Severe left ventricular systolic dysfunction increases atrial fibrillation after ablation of atrial flutter

Background: Atrial fibrillation (Afib) that occurs after a successful atrial flutter (AFL) ablation may negate the potential benefits of the ablation. Afib occurs more often when severe left ventricular systolic dysfunction (LVSD) is present. We hypothesized that even after a successful AFL ablation, the incidence of postablation Afib is increased when severe LVSD is present.
Methods: Ninety consecutive patients with LVSD who underwent ablation for AFL at Montefiore Medical Center from August 2001 to January 2005 were classified according to the severity of LVSD. Group 1 (n = 36) consisted of patients with EF ≤ 35%, and group 2 (n = 54) consisted of patients with EF 36–55%. There were no statistically significant differences in baseline patient characteristics between the two groups.
Results: During a mean follow up of 350 days, Afib occurred in 31% (n = 11; 8 with prior history of AFib) in group 1, and 7.4% (n = 4; all with prior history of Afib) in group 2. Cumulative probability of remaining Afib-free in group 1 versus group 2 was 75% versus 96% at 365 days, and 69% versus 91% at 600 days (P = 0.01). A prior history of Afib did not interact with EF when analyzed with a logistic regression analysis.
Conclusion: After an AFL ablation, the incidence of Afib is increased, and the probability of remaining free of Afib is decreased, when severe LVSD is present, independent of a prior history of Afib. This finding may have implications for optimal patient selection for AFL ablation, and the use of adjunctive therapies.     

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.     

The impact of atrial fibrillation ablation on left atrial function: association with baseline left atrial function

Background: The effect of atrial fibrillation (AF) ablation on left atrial (LA) function has not been sufficiently determined. Methods: We enrolled 115 consecutive patients with paroxysmal or persistent AF that underwent AF ablation. Multidetector computed tomography was performed in sinus rhythm before and 3 months after ablation to evaluate LA volume (LAV) and function. Estimates of maximum and minimum LAV were used to calculate LA emptying fraction (LAEF) ([maximum–minimum LAV]/maximum LAV × 100). Results: AF ablation significantly decreased maximum LAV (59.0 ± 20.4 to 53.3 ± 16.7 cm³, P = 0.001), and maintained LAEF (44.5 ± 13.1% to 43.7 ± 10.9%, P = 0.49). The larger the baseline maximum LAV, the greater the decrease in LAV after ablation, and a smaller baseline LAEF was associated with a larger recovery of LAEF after ablation (regression coefficient =−0.45 and −0.56, respectively, P < 0.0001). Multivariable analyses revealed that an impaired baseline LAEF was an independent predictor of an improvement in LA function (an increase in LAEF of >10%; odds ratio [OR] = 0.88, P < 0.0001), while an older age and preserved baseline LAEF were independently associated with a deterioration of LA function (a decrease in LAEF of >10%; OR = 1.06, P = 0.03; and OR = 1.10, P = 0.0001). Conclusions: AF ablation appears to have a beneficial effect on LA function in patients with impaired LA function at baseline. However, it may reduce LA function in patients with an older age and preserved baseline LAEF. (PACE 2011;1–8)     

Continuous versus intermittent monitoring of ventricular rate in patients with permanent atrial fibrillation

