Percutaneous closure of a left atrial appendage with relevant suture dehiscence

Atrial fibrillation is a widespread disease and highly relevant as it carries an extended risk for ischaemic stroke. Surgical closure of the left atrial appendage is routinely performed during open heart surgery in patients with atrial fibrillation with the aim of thromboembolic protection. In this report we present a successful percutaneous closure of a left atrial appendage, which showed clinically relevant suture dehiscence several years after surgical closure.     

经食道超声心动图评估特发性房颤左心房左心耳的价值

目的:研究经食道超声心动图(TEE)评估特发性房颤左心房左心耳的临床价值。方法:选择自2015年1月到2016年8月在医院接受诊治的特发性房颤患者100例纳入本次研究,阵发性房颤92例,记为阵发性房颤组;持续性房颤8例,记为持续性房颤组。另选同期在医院进行健康体检的心功能正常志愿者90例作为对照组。利用TEE对受试者进行检查,对比房颤组与对照组的左心房及左心耳参数,是否含有自发性显影(LASEC)的房颤患者的左心房及左心耳参数,利用TEE分析对房颤患者的预后情况。结果:阵发性房颤组左心房的前后径和左右径,左心耳血流最大的排空速度(Lev)均明显小于对照组,左心耳的面积变化率及最大的充盈速度(Lfv)均明显大于对照组,差异有统计学意义(P0.05)。持续性房颤组左心房的前后径和左右径均明显大于对照组,左心耳的面积变化率、Lev及Lfv均明显小于对照组,差异有统计学意义(P0.05)。阵发性房颤组左心房的前后径和左右径均明显小于持续性房颤组,左心耳的面积变化率、Lev及Lfv均明显大于持续性房颤组,差异有统计学意义(P0.05)。有LASEC者左心房的前后径和左右径均明显大于无LASEC者,左心耳的面积变化率、Lev及Lfv均明显小于无LASEC者,差异有统计学意义(P0.05)。100例房颤患者中发现34例LASEC,占34.00%,其中有18例患者合并有左心耳血栓,占18.00%。总计有66例患者接受导管射频消融疗法,占66.00%,均未在术中及术后7d内出现血栓及栓塞并发症。结论:利用TEE对特发性房颤的患者左心房及左心耳进行评估,有利于更好的辅助患者的临床治疗,值得重视。     

Variability of the Left Atrial Appendage in Human Hearts

Atrial fibrillation increases the risk of thrombus formation. It is commonly responsible for cerebral stroke whereas less frequently for pulmonary embolism. The aim of the study was to describe the morphology of the left atrial appendage in the human heart with respect to sex, age and weight. Macroscopic examination was carried out on 100 left appendages taken from the hearts of the patients aged 18–77, both sexes. All hearts preserved in 4% water solution of formaldehyde carried neither marks of coronary artery disease nor congenital abnormalities. Three axes of appendage orientation were performed. After the appendage had been cut off, morphological examination was performed in long and perpendicular axes. Measurements of the appendages were taken from anatomical specimens and their silicone casts. We classified the left atrial appendage into 4 morphological groups according to the number of lobes. Most left atrial appendages in female population were composed of 2 lobes. In the male group typically 2 or 3-lobed appendages were observed. The mean left atrial appendage orifice ranged from 12.0 to 16.0 mm and the most significant difference in the orifices between males and females was observed in LAA type 2 (about 3.3 mm). A smaller orifice and narrower, tubular shape of the LAA lobes could explain a higher risk of thrombus formation during nonvalvular atrial fibrillation in women. Knowledge of anatomical variability of the LAA helps diagnose some undefined echoes in the appendage during transesophageal echocardiographic examination.     

Evaluating the novel parameters for assessing the LAA function and thrombus formation with nonvalvular atrial fibrillation

