Predictors of atrial fibrillation recurrence in patients with long-lasting atrial fibrillation

BACKGROUND:

Limited data are available on the predictors of atrial fibrillation (AF) recurrence in patients with chronic AF.

OBJECTIVES:

To evaluate potential clinical, echocardiographic and electrophysiological predictors of AF recurrence after internal cardioversion for long-lasting AF.

METHODS:

A total of 99 consecutive patients (63 men and 36 women, mean age 63.33±9.27 years) with long-standing AF (52.42±72.02 months) underwent internal cardioversion with a catheter that consisted of two defibrillating coils. Shocks were delivered according to a step-up protocol. Clinical follow-up and electrocardiographic recordings were performed on a monthly basis for a 12-month period or whenever patients experienced symptoms suggestive of recurrent AF.

RESULTS:

Ninety-three patients (93.94%) underwent a successful uncomplicated cardioversion, with a mean atrial defibrillation threshold of 10.69±6.76 J. Immediate reinitiation of AF was observed in 15 patients (15.78%) of whom a repeated cardioversion restored sinus rhythm in 13 cases. Early recurrence of AF (within one week) was observed in 12 of 93 patients (12.90%). At the end of the 12-month follow-up period, during which seven patients were lost, 42 of the 86 remaining patients (48.84%) were still in sinus rhythm. Multivariate regression analysis showed that left atrial diameter (OR 1.126, 95% CI 1.015 to 1.249; P=0.025) and mitral A wave velocity (OR 0.972, 95% CI 0.945 to 0.999; P=0.044) were significant and independent predictors of AF recurrence, whereas age, left ventricular ejection fraction and AF cycle length were not predictive of arrhythmia recurrence.

CONCLUSION:

The present study showed that the left atrial diameter and mitral A wave velocity are the only variables associated with AF recurrence after successful cardioversion.     

心房颤动总是"引发"心房颤动吗?

心房颤动(AF)是临床上常见的心律失常,心房重构和AF"引发"AF概念的提出是对AF病理生理机制研究的重大进展,但临床上有关AF的诸多问题并不能都用AF"引发"AF和单纯的心房电重构来解释,本文就AF"引发"AF这一问题结合有关文献作一综述.     

植入型心房除颤器治疗心房颤动的临床应用

目的 评估入型心房除颤器（ｉｍｐｌａｎｔａｂｌｅ ａｔｒｉａｌ ｄｅｆｉｂｒｉｌｌａｔｏｒ，ＩＡＤ）治疗阵发性和持续性心房颤动（房颤）患者的有效性和安全性。方法 １１例患者（８例阵发性房颤，３例持续性房颤）安装了ＩＡＤ，型吨Ｍｅｔｒｉｘ＾ＴＭ３０００和Ｍｅｔｒｉｘ＾ＴＭ３０２０。所有的患者在室功能正常，４５％存在高血压等基础心脏病。ＩＡＤ在识别房颤和心室同步化后，通过右房－冠状静脉窦电流路线，发放     

