sinistro (LAA) del dispositivo. Il METRONOTTE è un dispositivo nitinol progettato per essere impiantato in modo permanente, o leggermente distale, l&#39;apertura del atriale sinistra (LAA) per intercettare coaguli di sangue prima di uscire LAA, impedendo ictus tromboembolico.

Il GUARDIANO atriale sinistra Appendage dispositivo di chiusura per la fibrillazione atriale

Atrial fibrillation (AF) is the most common cardiac arrhythmia, affecting an estimated 6 million people in the United States 1. Since AF affects primarily ...

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Research

JoVE Journal

Medicine

83.3K Views.  University of Leipzig Heart Center. Il video di accompagnamento descrive una procedura per il posizionamento percutaneo del guardiano Appendage atriale sinistro (LAA) del dispositivo. Il METRONOTTE è un dispositivo nitinol progettato per essere impiantato in modo permanente, o leggermente distale, l'apertura del atriale sinistra (LAA) per intercettare coaguli di sangue prima di uscire LAA, impedendo ictus tromboembolico.

Video: The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation

High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation

Atrial fibrillation (AF) is a complex cardiac arrhythmia with high morbidity and mortality.1,2 It is the most common sustained cardiac rhythm disturbance seen in clinical practice and its prevalence is expected to increase in the coming years.3 Increased intra-atrial pressure and dilatation have been long recognized to lead to AF,1,4 which highlights the relevance of using animal models and stretch to study AF dynamics. Understanding the mechanisms underlying AF requires visualization of the cardiac electrical waves with high spatial and temporal resolution. While high-temporal resolution can be achieved by conventional electrical mapping traditionally used in human electrophysiological studies, the small number of intra-atrial electrodes that can be used simultaneously limits the spatial resolution and precludes any detailed tracking of the electrical waves during the arrhythmia. The introduction of optical mapping in the early 90's enabled wide-field characterization of fibrillatory activity together with sub-millimeter spatial resolution in animal models5,6 and led to the identification of rapidly spinning electrical wave patterns (rotors) as the sources of the fibrillatory activity that may occur in the ventricles or the atria.7-9 Using combined time- and frequency-domain analyses of optical mapping it is possible to demonstrate discrete sites of high frequency periodic activity during AF, along with frequency gradients between left and right atrium. The region with fastest rotors activates at the highest frequency and drives the overall arrhythmia.10,11 The waves emanating from such rotor interact with either functional or anatomic obstacles in their path, resulting in the phenomenon of fibrillatory conduction.12 Mapping the endocardial surface of the posterior left atrium (PLA) allows the tracking of AF wave dynamics in the region with the highest rotor frequency. Importantly, the PLA is the region where intracavitary catheter-based ablative procedures are most successful terminating AF in patients,13 which underscores the relevance of studying AF dynamics from the interior of the left atrium. Here we describe a sheep model of acute stretch-induced AF, which resembles some of the characteristics of human paroxysmal AF. Epicardial mapping on the left atrium is complemented with endocardial mapping of the PLA using a dual-channel rigid borescope c-mounted to a CCD camera, which represents the most direct approach to visualize the patterns of activation in the most relevant region for AF maintenance.

This report provides a detailed description of the methodology and results of simultaneous endocardial and epicardial optical mapping of electrical excitation in the intact left atrium of a Langendorff-perfused sheep heart during stretch-induced atrial fibrillation.

Ad alta risoluzione Mappatura endocardica e epicardici ottico in un modello di pecora Stretch indotta fibrillazione atriale

 Atrial fibrillation (AF) is a complex cardiac arrhythmia with high morbidity and mortality.1,2 It is the most common sustained cardiac rhythm disturbance ...