Background: Ventricular rate control (VRC) is an important treatment strategy for patients with permanent atrial fibrillation (AF). We assessed the prevalence of poor VRC and the adequacy of various intermittent monitoring regimens to accurately characterize VRC during permanent AF. Methods: We retrospectively analyzed data from dual chamber implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy defibrillator (CRT‐D) patients in the Medtronic Discovery? Link having permanent AF (AF burden >23 hours/day) and ≥365 consecutive days of device data. Poor VRC was defined as a day with the mean ventricular rate during AF >100 beats/minute (bpm) for ICD patients and >90 bpm for CRT‐D patients. Intermittent monitoring regimens were simulated from continuous device data by randomly selecting subsets of days in which data were available for analysis. Assessments of poor VRC were computed after replicating 1,000 simulations. Results: ICD (n = 1,902, age = 71 ± 10) and CRT‐D (n = 3,397, age = 72 ± 9) patients were included and followed for 365 days. The prevalence of poor VRC was 24.8% among ICD patients and 28.6% among CRT‐D patients. Significantly more patients were identified as having poor VRC with continuous monitoring compared to all intermittent monitoring regimens (sensitivity range = 8%–31%). Furthermore, 11.6% of ICD patients and 17.9% of CRT‐D patients experienced ≥7 days with poor VRC, to which the sensitivities of annual 7‐ and 21‐day recordings were <7% and <20%, respectively. Conclusions: A significant proportion of permanent AF patients experience poor VRC that would be missed with random intermittent monitoring. Whether improved knowledge of VRC with continuous monitoring will lead to improved outcomes compared to intermittent monitoring requires further study. (PACE 2012;1–7)     

Quality of life and occurrence of atrial fibrillation in long-term follow-up of common type atrial flutter ablation:

Objectives The ablation of common type atrial flutter is mainly performed by two approved techniques, whose efficacy and outcome in terms of quality of life have not been evaluated so far in a long-term follow-up study over years. A high proportion of patients suffer from coexistent atrial fibrillation, which may worsen the ablation result. The question arises whether one technique is more effective than the other when immediate ablation results, the occurrence of atrial fibrillation and the quality of life are compared. Considering these facts, it is reasonable to think about new ablation strategies for common type atrial flutter in the era of new concepts in catheter ablation of atrial fibrillation. Methods In a retrospective study we evaluated a detailed questionnaire in 132 patients who underwent ablation of common type between 1999 and 2004. Radiofrequency ablation was performed irrespective of coexistent atrial fibrillation either with an irrigated tip or the 8 mm tip electrode. Acute and long-term ablation outcome, and the associated quality of life, pre-, under- and post-ablation was compared in the two different ablation groups. Recurrent tachycardia were re-evaluated by 12 lead ECG analysis and assessed for both ablation groups. Results 88 (67%) of the 132 patients contacted answered the questionnaire polling the perceived benefits of the procedure. Of the other 44 patients (33%); 4 (3%) had died, 7 (5.3%) had moved, 33 patients (25%) could not be included due to missing or incoherent answers. Independent of the ablation technique there was a high acute and long-term ablation success rate at about 95%. After a mean of 3 years of follow-up this benefit persists in spite of a high proportion of recurrent tachycardia, mainly atrial fibrillation (55/88 patients, 59.1%). Despite the occurrence of secondary tachycardia, there was a high significant long-term symptomatic benefit in the state of healthy and daily practice work, evaluated with a p-value of < 0.0005. The frequency of episodes and the symptom "tachycardia" were significantly reduced after effective ablation of common type atrial flutter, p-values of 0.003 and 0.002, respectively. Therefore the need for hospitalization was significant reduced (p = 0.001). Comparison of both approaches revealed that there was no significant difference related to the incidence and occurrence of atrial fibrillation. Conclusions The two mainly accepted and applied techniques for the ablation of common type atrial flutter show an excellent outcome under the aspect of ablation efficacy and quality of life in longterm follow-up. Three years after the ablation procedure the majority of patients consider the intervention beneficial. Despite the relatively high appearance of atrial fibrillation in the long-term follow-up this effect is still traceable.     

