Arrhythmia detection after atrial fibrillation ablation: value of incremental monitoring time

Background: After pulmonary vein isolation (PVI), patients need to be followed to analyze the effect of the treatment. We evaluated the influence of the duration of Holter monitoring on the detection of arrhythmia recurrences after a single PVI at 12 months. Methods: Consecutive patients with paroxysmal atrial fibrillation (AF) underwent successful PVI with phased radiofrequency and pulmonary vein ablation catheter. Follow‐up was performed with electrocardiogram at 3, 6, and 12 months and 7‐day Holter at 12 months. Symptomatic patients received additional event recording. The 7‐day Holters at 12 months were evaluated for documented left atrial tachyarrhythmia recurrences, and each individual day with AF was categorized. Results: At 12 months after the procedure, 21 of the 96 (22%) patients had AF on their 7‐day Holter. In the patients with AF recurrence, there was an increase in sensitivity from 53% of a 1‐day Holter up to 88% with 4‐day Holter, and 100% of a 7‐day Holter. Monitoring with duration of less than 4 days resulted in significantly less detection of patients with AF compared to 7‐day Holter. Conclusions: A 4‐day Holter at 12 months has an 88% sensitivity for arrhythmia detection, and appears to provide a sufficient monitoring time. Prolonging the monitoring time to 7 days does not significantly increase the yield. PACE 2012; 35:164–169)     

Comparison of the point-by-point versus catheter dragging technique for curative radiofrequency ablation of atrial fibrillation

Background: The relationship between the applied techniques and clinical outcomes after radiofrequency (RF) ablation of atrial fibrillation (AF) remains unclear. We compared the results of ablation by RF delivered via a point‐by‐point versus catheter dragging technique for the treatment of AF. Methods: This study included 66 patients with drug‐refractory AF who underwent circumferential pulmonary vein (PV) ablation. A point‐by‐point technique was used in 35 (53%) patients (Group I), and catheter dragging technique in the remaining 31 (47%) patients (Group II). If AF persisted or remained inducible after the PV isolation, additional ablation of complex fractionated atrial electrograms and linear ablation were performed. Results: Significantly, fewer RF applications were delivered in Group II than in Group I. The total RF energy duration delivered was comparable between the two groups (P = 0.55). However, the total energy of RF deliveries was significantly greater in Group II than in Group I (P = 0.02). Despite a longer fluoroscopic exposure time (P = 0.01), the total procedural duration was significantly shorter in Group II than in Group I (P = 0.005). Within 3 months after a single ablation procedure, 24 patients (69%) in Group I versus 13 patients (42%) in Group II had ≥1 recurrence(s) of atrial tachyarrhythmias (P = 0.03). A multivariate analysis showed that a point‐by‐point ablation was the only independent predictor of early atrial tachyarrhythmia recurrences. Conclusions: The catheter dragging technique for ablation of AF was associated with a lower early recurrence rate of atrial tachyarrhythmias than the point‐by‐point technique. (PACE 2011; 15–22)     

Catheter ablation for atrial fibrillation: mechanism-based curative treatment

The considerable cumulative morbidity and mortality burden resulting from atrial fibrillation has prompted renewed efforts to seek curative and widely applicable therapies. Currently used drugs are not only frequently ineffective at eliminating fibrillation, but may actually be life threatening. Extensive surgery involving both atria has shown that atrial fibrillation can be eliminated in most, if not all, patients, but at a significant cost. The recent discovery of the pivotal role that myocardial extensions into the pulmonary veins play in the initiation, and probably also the maintenance, of atrial fibrillation, has provided a relatively limited target conducive to catheter-based interventions. In experienced hands, paroxysmal atrial fibrillation can be eliminated in more than 85% of patients by a percutaneous intervention lasting less than 3 h with an attendant nonlethal complication risk of 1 to 2%. Thromboembolic complications and pulmonary vein stenosis are the principal complications that may result from this treatment, but their incidence is decreasing. Success rates in patients with persistent or permanent atrial fibrillation are lower, and it is anticipated that increased understanding of the underlying mechanisms will allow doctors to identify those subsets with the greatest potential for benefit from percutaneous catheter-based interventions. Such progress may allow doctors to extend the benefits of eliminating atrial fibrillation to the widest possible range of patients with this recalcitrant disorder.     

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。     

Case of catheter ablation of atrial fibrillation in a very young patient without structural heart disease

The patient was an 18‐year‐old man who suffered frequent supraventricular premature complexes (SVPCs) and atrial fibrillation. Catheter ablation was performed, and the left pulmonary vein had been isolated, although firing from within the left inferior pulmonary vein remained. After that, the patient did not exhibit SVPCs and atrial fibrillation.     

Ablation strategies for atrial fibrillation

Atrial fibrillation remains the most common arrhythmia in the USA and is associated with an increased risk for stroke, congestive heart failure and overall mortality. There has been a tremendous advance in the field of catheter ablation of atrial fibrillation that has resulted in better outcomes for patients. The approach for ablation of atrial fibrillation can be different depending on patients’ presentation of paroxysmal or persistent atrial fibrillation. Pulmonary vein isolation remains the cornerstone of any ablation strategy for atrial fibrillation; however, further ablation, end points of the procedure, clinical end points for successful ablation and appropriate follow-up remain controversial. We aim to discuss these different approaches and the major controversies in catheter ablation of atrial fibrillation.     

