Abstract 650: Animal Study Results Support that Biometal Artificial Muscle Restores Atrial Kick and Could Replace Oral Anticoagulation in Permanent Atrial Fibrillation

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Piergiorgio Tozzi ◽  
Daniel Hayoz ◽  
Francois Salchli ◽  
Ludwig K von Segesser
Keyword(s):  
Atrial Fibrillation ◽  
Thrombus Formation ◽  
Anticoagulation Therapy ◽  
Control Unit ◽  
Artificial Muscle ◽  
Persistent Atrial Fibrillation ◽  
Implantation Technique ◽  
Spontaneous Echo Contrast ◽  
Study Results ◽  
The Right

Treatment of persistent atrial fibrillation (AF) consists of ventricular rhythm control and the use of anticoagulant agents to decrease the high risk of stroke. However, patients under lifetime anticoagulation therapy are exposed to hemorrhagic stroke (1–3% patients/year). The best treatment to prevent stroke may induce stroke itself. Because decreased flow within the fibrillating atrium is associated with spontaneous echo contrast, thrombus formation and embolic events, any device able to restore the atrial kick (AK) should significantly reduce the risk of stroke and eventually improve cardiac output (CO). A motorless, volume displacement pump based on artificial muscle technology could reproduce the AK when placed onto a fibrillating atrium. This study has been designed to assess mechanical effects of this pump on the right cavities in an animal model of AF. Atripump (Nanopowers SA, Switzerland) is a dome shape silicone coated biometal actuator 5 × 45mm. The biometal is electrically actuated by a pacemaker like control unit. In 10 sheep the right atrium (RA) was surgically exposed and the dome sutured onto it. AF was induced with rapid epicardial pacing (600 beats/min). RA ejection fraction (EF) and spontaneous echo contrast was assessed with intracardiac ultrasound in baseline, AF and assisted AF status. A flow meter placed on pulmonary artery measured CO. Results The dome’s contraction rate was 60/min. Mean temperature on the RA was 39±1.5 °C. RA EF was 30% in baseline, 5% in AF and 22% in assisted AF conditions. During the AF state, spontaneous echo contrast was present in all animals and in 2 a thrombus appeared in the right appendix. Neither spontaneous echo contrast nor thrombi were present in baseline and AF assisted status. Thrombi were washed out when the pump was turned on. CO was 5.3±0.3 l/min in baseline, 4.4±0.6 l/min in AF and 5.1±0.3 l/min in assisted AF status (p<0.01). Placed on the right side, the artificial muscle restores the AK, improves CO and shows a mechanical anti coagulant effect. In patients with permanent AF, if implanted on both sides, it would improve CO and prevent embolism of cardiac origin. The implantation technique could be comparable to that of a pacemaker.

scholarly journals Anticoagulation in Atrial Fibrillation Cardioversion: What Is Crucial to Take into Account

2021 ◽  
Vol 10 (15) ◽  
pp. 3212
Author(s):  
Fabiana Lucà ◽  
Simona Giubilato ◽  
Stefania Angela Di Fusco ◽  
Laura Piccioni ◽  
Carmelo Massimiliano Rao ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Vitamin K ◽  
Thrombus Formation ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Anticoagulation Therapy ◽  
Significant Advance ◽  
Thromboembolic Events ◽  
Thromboembolic Risk ◽  
Pharmacological Cardioversion

The therapeutic dilemma between rhythm and rate control in the management of atrial fibrillation (AF) is still unresolved and electrical or pharmacological cardioversion (CV) frequently represents a useful strategy. The most recent guidelines recommend anticoagulation according to individual thromboembolic risk. Vitamin K antagonists (VKAs) have been routinely used to prevent thromboembolic events. Non-vitamin K antagonist oral anticoagulants (NOACs) represent a significant advance due to their more predictable therapeutic effect and more favorable hemorrhagic risk profile. In hemodynamically unstable patients, an emergency electrical cardioversion (ECV) must be performed. In this situation, intravenous heparin or low molecular weight heparin (LMWH) should be administered before CV. In patients with AF occurring within less than 48 h, synchronized direct ECV should be the elective procedure, as it restores sinus rhythm quicker and more successfully than pharmacological cardioversion (PCV) and is associated with shorter length of hospitalization. Patients with acute onset AF were traditionally considered at lower risk of thromboembolic events due to the shorter time for atrial thrombus formation. In patients with hemodynamic stability and AF for more than 48 h, an ECV should be planned after at least 3 weeks of anticoagulation therapy. Alternatively, transesophageal echocardiography (TEE) to rule out left atrial appendage thrombus (LAAT) should be performed, followed by ECV and anticoagulation for at least 4 weeks. Theoretically, the standardized use of TEE before CV allows a better stratification of thromboembolic risk, although data available to date are not univocal.

