射频消融治疗心房颤动和心房扑动策略探讨

目的评价射频消融使肺静脉电解剖隔离和消除左房碎裂电位治疗心房颤动（简称房颤）的效果,进一步探讨与心房扑动（简称房扑）的关系。方法63例房颤患者分为两组,其中阵发性房颤32例,持续性房颤31例。在Ensite NavX三维标测系统下,建立左心房一肺静脉电解剖模型,分别对左、右肺静脉前庭大环状消融达完全左心房．肺静脉电解剖隔离,若房颤未终止或被诱发,再标测左心房内碎裂电位,消融碎裂电位;对22例合并典型房扑者行三尖瓣峡部消融。随访9个月观察影响手术复发的因素。结果所有患者均达左心房一肺静脉电解剖隔离。32例阵发性房颤患者中23例（71．9％）和31例持续性房颤患者8例（25．8％）经单纯肺静脉电隔离后房颤终止,不被诱发,两者相比有统计学意义（P〈0．01）;7例（21．8％）阵发性房颤和19例（61．3％）持续性房颤患者经联合消融左心房碎裂电位转复窦律,2例阵发性房颤和4例持续性房颤患者住院期间转复,术中总房颤即刻终止率两组相比较无统计学意义（P〉0．05）。阵发性房颤和持续性房颤患者消融成功率分别为84．4％和80．6％（P=0．697）,多元Logistic回归分析显示合并典型房扑是房颤术后复发的一个危险因素（P=0．007）。结论肺静脉电解剖隔离结合消除左心房碎裂电位是治疗房颤的一种有效策略,房颤和房扑的启动与维持可能存在一些共同机制。     

导管射频消融术治疗心房颤动临床研究

目的分析导管射频消融术治疗心房颤动（房颤）的临床疗效。方法回顾性分析行导管射频消融治疗146例房颤患者的临床资料。结果本组射频消融治疗成功率86.30%、复发率13.70%;阵发性房颤治疗成功率高于持续性房颤,复发率低于持续性房颤（P〈0.05）;治疗成功组术后12个月左心房内径较术前明显缩小（P〈0.05）;复发组术前P波离散度大于成功组（P〈0.05）,术后房颤周长小于成功组（P〈0.05）。结论经导管射频消融术是治疗房颤的有效方法,对阵发性房颤疗效明显;P波离散度、术后房颤周长可作为房颤射频消融术治疗是否复发的临床预测指标。     

高血压患者心房颤动危险因素分析

目的探讨高血压患者引起心房颤动（房颤）的危险因素。方法194例高血压患者分为阵发性房颤组52例、永久性房颤组60例和非房颤组82例（对照组）;记录3组性别、年龄、家族史、目前用药情况、超声心动图以及血尿酸、C反应蛋白水平等,采用logistic回归分析房颤发生危险因素。结果3组年龄、β受体阻滞剂应用、左心房内径、左室射血分数及血尿酸、C反应蛋白水平比较差异有统计学意义（P〈0．05）;单因素logistic回归分析结果显示,性别、年龄、左心房内径、B受体阻滞剂的应用与房颤相关（P〈0．05）;logistic回归分析结果显示,永久性房颤与血尿酸独立相关（OR=3．096,95％CI：1.249～7．677,P=0．015）,阵发性房颤与血尿酸无明显相关性（OR=0．932,95％CI：0．355～2．444,P=0．886）。结论血尿酸水平增高可能是永久性房颤发生的危险因素。     