The dysfunction of left atrial appendage (LAA) is prone to form thrombus when atrial fibrillation (AF) sustained more than 48 h. Traditional 2D-TEE (transesophageal echocardiography) can not accurate evaluate the function of LAA. The purpose of this study is to analyze the relationship of LAA function parameters and thrombus formation in patients with non-valvular atrial fibrillation (NVAF) by real-time three-dimensional transesophageal echocardiography (RT-3D-TEE). High risk patients can be identified according to the characteristics of ultrasonic index in patients with left atrial appendage thrombosis, which has important clinical value and significance in the risk assessment, guiding treatment and judging prognosis. We examined the relationship between the echocardiographic parameters of LAA function and the incidence of thrombus in 102 NVAF patients. They underwent RT-3D-TEE and left atrial appendage thrombus (LAAT)/severe spontaneous echocardiographic contrast (SSEC) was found in 67 patients (thrombus group) but absent in the remaining 35 patients (non-thrombus group). After measured by QLAB software, the LAA functional parameters were significantly associated with LAAT/SEC formation. Univariate analysis indicated that AF time, LAD, LVEF, LAA-OAmax, LAAVmax, LAAVI and LAAEF demonstrated a positive association (P < 0.05). However, logistic regression analysis identified that AF time (OR:1.73, P < 0.05)、LAAEF (OR:4.09, P < 0.01)and LAAVI (OR:3.28, P < 0.01) were independent predictors of LAAT/SSEC. In patients with nonvalvular atrial fibrillation, echocardiographic parameters of LAA function are significantly associated with LAAT/SSEC.     

Epicardial fat pad within the transverse sinus mimicking a left atrial appendage thrombus

The presence of left atrial thrombus is a contraindication to cardioversion or catheter ablation in patients with atrial fibrillation, due to the increased risk of systemic thromboembolism. Management of this situation includes changes in the anticoagulation regimen and repeat imaging tests. Accurate diagnosis of left atrial appendage thrombus is therefore essential but can sometimes be challenging. Multiple imaging modalities may sometimes be required in the setting of anatomical variations of the left atrial appendage and surrounding structures.We present the case of a patient awaiting ablation for atypical atrial flutter, who underwent a transthoracic echocardiogram that showed an echodense, mobile structure within the vicinity of the left atrial appendage, suggesting a possible thrombus. A cardiac CT demonstrated the image to correlate with an epicardial fat pad within the transverse sinus.     

Characterizing left atrial appendage functions in sinus rhythm and atrial fibrillation using computational models

Clinical studies show that the left atrial appendage, a blind-ended structure that is attached to the left atrium, may be the cause of 90% of atrial thrombi in atrial fibrillation (abnormal heart rhythm), and it is much reduced in sinus (normal) rhythm. In this paper, the effects of blood flows in left atrium and left atrial appendage are studied to help characterize the atrial appendage functions in sinus rhythm and atrial fibrillation using mathematical models. Our results show that the left atrial appendage is not functional in sinus rhythm because the atrial transmitral velocities remained almost identical for atria with and without appendage, which agrees with the current clinical observations. However, in atrial fibrillation, a proper atrial contraction is absent, which causes the second emptying velocity (A-wave) to be missing in both transmitral velocity and appendage filling/emptying velocity. Without the proper emptying of the blood, vortices generated in the chamber remain high strengths and with longer durations. They induce ineffective emptying of the blood in the atrium and appendage, which then lead to blood stagnation and subsequent thrombus formation.     

Impact of left atrial appendage location on risk of thrombus formation in patients with atrial fibrillation

Biomechanics and Modeling in Mechanobiology - Most strokes in patients with atrial fibrillation (AF) are thought to arise from thrombus formation in the left atrial appendage (LAA). Assessing the...     

Optimal long-term antithrombotic management of atrial fibrillation: life cycle management

Optimal antithrombotic management of atrial fibrillation equals balancing between prevention of arterial thromboembolism, predominantly ischaemic stroke, and haemorrhagic complications. Over time different antithrombotic agents and strategies have been developed. At present, non-vitamin K antagonist oral anticoagulants (NOACs) are the first-line therapy for stroke prevention in patients with non-valvular atrial fibrillation (i.e. without a mechanical valve prosthesis or rheumatic heart disease). Considering the impact of the suboptimal adoption of recommended oral anticoagulant therapy, as experienced with the previous first-line vitamin K antagonists, this review focuses on adequate use of NOACs. As such, we address the most important and clinically challenging issues in the antithrombotic life cycle management for long-term stroke prevention in atrial fibrillation.     

Percutaneous closure of a patent foramen ovale after cryptogenic stroke

A patent foramen ovale is a common intracardiac finding that is located between the left and right atrium. It can cause right-to-left shunting and has a high prevalence in patients who suffer a cryptogenic stroke. Earlier trials did not show superiority of percutaneous patent foramen ovale closure with standard medical therapy over standard medical therapy alone in the treatment of cryptogenic stroke. Interestingly, several meta-analyses show positive results regarding closure, suggesting underpowering of the individual trials. Recently, two large prospective trials and one long-term follow-up study showed benefit of percutaneous closure over standard medical therapy in treatment of cryptogenic stroke. A larger right-to-left shunt or the presence of an atrial septal aneurysm were predictors for a recurrent event. Therefore, percutaneous patent foramen ovale closure after cryptogenic stroke should be recommended over antiplatelet therapy alone in patients younger than 55 years of age with a high-risk patent foramen ovale.     

