Left atrial appendage isolation during ablation in the interatrial septum: Rapid recognition by continuous monitoring of appendage electrograms

Extensive atrial ablation in the setting of atrial fibrillation (AF) and atrial tachycardia (AT) can affect interatrial connections. A 76-year-old man with a history of tachycardia-induced cardiomyopathy and nine ablation procedures for AF/AT over 15 years presented with highly symptomatic recurrent AT. Previous ablation lesions included pulmonary vein isolation, left atrial posterior wall isolation, mitral isthmus line, cavotricuspid isthmus line, and the ablation of areas of fractionated electrograms. Electroanatomical mapping found the pulmonary veins and the left atrial posterior wall to be silent, as was the posterior interatrial septum and the mitral isthmus area. Activation mapping showed progression of electrograms in the left atrial appendage (LAA) from the septal aspect posteriorly, and in the coronary sinus from proximal to distal; implying the existence of a septal circuit, where extensive fractionation was noted. This was targeted, while monitoring conduction into the LAA using a multielectrode catheter. Ablation led to prompt termination of tachycardia and simultaneous LAA isolation. Immediate cessation of ablation led to recovery of conduction into LAA. Additional lesions in the interatrial septum were required to render the tachycardia noninducible, accompanied by temporary isolation of LAA. The ablation lesion sets employed while ablating AF and left AT can block many interatrial pathways, rendering conduction dependent on muscle bundles in the interatrial septum and, therefore, vulnerable to block by lesions in this area. LAA isolation has been associated with high incidence of LAA thrombus formation and stroke despite oral anticoagulation. Continuous observation of LAA electrograms during ablation can help to avoid this complication.     

Efficacy and safety of catheter ablation combined with left atrial appendage occlusion for nonvalvular atrial fibrillation: A systematic review and meta-analysis

Atrial fibrillation (AF) is currently the most prevalent arrhythmia in clinical practice, with stroke being one of its major complications. Combining catheter ablation and percutaneous left atrial appendage occlusion (LAAO) into a “one-stop” intervention could reduce stroke incidence in selected high-risk patients and, at the same time, relieve AF symptoms in a single procedure. This meta-analysis analyzed the efficacy and safety of catheter ablation combined with LAAO for nonvalvular AF. PubMed, EMBASE, and the Cochrane Library were searched from inception to April 2019 to identify relevant citations. Efficacy indexes were procedural success, AF recurrence, stroke/transient ischemic attacks (TIA), and device-related thrombus (DRT). Safety indexes were all-cause death, major hemorrhagic complications, and pericardial effusion/cardiac tamponade. The incidence rate of events (ratio of events to patients) and 95% confidence interval (CI) were calculated as summary results. A forest plot was constructed to present pooled rates. Eighteen studies (two randomized controlled trials and 16 observational studies) were included. The results showed that one-stop intervention has significant efficacy and safety, with procedural success of .98 (95% CI, .97-1.00), AF recurrence of .24 (95% CI, .15-.35), stroke/TIA of .01 (95% CI, .00-.01), DRT of .00 (95% CI, .00-.01), all-cause mortality of .00 (95% CI, .00-.00), cardiac/neurological mortality of .00 (95% CI, .00-.00), major hemorrhagic complications of .01 (95% CI, .00-.02), and pericardial effusion/cardiac tamponade of .01 (95% CI, .00-.01). A single procedure with catheter ablation and LAAO in AF is a feasible strategy with significant efficacy and safety.     

Left atrial appendage occlusion for stroke prevention in patients with atrial fibrillation

The most severe consequence of atrial fibrillation (AF) is a cardioembolic stroke. The incidence of cardioembolic stroke increases significantly in patients with AF. Although warfarin has been the mainstay of the prevention of cardioembolic stroke, there are several limitations to the use of warfarin that hinder its effectiveness. This article provides the historical development of devices that exclude the left atrial appendage, their effectiveness and potential patient selection, as an alternative to warfarin and the novel oral anticoagulation therapy for the prevention of cardioembolic stroke in patients with AF.     