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Medicina

Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting millions of individuals worldwide 1-3. The rapid, irregular, and disordered electrical activity in the atria gives rise to palpitations, fatigue, dyspnea, chest pain and dizziness with or without syncope 4, 5. Patients with AF have a five-fold higher risk of stroke 6.
Oral anticoagulation (OAC) with warfarin is commonly used for stroke prevention in patients with AF and has been shown to reduce the risk of stroke by 64% 7. Warfarin therapy has several major disadvantages, however, including bleeding, non-tolerance, interactions with other medications and foods, non-compliance and a narrow therapeutic range 8-11. These issues, together with poor appreciation of the risk-benefit ratio, unawareness of guidelines, or absence of an OAC monitoring outpatient clinic may explain why only 30-60% of patients with AF are prescribed this drug 8.
The problems associated with warfarin, combined with the limited efficacy and/or serious side effects associated with other medications used for AF 12,13, highlight the need for effective non-pharmacological approaches to treatment. One such approach is catheter ablation (CA), a procedure in which a radiofrequency electrical current is applied to regions of the heart to create small ablation lesions that electrically isolate potential AF triggers 4. CA is a well-established treatment for AF symptoms 14, 15, that may also decrease the risk of stroke. Recent data showed a significant decrease in the relative risk of stroke and transient ischemic attack events among patients who underwent ablation compared with those undergoing antiarrhythmic drug therapy 16.
Since the left atrial appendage (LAA) is the source of thrombi in more than 90% of patients with non-valvular atrial fibrillation 17, another approach to stroke prevention is to physically block clots from exiting the LAA. One method for occluding the LAA is via percutaneous placement of the WATCHMAN LAA closure device. The WATCHMAN device resembles a small parachute. It consists of a nitinol frame covered by fabric polyethyl terephthalate that prevents emboli, but not blood, from exiting during the healing process. Fixation anchors around the perimeter secure the device in the LAA (Figure 1). To date, the WATCHMAN is the only implanted percutaneous device for which a randomized clinical trial has been reported. In this study, implantation of the WATCHMAN was found to be at least as effective as warfarin in preventing stroke (all-causes) and death (all-causes) 18. This device received the Conformit&eacute; Europ&eacute;enne (CE) mark for use in the European Union for warfarin eligible patients and in those who have a contraindication to anticoagulation therapy 19.
Given the proven effectiveness of CA to alleviate AF symptoms and the promising data with regard to reduction of thromboembolic events with both CA and WATCHMAN implantation, combining the two procedures is hoped to further reduce the incidence of stroke in high-risk patients while simultaneously relieving symptoms. The combined procedure may eventually enable patients to undergo implantation of the WATCHMAN device without subsequent warfarin treatment, since the CA procedure itself reduces thromboembolic events. This would present an avenue of treatment previously unavailable to patients ineligible for warfarin treatment because of recurrent bleeding 20 or other warfarin-associated problems.
The combined procedure is performed under general anesthesia with biplane fluoroscopy and TEE guidance. Catheter ablation is followed by implantation of the WATCHMAN LAA closure device. Data from a non-randomized trial with 10 patients demonstrates that this procedure can be safely performed in patients with a CHADS2 score of greater than 1 21. Further studies to examine the effectiveness of the combined procedure in reducing symptoms from AF and associated stroke are therefore warranted.

Catheter ablation is combined with placement of the WATCHMAN Left Atrial Appendage Closure Device to prevent ischemic stroke in a patient with non-valvular atrial fibrillation.

Ablazione transcatetere in combinazione con i tasti chiusura appendice atriale per la fibrillazione atriale

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting millions of individuals worldwide 1-3. The rapid, irregular, and ...