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.     

胸腔镜下单纯肺静脉隔离手术与左心房盒式消融术治疗孤立性房颤的临床价值比较

目的比较胸腔镜下单纯肺静脉隔离术(PVI)与左心房盒式消融术(Box)治疗孤立性房颤的临床价值。方法采用回顾性研究方法,选取2016年1月至2018年8月湖北省中医院收治的孤立性房颤患者80例,根据手术方法不同将患者分为PVI组和Box组,每组各40例。PVI组患者采用胸腔镜下单纯PVI术治疗,Box组患者采用双极射频消融钳完成Box术治疗。比较两组患者的术后和出院时的窦性心率转复率、早期与晚期复发率以及末次随访结果。结果术后随访1.0~2.7年,平均(1.84±0.57)年,两组随访有效率均为100%。Box组患者的术后与出院时窦性心律转复率(82.5%,72.5%)明显高于PVI组(67.5%,57.5%),差异具有统计学意义(P<0.05)。Box组患者早期复发率(12.5%)明显低于PVI组(25.0%),差异具有统计学意义(P<0.05)。Box组患者晚期复发率(7.5%)低于PVI组(17.5%),但差异无显著性(P>0.05)。末次随访结果显示,Box组患者窦性心率比率(82.5%)明显高于对PVI组(62.5%),房颤以及房扑心率比率(15.0%)明显低于PVI组(27.5%),差异具有统计学意义(P<0.05)。结论胸腔镜下Box术可有效提高孤立性房颤患者窦性心律转复率、降低早期复发率,具有较高的临床价值。     

Dissociated activity and pulmonary vein fibrillation following functional disconnection: impact for the arrhythmogenesis of focal atrial fibrillation

The present study sought to investigate the electrophysiological properties of isolated pulmonary veins following successful radiofrequency (RF) catheter ablation in patients with paroxysmal atrial fibrillation (PAF). Overall, 71 pulmonary veins in 37 consecutive patients (age: 56 +/- 9 years) with recurrent PAF were targeted for RF ablation at the ostial region in order to achieve a complete functional block. Following disconnection, the incidence of dissociated pulmonary vein (PV) activity and its response to orciprenalin were studied. RF ablation abolished conduction in 67 (94%) of 71 potentially arrhythmogenic PVs after a mean of 10.7 +/- 6.4 RF applications for each PV. After ablation, spontaneous dissociated automatic activity (9 to 52 beats/min, median 27) was found in 6 out of 67 isolated PVs (left superior: n = 1, left inferior: n = 1, right superior: n = 2, common left PV: n = 2). Slight acceleration (13 to 68 beats/min, median 29) of dissociated PV activity was observed during infusion of orciprenalin. Following isolation, initiation of sustained or nonsustained local fibrillation was recorded in only two cases of the common left sided PV with preceding automatic activity. In one patient PV fibrillation occurred during orciprenalin infusion following a repetitive response to a dissociated automatic rhythm with increasing duration as well as destabilization. In the other patient, PV fibrillation occurred immediately after the occurrence of PV automaticity. Slow dissociated automatic rhythms are detectable within 9% of disconnected PVs. The unique anatomic substrate of common left PVs seem to favor the occurrence of local fibrillation following isolation. The initiation pattern of fibrillation within the isolated PV has pathophysiological implications and underlines the contribution of multiple factors to the onset and sustenance of PAF.     

Real-time dominant frequency analysis of the pulmonary vein in patients with paroxysmal atrial fibrillation

Background: Paroxysmal atrial fibrillation (PAF) can be treated with pulmonary vein isolation (PVI). A spectral analysis can identify sites of high‐frequency activity during atrial fibrillation (AF). We investigated the role of the PVs on AF perpetuation by dominant frequency (DF) analysis. Methods: Thirty‐one consecutive patients with PAF who underwent PVI were included in the prospective study. DF was calculated in each of the PVs, 16, five, and five sites in the left atrium, the coronary sinus, and the right atrium, respectively. In patients presenting sinus rhythm at the baseline, AF was induced by pacing. The PVs were then divided into two groups; PVs demonstrated the highest DF (HDF‐PV) and others. Results: One patient was excluded from the analysis because sustained AF could not be induced. AF was terminated in 43.3% (13/30) of patients during ablation. Of 92 PVs isolated during AF, 30 and 62 PVs were classified into the HDF‐PV and others, respectively. PAF was more frequently terminated by the HDF‐PV isolation compared to the others (33.3%[10/30] vs 4.8%[3/62], P = 0.0004). Interestingly, nine of the 30 HDF‐PVs showing the highest DF among all 30 regions, including extra PVs, led to AF termination in 88.9% (eight out of nine) of cases. Moreover, the HDF‐PVs isolation resulted in a greater AF cycle length prolongation than the other PVs isolation (12.1±5.0 vs 2.7±7.6 ms, P = 0.007). Conclusion: Termination of PAF was more frequently observed during ablation of the PVs with the highest DF. The PV showing high DF played an important role in the maintenance of PAF. (PACE 2012; 35:28–37)     