An innovative appendage invagination procedure to reduce thrombus formation – a numerical model

Invagination is an innovative technique for closing the left atrial appendage (LAA) to reduce the risk of thrombi formation. The influence of LAA invagination on the flow fields in the atria was investigated based on a computational fluid dynamics. The simulation results demonstrated that the novel invagination process can eliminate low velocities (blood stasis) and low shear rate and thus decrease the risk of thrombus formation during atrial fibrillation. This innovative technique may enhance the clinical treatment of patients with atrial fibrillation by improving the atrial flow field while lowering the risk of creating emboli.     

Left Atrial Appendage Dysfunction in a Patient with Premature Ventricular Contractions - A Risk Factor for Stroke?

A 16-year-old female with ventricular dysfunction and frequent ventricular arrhythmia presented with a cardioembolic stroke. Prior electrophysiology study and ablation was performed for ventricular tachycardia (VT). For remaining ventricular ectopy, the patient was maintained on carvedilol and mexiletine. After one year on this regimen, she presented with an acute stroke. Transesophageal echocardiography revealed no evidence of an intracardiac or ventricular thrombus but demonstrated markedly decreased left atrial appendage (LAA) flow velocity worsened during frequent premature ventricular contractions (PVC). In the absence of atrial fibrillation (AF), the LAA dysfunction was considered secondary to the frequent PVCs and was thought to be the underlying cause for the stroke. We present this case to highlight a potential under recognized association between LAA dysfunction and ventricular arrhythmia, similar to that observed with atrioventricular dyssynchronous pacing.     

Stroke risk in patients with device-detected atrial high-rate episodes

Cardiovascular implantable electronic devices (CIEDs) can detect atrial arrhythmias, i.?e. atrial high-rate episodes (AHRE). The thrombo-embolic risk in patients showing AHRE appears to be lower than in patients with clinical atrial fibrillation (AF) and it is unclear whether the former will benefit from oral anticoagulants. Based on currently available evidence, it seems reasonable to consider antithrombotic therapy in patients without documented AF showing AHRE >24 hours and a CHA₂DS₂-VASc score (congestive heart failure, hypertension, age ≥75 years [doubled], diabetes mellitus, prior stroke [doubled], vascular disease, age 65–74 years and female sex) ≥1, awaiting definite answers from ongoing randomised clinical trials. In patients with AHRE <24 hours, current literature does not support starting oral anticoagulation. In these patients, intensifying CIED read-outs can be considered to find progression in AHRE duration sooner, enhancing timely stroke prevention. The notion that AHRE and stroke coincide perseveres but should be abandoned since CIED data show a clear disconnect.     

Is there an alternative treatment for patients intolerant to antiplatelet therapy if percutaneous left atrial appendage closure is considered?

Introduction

Left atrial appendage (LAA) closure has become of major interest for patients with atrial fibrillation intolerant to oral anticoagulation therapy (OAC). Patients with a contraindication to both OAC and antiplatelet therapy are not eligible for percutaneous LAA closure. We aimed to find an alternative treatment for these specific patients.

Methods

From March 2014 until December 2015 five patients were referred for percutaneous LAA closure. Alternative treatment was necessary due to an absolute contraindication to OAC and antiplatelet therapy (n = 4) or after previous failed percutaneous device implantation (n = 1). A stand-alone full thoracoscopic closure of the LAA using the Atriclip PRO device (AtriCure Inc., Dayton, OH, USA) was performed under guidance of transoesophageal echocardiography (TEE). After three months all patients underwent a computed tomography scan. Mean follow-up was 7.2 months [range 4.5–9.8 months].

Results

All procedures were achieved without the occurrence of complications. Complete LAA closure was obtained in all patients without any residual flow confirmed by TEE. Postoperative computed tomography confirmed persisting adequate clip positioning with complete LAA closure and absence of intracardial thrombi. During follow-up no thromboembolic events occurred.

Conclusion

For atrial fibrillation patients with an absolute contraindication to OAC and antiplatelet therapy a stand-alone, minimally invasive thoracoscopic closure of the LAA is a safe and feasible alternative treatment. This might be a solution to avoid serious bleeding complications while eliminating the thromboembolic risk originating from the LAA in patients who are not eligible for percutaneous LAA closure.

