Catheter ablation of atypical atrial flutter and atrial tachycardia within the coronary sinus after left atrial ablation for atrial fibrillation

OBJECTIVES: The goal of this study was to describe the prevalence and ablation of coronary sinus (CS) arrhythmias after left atrial ablation for atrial fibrillation (AF). BACKGROUND: The CS has been implicated in a variety of supraventricular arrhythmias. METHODS: Thirty-eight patients underwent mapping and ablation of atypical flutter that developed during (n = 5) or after (n = 33) ablation for AF. Also included were two patients with focal CS arrhythmias that occurred during an AF ablation procedure. A tachycardia was considered to be originating from the CS if the post-pacing interval in the CS matched the tachycardia cycle length and/or if it terminated during ablation in the CS. RESULTS: Among the 33 patients who developed atypical flutter late after AF ablation, 9 (27%) were found to have a CS origin. Overall, 16 of the 40 patients in this study had a CS arrhythmia. The tachycardia was macro-re-entrant in 14 patients (88%) and focal in two patients. Radiofrequency ablation with an 8-mm-tip catheter was successful in 15 patients (94%) without complication. In eight patients (50%), > or = 45 W was required for successful ablation. Thirteen of the 15 patients (87%) with a successful ablation acutely remained arrhythmia-free during 5 +/- 5 months of follow-up. CONCLUSIONS: The musculature of the CS serves as a critical component of the re-entry circuit in approximately 25% of patients with atypical flutter after ablation for AF. The CS may also generate focal atrial arrhythmias that may play a role in triggering and/or maintaining AF. Catheter ablation of these arrhythmias in the CS can be performed safely.     

Reliable atrial septostomy by stenting of the atrial septum.

The aim of this report was to describe our experience with creating an interatrial communication by stenting the interatrial septum. In many forms of congenital heart disease, the presence of an appropriate interatrial shunt is critical. After the first several weeks of life, balloon atrial septostomy is not effective, and success with other methods is limited. Clinical records, echocardiograms, and catheterization data in patients who had an atrial septal stent placed between 2001 and 2004 at UCLA were reviewed. Changes in atrial pressures and systemic saturations were analyzed. Follow-up data and explant pathology were reviewed as available. Thirteen patients had stenting of the atrial septum (four restrictive, nine nonrestrictive). In patients with elevated right and left atrial pressures, there was a mean reduction of 2.4 and 7.4 mm Hg in right atrial and left atrial pressures, respectively. In patients with transposition physiology, there was a mean increase in oxygen saturation of 11.3%. Follow-up echocardiograms revealed patent stents with excellent position relative to the atrial septum. In six cases, the stents were removed during subsequent surgery and appeared endothelialized and patent. Stenting of the atrial septum is safe and effective in selected cases, allowing for a reliable, long-lasting, restrictive or nonrestrictive interatrial communication.     

环肺静脉口外线性消融治疗心房颤动术后房性心律失常的随访研究

目的通过随访探讨心房颤动(房颤)射频消融术后近期房性心律失常发作对远期成功率的影响,并探讨发生机制。方法2004年4月至2005年9月共入选52例房颤患者,男性44例,女性8例,年龄24～67(52．6±12．0)岁,病程2-280(35．8±37)个月。其中42例为阵发性房颤,10例为持续性房颤,所有患者均有房颤发作的心电图。13例合并原发性高血压,2例合并房间隔缺损,2例为峡部依赖型心房扑动消融术后,余均无器质性心脏病。所有患者在建立En- Site-NavX左心房几何构型后,于肺静脉口外0．5～1．0 cm处环左侧和右侧肺静脉设置消融线。盐水灌注消融导管于系统导航下沿拟定的消融线逐点消融至肺静脉电位消失。阵发性房颤患者均每日服用普罗帕酮450 mg,培哚普利4 mg,共3个月;持续性房颤患者服用胺碘酮第1周0．6 g／d,第2周O．4g/d,以后0．2g／d,共3个月;培哚普利4 mg／,d,共3个月。结果术后随访6～23 (15．0±5．1)个月。4例因并发症排除;余48例患者,1例术后1个月内发作非典型心房扑动,持续2 d后自行转复窦性心律,随访7个月未有房性心律失常发作。20例患者术后3个月内有阵发性房颤发作,3个月后,12例患者房颤不再发作,余8例随访至6个月,仍有房颤发作。结论心房颤动射频消融术后近期房颤发作者,并不能预测远期房性心律失常发作。术后3个月内有房性心律失常发作而以后不再发作者,可能是心房电学和组织学重构逆转的一个步骤。     

Septal atrial pacing for the prevention of atrial fibrillation.

