Atypical Electrocardiographic Features of Cavotricuspid Isthmus‐Dependent Atrial Flutter Occurring during Left Atrial Fibrillation Ablation

Background: Patients who have undergone percutaneous catheter ablation for atrial fibrillation (AF) may develop cavotricuspid isthmus (CTI)‐dependent atrial flutter (AFL), which can occur either spontaneously during left atrial (LA) ablation for AF or by induction from sinus rhythm during the procedure. The electrocardiographic (ECG) characteristics of CTI‐dependent AFL occurring during LA ablation have not been described. The purpose of this study was to describe the ECG features of CTI‐dependent AFL occurring during percutaneous LA catheter ablation for AF. Methods and Results: Of 223 patients presenting for first AF ablation at our institution between May 2004 and February 2008, 20 patients (9%) developed CTI‐dependent AFL during LA ablation for AF. CTI‐dependent AFL developed spontaneously in 4 patients (20%) and was induced in 16 patients (80%). Among these 20 patients, 3 (15%) had typical ECG patterns and 17 (85%) had atypical ECG patterns. Flutter waves in the inferior leads were biphasic in 10 patients (50%), downward in 3 patients (15%), positive in 3 patients (15%), and not fitting the above classifications in 4 patients (20%). There was no statistically significant association between AFL pattern and LA size, left ventricular ejection fraction, total ablation time, duration of prior AF, or type of prior AF. Conclusion: A majority of patients with CTI‐dependent AFL occurring during LA ablation have atypical ECG patterns. Biphasic flutter waves in the inferior leads are common ECG features, occurring in one‐half of patients. Right atrial CTI‐dependent AFL should be suspected even if the ECG appearance is atypical. Ann Noninvasive Electrocardiol 2010;15(3):200–208     

Reversal of left ventricular dysfunction following ablation of atrial fibrillation

Background: Evaluation of ventricular rate control in atrial fibrillation (AF) can be difficult, and the presence of an AF‐induced ventricular cardiomyopathy due to intermittent poor rate control or other causes may be underestimated. The outcome with AF ablation in patients with a decreased left ventricular ejection fraction (LVEF) may provide insight into this important clinical issue. Objective: To determine the effect of pulmonary vein isolation on LVEF in patients with AF and decreased LVEF (≤50%). Methods: Ablation consisted of proximal isolation of arrhythmogenic pulmonary veins (PVs) and elimination of non‐PV triggers. LVEF was determined within 24 hours after ablation and again at up to 6 months follow‐up. Transtelephonic monitoring was performed routinely for 2–3 weeks prior to ablation, at 6 weeks, and 6 months post and with symptoms following ablation. AF control was defined as freedom from AF or marked (>90%) reduction in AF burden on or off previously ineffective antiarrhythmic medication. Results: AF ablation was performed in 366 patients and 67 (18%) patients had decreased LV function with a mean LVEF of 42 ± 9%. An average of 3.4 ± 0.9 PVs were isolated. AF control in the depressed LVEF group compared favorably with the normal EF group (86% vs. 87% P = NS), although more redo procedures were required (1.6 ± 0.8 vs 1.3 ± 0.6 procedures; P ≤ 0.05). Only 15 of 67 patients (22%) with decreased LVEF had shown tachycardia (>100 bpm) on repeated preablation ECG recordings during AF. In the decreased LVEF group, the LVEF increased from 42 ± 9% to 56 ± 8% (P < 0.001) after ablation. Conclusions: Patients with AF and decreased LVEF undergoing AF ablation have similar success to patients with normal LVEF and have improvement in LVEF after ablation. These results suggest the presence of a reversible AF‐induced ventricular cardiomyopathy in many patients with AF and depressed LV function. The presence of under‐recognized and reversible cardiomyopathy even when tachycardia is not persistent is important to recognize.     