左心房追踪技术评价高血压心房颤动和孤立性心房颤动患者左心房功能

目的应用左心房追踪技术(LAVT)评价高血压心房颤动(房颤)和孤立性房颤患者左心房功能。方法实验组为50例房颤患者,分为孤立性房颤组24例,高血压房颤组26例,对照组为25例健康成人,用M型超声测量左心室舒张末期内径(LVEDD)、左心室收缩末期内径(LVESD)、舒张末期室间隔厚度(IVSTd)、舒张末期左心室后壁厚度(LVPWTd),用校正立方体积法(Teich)计算左心室射血分数(LVEF);二维超声测量患者收缩末期左心房前后径(LAD1)、上下径(LAD2)、横径(LAD3),收缩末期右心房上下径(RAD1)、横径(RAD2),应用LAVT测量左心房最大面积(LAAmax)、左心房最大容积(LAVmax)、最小容积(LAVmin)、收缩期左心房充盈速率峰值(dv/dtS)、舒张早期左心房排空速率峰值(dv/dtE)及舒张晚期左心房排空速率峰值(dv/dtA),并计算左心房排空分数(LAEF)。比较左心房的收缩及舒张功能。结果孤立性房颤组LAD1:(42.43±4.24)mm、LAD2:(60.22±5.79)mm、LAD3:(47.90±4.86)mm、RAD1:(55.04±5.06)mm、RAD2:(43.25±2.56)mm、LAAmax、LAVmax、LAVmin、dv/dtE与正常对照组LAD1:(33.81±2.96)mm、LAD2:(47.29±6.79)mm、LAD3:(39.04±3.53)mm、RAD1:(44.34±4.12)mm、RAD2:(36.06±3.16)mm、LAAmax、LAVmax、LAVmin、dv/dtE比较均明显升高(均为P<0.05),孤立性房颤组LAEF、dv/dtS、dv/dtA与正常对照组比较均明显减低(均为P<0.05),LVEDD、LVESD、IVSTd、LVPWTd、LVEF与正常对照组比较差异均无统计学意义(均为P>0.05)。与正常对照组比较,高血压房颤组的LAD1:(45.47±7.33)mm、LAD2:(61.35±7.39)mm、LAD3:(49.27±5.25)mm、RAD1:(56.18±4.36)mm、RAD2:(45.13±3.21)mm、LAAmax、LAVmax、LAVmin、dv/dtE均明显升高,LAEF、dv/dtS、dv/dtA均明显减低(均为P<0.05),LVEDD、LVESD、IVSTd、LVPWTd、LVEF差异均无统计学意义(均为P>0.05)。与孤立性房颤组相比,高血压房颤组LAAmax、LAVmax、LAVmin均明显升高(均为P<0.05),LAEF、dv/dtS、dv/dtE、dv/dtA均明显减低(均为P<0.05),LVEDD、LVESD、IVSTd、LVPWTd、LVEF、LAD1、LAD2、LAD3、RAD1、RAD2差异均无统计学意义(均为P>0.05)。结论 AF患者左心房功能明显下降高血压房颤患者左心房功能损害较孤立性房颤患者明显。LAVT能准确、快速的反映房颤患者左心房大小及功能的变化,在评价左心房功能方面有较高的重复性。     

Electroanatomic characteristics of atrial premature beats triggering atrial fibrillation in patients with persistent versus paroxysmal atrial fibrillation

APBs in Persistent Versus Paroxysmal AF. BACKGROUND: Although the electrical disconnection between the left atrium (LA) and pulmonary veins (PVs) by radiofrequency catheter ablation has been proven to be effective in controlling atrial fibrillation (AF), the recurrence rate is higher in patients with persistent AF (PeAF) than with paroxysmal AF (PAF). We hypothesized that the origin of the atrial premature beats (APBs) that trigger AF and the pattern of their breakthrough into the LA differ between PAF and PeAF. METHODS: We mapped 75 APBs (53 APBs triggering AF, 22 isolated APBs) from the LA and PVs in 26 patients with AF (age: 49.5 +/- 9.6, males: 23, PAF = 17, PeAF = 9), using a noncontact endocardial mapping (NCM) system. The location of the preferential conduction (PC) sites and their conduction velocity (CV) were compared. RESULTS: In patients with PeAF, the earliest activation (EA) site and exit of the PC were more frequently located on the LA side of the LA-PV junction as compared with PAF (P < 0.001). Eighty-one percent of the PCs were located in the area between the left and right superior PVs. The incidence of PCs was similar between the PeAF and PAF patients (P = NS). PCs were more commonly found with APBs inducing AF (63.3%) than with those not inducing AF (35.2%, P = 0.01). The CV of the PC was slower for PeAF than PAF (P < 0.001). The CV in the LA during sinus rhythm was also slower for PeAF than PAF (P < 0.01). CONCLUSION: PeAF was more frequently triggered by APBs from the LA side of the LA-PV junction than PAF and resulted in slower conduction than did PAF. These findings may help explain the higher potential for recurrence after electrical PV isolation in patients with PeAF.     