环肺静脉电隔离术对心房颤动患者左心房、左心耳、左心房顶部结构的影响

目的应用64排螺旋CT观察环肺静脉电隔离（CPVA）术对心房颤动患者左心房（LA）、左心耳（LAA）、LA顶部结构的影响。方法心房颤动患者共28例,行CPVA术3~14.8（6.5±3.9）个月后进行随访,根据术后有无复发分为成功组（22例）和复发组（6例）。应用64排螺旋CT测量CPVA术前、后LA[包括LA横径（LA1）、上下径（LA2）和前后径（LA3）、LA容积]、LAA（包括LAA口长径、短径和面积、LAA长度、LAA容积）、LA顶部（包括LA顶长度、距离和深度）的相关径线。结果成功组CPVA术后的LA1、LA2、LA3、LA容积、LAA口长径、LAA口面积、LAA容积、LAA长度、LA顶长度、LA顶距离术后比术前减小,术前术后分别为LA1（6.97±0.87）cm vs（6.32±0.94）cm,LA2（6.02±0.84）cm vs（5.63±0.63）cm,LA3（3.71±0.64）cm vs（3.46±0.59）cm,LA容积（83.61±25.98）cm3vs（66.11±22.84）cm3,LAA口长径（3.01±0.54）cm vs（2.64±0.62）cm,LAA口面积（4.99±1.79）cm2vs（4.11±1.94）cm2,LAA容积（11.11±4.34）cm3vs（9.59±4.82）cm3,LAA长度（3.99±0.84）cm vs（3.74±0.82）cm,LA顶长度（4.02±0.89）cm vs（3.55±0.76）cm,LA顶距离（3.90±0.88）cm vs（3.43±0.73）cm（均P〈0.05）;LAA口短径和LA顶深度无明显变化（P〉0.05）。复发组CPVA术前、后比较,除了LA2较术前减小（6.43±1.04）cm vs（5.92±1.27）cm（P〈0.05）,余LA、LAA、LA顶部结构无明显变化（P〉0.05）。结论成功组CPVA术后的LA、LAA、LA顶部较术前减小,即结构重构可以逆转;而复发组CPVA术前、后比较LA、LAA、LA顶部无明显变化,未出现逆重构。     

Catheter ablation for atrial fibrillation: a promising therapy for congestive heart failure

Atrial fibrillation (AF) and congestive heart failure (CHF) are cardiovascular epidemics. Catheter ablation of AF is increasingly performed in patients with CHF. Atrioventricular junction ablation (AVJA) and pulmonary vein isolation are the two predominant ablation strategies used to treat AF patients who are refractory to drugs. In patients with CHF refractory to drugs, AVJA with a biventricular device is associated with improvement in exercise capacity and quality of life. However, in a head-to-head comparison, pulmonary vein antrum ablation was shown to be superior to AVJA. Cure of AF in patients with CHF resulted in more significant morphological and functional improvements than AVJA.     

Catheter ablation vs. amiodarone plus losartan for prevention of atrial fibrillation recurrence in patients with paroxysmal atrial fibrillation

Background  Although amiodarone plus angiotensin II receptor blockers (ARBs) and catheter ablation may improve sinus rhythm maintenance of paroxysmal atrial fibrillation (AF), their clinical efficacies have not been compared. This prospective cohort study was designed to compare clinical efficacy of catheter ablation and amiodarone plus losartan on sinus rhythm maintenance in patients with paroxysmal AF.
Materials and methods  A total of 240 patients with paroxysmal AF were assigned to four groups. CPVA group ( n =  60) was treated with circumferential pulmonary vein ablation (CPVA), SPVI group ( n  = 60) with segmental pulmonary vein isolation, AMIO group ( n  = 60) with amiodarone and AMIO + LO group ( n  = 60) with amiodarone plus losartan. The endpoint was documented recurrence of AF > 30 s by Holter or conventional 12-lead ECG in the 1-year follow-up period.
Results  During 12 months of follow-up, the primary end point was reached in 28 patients in CPVA group, 14 patients in SPVI group, 25 patients in AMIO group and 13 patients in AMIO + LO group, respectively. The sinus rhythm in SPVI and AMIO + LO group were significant higher than that in CPVA and AMIO group ( P  < 0·01 and 0·025), and no difference between CPVA and AMIO group. The maintenance rate of sinus rhythm in SPVI group was similar to that in AMIO + LO group.
Conclusions  This study demonstrates that segmental pulmonary vein isolation in preventing AF recurrence is similar to amiodarone plus losartan, but it is superior to CPVA and amiodarone alone in patients with paroxysmal AF. Larger multicentre studies are needed to confirm its long-term outcomes.     