AIMS: Atrial fibrillation (AF) produces significant morbidity and mortality. The current method of permanent pacing of the right atrium (RA) may cause delayed interatrial conduction and predispose to AF. We hypothesized that atrial septal pacing would reduce AF compared with high RA pacing. METHODS AND RESULTS: The patients were randomized into two groups. After randomization, patients received a dual-chamber rate-responsive device capable of mode-switching with advanced telemetry features. Devices were programmed in a standardized manner. To be eligible, the patients were required to have a conventional indication for a permanent pacemaker and recurrent paroxysmal AF. Group 1 was paced from high RA and Group 2 was paced from the atrial septum. Analysis of 43 patients who have completed 6 months of follow-up and 22 patients who completed 12 months of follow-up showed no significant differences in the number of mode-switching episodes or in AF burden between groups (P = NS by Mann-Whitney) although there was a trend for less AF with septal pacing. There were no differences in thresholds, sensing, or lead impedance. Lead parameters remained stable over time and there were no displacements of the electrodes after implantation. No patient experienced lead-related complications. A significant variability in AF burden was noted in this patient population. CONCLUSIONS: Implantation of an atrial-active fixation lead on the atrial septum is safe and feasible. However, this study showed no significant difference between septal pacing and high atrial pacing, using the endpoints of AF duration and number of AF episodes.     

Left atrial electrophysiologic feature specific for the genesis of complex fractionated atrial electrogram during atrial fibrillation

Complex fractionated atrial electrogram (CFAE) has been suggested to contribute to the maintenance of atrial fibrillation (AF). However, electrophysiologic characteristics of the left atrial myocardium responsible for genesis of CFAE have not been clarified. Non-contact mapping of the left atrium was performed at 37 AF onset episodes in 24 AF patients. Electrogram amplitude, width, and conduction velocity were measured during sinus rhythm, premature atrial contraction (PAC) with long- (L-PAC), short- (S-PAC) and very short-coupling intervals (VS-PAC). These parameters were compared between CFAE and non-CFAE regions. Unipolar electrogram amplitude was higher in CFAE than non-CFAE during sinus rhythm, L-, S- and VS-PAC (1.82 ± 0.73 vs. 1.13 ± 0.38, p < 0.001; 1.44 ± 0.54 vs. 0.92 ± 0.35, p < 0.001; 1.09 ± 0.40 vs. 0.70 ± 0.27, p < 0.001; 0.76 ± 0.30 vs. 0.53 ± 0.25 mV, p < 0.001). Laplacian bipolar electrogram amplitude was also higher in CFAE than non-CFAE during sinus rhythm, L-, S- and VS-PAC. Unipolar electrogram width was similar in CFAE and non-CFAE. Laplacian bipolar electrogram width was wider in CFAE than non-CFAE during L-, S- and VS-PAC (85.5 ± 6.8 vs. 79.6 ± 4.5, p < 0.001; 96.1 ± 9.7 vs. 84.5 ± 5.9, p < 0.001; 122.4 ± 16.0 vs. 99.6 ± 9.6 ms, p < 0.001), but not during sinus rhythm. The conduction velocity was slower in CFAE during sinus rhythm, L-, S- and VS-PAC than non-CFAE (1.7 ± 0.3 vs. 2.4 ± 0.4, p < 0.001; 1.4 ± 0.3 vs. 2.0 ± 0.5, p < 0.001; 1.2 ± 0.3 vs. 1.7 ± 0.5, p < 0.001; and 0.9 ± 0.3 vs. 1.4 ± 0.4 m/s, p < 0.001). CFAE was generated in the high amplitude atrial myocardium with slow and non-uniform conduction properties which were pronounced associated with premature activation, suggesting that heterogeneous conduction produced in high amplitude region contributes to the genesis of CFAE.     