Canadian Cardiovascular Society atrial fibrillation guidelines 2010: rate and rhythm management

The goals of atrial fibrillation (AF) and atrial flutter (AFL) arrhythmia management are to alleviate patient symptoms, improve patient quality of life, and minimize the morbidity associated with AF and AFL. Arrhythmia management usually commences with drugs to slow the ventricular rate. The addition of class I or class III antiarrhythmic drugs for restoration or maintenance of sinus rhythm is largely determined by patient symptoms and preferences. For rate control, treatment of persistent or permanent AF and AFL should aim for a resting heart rate of <100 beats per minute. Beta-blockers or nondihydropyridine calcium channel blockers are the initial therapy for rate control of AF and AFL in most patients without a history of myocardial infarction or left ventricular dysfunction. Digoxin is not recommended as monotherapy for rate control in active patients. Digoxin and dronedarone may be used in combination with other agents to optimize rate control. The first-choice antiarrhythmic drug for maintenance of sinus rhythm in patients with non structural heart disease can be any one of dronedarone, flecainide, propafenone, or sotalol. In patients with abnormal ventricular function but left ventricular ejection fraction >35%, dronedarone, sotalol, or amiodarone is recommended. In patients with left ventricular ejection fraction <35%, amiodarone is the only drug usually recommended. Intermittent antiarrhythmic drug therapy ("pill in the pocket") may be considered in symptomatic patients with infrequent, longer-lasting episodes of AF or AFL as an alternative to daily antiarrhythmic therapy. Referral for ablation of AF may be considered for patients who remain symptomatic after adequate trials of antiarrhythmic drug therapy and in whom a rhythm control strategy remains desired.     

典型心房扑动对心房颤动导管消融复发的影响

目的 评价典型心房扑动(房扑)对心房颤动(房颤)导管消融复发的影响.方法 120例药物治疗无效的阵发性房颤患者在三维电解剖标测系统和肺静脉环状标测电极导管联合指导下行环肺静脉电隔离.其中17例(14.2%)合并典型房扑(房扑组,其余作为对照组),行三尖瓣环峡部消融,三尖瓣环峡部消融终点为三尖瓣环峡部双向阻滞.房颤复发定义为导管消融3个月后发生房性快速心律失常.结果 房扑组房颤病程(9.8±10.7)年,长于对照组(5.9±6.3)年,差异有统计学意义(P=0.036).房扑组与对照组相比,年龄、性别、合并器质性心脏病、左心房直径、左心室射血分数差异无统计学意义.随访91～401(237±79)d,房扑组房颤复发率为47.1%,对照组房颤复发率为12.6%,两组间差异有统计学意义(P=0.001).经校正年龄、房颤病程、合并器质性心脏病、左心房直径等因素,Cox多因素分析发现消融术前合并房扑是房颤复发的独立危险因素(危险比3.52,95%可信区间1.32～9.34,P=0.012).结论 典型房扑可能增加房颤导管消融术后房颤的复发,房颤导管消融前应对患者是否合并典型房扑进行认真评价.     

Surgical ablation of atrial fibrillation in patients with congestive heart failure

BackgroundCongestive heart failure (CHF) and atrial fibrillation (AF), both of which cause morbidity and mortality, are mutually promoting diseases. We aimed to evaluate surgical AF ablation in CHF.Methods and ResultsAmong 212 patients (age 69 ± 8.8 years, 87% with persistent AF) undergoing concomitant left atrial (LA) ablation, 79 (37.3%) presented CHF (n = 62 with a left ventricular ejection fraction [LVEF] 0.31–0.45, n = 17 with an LVEF ≤ 0.30). Patients with CHF were similar to controls regarding AF duration (61 ± 65.1 months vs. 54 ± 67.2 months, not significant [NS]), LA diameter (49 ± 7.5 mm vs. 50 ± 9.2 mm, NS), and heart rate (78 ± 18.4 min⁻¹ vs. 81 ± 21.3 min⁻¹, NS), but they required more circulatory support (17.7% vs. 1.5%, P < .001) and a longer intensive care unit stay (6 ± 9.5 days vs. 4 ± 10.5 days, P = .032). At follow-up after 13 ± 7.3 months, 42 patients (66%) with CHF and 81 controls (74%, NS) were in sinus rhythm (SR) (55% and 64% without antiarrhythmic drugs, respectively, NS). Univariate and logistic regression analysis revealed that AF duration and LA diameter predicted rhythm outcome but not CHF. In patients with an LVEF of 0.30 or less, SR conversion significantly improved LVEF, New York Heart Association class, and Minnesota Living with Heart Failure score. Kaplan-Meier estimates suggested superior survival of patients with stable SR (100% vs. 73%, log-rank P < .05).ConclusionsIf patients presenting with CHF and AF require cardiac surgery, concomitant AF ablation should be considered, especially if left ventricular function is severely impaired.     