P波离散度预测阵发性心房颤动射频消融术后复发的价值

【目的】探讨阵发性房颤射频消融术后复发的预测因素。【方法】145例行环肺静脉导管射频消融术的阵发性房颤患者,记录术前及术后心电图,测量最大、最小P波时限,计算P波离散度。【结果】术后平均随访（6．1±0．2）个月,根据是否复发房颤分为复发组51例和未复发组94例。复发组较未复发组的术前最大P渡时限增大[（120．2±11．0）ms比（105．6±7．8）ms,P〈0．001];P波离散度明显增大[（53．6±6．2）ms比（39．9±4．7）ms,P〈0．001];两组P波最小时限及其他临床指标均无统计学差异。多因素分析示术前P波离散度≥46ms（P=0．04）和发作频率≥5次／月（P=0．01）是房颤复发的预测因素,二者预测复发的灵敏度分别是87％和86％;特异度92％和85％。【结论】术前P波离散度及房颤发作频率一定程度上可预测阵发性房颤射频消融术后的复发。     

P波离散度与阵发性房颤经导管射频消融术后复发的关系

目的：探讨P波离散度与阵发性房颤经导管射频消融术后房颤复发的关系。方法：78例初次行导管射频消融治疗的阵发性房颤患者,消融术式为电解剖标测系统加单环状标测电极指导下的环肺静脉线性消融术。测量术前体表心电图各导联的P波时限,计算P波离散度。结果：术后随访32．9±4．8个月,有效组64例,复发组14例。复发组术前的P波离散度（46．2±11．8ms）较有效组（37．4±14．2ms）大（P〈0．05）。若以40ms为界值,术前P波离散度预测术后房颤复发的敏感性为86％,特异性为59％。其他的临床及心电图指标在两组间无显著差异。结论：经导管射频消融治疗阵发性房颤的疗效肯定,复发组患者术前的P波离散度明显大于非复发组,术前P渡离散度对术后房颤的复发有一定预测价值。     

房颤电复律相关影响因素分析

目的探讨影响房颤电复律成功的因素。方法试验组房颤患者62例，对照组门诊查体窦性心律者60例。将试验组分为复律成功组（A组）和复律失败组（B组），比较试验组、对照组以及试验组各组间左心房内径、左心室舒张末期内径、左心室射血分数、c反应蛋白（CRP）水平的差异。所有患者于入院后或入组后第2天常规空腹抽血，采用免疫比浊法测定高敏感CRP（hs—CRP）。结果①A、B组与对照组相比，左心房内径大于对照组（P〈0．05），CRP高于对照组（P〈0．05）；②B组左心房内径更大（P〈0．05），多合并瓣膜性病变（P〈0．05），房颤持续时间长于复律成功组（P〈0．05），CRP更高（P〈0．05）。经多因素分析，CRP水平OR为2．1（95％CI 1．4～3．2，P=0．004），左房直径OR为1．8（95％CI 1．2～2．2，P=0．006），房颤持续时间OR为2．8（95％CI 1．6～4．0，P=0.007）。结论高敏感CRP、左房直径及房颤持续时间是影响房颤电复律成功的独立预测因素。     

阵发性心房颤动患者射频消融术后心房颤动晚期复发的相关因素

目的探讨阵发性心房颤动患者射频消融术后心房颤动晚期复发的相关因素。方法收集接受三维电解剖标测系统指导下射频消融手术治疗的阵发性心房颤动患者80例,对其年龄、左房内径、术后48h内心房颤动复发及术中电复律等情况进行多因素分析,寻找心房颤动晚期复发的相关因素。结果80例患者接受82次心房颤动射频消融手术;在术后12个月的随访期内,共有25例患者心房颤动晚期复发。组间比较显示年龄、左房内径及术后48h内心房颤动复发两组之间差异有统计学意义;多元Logistic回归分析提示术后48h内心房颤动复发是阵发性心房颤动射频消融术后心房颤动晚期复发的临床预测指标（OR=3．861,95％CI=1．142～13．056,P=0．03）。结论术后48h内心房颤动复发是阵发性心房颤动射频消融术后心房颤动晚期复发的临床预测指标,术后48h内心房颤动复发患者晚期复发率增高。     