     

Incidence and predictors of left atrial thrombus in patients with atrial fibrillation prior to ablation in the real world of China

BackgroundThe present study was to evaluate the value of CHADS2 and CHA2DS2VASC scores on predicting left atrial (LA) or left atrial appendage (LAA) thrombus in atrial fibrillation (AF) patients prior to ablation in the real world of China.Methods and resultsA total of 397 patients with non-valvular AF were analyzed to determine the relationship between CHADS2 and CHA2DS2VASC scores and LA/LAA thrombus identified on transesophageal echocardiography prior to radiofrequency ablation(RFA). LA/LAA thrombus was present in 38 patients (9.6%). There was a strong association between higher CHADS2 score or CHA2DS2VASC score and LA/LAA thrombus. No thrombus was identified in patients with CHA2DS2VASC score of 0 regardless of anticoagulation status. However, LA/LAA thrombus was detected in 2.9% patients with CHADS2 score of 0 without adequate anticoagulation, while no thrombus was present in the patients with CHADS2 score of 0 with adequate anticoagulation. Univariate analysis showed that heart failure (LVEF＜50%), LA≥40 mm, diabetes mellitus, previous stroke or TIA, CAD, hypertension, inadequate anticoagulation therapy, CHADS2 score of ≥2 and CHA2DS2VASC score of ≥2 were significantly associated with LA/LAA thrombus. Multivariable Cox regression analysis demonstrated that CHA2DS2VASC score of ≥2 (p = 0.02) and previous stroke or TIA (p = 0.04) were independently associated with LA/LAA thrombus regardless of anticoagulation status. ROC curve analysis showed that higher CHADS2 score and CHA2DS2VASC score could be similarly used to predict the presence of LA thrombus.ConclusionsBoth higher CHA2DS2VASC and CHADS2 scores were associated with LA/LAA thrombus in non-valvular AF patients prior to ablation. Although CHA2DS2VASC score and CHADS2 score had similar value to predict LA/LAA thrombus, CHA2DS2VASc score was better to identify low-risk patients for LA/LAA thrombus than CHADS2 score without anticoagulation. There will be a possibility of performing AF ablation or cardioversion in patients with a CHA2DS2VASC of 0 without TEE or anticoagulation therapy. The safety need to be verified by more multicentre randomized controlled clinical trails.     

Left Atrial Appendage Morphology in Patients with Suspected Cardiogenic Stroke without Known Atrial Fibrillation

The left atrial appendage (LAA) is the typical origin for intracardiac thrombus formation. Whether LAA morphology is associated with increased stroke/TIA risk is controversial and, if it does, which morphological type most predisposes to thrombus formation. We assessed LAA morphology in stroke patients with cryptogenic or suspected cardiogenic etiology and in age- and gender-matched healthy controls. LAA morphology and volume were analyzed by cardiac computed tomography in 111 patients (74 males; mean age 60 ± 11 years) with acute ischemic stroke of cryptogenic or suspected cardiogenic etiology other than known atrial fibrillation (AF). A subgroup of 40 patients was compared to an age- and gender-matched control group of 40 healthy individuals (21 males in each; mean age 54 ± 9 years). LAA was classified into four morphology types (Cactus, ChickenWing, WindSock, CauliFlower) modified with a quantitative qualifier. The proportions of LAA morphology types in the main stroke group, matched stroke subgroup, and control group were as follows: Cactus (9.0%, 5.0%, 20.0%), ChickenWing (23.4%, 37.5%, 10.0%), WindSock (47.7%, 35.0%, 67.5%), and CauliFlower (19.8%, 22.5%, 2.5%). The distribution of morphology types differed significantly (P<0.001) between the matched stroke subgroup and control group. The proportion of single-lobed LAA was significantly higher (P<0.001) in the matched stroke subgroup (55%) than the control group (6%). LAA volumes were significantly larger (P<0.001) in both stroke study groups compared to controls patients. To conclude, LAA morphology differed significantly between stroke patients and controls, and single-lobed LAAs were overrepresented and LAA volume was larger in patients with acute ischemic stroke of cryptogenic or suspected cardiogenic etiology.     

Optimal antithrombotic treatment of patients with atrial fibrillation undergoing percutaneous coronary intervention: triple therapy is too much!