递进式射频消融逆转伴持续性心房颤动“扩张型心肌病”20例的疗效

目的评价递进式射频消融对于心脏扩大的持续性心房颤动的临床效果。方法20例心脏扩大的持续性心房颤动患者接受在接触式三维标测系统(CARTO)指导下的递进式射频消融治疗,术中尽量终止心房颤动。手术6个月后进行随访,比较患者术前及术后的症状、左心房前后径、左心室舒张末内径、左心室收缩末内径、左心室射血分数。结果 (1)术中有40%的患者在消融过程中直接转复为窦性心律,其余经过电复律后转为窦性心律;(2)术后有15%的患者为阵发性心房扑动,85%的患者维持窦性心律;(3)术后患者症状明显好转,左心房前后径、左心室舒张末内径、左心室收缩末内径纽约心脏协会(NYHA)心功能分级较术前明显好转,差异有统计学意义(P<0.01);左心室射血分数较术前提高,差异有统计学意义(45.00%±15.00%vs.36.50%±19.50%,P<0.05)。结论对于高度选择性的伴有心脏扩大的持续性心房颤动患者进行递进式射频消融治疗是安全的,术后大部分患者可以维持窦性心律,同时心腔发生了逆重构,左心室收缩功能得以改善,心功能不全症状好转。     

预激合并室上性快速心律失常所致的心肌病

４例因长期心动过速而发生心功能障碍的患者，经检查除外其他器质性心脏病后，予以射频消融终止心动过速。分别于术后２周及４个月行超声心动图检查，结果显示ＬＶＥＦ、ＬＶＥＤＤ、ＬＶＥＳＤ均较术前有明显改善。提示对于长期快速心律失常患者，即使在心功能受损的情况下，也应积极治疗，以便改善患者预后。     

Late dislodgement of left bundle branch pacing lead and successful extraction

A 61-years-old male underwent left bundle branch pacing for nonischemic dilated cardiomyopathy with recurrent heart failure. Left bundle branch pacing (LBBP) resulted in reduction in QRS duration along with improvement in left ventricular ejection fraction (LVEF) to 64% during follow-up. Two years after implantation he had recurrence of symptoms along with decline in LVEF to 51%. Late lead dislodgement was diagnosed and re-do LBBP was planned. The lead was extracted en-masse without complication and a new 3830 lead was positioned deep inside the proximal septum to capture the left bundle. Postprocedure echocardiography showed no ventricular septal defect or damage to tricuspid leaflet.     

Intermediate-term Results of Partial Left Ventriculectomy

A bstract Partial left ventriculectomy (PLV) has been introduced as an option for patients with end-stage dilated cardiomyopathy. We report the result of a prospective trial of PLV in patients with idiopathic dilated cardiomyopathy, left ventricular end-diastolic diameter (LVEDD) > 7 cm, refractory New York Heart Association (NYHA) Class IV symptoms, and depressed exercise oxygen consumption studies. Sixteen patients underwent a PLV with a mean follow-up of 13 months. Fourteen patients were male. Mean age was 49.6 ± 10.5 years (range 30 to 67 years). Left ventricular ejection fraction (LVEF) improved after surgery from 13.9 ± 5.6 to 21.0 ± 8.4, and this improvement persisted for up to 12 months after operation. LVEDD and NYHA Class also were significantly improved after surgery and for up to 12 months of follow-up. Operative mortality was 6.25%. Twelve-month survival was 86% by Kaplan-Meier analysis. Four (25%) of 16 patients that had initial improvement after PLV developed recurrent heart failure and were listed for transplantation. Freedom from need for listing for heart transplantation was 65% at 12 months. Freedom from death or the need for relisting at 12 months was 56%. PLV can be performed with acceptable early and 12-month mortality. Significant improvements in LVEF, LVEDD, and NYHA Class are seen at up to 12 months of follow-up. Some patients will develop recurrent heart failure and require relisting for heart transplantation.     