体外电复律治疗房颤对植入左心耳封堵器患者的影响

目的：探讨植入左心耳封堵器的房颤患者接受体外电复律治疗的可行性和安全性。方法：选取2016年5月至2019年12月北京医院收治的经皮成功植入左心耳封堵器患者51例，其中接受体外电复律治疗7例（13.7%），观察电复律对装置的影响及相关不良事件。结果：51例患者中，接受电复律治疗的7例（13.7%）患者未发生封堵器移位或脱落，围手术期未发生严重不良事件。结论：植入左心耳封堵器的房颤患者接受体外电复律治疗是安全、可行的。     

左心耳封堵在非瓣膜性心房颤动卒中的预防作用

血栓栓塞事件是心房颤动(房颤)最严重的并发症,及早识别并预防其栓塞风险至关重要。传统的抗凝治疗在预防非瓣膜性房颤患者的血栓栓塞事件方面存在一定局限性。左心耳部被证实为房颤患者血栓形成的主要部位,这一发现促使了经皮左心耳封堵技术的迅速发展。与抗凝药物相比,经皮左心耳封堵术可有效降低房颤患者血栓栓塞事件的发生率,且适用于抗凝禁忌的房颤患者。目前,WATCHMAN与ACP封堵装置已被授权进入欧盟市场,LARIAT左心耳结扎装置也因其有效性及安全性被美国FDA批准应用。经皮左心耳封堵及结扎术的适应证广,安全性高,有望成为多数房颤患者预防血栓栓塞事件的选择。     

Usefulness of an isoproterenol infusion to differentiate a left atrial appendage thrombus in a patient with nonvalvular atrial fibrillation

A 78‐year‐old male with a history of a cardiac embolic stroke due to persistent AF and cerebral bleeding (CHADS2 score 4, HAS‐BLED score 4) was referred to our hospital to implant a left atrial appendage (LAA) closure (LAAC) device. A trans esophageal echocardiography was performed and a high echoic lesion that was difficult to differentiate the spontaneous echo contrast or thrombus was found in the LAA cavity. After isoproterenol infusion, a high echoic lesion disappeared and we confirmed that it was not an LAA thrombus. Successful LAAC device implantation was performed without any thromboembolic events.     

Nonpharmacologic stroke prevention in atrial fibrillation

Atrial fibrillation is associated with significant mortality and morbidity. The burden of morbidity in atrial fibrillation is mostly due to stroke, one of the major causes of death and the leading cause of long-term disability. Although highly effective in prevention of thromboembolic stroke, several factors limit utilization of chronic oral anticoagulation therapy. Eradication of atrial fibrillation and restoration of effective atrial contraction by surgical methods, or recently, by percutaneous catheter ablation methods, are two attractive approaches for stroke prophylaxis. Surgical exclusion of the left atrial appendage has generated considerable interest in the past decades and it is now performed routinely during mitral valve surgery in many centers. Recently, minimally invasive and percutaneous methods for the exclusion of left atrial appendage have been introduced. Currently, these approaches are being evaluated in ongoing trials. This review will discuss the current status of nonpharmacologic methods in the prevention of stroke in atrial fibrillation.     

Left atrial flutter after segmental ostial radiofrequency catheter ablation for pulmonary vein isolation

Segmental ostial ablation to electrically isolate pulmonary veins has been performed for atrial fibrillation. Left atrial flutter that utilized a critical isthmus adjacent to the ostium of the left superior pulmonary vein was diagnosed and successfully ablated in a patient 3 months after a successful pulmonary vein isolation procedure. Documenting the cause of symptoms after pulmonary vein isolation in patients with atrial fibrillation is critical in guiding therapy.     

Is left atrial appendage occlusion useful for prevention of stroke or embolism in atrial fibrillation?

Summary Since in atrial fibrillation more than 90% of the thrombi are located in the left atrial appendage, an “elimination” of the left atrial appendage, either by resection or occlusion, seems an attractive alternative to oral anticoagulation. Although frequently regarded as an useless appendage, data from animal and human investigations show that the left atrial appendage may play an important role in the maintenance and regulation of the cardiac function, especially in arterial hypertension, atrial fibrillation, coronary heart disease, valvular heart disease and heart failure. Elimination of the left atrial appendage may impede thirst in hypovolemia, deteriorate hemodynamic responses to volume or pressure overload, decrease cardiac output and promote heart failure. Instead of preventing stroke, the consequences of left atrial appendage elimination may create new risk factors for stroke and thus might induce more harm than benefit to patients with atrial fibrillation. As long as the physiologic and pathophysiologic role of the left atrial appendage is not fully understood, left atrial appendage elimination should not be an alternative to oral anticoagulation. Received: 25 January 2002 Accepted: 29 January 2002     