Robotic Ablation of Atrial Fibrillation

Background: Pulmonary vein isolation (PVI) is an established treatment for atrial fibrillation (AF). During PVI an electrical conduction block between pulmonary vein (PV) and left atrium (LA) is created. This conduction block prevents AF, which is triggered by irregular electric activity originating from the PV. However, transmural atrial lesions are required which can be challenging. Re-conduction and AF recurrence occur in 20 - 40% of the cases. Robotic catheter systems aim to improve catheter steerability. Here, a procedure with a new remote catheter system (RCS), is presented. Objective of this article is to show feasibility of robotic AF ablation with a novel system. Materials and Methods: After interatrial trans-septal puncture is performed using a long sheath and needle under fluoroscopic guidance. The needle is removed and a guide wire is placed in the left superior PV. Then an ablation catheter is positioned in the LA, using the sheath and wire as guide to the LA. LA angiography is performed over the sheath. A circular mapping catheter is positioned via the long sheath into the LA and a three-dimensional (3-D) anatomical reconstruction of the LA is performed. The handle of the ablation catheter is positioned in the robotic arm of the Amigo system and the ablation procedure begins. During the ablation procedure, the operator manipulates the ablation catheter via the robotic arm with the use of a remote control. The ablation is performed by creating point-by-point lesions around the left and right PV ostia. Contact force is measured at the catheter tip to provide feedback of catheter-tissue contact. Conduction block is confirmed by recording the PV potentials on the circular mapping catheter and by pacing maneuvers. The operator stays out of the radiationfield during ablation. Conclusion: The novel catheter system allows ablation with high stability on low operator fluoroscopy exposure.

Pulmonary vein isolation (PVI) with an ablation catheter is a curative treatment for atrial fibrillation (AF). Robotic catheter systems aim to improve catheter steerability. Here, a procedure with a new robotic catheter system is presented. The goal of the procedure is electrical block between pulmonary vein and left atrium.

Robotic Ablazione della fibrillazione atriale

Background: Pulmonary vein isolation (PVI) is an established treatment for atrial fibrillation (AF). During PVI an electrical conduction block between ...

Left Atrial Stenosis Induced Pulmonary Venous Arterialization and Group 2 Pulmonary Hypertension in Rat

The mechanism of mitral stenosis-induced pulmonary venous arterialization and group 2 pulmonary hypertension (PH) is unclear. There is no rodent model of group 2 PH, due to mitral stenosis (MS), to facilitate the investigation of disease mechanisms and potential therapeutic strategies. We present a novel rat model of pulmonary venous congestion-induced pulmonary venous arterialization and group 2 PH caused by left atrial stenosis (LAS). LAS is achieved by constricting the left atrium using a half-closed titanium clip. After the LAS surgery, a rat model with a transmitral inflow velocity greater than or equal to 2.0 m/s on echocardiography gradually develops pulmonary venous arterialization and group 2 PH over an 8- to 10-week period. In this protocol, we provide the step-by-step procedure of how to perform the LAS surgery. The presented LAS rat model mimics MS in humans and is useful for studying the underlying molecular mechanism of pulmonary venous arterialization and for the preclinical evaluation of therapies for group 2 PH.

Left atrial stenosis (LAS) is a novel surgical technique used for studying group 2 pulmonary hypertension (PH) and mechanisms underlying pulmonary venous arterialization. Here, we present a protocol to constrict the left atrium using a titanium clip to cause pulmonary venous arterialization and moderate PH in a rat.

Stenosi di sinistra atriale indotta arterializzazione venosa polmonare e l'ipertensione polmonare gruppo 2 nel ratto

The mechanism of mitral stenosis-induced pulmonary venous arterialization and group 2 pulmonary hypertension (PH) is unclear. There is no rodent model of ...

Isolation of Atrial Myocytes from Adult Mice

The electrophysiological properties of atrial myocytes importantly affect overall cardiac function. Alterations in the underlying ionic currents responsible for the action potential can cause pro-arrhythmic substrates that underlie arrhythmias, such as atrial fibrillation, which are highly prevalent in many conditions and disease states. Isolating adult mouse atrial cardiomyocytes for use in patch-clamp experiments has greatly advanced our knowledge and understanding of the cellular electrophysiology in the healthy atrial myocardium and in the setting of atrial pathophysiology. In addition, studies using genetic mouse models have elucidated the role of a vast array of proteins in regulating atrial electrophysiology. Here we provide a detailed protocol for the isolation of cardiomyocytes from the atrial appendages of adult mice using a combination of enzymatic digestion and mechanical dissociation of these tissues. This approach consistently and reliably yields isolated atrial cardiomyocytes that can then be used to characterize cellular electrophysiology by measuring action potentials and ionic currents in patch-clamp experiments under a number of experimental conditions.