Postoperative atrial fibrillation in patients with left atrial myxoma

Paroxysmal atrial fibrillation (AF) is the most common arrhythmia following cardiac surgery such as coronary artery bypass grafting (CABG), and often occurs between the second and fourth postoperative days.1,2 The reported incidence of paroxysmal AF after CABG surgery varies widely, from five to 40%, which is lower than in cases of valvular cardiac surgery.3,4 Although this arrhythmia is usually benign and self-limiting, it may also be associated with increased risk of embolic events, haemodynamic instability, haemorrhagic complications, prolonged hospital stay and higher rates of re-admissions, increasing the healthcare costs.5-7Several risk factors have been proposed for paroxysmal AF after CABG or valvular cardiac surgery, such as advanced age, genetic predisposition, chronic obstructive pulmonary disease, heart failure or increased peri-operative ischaemia.8-10 In addition, certain echocardiographic parameters such as left atrial (LA) diameter or left ventricular (LV) function, and electrocardiographic parameters including P-wave duration and P-wave dispersion (Pd) have been shown to be associated with postoperative AF.11-13Although postoperative AF and its predictors after CABG and valvular surgery have been well researched, no study has been performed to explore the incidence or predictors of postoperative AF in patients with LA myxoma. The aim of this study was to identify the prevalence and predictors of postoperative AF in a pure cohort of patients with LA myxoma.     

Regional left atrial voltage in patients with atrial fibrillation

BACKGROUND: Regional differences in fibrosis, particularly related to the posterior wall and septum, may be important in atrial fibrillation (AF). Using electroanatomic mapping, voltage can be used as a measure of fibrosis. OBJECTIVES: The purpose of this study was to determine if patients with AF have disproportionately lower voltage in the septal and posterior walls of the left atrium. METHODS: Sinus rhythm left atrial electroanatomic maps were used in serial patients presenting for left atrial ablation of AF (8-mm tip). Patients undergoing left atrial mapping for focal atrial tachycardia (AT) were used as a comparison group (4-mm tip). Animal experiments were performed to assess the influence of ablation catheter tip size on voltage amplitude. RESULTS: The posterior and septal walls exhibited the lowest voltages in both groups. Compared with the anterior wall, there was a 3.78-fold greater odds of finding a low-voltage point (<0.5 mV) in the septum (P <.001) and a 3.37-fold greater odds of finding a low-voltage point in the posterior wall (P <.001) in the AF patients; the proportion of low-voltage points by region were not significantly different in the AT group. In the animal model, the mean voltage obtained from an 8-mm ablation catheter was significantly higher (0.30 +/- 0.17 mV) than that obtained from the same points using a 4-mm catheter (0.22 +/- 0.17, P = .05). CONCLUSION: Regional differences in voltage are present in patients with atrial arrhythmias, with AF patients exhibiting significantly more low-voltage areas in the septum and posterior walls.     

左旋氨氯地平对阵发性房颤并高血压患者房颤的影响

目的观察左旋氨氯地平对阵发性房颤并高血压患者P波离散度（Pd）、左房内径、高敏C反应蛋白（hs—CRP）水平、房颤发作情况的影响。方法将阵发性房颤并高血压患者100例随机分为治疗组（50例）和对照组（50例）。降压药物治疗组给予左旋氨氯地平,对照组给予坎地沙坦,随访1年,观察治疗前后Pd、左房内径、hs—CRP水平及房颤发作情况。结果至随访结束,在长期应用胺碘酮的患者中,对照组房颤复发17例,占81．0％,治疗组房颤复发22例,占95．7％,两组之间差异无统计学意义（x^2=1．122,P〉0．05）。未长期应用胺碘酮的患者,对照组、治疗组在7-12个月时房颤发作次数均较治疗前减少（t=2．823,P〈0．01;t=2．655,P〈0．05）,但两组之间差异无统计学意义（t=0．594,P〉0．05）。与治疗前比较,对照组、治疗组的Pd、左房内径、hs—CRP均降低（t=4．025-13．546,P〈0．01）,治疗后两组之间Pd、左房内径、hs—CRP比较,差异无统计学意义（t=1．234-1．514,P〉0．05）。结论左旋氨氯地平可减少阵发性房颤并高血压患者房颤的复发,降低Pd、左房内径和hs—CRP水平,其效果与坎地沙坦没有差异。     