Progression of left ventricular enlargement in patients with hypertrophic cardiomyopathy: Incidence and prognostic value–K. Hina ef al.: Ventricular enlargement in HCM

A total of 51 patients with hypertrophic cardiomyopathy (HCM) were followed for at least 3 years (mean follow-up period 6.5 years) by serial M-mode and two-dimensional echocardiography. An increase of the left ventricular diastolic dimension (LVDd) to ≥ 55 mm with a decrease in the left ventricular ejection fraction (LVEF) to < 55% was observed in eight (15.7%) patients (progressive disease group). In five of these eight patients, the LVDd was ≥ 60 mm and the LVEF was < 40%. Ventricular enlargement was closely related to mortality and death due to congestive heart failure occurred in three of these patients. No deaths occurred among the 37 patients without significant progression of ventricular enlargement (nonprogressive group). The annual changes of LVEF and LVDd in the progressive disease group were larger than in the nonprogressive group (LVEF – 0.18 ± 1.45 vs. – 2.46 ± 1.47 %/year; LVDd 0.22 ± 0.81 vs. 1.43 ± 0.77 mm/year). An increment in LVDs occurred earlier than the enlargement of the LVDd. Therefore, close attention to the LVDs seems to be important to detect early left ventricular morphological changes in HCM. In summary, this study indicates that HCM patients include a subgroup with symptoms resembling dilated cardiomyopathy, in whom the left ventricle enlarges with hypofunction and in whom there is high mortality due to congestive heart failure.     

Time course for resolution of left atrial appendage stunning after catheter ablation of chronic atrial flutter

OBJECTIVES: This study assessed the time course of resolution of left atrial appendage (LAA) stunning after catheter ablation of chronic atrial flutter (AFL). BACKGROUND: Although the presence of LAA stunning after ablation of chronic AFL calls for anticoagulation in the post-cardioversion period, limited information has been obtained, particularly regarding its duration. METHODS: Sixteen patients who underwent ablation of chronic, pure AFL were studied, only five of whom had structural heart disease and one of whom had a reduced left ventricular ejection fraction. The LAA emptying velocities (LAAEV) and left atrial spontaneous echo contrast (SEC) were assessed using transesophageal echocardiography before, within 24 h after, one week after, and two weeks after ablation. RESULTS: Within 24 h after ablation, the LAAEV decreased from 39 +/- 10 cm/s during AFL to 21 +/- 10 cm/s during sinus rhythm (p < 0.01), with eight patients (50%) having documented SEC. After one week, the LAAEV increased (39 +/- 17 cm/s, p < 0.01 vs. within 24 h) and SEC resolved in five of eight patients. After two weeks, the increase in LAAEV persisted (54 +/- 14 cm/s, p < 0.01 vs. 1 week) and SEC was no longer present in any of the patients. The numbers of patients with LAAEV >30 cm/s and absence of SEC were three within 24 h, 11 at one week, and 16 at two weeks after ablation. CONCLUSIONS: Patients with chronic, pure AFL and preserved left ventricular function who will undergo catheter ablation may not require anticoagulation therapy for more than two weeks after the procedure because of the presence of forceful mechanical LAA contractions and the absence of SEC.     