辛伐他汀对急性心肌梗死合并房颤患者的临床疗效观察

目的观察辛伐他汀对急性心肌梗死合并阵发性房颤患者血脂、房颤再发率和缺血事件发生的影响。方法103例急性心肌梗死合并阵发性心房颤动患者分为两组：治疗组45例，常规治疗同时，口服辛伐他汀剂量20mg／日；对照组58例，仅给予常规治疗。追踪18个月，观察血脂、阵发性房颤再发率和转为持续性或永久性房颤的发生率，以及缺血相关事件的发生情况。结果1．对照组治疗前后血脂无显著性变化（P〉0．05）；治疗组治疗前后总胆固醇和低密度胆固醇显著下降（P〈0．05）。2．阵发性房颤再发率和转为持续性或永性房颤发生率：治疗组阵发性房颤再次发作5例（11．1％），明显低于对照组7例（12．1％，P〈0．05）；转为持续性或永久性房颤2例（4．4％）；明显低于对照组14例（24．1％，P〈0．05）。3．缺血性事件的发生率：治疗组发生缺血性事件9例（20．0％），其中心力衰竭3例（6．6％），冠心病恶化再人院2例（4．4％），心源性死亡3例（6．6％），脑卒中1例（2．2％），明显低于对照组24例（41．4％，P〈0．05，见表5）。结论急性心肌梗死合并心房颤动的患者应用辛伐他汀治疗，不仅能够降低血清总胆固醇和低密度胆固醇，而且能够降低阵发性房颤的再发率，减少持续性或永久性房颤的发生率，降低缺血事件的发生。     

食道三维重建、食道吞钡在心房颤动消融术中的应用

心房颤动（atrial fibrillation）简称房颤,是最常见的心律失常之一,人群总的发病率为0．5％～1．0％,随着年龄增大发病率明显增加。房颤的经导管射频消融治疗经过10多年的探索与发展,特别是三维标测系统（EnSite NavX或CARTO）指导下环肺静脉消融术的应用,消融成功率大为提高,已成为房颤的常规治疗方法。由于食道和左房的特殊解剖关系,术中可能出现致命的并发症——左房食道瘘。     

血清尿酸水平和左房内径与老年人房颤的相关性研究

目的观察老年人房颤与血尿酸水平、左房大小的关系,并分析这一关系的临床意义。方法选择2012年4月至2013年3月住院的房颤患者89例作为房颤研究组,同期住院窦性心律患者85例作为非房颤对照组。记录各组一般资料及超声心动图、血生化水平。用Logistic回归分析房颤发生的危险因素。结果单因素分析结果显示,房颤研究组与非房颤对照组相比,年龄较大（P〈0．017）,超声心动测量左房内径偏大（P〈0．001）,左室射血分数较低（P〈0．001）,血肌酐（P=0．003）、尿酸（P=0．001）、尿素氮（P〈0．001）均增高。Logistic回归分析显示,尿酸水平和左心房内径是房颤发生的独立危险因素,与房颤的发生存在显著的关系。结论血尿酸水平和左心房大小与老年患者房颤的发生密切相关。     

Significant Reduction of Atrial Defibrillation Threshold and Inducibility by Catheter Ablation of Atrial Fibrillation

Background: Radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) has antiarrhythmic effects by multiple mechanisms. We hypothesized that RFCA curtails atrial defibrillation threshold (A‐DFT) and postablation induction pacing cycle length (iPCL), making critical mass reduction one potential mechanism by which antiarrhythmic effect is achieved. Methods: We included 289 patients with AF (male 77.9%, 55.7 ± 10.8 years old; 197 paroxysmal AF: 92 persistent AF) who underwent RFCA. A‐DFT (serial internal cardioversion 2, 3, 5, 7, and 10 J) and iPCL (serial 10 mA 10‐second atrial pacing with pacing cycle length 250, 200, 190, 180, 170, 160, and 150 ms) were evaluated before and after RFCA. Results: (1) RFCA of AF reduced the A‐DFT from 6.7 ± 3.7 J to 3.0 ± 3.0 J (P < 0.001). (2) AF ablation reduced AF inducibility from 95.4% before the procedure to 56.3% after the procedure (P < 0.001), and the iPCL from 194.8 ± 32.6 to 160.9 ± 26.2 ms (P < 0.001). (3) In patients who underwent a greater number of ablation lines, the post‐RFCA A‐DFT (P < 0.001) was lower, and %ΔA‐DFT (P = 0.003) and proportion of atrial tachycardia (P = 0.022) were higher than those with a lower number of ablation lines. Conclusion: AF ablation significantly reduced A‐DFT, AF inducibility, and iPCL, and the degree of their reduction was related to the number of ablation lines. (PACE 2012;35:1428–1435)     