Correlations among the frequencies of atrial activity on the surface electrocardiogram, intracardiac atrial electrograms, and the atrial effective refractory period in patients with atrial fibrillation

BackgroundThe frequency of surface atrial electrocardiogram (ECG) depolarization has been postulated to reflect the atrial effective refractory period (AERP).MethodsFrequency analysis of surface ECGs after QRST subtraction and of electrograms from 4 right atrium and 4 coronary sinus electrode pairs was performed in 38 patients in atrial fibrillation. The AERP was measured in the right atrium and coronary sinus 10 minutes after cardioversion.ResultsThe correlation between the dominant frequencies of intracardiac electrograms and atrial activity in leads I, II, and V₁ were 0.89, 0.85, and 0.88, respectively (all P < .001). The correlation between the average AERP and the frequency of atrial activity in the surface leads was 0.50, 0.45, and 0.47 (all P < .005).ConclusionIn atrial fibrillation, the frequency of atrial depolarization measured from the surface ECG is highly correlated with intracardiac atrial frequency. However, the correlation between the frequency of surface atrial activity and atrial refractoriness, although significant, is not strong.     

心房复极波增大诱发房早与阵发房颤的关系

目的 探讨心房复极波增大诱发的房性早搏与阵发性心房颤动的关系.方法 对频发房早患者进行随访,行心电图和动态心电图检查,房早前有心房复极波增大的为观察组,反之为对照组.观察两组阵发房颤的发生率、持续时间、发作时的临床诊断和并发症.结果 与对照组比较,观察组阵发房颤的发病率较高、发作阵次较多、持续时间较长,分别为31.13...     

Ectopic atrial tachycardia due to aneurysm of the right atrial appendage

We report an infant with ectopic atrial tachycardia, due to an aneurysm of the right atrial appendage, who developed congestive heart failure. Although catheter ablation was transiently successful, tachycardia recurred 2 days later. The aneurysm of the right atrial appendage was resected successfully by surgery, and thereafter she did well, reverting to normal sinus rhythm.     

不同部位起搏对阵发性心房颤动患者心房激动时间的影响

目的　比较右心耳 (RAA)、冠状窦远端 (DCS)、右心房双部位 (右心耳加冠状窦口 ,DSA)和双房 (右心耳加冠状窦远端 ,Bi A)起搏对阵发性心房颤动 (PAf)患者心房激动时间的影响。方法 2 2例接受心脏电生理评价试验的PAf患者在窦性心律下行心房不同部位起搏 ,同步记录 12导心电图 ,测量最大 P波时限。结果　与窦性 P波时限相比 ,RAA起搏明显延长 P波时限 (P<0 .0 1) ,DCS、DSA及 Bi A起搏则明显缩短 P波时限 (P<0 .0 1,P<0 .0 1,P<0 .0 1)。结论　 DCS、DSA及 Bi A起搏明显缩短心房激动时间 ,减少心房电活动的离散度 ,有利于 PAf的防治。     

Relation between the widening of the fragmented atrial activity zone and atrial fibrillation

Fragmented electrical activity is often recorded by a local atrial electrogram in response to atrial extrastimuli. To assess the relation between fragmented activity and the spontaneous occurrence of atrial fibrillation or flutter (AFF), the fragmented activity zone was measured in 57 patients. The electrograms of the high right atrium, low right atrium and left atrium (through the coronary sinus) were recorded simultaneously during high right atrial stimulation. The fragmented activity zone was defined as the S₁–S₂ interval (S₁ = stimulus of a basic beat, S₂ = stimulus of a premature beat) during which a significant fragmented activity was recorded by a high right atrial electrogram after S₂. Fifteen patients had neither sinoatrial disease nor atrial arrhythmias (Group I, controls), 16 had sick sinus syndrome (SSS) with a history of paroxysmal AFF (Group II), 14 had SSS without a history of paroxysmal AFF (Group III), and 12 had idiopathic paroxysmal AFF (Group IV). The fragmented activity zone was significantly wider in Group II (112 ± 26 ms [mean ± standard deviation], p < 0.001), Group III (77 ± 38 ms, p < 0.001) and Group IV (86 ± 19 ms, p < 0.001) than in Group I (31 ± 25 ms). Patients in Group II had a wider fragmented activity zone than those in Group III (p < 0.01). Thus, the widening of the fragmented atrial activity zone is characteristic of AFF and may be a good index of a tendency to develop spontaneous AFF.