扩张性心肌病伴高血压患者心功能及预后的变化

目的观察扩张性心肌病患者伴有高血压与不伴高血压者临床特征的差异。方法对我院1989年至2006年155例诊断扩张性心肌病的住院病例的临床资料进行回顾性分析。结果(1)扩张性心肌病伴高血压的患者出现心力衰竭后血压高于140/90 mm Hg者占30%。(2)伴高血压的扩张性心肌病组左心室后壁厚度(LVPW)、室间隔厚度(IVS)、左心室射血分数(LVEF)、左心室心肌重量(LVMW)等各指标高于无高血压组。(3)治疗后伴有高血压组心功能改善更明显。结论(1)利用血压水平作为排除高血压所引起的心脏损害的标准有一定的局限性。(2)少部分伴高血压的扩张性心肌病可能由于高血压病史不详而属于高血压引起的心脏损害的范畴。     

Evaluation of myocardial disorders in patients with dilated cardiomyopathy and left ventricular eccentric hypertrophy--by 201Tl myocardial SPECT]

201Tl myocardial SPECT was performed in cases of dilated cardiomyopathy and valvular heart disease with left ventricular eccentric hypertrophy, and the two groups were compared from the standpoint of the mechanism of onset of myocardial disorders. Significant coefficients of correlation were seen between the Tl score and LVDd (r = 0.792, r = 0.785) and Tl score and LVEF (r = -0.634, r = -0.555) in both dilated cardiomyopathy and valvular heart disease. In cases of valvular heart disease, significant correlation coefficients (r = -0.756, r = -0.720) between LVDd and r-WR (relative-washout rate), and Tl score and r-WR were observed, but no such correlation was seen in dilated cardiomyopathy. In valvular heart disease, a decrease in myocardial perfusion associated with enlargement of the left ventricle appeared, while in dilated cardiomyopathy, there was a marked decrease in LVEF in proportion to the thallium defect. Therefore, it was assumed that left ventricular wall disorders occur due to myocardial metabolic disorders and coronary microcirculation disorders.     

Efficiency of radiofrequency ablation for surgical treatment of chronic atrial fibrillation in rheumatic valvular disease

Background

It remains unclear whether concomitant radiofrequency ablation procedure in valvular surgery could offer additional benefits to patients with rheumatic valvular disease. We designed a prospective and randomized control study to evaluate the efficacy of surgical radiofrequency ablation in patients with rheumatic heart disease.

Methods

From June 2008 to July 2011, 210 patients with chronic atrial fibrillation and rheumatic heart disease were randomized: (1) control group, patients underwent only valve replacement followed by amiodarone for rhythm control, (2) left atrial group (LA group), patients underwent valve replacement and left atrial mono-polar radiofrequency ablation, (3) bi-atrial group (BA group), patients underwent valve replacement and bi-atrial mono-polar radiofrequency ablation. The primary endpoints included: cardiac death, stroke, and recurrent AF after discharge.

Results

There was no perioperative death. One patient died 4 months after MVR in BA group. In univariate Cox analysis, the two ablation groups were associated with less AF (BA group vs control group: P < 0.001; LA group vs control group: P < 0.001) as well as atrial tachycardia arrhythmia (AF/AT/AFL) recurrent (BA group vs control group: P < 0.001; LA group vs control group: P = 0.02). The comparison between BA and LA groups revealed no differences in terms of AF (P = 0.06) or AF/AT/AFL (P = 0.09). Atrial transport function restoration rate 12 months after operation was 31.4% in LA group, 32.9% in BA group, and 8.6% in control group respectively (P < 0.01).

Conclusions

Radiofrequency ablation concurring with valvular surgery can bring a higher sinus rhythm restoration rate when compared with medical anti-arrhythmic drug therapy in low-medium risk rheumatic heart disease.The trial was registered on Clinicaltrials.gov (registry number NCT01013688).     