Clinical Impact of an Open‐Irrigated Radiofrequency Catheter with Direct Force Measurement on Atrial Fibrillation Ablation

Background: Electrode‐tissue contact is crucial for adequate lesion formation in radiofrequency catheter ablation (RFCA). Objective: We assessed the impact of direct catheter force measurement on acute procedural parameters during RFCA of atrial fibrillation (AF). Methods: Fifty consecutive patients (28 male) with paroxysmal AF who underwent their first procedure of circumferential pulmonary vein (PV) isolation (PVI) were assigned to either RFCA using (1) a standard 3.5‐mm open‐irrigated‐tip catheter or (2) a catheter with contact force measurement capabilities. Using the endpoint of PVI with entry and exit block, acute procedural parameters were assessed. Results: Procedural data showed a remarkable decline in ablation time (radiofrequency time needed for PVI) from 50.5 ± 15.9 to 39.0 ± 11.0 minutes (P = 0.007) with a reduction in overall procedure duration from 185 ± 46 to 154 ± 39 minutes (P = 0.022). In parallel, the total energy delivered could be significantly reduced from 70,926 ± 19,470 to 58,511 ± 14,655 Ws (P = 0.019). The number of acute PV reconnections declined from 36% to 12% (P = 0.095). Conclusions: The use of contact force sensing technology is able to significantly reduce ablation and procedure times in PVI. In addition, energy delivery is substantially reduced by avoiding radiofrequency ablation in positions with insufficient surface contact. Procedural efficacy and safety of this new feature have to be evaluated in larger cohorts. (PACE 2012; 35:1312–1318)     

Catheter ablation for atrial fibrillation and intervention for pulmonary vein stenosis in a patient with Fontan circulation

Incidence of atrial fibrillation (AF) is high in patients with congenial heart disease. However, management of AF is challenging in these patients. Although radiofrequency catheter ablation (RFCA) is effective therapeutic option for AF, RFCA for AF is not common in patients who underwent Fontan operation. We present a 24‐year‐old woman with paroxysmal AF, who underwent lateral tunnel Fontan operation for functional single ventricle. Circumferential pulmonary vein isolation was successfully performed. However, significant pulmonary vein stenosis developed after RFCA. Pulmonary vein stenosis was successfully treated by transcatheter intervention.     

Atrial Conduction Delay Predicts Atrial Fibrillation in Paroxysmal Supraventricular Tachycardia Patients after Radiofrequency Catheter Ablation