This protocol is used to isolate single atrial cardiomyocytes from the adult mouse heart using a chunk digestion approach. This approach is used to isolate right or left atrial myocytes that can be used to characterize atrial myocyte electrophysiology in patch-clamp studies.

Isolamento dei miociti atriale dai topi adulti

The electrophysiological properties of atrial myocytes importantly affect overall cardiac function. Alterations in the underlying ionic currents ...

Cooling or Warming the Esophagus to Reduce Esophageal Injury During Left Atrial Ablation in the Treatment of Atrial Fibrillation

Ablation of the left atrium using either radiofrequency (RF) or cryothermal energy is an effective treatment for atrial fibrillation (AF) and is the most frequent type of cardiac ablation procedure performed. Although generally safe, collateral injury to surrounding structures, particularly the esophagus, remains a concern. Cooling or warming the esophagus to counteract the heat from RF ablation, or the cold from cryoablation, is a method that is used to reduce thermal esophageal injury, and there are increasing data to support this approach. This protocol describes the use of a commercially available esophageal temperature management device to cool or warm the esophagus to reduce esophageal injury during left atrial ablation. The temperature management device is powered by standard water-blanket heat exchangers, and is shaped like a standard orogastric tube placed for gastric suctioning and decompression. Water circulates through the device in a closed-loop circuit, transferring heat across the silicone walls of the device, through the esophageal wall. Placement of the device is analogous to the placement of a typical orogastric tube, and temperature is adjusted via the external heat-exchanger console.

The goal of this protocol is to describe the use of esophageal temperature modulation to counteract esophageal thermal injury from left atrial ablation for the treatment of atrial fibrillation.

Raffreddamento o riscaldamento dell'esofago per ridurre le lesioni esofagehe durante l'ablazione atriale sinistra nel trattamento della fibrillazione atriale

Ablation of the left atrium using either radiofrequency (RF) or cryothermal energy is an effective treatment for atrial fibrillation (AF) and is the most ...

Echocardiographic Evaluation of Atrial Communications before Transcatheter Closure

Transthoracic (TTE) and transesophageal echocardiography (TEE) is the standard imaging method for atrial septal defect (ASD) and patent foramen ovale (PFO) detection, for patient selection for transcatheter ASD/PFO closure,&#160;for intraoperative guidance and for long-term follow-up. The size, shape, location and the number of the atrial communications schould be determined. The accuracy of PFO detection can be improved by using agitated saline together with maneuvers to transiently increase the right atrial (RA) pressure. The appearance of microbubbles in the left atrium (LA) within 3 cardiac cycles after opacification of the RA is considered positive for the presence of an intracardiac shunt. Three dimensional TEE identifies further septal fenestrations and describes the dynamic morphology of ASD/PFO and atrial septal aneurysm. Follow-up evaluations with TTE is recommended at 1, 6, and 12 months after the procedure, with a subsequent evaluation every year. Previous studies showed an increased incidence of atrial arrhythmias early after device closure. Speckle tracking analysis may help to understand functional left atrial remodeling following percutaneous closure and its impact on atrial arrhythmias.

Transthoracic (TTE) and transesophageal (TEE) echocardiography represent the basic imaging tools for interatrial septum examination. Three dimensional (3D) TEE provides incremental information in the assessment of the interatrial septum. Further advanced echocardiography techniques using speckle tracking echocardiography are applied for sensitive volumetric and functional assessment of the heart chambers.&#160;

Valutazione ecocardiografica delle comunicazioni atriali prima della chiusura transcatetere

Transthoracic (TTE) and transesophageal echocardiography (TEE) is the standard imaging method for atrial septal defect (ASD) and patent foramen ovale ...