Pulmonary vein morphology before and after segmental isolation in patients with atrial fibrillation

BACKGROUND: The morphology of the pulmonary veins (PVs) before and after segmental isolation of the PVs has not been sufficiently characterized. METHODS AND RESULTS: Multi-slice computed tomography was performed before and 3 +/- 1 months after ablation in 30 patients with atrial fibrillation who underwent PV isolation. Before ablation, PV narrowing (> or =25% luminal reduction) was found in nine (8%) PVs. After ablation, de novo PV narrowing was found in 24 PVs (26%) and was detected only in the supero-inferior direction in 14 PVs (58%). The diameter reduction inside the PVs after ablation was greater in the supero-inferior direction (14 +/- 12%) than in the antero-posterior direction (9 +/- 13%; P < 0.0001). In the ablated PVs, the PV trunk was shorter than before ablation (P < 0.0001). The reduction in the diameters of both the PV ostium and the ablation site in the ablated PVs, as well as the diameter of the PV ostium in the nonablated PVs, correlated with the decrease in the left atrial diameter. Shortening of the PV trunk correlated with the severity of PV narrowing, but it was not related to the percent diameter reduction of the left atrium. PV narrowing before or after ablation did not result in any clinical consequences. CONCLUSIONS: PV narrowing is present in about 10% of PVs before ablation. Asymmetric luminal reduction and longitudinal shrinkage of the PV trunk occur after ablation. Reverse remodeling of the PV and contraction of the PV wall may contribute to the reduction in the PV diameter. PV morphology should be assessed with multi-directional views to avoid missing heterogeneous legions.     

Left atrial appendage aneurysm presenting with recurrent embolic strokes

A case of left atrial appendage aneurysm is described in a 40-year-old man, who presented with recurrent embolic strokes and was asymptomatic until the last 6 months. Chest X-ray revealed a slightly prominent upper left heart border. The diagnosis was made by transthoracic two-dimensional echocardiography and confirmed by transesophageal echocardiography, magnetic resonance imaging and also by surgery.     

Safety and efficacy analysis of one‐stop intervention for treating nonvalvular atrial fibrillation

1 Background

Nonvalvular atrial fibrillation (AF) is a common arrhythmia. The treatment strategy for AF mainly includes controlling symptoms and decreasing the rate of complications. Our study aimed to evaluate the safety and efficacy of combination treatment of catheter ablation and left atrial appendage (LAA) closure (one‐stop intervention) in patients with nonvalvular AF.

2 Methods and results

Thirty‐four patients with symptomatic AF (mean CHA₂DS₂‐VASc score 4.1 ± 1.3, mean HAS‐BLED score 3.8 ± 1.2) were included. Patients first received radiofrequency‐based left atrial ablation, and then the Watchman device (Boston Scientific, Natick, MA, USA) or AMPLATZER Cardiac Plug (ACP) (St. Jude Medical, Inc., St. Paul, MN, USA) was implanted for LAA closure. Follow‐up was performed at 45 days and 3 months after LAA closure to assess for recurrence of AF and prevent stroke. Radiofrequency ablation and LAA closure were successful in 100% of patients without evidence of residual flow at the final transesophageal echocardiography evaluation. A Watchman device was implanted in 29 (85.3%) patients, and an ACP was implanted in five (14.7%) patients. No device‐related thrombus formation or embolization was identified at the 45‐day or 3‐month follow‐up. Serious complications, including death, transient ischemic attack, ischemic or hemorrhagic stroke, or major bleeding, were also not identified during the follow‐ups.

3 Conclusion

For symptomatic patients with nonvalvular AF and a high risk of stroke, the one‐stop intervention is feasible, safe, and efficacious.     

经皮左心耳封堵的研究进展

心房颤动（房颤）在人群中的发病率逐年升高,成为临床中最常见的心律失常之一。脑栓塞是房颤最主要的并发症。抗凝治疗仍然是预防房颤脑卒中的主要手段,但无论是华法林还是新型抗凝药都有一定的局限性,存在相关的风险及禁忌,且依从性差。鉴于非瓣膜病性房颤患者90%以上的血栓来源于左心耳（LAA),故对于一些栓塞风险高的房颤患者,经皮左心耳封堵术已成为长期华法林替代治疗以降低新发脑卒中风险的另一选择。