Catheter ablation of atrial fibrillation: long-term outcomes

The benefits of percutaneous coronary intervention (PCI) can be offset by periprocedural complications such as acute vessel closure and stent thrombosis in the absence of adequate antiplatelet and antithrombotic therapy. Additionally, conditions occurring after 30 days post-PCI, such as in-stent restenosis or late stent thrombosis can occur. Excess antithrombotic therapy, on the other hand, carries a risk of major gastrointestinal or intracranial bleeding as well as vascular access site bleeding complications. In this review, evidence related to the various pharmacological agents for reduction of stent thrombosis available to clinicians during and after PCI will be explored.     

心房颤动患者高凝状态研究

目的研究心房颤动(房颤)患者高凝相关指标及影响因素,探讨其临床意义。方法根据房颤患者是否有心力衰竭分为两组:房颤1组为无心力衰竭者(30例),房颤2组为有心力衰竭者(30例)。具器质性心脏病且心功能正常的窦性心律患者(40例)为窦性心律组,另选33例正常健康者为正常对照组。在慢性房颤患者、心脏病无房颤患者和健康正常人中,用酶联免疫法测定血浆D二聚体、用全自动血凝分析仪测定血浆纤维蛋白原(fibrinogen,Fg)。结果房颤1组患者D二聚体为474.5μg/L(220.0~843.9μg/L),房颤2组患者血浆D二聚体为657.9μg/L(365.8~1 448.6μg/L),明显高于窦性心律组271.6μg/L(186.6~426.2μg/L)和正常对照组179.5μg/L(131.4~235.1μg/L),(P<0.05)。房颤1组患者血浆Fg(3.74±0.76)g/L和房颤2组患者血浆Fg(4.25±0.95)g/L明显高于窦性心律组(3.26±0.80)g/L和正常对照组(2.97±0.72)g/L,(P<0.05)。与房颤1组比,房颤2组患者D二聚体、Fg显著升高(P<0.05)。与左房内径<40 mm的房颤患者比,左房内径≥40 mm的房颤患者D二聚体、Fg升高(P<0.05)。结论房颤患者存在着高凝状态,并且心力衰竭和左房扩大增加房颤的高凝状态,这些异常可能与房颤患者血栓形成和(或)栓塞事件相关。     

Atrioventricular junction ablation followed by resynchronization therapy in patients with congestive heart failure and atrial fibrillation (AVERT-AF) study design

Atrial fibrillation (AF) and congestive heart failure (CHF) affect millions of patients in the United States. Several studies suggest that AF and in particular the irregular ventricular response might be contributing to the left ventricular dysfunction. Studies that compared pharmacologic rate control to atrioventricular junction (AVJ) ablation followed by right ventricular pacing which restores a regular ventricular response, failed to show an improvement when compared to pharmacological rare control. These results might be explained by the fact that while AVJ ablation restored a regular ventricular response, it subjected patients to the detrimental effects of RV apical pacing. The AVERT-AF trial (Atrio-VEntricular Junction Ablation Followed by Resynchronization Therapy in patients with CHF and AF) is a prospective, randomized, double-blinded, multicenter trial that will be testing the hypothesis that AVJ ablation followed by biventricular pacing significantly improves exercise capacity and functional status compared to pharmacologic rate control in patients with chronic AF and depressed ejection fraction, regardless of rate or QRS duration. A total of 180 patients will be enrolled to test the primary endpoint, which is exercise duration. Patients_enrollment will begin in summer 2006 and is expected to be completed in 2008. The results of this trial should help define the best treatment option for this common arrhythmia in patients with left ventricular dysfunction.     