Modifications of the Langendorff Method for Simultaneous Isolation of Atrial and Ventricular Myocytes from Adult Mice

A single cardiomyocyte is a vital tool in the cellular and subcellular level studies of cardiac biology and diseases as a fundamental unit of contraction and electrical activity. Hence, isolating viable, high-quality cardiomyocytes from the heart is the initial and most crucial experimental step. Comparing the various protocols for isolating the cardiomyocytes of adult mice, the Langendorff retrograde perfusion is the most successful and reproducible method reported in the literature, especially for isolating ventricular myocytes. However, isolating quality atrial myocytes from the perfused heart remains challenging, and few successful isolation reports are available. Solving this complicated problem is extremely important because apart from ventricular disease, atrial disease accounts for a large part of heart diseases. Therefore, further investigations on the cellular level to reveal the mechanisms are warranted. In this paper, a protocol based on the Langendorff retrograde perfusion method is introduced and some modifications in the depth of aorta cannulation and the steps that may affect the digestion process to isolate atrial and ventricular myocytes were simultaneously made. Moreover, the isolated cardiomyocytes are confirmed to be amenable to patch clamp investigation.

This protocol describes modifications of the Langendorff method including the depth of aorta cannulation for simultaneous Isolation of atrial and ventricular myocytes from adult mice.

Modifiche del metodo Langendorff per l'isolamento simultaneo di miociti atriali e ventricolari da topi adulti

A single cardiomyocyte is a vital tool in the cellular and subcellular level studies of cardiac biology and diseases as a fundamental unit of contraction ...

Sterile Pericarditis in Aachener Minipigs As a Model for Atrial Myopathy and Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia caused by structural remodeling of the atria, also called atrial myopathy. Current therapies only target the electrical abnormalities and not the underlying atrial myopathy. For the development of novel therapies, a reproducible large animal model of atrial myopathy is necessary. This paper presents a model of sterile pericarditis-induced atrial myopathy in Aachener minipigs. Sterile pericarditis was induced by spraying sterile talcum and leaving a layer of sterile gauze over the atrial epicardial surface. This led to inflammation and fibrosis, two crucial components of the pathophysiology of atrial myopathy, making the atria susceptible to the induction of AF. Two pacemaker electrodes were positioned epicardially on each atrium and connected to two pacemakers from different manufacturers. This strategy allowed for repeated non-invasive atrial programmed stimulation to determine the inducibility of AF at specified time points after surgery. Different protocols to test AF inducibility were used. The advantages of this model are its clinical relevance, with AF inducibility and the rapid induction of inflammation and fibrosis-both present in atrial myopathy-and its reproducibility. The model will be useful in the development of novel therapies targeting atrial myopathy and AF.

We describe a sterile pericarditis model in minipigs to study atrial myopathy and atrial fibrillation (AF). We present surgical and anesthetic techniques, strategies for vascular access, and a protocol to study the inducibility of AF.

Pericardite sterile in Aachener Minipigs come modello per la miopatia atriale e la fibrillazione atriale

Atrial fibrillation (AF) is the most common arrhythmia caused by structural remodeling of the atria, also called atrial myopathy. Current therapies only ...

Transesophageal Atrial Burst Pacing for Atrial Fibrillation Induction in Rats

Animal studies have brought important insights into our understanding regarding atrial fibrillation (AF) pathophysiology and therapeutic management. Reentry, one of the main mechanisms involved in AF pathogenesis, requires a certain mass of myocardial tissue in order to occur. Due to the small size of the atria, rodents have long been considered 'resistant' to AF. Although spontaneous AF has been shown to occur in rats, long-term follow-up (up to 50 weeks) is required for the arrhythmia to occur in those models. The present work describes an experimental protocol of transesophageal atrial burst pacing for rapid and efficient induction of AF in rats. The protocol can be successfully used in rats with healthy or remodeled hearts, in the presence of a wide variety of risk factors, allowing the study of AF pathophysiology, identification of novel therapeutic targets, and evaluation of novel prophylactic and/or therapeutic strategies.

The present work describes an experimental protocol of transesophageal atrial burst pacing for efficient induction of atrial fibrillation (AF) in rats. The protocol can be used in rats with healthy or remodeled hearts, allowing the study of AF pathophysiology, identification of novel therapeutic targets, and evaluation of new therapeutic strategies.

Stimolazione atriale transesofagea per l'induzione della fibrillazione atriale nei ratti

Animal studies have brought important insights into our understanding regarding atrial fibrillation (AF) pathophysiology and therapeutic management. ...