Consideration of non-valvular atrial fibrillation with left atrial appendage thrombus formation despite under appropriate oral anticoagulation therapy

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
H Shiraki ◽  
H Tanaka ◽  
K Yamashita ◽  
Y Tanaka ◽  
K Sumimoto ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Logistic Regression ◽  
Regression Analysis ◽  
Oral Anticoagulation ◽  
Left Atrial ◽  
Thrombus Formation ◽  
Anticoagulation Therapy ◽  
Left Ventricular ◽  
Volume Index ◽  
Oral Anticoagulation Therapy

Abstract Background Atrial fibrillation (AF) is the most frequently sustained cardiac arrhythmia, with a prevalence of about 2–3% in the general population. In accordance with CHADS2 or CHA2DS2-VASc score, appropriate oral anticoagulation therapy such as warfarin or direct oral anticoagulants (DOAC) significantly reduced the risk of thromboembolic events. However, left atrial (LA) thrombus can be detected in the LA appendage (LAA) in AF patients despite appropriate oral anticoagulation therapy. Purpose Our purpose was to investigate the associated factors of LAA thrombus formation in non-valvular atrial fibrillation (NVAF) patients despite under appropriate oral anticoagulation therapy. Methods We retrospectively studied consecutive 286 NVAF patients for scheduled catheter ablation or electrical cardioversion for AF in our institution between February 2017 and September 2019. Mean age was 67.1±9.4 years, 79 patients (29.5%) were female, and 140 (52.2%) were paroxysmal AF. All patients underwent transthoracic and transesophageal echocardiography before catheter ablation or electrical cardioversion. All patients received appropriate oral anticoagulation therapy including warfarin or DOAC for at least 3 weeks prior to transesophageal echocardiography based on the current guidelines. LAA thrombus was defined as an echodense intracavitary mass distinct from the underlying endocardium and not caused by pectinate muscles by at least three senior echocardiologists. Results Of 286 NVAF patients with under appropriate oral anticoagulation therapy, LAA thrombus was observed in 9 patients (3.3%). Univariate logistic regression analysis showed that age, paroxysmal AF, CHADS2 score ≥3, left ventricular end-diastolic volume index (LVEDVI), left ventricular ejection fraction (LVEF), left ventricular mass index (LVMI), LA volume index (LAVI), mitral inflow E and mitral e' annular velocities ratio (E/e'), and LAA flow were associated with LAA thrombus formation. It was noteworthy that multivariate logistic regression analysis showed that LAA flow was independent predictor of LAA thrombus (OR: 0.72, 95% CI: 0.59–0.89, p&lt;0.005) as well as LVEF. Furthermore, receiver operating characteristic (ROC) curve analysis identified the optimal cutoff value of LAA flow for predicting LAA thrombus as ≤15cm/s, with a sensitivity of 88%, specificity of 93%, and area under the curve (AUC) of 0.95. Conclusions LAA flow was strongly associated with LAA thrombus formation even in NVAF patients with appropriate oral anticoagulation therapy. According to our findings, further strengthen of oral anticoagulation therapy or percutaneous transcatheter closure of the LAA may be considered in NVAF patients with appropriate oral anticoagulation therapy but low LAA flow, especially &lt;15cm/s. Funding Acknowledgement Type of funding source: None

Abstract 15570: Direct Evidence of Endo-Epicardial Dissociation of the Atrial Wall in Patients With Longstanding Persistent Atrial Fibrillation