Electrophysiology and endocardial mapping of induced atrial fibrillation in patients with spontaneous atrial fibrillation

We analyzed the patterns of atrial activation and characterized the electrophysiologic properties of regional atrial sites in the, right atrium and left atrium at the onset of atrial fibrillation (AF) induced with programmed right atrial (RA) stimulation. Intraatrial conduction, atrial electrogram return cycle lengths for the first AF cycle, RA and left atrial (LA) activation maps during AF, and the stability and reproducibility of atrial activation sequences at AF onset and maintenance were analyzed in 23 patients with AF. Correlation of intracardiac electrograms with surface electrocardiographic morphology was attempted. Maximum intraatrial conduction delay for high RA premature beats was observed at the coronary sinus ostium (n = 15), His bundle region (n = 13) or interatrial septum (n = 15). The return cycle lengths for the first AF cycle showed increasing conduction delay with increasing prematurity of the last extrastimulus in most patients. Suprisingly, discrete atrial electrograms with regular or irregular cycle lengths were present at the onset of electrocardiographic documented coarse AF in 13 of 15 patients (87%). Fragmented or chaotic atrial activity were present in 2 of 15 patients (13%) in coarse AF but observed at > or = 1 atrial sites in 7 of 8 patients (88%) with fine AF (p = 0.001). The atrial activation sequence at the onset of the induced AF elicited by high RA extrastimuli usually showed the earliest activation site at the crista terminalis (9 patients) or interatrial septum (9 patients). In contrast, induced AF elicited from other RA sites usually showed earliest atrial activation at the septum (3 patients) or coronary sinus ostium (3 patients). Atrial activation sequences for the first induced AF cycle were usually reproducible in most patients. Atrial activation patterns during the first 10 cycles for AF were stable in RA and LA regions in 6 of 23 patients (260%) but demonstrated significant change(s) at > or = 1 region in 17 of 23 patients (74%) (p <0.05). We conclude that pacing induced AF elicited by RA premature beats commences as a regular or irregular rapid atrial tachycardia consistent with a transitional, but often organized, arrhythmia. The activation sequence and electrophysiologic behavior of the first induced AF cycle is consistent with intraatrial reentry and reproducible in most patients. More than 1 atrial activation sequence can sometimes be observed, emphasizing the dynamic nature of the initial RA reentrant circuits.     

Left ventricular relaxation in lone atrial fibrillation and atrial fibrillation with heart disease]

Atrial fibrillation with organic heart disease shows a steady value for the time constant of left ventricular isovolumetric relaxation (TC), whereas left ventricular contractility varies from beat to beat. However, there is no report on left ventricular relaxation in lone atrial fibrillation. This study assessed left ventricular relaxation in 5 patients with lone atrial fibrillation, 3 with ischemic heart disease and one with hypertrophic cardiomyopathy. Left ventricular pressure was recorded at 3 msec intervals, with a high fidelity micromanometer-tipped catheter. Maximal positive dP/dt (dP/dtmax) and TC of isovolumetric left ventricular relaxation period [P(t) = (P0-P infinity) exp (-t/TC) + P infinity] were measured as indices of left ventricular contractility and left ventricular relaxation, respectively. Correlation coefficients of dP/dtmax and TC versus the ratio of the preceding to the pre-preceding RR-interval (RR2/RR1) were calculated. A good correlation was found between dP/dtmax and RR2/RR1 in all patients (r = 0.71-0.84, p < 0.0001). No correlation between TC and RR2/RR1 was found in patients with atrial fibrillation with organic heart disease, but a good correlation was found between TC and RR2/RR1 in patients with lone atrial fibrillation (r = 0.74-0.95, p < 0.0001). The correlation between TC and RR2/RR1 is well preserved in lone atrial fibrillation. The mechanism of the variation of TC with the RR2/RR1 interval in lone atrial fibrillation may be similar to the change of TC in postextrasystolic potentiation, which is attributed to the change of intracellular Ca2+ concentration. Absence of correlation between TC and RR2/RR1 interval may indicate that left ventricular relaxation is disturbed in patients with atrial fibrillation with organic heart disease.     