This study aimed to assess whether intra- and inter-atrial conduction delay could predict atrial fibrillation (AF) for paroxysmal supraventricular tachycardia (PSVT) patients after successful treatment by radiofrequency catheter ablation (RFCA). Echocardiography examination was performed on 524 consecutive PSVT patients (15 patients were excluded). Left atrial dimension, right atrial diameter and intra- and inter-atrial conduction delay were measured before ablation. Patients were divided into group A (n = 32): occurrence of AF after the ablation and group B (n = 477): remained in sinus rhythm during follow-up. Receiver operating characteristic (ROC) curve analysis was performed to estimate the predictive value of intra- and inter-atrial conduction delay. Both intra- and inter-atrial conduction delay were higher in group A than in group B (4.79 ± 0.30 msec vs. 4.56 ± 0.32 msec; 21.98 ± 1.32 msec vs. 20.01 ± 1.33; p < 0.05). Binary logistic regression analysis showed that intra- and inter-atrial conduction were significant influential factors for the occurrence of AF (odds ratio [OR] = 13.577, 95% confidence interval [CI], 3.469–48.914; OR = 2.569, 95% CI, 1.909−3.459, p < 0.05). The ROC cure analysis revealed that intra-atrial conduction delay ≥ 4.45 msec and inter-atrial conduction delay ≥ 20.65 were the most optimal cut-off value for predicting AF in PSVT patients after RFCA. In conclusion, this is the first study to show that the intra- and inter-atrial conduction delay could effectively predict AF in post-ablation PSVT patients.     

Predictive Capability of Left Atrial Size Measured by CT,TEE, and TTE for Recurrence of Atrial Fibrillation Following Radiofrequency Catheter Ablation

Background: Recurrence of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA) has been well established and is in part related to left atrial (LA) size. The purpose of this study was to assess the predictive capability of LA diameter (LAD) and LA volume (LAV) by echocardiography and computed tomography (CT) to determine success in patients undergoing RFCA of AF. Methods: Eighty‐eight patients with paroxysmal or persistent AF who had undergone RFCA and had a prior transthoracic echocardiogram (TTE), transesophageal echocardiogram (TEE), and CT were enrolled in the study. TTE LADs and LV ejection fraction as well as TEE LADs and LAVs in three views were recorded. CT LAVs were also recorded. Clinical parameters prior to ablation as well as at 1‐year follow‐up were assessed. Results: A total of 40 (45%) patients with paroxysmal AF and 48 (55%) patients with persistent AF were analyzed. Paroxysmal AF patients had a RFCA success rate of 88% at 1 year with persistent AF patients having a 52% success rate (P < 0.001). A CT‐derived LAV ≥ 117 cc was associated with an odds ratio (OR) for recurrence of 4.8 (95% confidence interval [CI]=[1.4–16.4], P = 0.01) while a LAV ≥130 cc was associated with an OR for recurrence of 22.0 (95% CI =[2.5–191.0], P = 0.005) after adjustment for persistent AF. Conclusions: LA dimensions and AF type are highly predictive of AF recurrence following RFCA. LAV by CT has significant predictive benefit over standard LADs in severely enlarged atria even after adjustment for AF type. (PACE 2010; 532–540)     

Prevalence and Characteristics of Left Atrial Tachycardia Following Left Atrial Catheter Ablation

Background: Left atrial tachycardia (AT) is a complication of left atrial catheter ablation (LACA) of atrial fibrillation (AF). However, its prevalence and characteristics have not been sufficiently clarified.
Methods: We divided 121 patients who underwent LACA into 2 groups based on the results of AT occurrence after LACA (follow-up period; 12 ± 7 months): an AT+ group and AT– group.
Results: New-onset left AT occurred in 30 patients (25%) 31 ± 51 days after LACA. Among the 26 patients with an early onset of AT, 4 underwent a second ablation for AT, and 21 became free of AT within 6 months without a repeat ablation procedure. Among the 4 patients with a late onset of AT (>2 months after the LACA), the tachycardia remitted without a repeat ablation procedure in a single patient within 6 months. Among 71 patients who underwent LACA with additional ablation lines, 22 (31%) developed new-onset left AT. Among 50 patients who underwent LACA alone, 8 (16%) developed new-onset left AT (P = 0.02).
Conclusions: New-onset left AT is a frequent complication of LACA for AF, especially in men and in patients with a low left ventricular ejection fraction. Early (<2 months) onset AT does not require a repeat ablation because it often represents a transient phenomenon and disappears spontaneously.     