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Natasja de Groot ◽  
Lisette vd Does ◽  
Ameeta Yaksh ◽  
Paul Knops ◽  
Pieter Woestijne ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Direct Evidence ◽  
Persistent Atrial Fibrillation ◽  
Right Atrial ◽  
Electrode Arrays ◽  
Atrial Wall ◽  
Ablative Therapies ◽  
Epicardial Layer ◽  
Right Atrial Appendage ◽  
The Right

Introduction: Transition of paroxysmal to longstanding persistent atrial fibrillation (LsPAF) is associated with progressive longitudinal dissociation in conduction and a higher incidence of focal fibrillation waves. The aim of this study was to provide direct evidence that the substrate of LsPAF consists of an electrical double-layer of dissociated waves, and that focal fibrillation waves are caused by endo-epicardial breakthrough. Hypothesis: LsPAF in humans is caused by electrical dissociation of the endo- and epicardial layer. Methods: Intra-operative mapping of the endo- and epicardial right atrial wall was performed in 9 patients with induced (N=4), paroxysmal (N=1), persistent (N=2) or longstanding-persistent AF (N=2). A clamp of two rectangular electrode-arrays (128 electrodes; inter-electrode distance 2mm) was introduced through an incision in the right atrial appendage. Series of 10 seconds of AF were analyzed and the incidence of endo-epicardial dissociation (≥15ms) was determined for all 128 endo-epicardial recording sites. Results: In patients with LsPAF the averaged degree of endo-epicardial dissociation was highest (24.9% vs. 5.9%). Using strict criteria for breakthrough (presence of an opposite wave within 4mm and <15ms before the origin of the focal wave), the far majority (77%) of all focal fibrillation waves could be attributed to endo-epicardial excitation. Conclusions: During LsPAF considerable differences in activation of the right endo- and epicardial wall exist. Endo-epicardial fibrillation waves that are out of phase, may conduct transmurally and create breakthrough waves in the opposite layer. This may explain the high persistence of AF and the low succes rate of ablative therapies in patients with LsPAF.

scholarly journals Poziom wiedzy na temat profilaktyki przeciwzakrzepowej wśród pacjentów z migotaniem przedsionków

2020 ◽  
Vol 5 (3) ◽  
pp. 24-53
Author(s):  
Anna Emilia Chwalisz ◽  
◽  
Grażyna Chojnacka-Kowalewska ◽  
Keyword(s):  
Atrial Fibrillation ◽  
Oral Anticoagulants ◽  
Anticoagulation Therapy ◽  
Medical Knowledge ◽  
Persistent Atrial Fibrillation ◽  
Permanent Disability ◽  
Level Of Knowledge ◽  
Anticoagulant Prophylaxis ◽  
Prophylactic Anticoagulation ◽  
Age Range

Introduction. In modern therapy of patients with atrial fibrillation, which belongs to the group particularly at risk of stroke, prophylactic anticoagulation is of primary importance. The initiation and subsequent proper monitoring of long-term anticoagulation therapy is very important for this group of patients. The use of oral anticoagulants significantly reduces the risk of ischemic stroke, and thus ensures longer survival and avoidance of permanent disability among patients with atrial fibrillation. Aim. Assessment of the level of knowledge of patients with atrial fibrillation on thromboprophylaxis in internal departments and cardiology of the Provin-cial Specialist Hospital in Włocławek. Materials and methods. The study group consisted of 100 people (63 men and 37 women) with diagnosed atrial fibrillation, taking oral anticoagulants. The research tool was the author's questionnaire. To assess the risk of ischem-ic stroke in this group of patients, the CHA2DS2-VASc scale was used and ques-tions about these factors were included in the survey. Results. Studies show that anticoagulant prophylaxis in the form of oral anti-coagulants is used in every patient with diagnosed atrial fibrillation. Most pa-tients use new generation drugs (NOAC) that do not require dose adjustment based on a normalized INR. Persistent atrial fibrillation was found in 51% of the patients. The most numerous group were patients in the 65-74 age range. The annual risk of stroke in my subjects was on average 11%. In most cases, patients correctly answered questions about the rules of conduct when using oral anticoagulants, factors that increase and weaken the effects of these drugs and the symptoms of their overdose. There were no significant differences in the level of knowledge between the women and men studied, while younger, better educated patients who declared a very good or satisfactory material situ-ation showed more knowledge. Conclusions. The study showed that the level of patients' knowledge about antithrombotic prophylaxis in atrial fibrillation is at a good level and corresponds to current medical knowledge.

scholarly journals P1705 Is mitral stenosis per se worthy of anticoagulation therapy?