Patients with atrial fibrillation who undergo a coronary intervention are eligible for both anticoagulation and (dual) antiplatelet therapy ((D)APT). An optimal balance has to be found to reduce the thromboembolic risk (i.e. stroke, systemic embolism and myocardial infarction) and to minimise the increased risk of bleeding with concomitant use of an anticoagulant and (D)APT. Owing to a lack of evidence, the guideline recommendations are predominantly based on expert opinion. Current evidence indicates that the combination of a non-vitamin K oral anticoagulant (NOAC) and clopidogrel is safer than vitamin-K oral antagonists plus DAPT, which increases the risk of bleeding, without clear advantages in regard to efficacy. Concerning whether (N)OACs should be combined with single APT rather than DAPT, the findings of the WOEST, PIONEER AF-PCI and RE-DUAL PCI trials seem to favour a combination with clopidogrel only, thus omitting aspirin. Choosing the optimal treatment strategies for individual patients on NOACs and (D)APT will remain a challenge for clinicians, though triple therapy seems to be the less favourable option owing to the increased risk of bleeding.     

左心房顿抑的影响因素和发生机制

心房顿 抑是 指与 复律 前 相比 ,心房 颤动 复律 后 心房 和 心耳 机械 功能 暂 时被 抑 制的 现象 .心房 颤动 复律 方式 、心房 颤 动持 续 的时 间、心 房的 大小 、潜在 的结 构 性心 脏 病是 影响 心房 顿 抑的 因 素 .目前 心 房顿 抑可 能的 机制 有 :单 纯 性心 房颤 动 引起 的心 房 细胞 结构 的 变化 ;心房 的心 肌 细胞 内钙 离 子的 变化 ;快速 房 性心 肌炎 和心 房纤 维 症 .这 里主 要讨 论 心房 颤动 复 律后 左心 房 和左 心耳 发 生的 顿抑 现 象 .     

Haemodynamic and functional consequences of the iatrogenic atrial septal defect following Mitraclip therapy

Percutaneous MitraClip placement for treatment of severe mitral regurgitation in high surgical risk patients is a commonly performed procedure and requires a transseptal puncture to reach the left atrium. The resulting iatrogenic atrial septal defect (iASD) is not routinely closed, yet the haemodynamic and functional consequences of a persisting defect are not fully understood. Despite positive effects such as acute left atrial pressure relief, persisting iASDs are associated with negative consequences, namely significant bidirectional shunting and subsequent worse clinical outcome. Percutaneous closure of the iASD may therefore be desirable in selected cases. In this review we discuss the available literature on this matter.     

Safe and complete exclusion of the left atrial appendage: a simple epicardial approach

A standardized technique to permanently exclude the left atrial appendage during cardiac surgical procedures to potentially prevent stroke has never been established. We describe a simplified technique using a combination of endoloop occlusion with direct purse-string suturing supported with multiple teflon pledgets placed epicardially at the base of the appendage. The left atrial appendage is subsequently opened and decompressed to facilitate contraction and scarring, reducing or eliminating the possibility of recannalization. The technique was used successfully in 195 off-pump coronary bypass grafting patients with long-term echocardiographic follow-up.     

Use of three-dimensional computed tomography overlay for real-time cryoballoon ablation in atrial fibrillation reduces radiation dose and contrast dye

Aims

Cryoballoon pulmonary vein (PV) isolation in patients with atrial fibrillation has proven to be effective in short-term and long-term follow-up. To visualise the PV anatomy, pre-ablation contrast pulmonary venography is commonly performed. Three-dimensional (3D) computed tomography (CT) overlay is a new technique creating a live 3D image of the left atrium by integrating a previously obtained CT scan during fluoroscopy. To evaluate the benefits of 3D CT overlay during cryoballoon ablation, we studied the use of 3D CT overlay versus contrast pulmonary venography in a randomised fashion in patients with paroxysmal atrial fibrillation undergoing cryoballoon PV isolation.

Methods and results

Between October 2012 and June 2013, 30 patients accepted for PV isolation were randomised to cryoballoon PV isolation using either 3D CT overlay or contrast pulmonary venography. All patients underwent a pre-procedural cardiac CT for evaluation of the anatomy of the left atrium (LA) and the PVs. In the 3D CT overlay group, a 3D reconstruction of the LA and PVs was made. An overlay of the CT reconstruction was then projected over live fluoroscopy. Patients in the contrast pulmonary venography group received significantly more contrast agent (77.1 ± 21.2 cc vs 40.1 ± 17.6 cc, p < 0.001) and radiation (43.0 ± 21.9?Gy.cm2 vs 28.41 ± 11.7?Gy.cm2, p = 0.04) than subjects in the 3D CT overlay group. There was no difference in total procedure time, fluoroscopy time and the amount of cryoapplications between the two groups.

Conclusion

The use of 3D CT overlay decreases radiation and contrast dye exposure and can assist in guiding cryoballoon-based PV isolation.