Long term outcome of cavotricuspid isthmus cryoablation for the treatment of common atrial flutter in 180 patients: A single center experience

Objective Recent literature has shown that common type atrial flutter (AFL) can recur late after cavotricuspid isthmus (CTI) catheter ablation using radiofrequency energy (RF). We report the long term outcome of a large group of patients undergoing CTI ablation using cryothermy for AFL in a single center. Methods Patients with AFL referred for CTI ablation were recruited prospectively from July 2001 to July 2006. Cryoablation was performed using a deflectable, 10.5 F, 6.5 mm tip catheter. CTI block was reassessed 30 min after the last application during isoproterenol infusion. Recurrences were evaluated by 12-lead ECG and 24 h Holter recording every clinic visit (1/3/6/9 and 12 months after the procedure and yearly thereafter) or if symptoms developed. Results The 180 enrolled patients had the following characteristics: 39 women (22%), mean age 58 years, no structural heart disease in 86 patients (48%), mean left atrium diameter 44 ± 7 mm and mean left ventricular ejection fraction 57 ± 7%. The average number of applications per patient was 7 (3 to 20) with a mean temperature and duration of −88°C and 3 min, respectively. Acute success was achieved in 95% (171) of the patients. There were no complications. After a mean follow-up of 27 ± 17 (from 12 to 60) months, the chronic success rate was 91%. The majority of the recurrences occurred within the first year post ablation. One hundred and twenty three patients had a history of atrial fibrillation (AF) prior to CTI ablation and 85 (69%) of those remained having AF after cryoablation. In 20 of 57 (35%) patients without a history of AF prior to CTI ablation, AF occurred during follow-up. Conclusions This prospective study showed a 91% chronic success rate (range 12 to 60 months) for cryoablation of the CTI in patients with common type AFL and ratified the frequent association of AF with AFL. Disclosures: Drs Rodriguez and Timmermans have received a modest research grant from CryoCor, San Diego, CA, USA. Dr Wellens is a consultant for CryoCor, San Diego, CA, USA.     

射频消融频发室性早搏逆转"扩张性心肌病"

目的 评价心脏扩大合并右心室流出道频发室性早搏(室早)的患者行射频消融治疗后心脏大小和功能的变化.方法 本文对5例频发右心室流出道室早合并左心室扩大的患者行常规电生理检查及射频消融治疗.所有患者消融术前及术后6个月测定左心室收缩末内径(LVESD)、左心室舒张末内径(LVEDD)、左心室射血分数(LVEF)、心胸比例(CTR)、心功能(NYHA分级)等指标.结果 射频消融术前,所有患者均显示LVESD和LVEDD扩大、LVEF下降、CTR增大和心功能减退.成功消融室早后随访6个月,上述指标均获得明显改善.结论 频发右心室流出道室早是临床上少数"扩张性心肌病"患者的根本病因,射频消融根治室早后心脏扩大和心功能减退可完全或部分得到逆转.     

扩张性心肌病患者左室射血分数与胆固醇水平的相关性

目的 目的 分析扩张性心肌病（DCM）患者左室射血分数(LVEF)与血清总胆固醇（TC）的关系。方法 选取住院DCM患者123例，分为LVEF>40％组（34例）和 LVEF≤40％组（89例）。入院后收集患者一般情况及测定血液生化，以超声心动图检查患者的心脏功能及结构，并进行比较。结果 LVEF>40%组与LVEF≤40%患者比较:LVEF>40%组年龄小于LVEF≤40%组(P<0.05)；LVEF>40%组TC显著高于LVEF≤40%组(P<0.05)。TC与LVEF呈正相关（r=0.287,P<0.01）。结论 DCM患者LVEF与TC有相关性。     

持续性心房颤动合并心力衰竭患者经射频导管消融后的心功能变化

目的 评价持续性心房颤动合并心力衰竭患者经射频导管消融（下称＂消融＂）治疗后的心功能变化. 方法 23例持续性心房颤动合并心力衰竭患者接受消融治疗和抗心力衰竭药物治疗.随访12个月时有15例患者仍为窦性心律或阵发性心房颤动,比较该组患者术前、术后3个月和术后12个月的左心室射血分数（LVEF）、左心室舒张末期内径（LVEDd）、左心房内径（LAD）,X线胸片中心胸比例和6min步行距离. 结果 术后3个月与术前比较,LAD缩小而 LVEF增加（均P〈0.05＝,其他参数无明显变化（均P〉0.05）.术后12个月与术前及术后3个月比较,LVEF和6min步行距离增加（均P〈0.05＝,而LVEDd,LAD和心胸比例缩小（均P〈0.05）. 结论 持续性心房颤动合并心力衰竭患者经消融治疗后,长期维持窦性心律者心功能得到明显改善.     