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
S Suma ◽  
N Gaibazzi
Keyword(s):  
Atrial Fibrillation ◽  
Mitral Valve ◽  
Left Atrium ◽  
Thrombus Formation ◽  
Anticoagulation Therapy ◽  
Mitral Valve Regurgitation ◽  
Low Flow ◽  
Mitral Valve Stenosis ◽  
Color Flow ◽  
Tight Correlation

Abstract We present the case of a 76-year-old man with hypertension and previous mitral valve repair (MVR) due to severe mitral valve regurgitation. He had never experienced atrial fibrillation (AF), and therefore he was not anticoagulated. He had been asymptomatic for 15 years, however, recently he reported the onset of dyspnoea and a transthoracic echocardiogram showed moderate to severe mitral valve stenosis (MVS) in the context of previous MVR. A transesophageal echocardiogram was then requested and it confirmed the degree of MVS (panel A Color flow on mitral valve, panel B CW Doppler), but, astonishingly, it also showed the presence of a giant thrombus in the roof of the left atrium (Panel C,D,F 2D TOE, Panel E 3D TOE). The maximal dimensions of the mass were 3.3 to 4.5 centimetres and, surprisingly, no thrombus was found in the left appendage, which nevertheless had low-flow. MVS is very often associated with severe left atrial dilation and with the onset of atrial fibrillation. However, when a patient has at least moderate MVS and he is in sinus rhythm, there is no robust evidence supporting the initiation of anticoagulants. Though, this case underlines the tight correlation between MVS and thrombus formation regardless of the detectable presence of AF. Moreover, in contrast to usual AF patients, in this particular case left appendage was not involved and the huge mass occupied most of the left atrium, showing that MVS provokes significant low-flow in the atrium too. Abstract P1705 Figure.

Electrophysiological and Electroanatomical Mapping of the Right Atrium in Persistent Atrial Fibrillation: Relation to Collagen Turnover

2015 ◽  
Vol 38 (9) ◽  
pp. 1039-1048 ◽  
Author(s):  
CHRISTOS A. GOUDIS ◽  
ELEFTHERIOS M. KALLERGIS ◽  
EMMANUEL M. KANOUPAKIS ◽  
HERCULES E. MAVRAKIS ◽  
NIKI E. MALLIARAKI ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Right Atrium ◽  
Persistent Atrial Fibrillation ◽  
Electroanatomical Mapping ◽  
Collagen Turnover ◽  
The Right

scholarly journals An off-pump biatrial mini-maze procedure for treatment of long-standing persistent atrial fibrillation

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
T Yan ◽  
S.J Zhu ◽  
M Zhu ◽  
C.F Guo
Keyword(s):  
Atrial Fibrillation ◽  
Left Atrial ◽  
Vena Cava ◽  
Persistent Atrial Fibrillation ◽  
Maze Procedure ◽  
Purse String ◽  
Off Pump ◽  
Bipolar Radiofrequency ◽  
The Right