Different clinical courses and predictors of atrial fibrillation occurrence after transisthmic ablation in patients with preablation lone atrial flutter, coexistent atrial fibrillation, and drug induced atrial flutter

The aim of this prospective study was to compare the long-term follow-up after transisthmic ablation of patients with preablation lone atrial flutter, coexistent AF, and drug induced atrial flutter to determine if postablation AF followed a different clinical course and displayed different predictors in these groups. The study evaluated 357 patients who underwent transisthmic ablation for typical atrial flutter. These were divided into four groups according to their preablation history. Group A included patients with typical atrial flutter and without preablation AF (n=120, 33.6%). Group B included patients with preablation AF and spontaneous atrial flutter (n=132, 37.0%). Group C patients had preablation AF and atrial flutter induced by treatment with IC drugs (propafenone or flecainide) (n=63, 17.6%) Group D included patients with preablation AF and atrial flutter induced by treatment with amiodarone (n=42, 11.8%). During a mean follow-up of 15.2 double dagger 10.6 months (range 6-55 months) AF occurred more frequently in groups B (56.1%) and C (57.1%) patients than in groups A (20.8%, P <0.0001) and D (31.0%, P <0.0001) patients. The results of multivariate analysis revealed that different clinical and echocardiographical variables were correlated with postablation AF occurrence in the different groups. Patients with atrial flutter induced by amiodarone have a significantly lower risk of postablation AF than patients with spontaneous atrial flutter and AF, and those with atrial flutter induced by IC drugs. Different clinical and echocardiographical variables predict postablation AF occurrence in different subgroups of patients.     

Noncavotricuspid isthmus-dependent right atrial tachycardia after paroxysmal atrial fibrillation ablation

Background: Atrial tachycardia (AT) is commonly encountered after atrial fibrillation (AF) ablation. But no study exclusively on noncavotricuspid isthmus‐dependent right AT (NCTI‐RAT) post‐AF ablation has been reported. The present study aims to describe its prevalence, electrophysiological mechanisms, and ablation strategy and to further discuss its relationship with AF. Methods: From July 2006 to November 2009, 350 consecutive patients underwent catheter ablation for paroxysmal AF. A total of seven patients (2.0%) developed NCTI‐RAT after left atrium ablation for AF. In these highly selected patients (two male, mean age 54 ± 11 years, mean left atrium diameter of 34 ± 7 cm), all had circumferential pulmonary vein isolation in their initial procedures and three of them had additional complex fractionated electrograms ablation in the left atrium and the coronary sinus. Results: Totally, nine NCTI‐RATs were mapped and successfully ablated in the right atrium with a mean cycle length of 273 ± 64 ms in seven patients. Five ATs in three patients were electrophysiologically proved to be macroreentry and the remaining four were focal activation. All the ATs were successfully abolished by catheter ablation. After a mean follow‐up of 29 ± 15 months post‐AT ablation, all patients were free of AT and AF off antiarrhythmic drugs. Conclusions: NCTI‐RAT is relatively less common post‐AF ablation. Totally, 2.0% of paroxysmal AF patients were revealed to have NCTI‐RAT. (PACE 2011; 34:391–397)     

Catheter ablation as first-line therapy for patients with symptomatic atrial fibrillation

Atrial fibrillation (AF) is a common clinical problem that is associated with an impaired quality of life, thromboembolism, heart failure and death. Medical treatment of AF remains suboptimal and is associated with potentially serious side effects. The disappointing outcomes with medical therapy have spurred the age of catheter ablation of AF. In the last 10 years, catheter ablation of AF has evolved dramatically and has been shown to be superior to medical therapy in multiple studies. As a result, catheter ablation may be offered to the symptomatic patient as first-line therapy in lieu of antiarrhythmic medications, which have limited efficacy and are associated with significant toxicity.