用实验性心力衰竭制作持续性心房颤动模型

为探讨实验性心力衰竭（简称心衰）形成持续性心房颤动（简称房颤）的可行性，用２００～２５０ｐｐｍ的频率以ＶＯＯ方式起搏犬心室３～７周形成实验性心衰，在犬清醒状态下观察心衰前、后刺激诱发的房性快速心律失常。快速起搏右室３～７周，８条犬均发生充血性心衰，３周时体重由心衰前的２８±６ｋｇ降至２４±４ｋｇ（Ｐ＜０．０５）；左室射血分数由０．６４±０．０６降至０．２３±０．０９（Ｐ＜０．０１），右房直径由２５±３ｍｍ增至３６±６ｍｍ（Ｐ＜０．０１），心房不应期由１１６±５ｍｓ增至１３７±１２ｍｓ（Ｐ＝０．０１），不应期离散度无显著性改变（１６±１２ｍｓｖｓ２０±９ｍｓ，Ｐ＝０．２０），心房平均传导时间亦无显著性变化（６１±１９ｍｓｖｓ６６±２４ｍｓ，Ｐ＝０．２０）。１条犬于起搏后第６周夜间突然死亡。心衰前，８条犬均未诱发心房扑动，４条犬诱发短暂房颤；心衰后，８条犬均可反复诱发心房扑动和持续性房颤（持续时间超过１５ｍｉｎ，平均周长９５±５ｍｓ），最长者持续２４ｈ以上。结果表明起搏心室导致犬心衰可形成非瓣膜病性慢性房颤的实验模型。     

Prevalence of Left Atrial Thrombus in Anticoagulated Patients With Atrial Fibrillation

BackgroundThe prevalence of left atrial (LA) thrombus in patients with atrial fibrillation (AF) or atrial flutter (AFL) on guideline-directed anticoagulation is not well known, yet this may inform transesophageal echocardiogram (TEE) use before cardioversion or catheter ablation.ObjectivesThe purpose of this study was to quantify LA thrombus prevalence among patients with AF/AFL on guideline-directed anticoagulation and to identify high-risk subgroups.MethodsEMBASE, MEDLINE, and CENTRAL were systematically searched from inception to July 2020 for studies reporting on LA thrombus prevalence among patients with AF/AFL undergoing TEE following at least 3 weeks of continuous therapeutic oral anticoagulation with vitamin K antagonists (VKAs) or direct oral anticoagulants (DOACs). Meta-analysis was performed using random effects models.ResultsThirty-five studies describing 14,653 patients were identified. The mean-weighted LA thrombus prevalence was 2.73% (95% confidence interval [CI]: 1.95% to 3.80%). LA thrombus prevalence was similar for VKA- and DOAC-treated patients (2.80%; 95% CI: 1.86% to 4.21% vs. 3.12%; 95% CI: 1.92% to 5.03%; p = 0.674). Patients with nonparoxysmal AF/AFL had a 4-fold higher LA thrombus prevalence compared with paroxysmal patients (4.81%; 95% CI: 3.35% to 6.86% vs. 1.03%; 95% CI: 0.52% to 2.03%; p < 0.001). LA thrombus prevalence was higher among patients undergoing cardioversion versus ablation (5.55%; 95% CI: 3.15% to 9.58% vs. 1.65%; 95% CI: 1.07% to 2.53%; p < 0.001). Patients with CHA₂DS₂-VASc scores ≥3 had a higher LA thrombus prevalence compared with patients with scores ≤2 (6.31%; 95% CI: 3.72% to 10.49% vs. 1.06%; 95% CI: 0.45% to 2.49%; p < 0.001).ConclusionsLA thrombus prevalence is high in subgroups of anticoagulated patients with AF/AFL, who may benefit from routine pre-procedural TEE use before cardioversion or catheter ablation.