Abstract Background Surgical treatment has assumed a more prominent role in the therapy of atrial fibrillation (AF) with favorable efficiency and acceptable safety during the last decades. The traditional Cox-Maze procedure and Wolf Mini-Maze procedure focused on left atrial ablation. However, it is ubiquitous that patients with long-standing persistent atrial fibrillation (LSPAF) typically suffer from biatrial electrical and structural remodeling. The left atrial procedures are still not enough in patients with LSPAF. Purpose Herein, we aimed to introduce a modified biatrial off-pump ablation procedure based on the Wolf Mini-Maze procedure and to detect the safety and efficacy of the surgery for patients with LSPAF. Methods Between January 2016 and September 2020, 102 patients of LSPAF underwent our modified Mini-Maze procedure using bipolar radiofrequency ablation. Those patients firstly underwent a Mini-Maze procedure using Dallas lesion set, including video-assisted bilateral mini-thoracotomy, left atrial appendage excision, bilateral pulmonary vein isolation, ganglionic plexi evaluation and destruction, left atrial roof connecting lesion, and a linear lesion connecting this roofline to the root of the aorta at the junction of the left coronary and the non-coronary cusp. Secondly, a purse-string suture was performed on the right atrium, and then four ablation lesions were made to the superior vena cava, to the inferior vena cava, to the appendix of the right atrium, and to the tricuspid valve annulus from the purse-string suture point by the bipolar radiofrequency clamp. After the operation, the patients were followed up at an interval of 3, 6, 12 months, and every 1 year after that. Results No mortality No surgical re-exploration for bleeding. No permanent pacemaker implantation. 99 patients were free from LSPAF upon discharge. A follow-up at interval of 3, 6, 12, 24, 36, and 48 months showed a success rate free from LSPAF was 95.1% (97/102), 94.4% (85/90), 94.8% (73/77), 91.5% (54/59), 90.3% (28/31) and 100% (9/9), respectively Conclusions The modified biatrial Mini-Maze suggested a safe and feasible procedure. Early follow-up demonstrated an acceptable success rate free from AF. It might have the potential to become another option for clinical treatment of LSPAF. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): General Program of the National Natural Science Foundation of China Schematic of the procedure

scholarly journals A jobb pitvari fülcse echokardiográfiás vizsgálata és annak klinikai jelentősége

2019 ◽  
Vol 160 (12) ◽  
pp. 443-447
Author(s):  
Attila Nemes ◽  
Kálmán Havasi ◽  
László Sághy ◽  
Mária Kohári ◽  
Tamás Forster
Keyword(s):  
Atrial Fibrillation ◽  
Clinical Data ◽  
Thrombus Formation ◽  
Atrial Appendage ◽  
Present Review ◽  
Right Atrial ◽  
Right Heart ◽  
Right Atrial Appendage ◽  
The Right

Abstract: In case of atrial fibrillation, there is a higher risk of thrombus formation, which could affect the right heart as well. Visualization of the right atrial appendage is difficult; the aim of the present review was to demonstrate the role of routine echocardiographic techniques and to show related clinical data. Orv Hetil. 2019; 160(12): 443–447.

Atrial Fibrillation

2011 ◽  
Author(s):  
Gregory F. Michaud ◽  
Roy M. John
Keyword(s):  
Atrial Fibrillation ◽  
Rate Control ◽  
Oral Anticoagulation ◽  
Thrombus Formation ◽  
Control Strategies ◽  
Anticoagulation Therapy ◽  
Scoring Systems ◽  
Right Atrial ◽  
Medical Attention ◽  
Clinical Consequences

Atrial fibrillation (AF) is an abnormal rhythm characterized by chaotic atrial electrical activity resulting in loss of atrial contraction, an irregular and unpredictable heart rate, and a tendency for thrombus formation. The prevalence of AF is estimated at 1 to 2%, but it’s likely higher than that because one-third of patients may have no symptoms and might never seek medical attention. Data suggest that 1 in 4 people over the age of 40 will develop AF in their lifetime. About 10% of patients over age 80 have experienced the arrhythmia, and some estimates predict the prevalence will double in the next 50 years. This chapter discusses the pathophysiology, genetics, diagnosis, classification, and treatment of AF. Figures show atrial fibrillation and coarse atrial fibrillation plus common right atrial flutter. One algorithm is for oral anticoagulation therapy, and a second shows a recommended hierarchical choice of antiarrhythmic therapies versus catheter ablation for recurrent symptomatic atrial fibrillation. Tables list classification, diagnostic evaluation of, clinical consequences of, and conditions often associated with atrial fibrillation. Three scoring systems are included: 1) for congestive heart failure, hypertension, diabetes, stroke, and transient ischemic attack; 2) to assess the risk of bleeding with oral anticoagulation, and 3) data and proportion of patients from the Euro Heart Survey. Other tables include long-term anticoagulation guidelines for atrial fibrillation, intravenous drugs used for acute rate control, oral drugs used for chronic rate control, and antiarrhythmic drugs for conversion of atrial fibrillation and/or maintenance of sinus rhythm. In addition, there’s a summary of randomized trials weighing rate control and rhythm control strategies, plus schemes for categorizing thromboembolism risk. This review contains 4 highly rendered figures, 13 tables, and 129 references.

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