Increased NT-pro-B-type natriuretic peptide independently predicts outcome following catheter ablation of atrial fibrillation

Abstract

Aims: To investigate whether NT-proBNP before ablation treatment and after exercise testing has predictive information regarding the clinical outcome following pulmonary vein isolation in patients with atrial fibrillation (AF). Methods: NT-proBNP analysis were obtained before the ablation (before and after exercise test), and repeated at 1, 3, and 12 months after the final procedure. Results: A total of 51 patients were included. At study entry, the median NT-proBNP concentration was 14.0 pmol/L (quartiles: 8.0 and 27.0). After the exercise test, the mean NT-proBNP value increased from 13.0 pmol/L (quartiles: 7.5 and 26.0) to 15.0 pmol/L (quartiles: 9.0 and 34.0), p < 0.001. Following a maximum of two ablations, 22 patients were free of AF while 29 patients experienced recurrent AF. In patients with successful ablation, the mean NT-proBNP concentration at baseline was 10.0 pmol/L (quartiles: 7.0 and 22.2) compared to 22.0 pmol/L (quartiles: 12.0 and 34.5) in patients with ablation failure, p = 0.02. With respect to exercise testing, a trend towards a higher increases during exercise were seen in patients with recurrent AF compared to patients without: 2.0 pmol/L (quartiles 1.9 and 7.0) vs. 1.5 pmol/L (quartiles 0 and 3.0), p = 0.07. A baseline NT-proBNP concentration >15.0 pmol/L was found to be an independent predictor of ablation failure. Conclusion: A significantly lower NT-proBNP concentration at baseline and a trend towards a diminished increase during exercise was seen in patients successfully ablated for AF compared to patients with recurrent AF. A baseline NT-proBNP concentration ≤15 pmol/l independently predicts ablation success.     

Atrial fibrillation catheter ablation in females: same hardware,different findings

Atrial fibrillation catheter ablation has gained a significant role in the management of the frequent arrhythmia and has been shown to be safe and effective. As with many other interventional therapies, gender bias is present and females are referred for catheter ablation less frequently than their male counterparts. Women referred for catheter ablation tend to be older, more symptomatic, have failed more antiarrhythmic agents and may have poorer procedure success and increased vascular complication rates. Efforts to close this referral gap are clearly needed and it is likely that early referral will reduce gender differences in atrial fibrillation catheter ablation success rates.     

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.     

Magnetic resonance angiography of pulmonary veins: implications for catheter ablation of atrial fibrillation

INTRODUCTION: Catheter ablation of atrial fibrillation (AF) requires exact anatomical information about pulmonary venous (PV) ostia. In this study, anatomy of pulmonary veins (PVs) was assessed using three-dimensional (3D) reconstructions of magnetic resonance angiography (MRA). METHODS AND RESULTS: Contrast-enhanced MRA of the PVs was performed in 40 patients (mean age 53 +/- 9 years) with paroxysmal (30 patients) or persistent (10 patients) AF, scheduled for circumferential ablation around PV ostia. PV ostial anatomy and diameters were evaluated from multiplanar reconstructions and compared with 3D reconstructions. Thirty (75%) patients presented with a common left-sided antrum (21 short and 9 long trunk), while additional PVs were found on right side in 23%. PV ostia were oblong in shape (mean diameters 17.0 +/- 4.3 vs 10.5 +/- 2.5 mm by two-dimensional (2D) measurements, and 20.8 +/- 7.6 mm vs 12.9 +/- 3.3 mm by 3D reconstruction, in long and short axis, respectively). There was a correlation between measurements obtained from 2D and 3D images, although 3D imaging provided slightly larger diameters. CONCLUSIONS: MRA with 3D reconstructions is an important technique for preprocedural assessment of PVs that allows full understanding of their anatomy and size. This information may be important for selection of appropriate tools.     

Incremental value of isolating the right inferior pulmonary vein during pulmonary vein isolation procedures in patients with paroxysmal atrial fibrillation

Electrical isolation of the left superior, left inferior, and right superior pulmonary veins (PVs) is often, but not always, effective in eliminating paroxysmal atrial fibrillation (PAF). The incremental clinical value of also isolating the right inferior PV has not been well defined. PV isolation by ostial applications of radiofrequency energy guided by PV potentials was performed in 176 consecutive patients (mean age 52 +/- 11 years) with PAF. The left superior, left inferior, and right superior PVs were targeted in 106 patients, and all four PVs were targeted 70 patients. Successful isolation was achieved in 96% of targeted PVs. The mean duration of follow-up was 15 +/- 7 months. At 1-year follow-up, 58% of patients in whom three PVs were isolated were free of recurrent PAF in the absence of antiarrhythmic drug therapy, compared to 73% of patients in whom all four PVs were isolated (P = 0.07). There is a trend towards a better outcome when all four PVs are isolated than when only the three major PVs are isolated. Whenever feasible, the right inferior PV should be isolated along with the other three PVs during the first ablation procedure in patients with PAF.