Familial atrial fibrillation with fetal onset

A woman presented during two pregnancies (at 25 and 23 weeks' gestation, respectively) because the fetuses had rapid, irregular tachycardia and hydrops. After maternal drug treatment and achievement of slower fetal heart rates, the hydrops gradually resolved. Both babies were born full term with continuing atrial fibrillation. In the first, an ectopic atrial rhythm was temporarily achieved during high dose flecainide treatment but, in the younger sibling, all medications and repeated cardioversions failed even temporarily to convert the atrial fibrillation with an almost isoelectric baseline in ECG to sinus rhythm. Good rate control has been achieved with digoxin in both patients. No infective, immunological, or structural cause was found in either case, and thus an inherited aetiology is probable.

Keywords: atrial fibrillation; arrhythmias; fetal atrial fibrillation; familial arrhythmias     

心房纤颤的抗凝治疗

心房纤颤是一种常见的室上性快速性心律失常,脑卒中、栓塞和心力衰竭是心房纤颤导致患者死亡的主要原因。它所致的脑卒中,是无心房纤颤脑中风的2～7倍。风湿性心脏病心房纤颤所致的脑中风,是无心房纤颤脑中风的17倍。普通人群心房纤颤的发病率约为0.4%,60岁以下人群心房纤颤的发病率低于1%。随着年纪的增大,心房纤颤的发病率逐渐增高,80岁以上老年患者心房纤颤的患病率几乎达到10%。根据Framingham研究,60～69岁心房纤颤患者脑中风的发病率是21‰,70～79岁心房纤颤患者脑中风的发病率是49‰,80～89岁心房纤颤患者脑中风的发病率是71‰。虽…     

Focal atrial fibrillation treated with radiofrequency

Atrial fibrillation is usually thought to be due to multiple circulating reentrant wavelets. From previous studies, a focal mechanism is considered to be very unlikely. This focal source could be successfully treated by radiofrequency catheter ablation. We report a patient without structural heart disease, but with multiple episodes of syncope and palpitations related to atrial tachycardia and atrial fibrillation. Electrophysiological study demonstrated that all atrial arrhythmias were due to one focus located in the left atrium at the ostium of the left superior pulmonary vein that was successfully treated with the use of a mean of three radiofrequency pulses, without complications. The pulmonary veins are an important source of ectopic beats, initiating frequent paroxysm of atrial fibrillation. These foci respond to treatment with radiofrequency ablation.     

肥厚型心肌病合并心房颤动导管消融术后复发的相关因素分析

目的 探讨国人肥厚型心肌病(HCM)合并心房颤动(房颤)患者导管消融术的疗效及术后心律失常复发的危险因素.方法 纳入2005年6月至2013年6月在北京安贞医院行导管消融术的HCM合并房颤患者共40例(阵发性房颤27例,持续性房颤13例).阵发性房颤的消融策略为双侧环肺静脉隔离(PVI)持续性房颤的消融策略为PVI基础上加行左心房顶部、二尖瓣峡部和三尖瓣峡部线性消融.术后以常规心电图和长程心电图随访患者心律失常复发情况,用回归分析方法甄别与心律失常复发相关的危险因素并检测其预测效力.结果 单次消融术后随访(34±18)个月,窦性心律维持率为30％ (12/40),64.3％ (18/28)的心律失常复发出现在消融术后1年.Cox多因素分析显示左心房内径(LAD)和女性是术后快速房性心律失常复发的独立危险因素(LAD:HR=1.124,95％ CI1.051～1.202,P=0.001;女性:HR=3.304,95％CI1.397 ～7.817,P=0.007).其中LAD的截断值为43.5 mm时的预测敏感度为93.5％,特异度为60.0％;LAD每增加1 mm,心律失常复发的风险比为1.095(95％CI1.031～1.163,P=0.003).结论 HCM合并房颤行导管消融术虽安全可行,但单次手术后长期随访的窦性心律维持率较低,大部分心律失常复发出现在术后1年内,左心房内径增大和女性是术后复发的独立危险因素.