Impact of integration of multislice computed tomography imaging into three-dimensional electroanatomic mapping on clinical outcomes, safety, and efficacy using radiofrequency ablation for atrial fibrillation

BACKGROUND: Circumferential radiofrequency catheter ablation (RFCA) around the orifices of the pulmonary veins (PV) is a curative catheter-based therapy of paroxysmal, persistent, and permanent atrial fibrillation (AF). Integration of multislice computed tomography into three-dimensional electroanatomic mapping to guide catheter ablation has been shown to be accurate and feasible. This study investigated whether the use of such sophisticated imaging technology translates into better clinical outcomes, procedural efficacy, and safety in comparison with a control group treated with conventional three-dimensional electroanatomic mapping. METHODS: A total of 100 consecutive patients (85 male, mean age 55 +/- 9 years) with multi-drug-resistant AF underwent RFCA. In this study we used a wide area circumferential approach with confirmed PV isolation (requiring additional ablations at the ostial level) and further lines as needed. RESULTS: Comparison of outcome data between the conventional electroanatomic mapping (Carto XP, Biosense Webster, Diamond Bar, CA, USA) and the image integration technology (Carto MERGE, Biosense Webster) resulted in a significant improvement in procedural success for the image integration group (85.1% vs 67.9%; P = 0.018). No single case of significant PV stenosis occurred in the Carto MERGE group versus three significant stenoses in the conventional group (P = 0.098). Both procedure and fluoroscopy times remained unchanged. CONCLUSION: Multislice computed tomography image integration into electroanatomic mapping significantly improves the success of wide area circumferential ablation with confirmed isolation of the PV and additional lines. In addition, the safety of radiofrequency ablation with regard to the occurrence of PV stenosis is increased in comparison with a control group using conventional electroanatomic mapping alone. Procedural efficacy remains unchanged.     

A novel predictive model for late recurrence after catheter ablation for atrial fibrillation using left appendage volume measured by cardiac computed tomography

Larger left atrial appendage (LAA) volume is associated with a higher risk of late recurrence (LR) in patients undergoing radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF). However, it is unclear whether LAA volume predicts LR, independent of established risk factors. We sought to evaluate the value of LAA volume in predicting LR after RFCA for AF and to develop a score prediction model including LAA volume for these patients. We retrospectively studied 992 patients who underwent RFCA for AF and cardiac computed tomography before RFCA at a single center. At 3 years after RFCA, 362 patients (36.5?%) experienced recurrence. The multivariate Cox regression model showed that age?≥?75 years (10 points), non-paroxysmal AF (9 points), diabetes mellitus (4 points), left atrial volume index (1 point per 10 ml/m² rounded to the nearest integer), and the second (4.7 to < 7 ml/m²; 4 points) and third (≥?7 ml/m²; 5 points) tertiles of the LAA volume index were independent risk factors LR. The above-mentioned risk factors were included in the integrated score model, and the C-index of the proposed score model was 0.715 (95?% confidence interval [CI] 0.679–0.752). LAA volume is an independent predictor of LR and the predictive model including LAA volume showed good discrimination power. These findings provide evidence for the inclusion of LAA volume in the risk stratification for AF recurrence in patients undergoing RFCA for AF.

     

Catheter ablation of atrial flutter and atrial fibrillation

Within the past 20 years, refinements in electrophysiologic mapping techniques have provided a better understanding of the pathophysiology of atrial flutter and atrial fibrillation (AF), which resulted in the development of catheter ablation techniques for this arrhythmias. Nowadays, catheter ablation has become the first line treatment of recurrent symptomatic or hemodynamically significant atrial flutter. In contrast, catheter ablation of AF is still an investigational procedure and should be restricted to patients with symptomatic AF who have been refractory to multiple antiarrhythmic drugs. In symptomatic patients with AF and an uncontrolled ventricular rate who have failed treatment with several antiarrhythmic drugs and who do not fit for primary catheter ablation of AF atrioventricular junction ablation with prior pacemaker implantation is recommended.