Long‐Term Outcome of Atrial Fibrillation Ablation: Impact and Predictors of Very Late Recurrence

Long‐Term Outcome of AF Ablation. Introduction: Ablation eliminates atrial fibrillation (AF) in studies with 1 year follow‐up, but very late recurrences may compromise long‐term efficacy. In a large cohort, we sought to describe the determinants of delayed recurrence after AF ablation. Methods and Results: Seven hundred and seventy‐four patients with AF (428 paroxysmal [PAF, 55%] and 346 persistent or longstanding persistent [PersAF, 45%]) underwent wide area circumferential ablation (WACA, 62%) or pulmonary vein isolation (38%). Over 3.0 ± 1.9 years, there were 135 recurrences in PAF patients and 142 in PersAF patients. AF elimination was achieved in 61% of patients with PersAF at 2 years after last ablation and in 71% of patients with PAF (P = 0.04). This finding was related to a higher initial rate of very late recurrence in PersAF. From 1.0 to 2.5 years, the recurrence increased by 20% (from 37% to 57%) in PersAF patients versus only 12% (from 27% to 39%) in PAF patients. Independent predictors of overall recurrence included diabetes (HR 1.9 [1.3–2.9], P = 0.002) and PersAF (HR 1.6 [1.2–2.0], P < 0.001). Independent predictors of very late recurrence included PersAF (HR 1.7 [1.1–2.7], P = 0.018) and WACA (HR 1.8 [1.1–2.7], P = 0.018), while diabetes came close to significance. In PAF patients, left atrial size >45 mm was identified as an AF‐type specific predictor (HR 2.4 [1.3–4.7], P = 0.009), whereas in PersAF patients, no unique predictors were identified. Conclusion: Late recurrences reduced the long‐term efficacy of AF ablation, particularly in patients with PersAF and underlying cardiovascular diseases. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1071‐1078)     

Single 3-min freeze per vein ablation strategy with the second-generation cryoballoon for atrial fibrillation in a large cohort of patients: long term outcome after a single procedure

Purpose

The purpose of the present study was to assess the long-term success rate of a single 3-min freeze per vein ablation strategy in the setting of pulmonary vein isolation (PVI) by means of second-generation cryoballoon (CB-A; Arctic Front Advance, Medtronic, Minneapolis, MN, USA) in a large cohort of patients.

Methods

Three hundred and one patients with drug resistant atrial fibrillation (AF) having undergone PVI by means of CB-A using a single 3-min freeze per vein ablation strategy were included in the analysis.

Results

Paroxysmal AF (PAF) was documented in 70.8% of the patients, while 29.2% presented with persistent AF (PersAF). The mean number of CB applications was 1.09?±?0.3 in the left superior pulmonary vein (LSPV), 1.04?±?0.2 in the left inferior pulmonary vein (LIPV), 1.12?±?0.3 in the right superior pulmonary vein (RSPV), and 1.12?±?0.3 in the right inferior pulmonary vein (RIPV). All PVs were successfully isolated with a 28-mm CB-A only. After a mean follow-up of 38.1?±?7.5 months, 207 (68.8%) patients were free of atrial tachyarrhythmia (ATa) recurrences following a single procedure. Specifically, 72.8% of patients presenting with PAF and 59.1% of individuals with PersAF did not experience a recurrence.

Conclusions

A single 3-min freeze per vein strategy is effective in treating AF on a long term follow-up of 38 months. Specifically, it can afford freedom from ATa recurrences in 72.8% of patients affected by PAF and 59.1% of patients initially presenting with PersAF after a single CB-A procedure.

     

Ablation of paroxysmal and persistent atrial fibrillation: 1-year follow-up through continuous subcutaneous monitoring

Ablation of Paroxysmal and Persistent Atrial Fibrillation . Background: The aim of this prospective observational study was to identify responders to ablation through continuous subcutaneous monitoring for 1 year after ablation in patients with paroxysmal atrial fibrillation (PAF) or persistent AF (PersAF). Method: Patients with symptomatic drug refractory AF were enrolled. Real‐time three‐dimensional (3D) left atrium maps were reconstructed by using a nonfluoroscopic navigation system (CARTO, Biosense‐Webster Inc., Diamond Bar, CA, USA). The ipsilateral left and right pulmonary veins (PVs) were encircled in 1 lesion line by circumferential PV isolation. All patients were implanted with Reveal XT (Medtronic Inc.) for continuous AF monitoring and data collected every month during the 12‐month follow‐up. Results: We enrolled 129 patients (56 ± 9 years, 102 males), all of whom were followed‐up for 12 months after the last ablation procedure: 58 (45%) had a history of PersAF. After only 1 ablation procedure, 76 (59%) of the 129 patients were AF‐free at 12‐month: 48 out of 71 (68%) in the PAF group and 28 out of 58 (48%) in the PersAF group. After 1 or more ablation procedures, 94 (73%) of the 129 patients were AF‐free 12 months after the last procedure: 57 out of 71 (80%) in the PAF group and 37 out of 58 (64%) in the PersAF group. Conclusion: Ablation is highly effective in treating AF, as assessed through detailed 1‐year continuous monitoring: success rate is higher in PAF than in PersAF patients. The use of subcutaneous monitors is a valuable means of identifying responders and nonresponders, and can potentially guide antiarrhythmic and antithrombotic therapies. (J Cardiovasc Electrophysiol, Vol. 22, pp. 369‐375)     

What is the real atrial fibrillation burden after catheter ablation of atrial fibrillation? A prospective rhythm analysis in pacemaker patients with continuous atrial monitoring.

AIMS: Rhythm follow-up after catheter ablation of atrial fibrillation (AF ablation) is mainly based on Holter electrocardiogramm (ECG), tele-ECG or on patients symptoms. However, studies using 7-day Holter or tele-ECG follow-up revealed a significant number of asymptomatic recurrences. Thus, the aim of this study was to analyse continuous atrial recordings in pacemaker patients with an incorporated Holter function before and after AF ablation in order to determine all AF recurrences and thereby the 'real' success rates. METHODS AND RESULTS: The study comprised 37 patients (64.6 +/- 10 years) with prior pacemaker/implantable cardioverter defibrillator (ICD) implantation including an atrial Holter function referred for AF ablation. Holter data were obtained and correlated to patients' symptoms before and every 3-month after AF ablation. AF recurrence was defined as an atrial high frequency episode of less than 330 ms (180 b.p.m.) lasting longer than 30 s. The ablation procedure consisted of pulmonary vein isolation (PVI) in patients with paroxysmal atrial fibrillation (PAF, n = 20) and additional substrate modification aiming arrhythmia termination in patients with persistent or inducible AF after PVI as well as in patients with a history of long-lasting persistent AF (PersAF, n = 17). The mean atrial Holter monitoring period was 7.4 +/- 3.3 months before and 13.5 +/- 4.2 months after ablation with an overall AF burden of 33.7% prior to ablation. During follow-up, AF burden decreased from 17.3-0.65% (P = 0.001) in PAF patients and from 57.4 to 13.9% (P = 0.024) in patients with PersAF. Complete AF freedom was observed in 85% (17 patients) of PAF patients and 59% (10 patients) in patients with PersAF. The absence of symptoms correlated well with documented freedom of AF. CONCLUSION: In the present study we could show, that freedom from AF can be achieved by catheter ablation in a high percentage of patients even with PersAF. Continuous atrial monitoring reveals AF ablation success rates comparable with those assessed by clinical evaluation. Symptomatic freedom of AF correlated well with the actual freedom of AF at least in this highly symptomatic patient cohort.     

Electrocardiographic P wave changes after thoracoscopic pulmonary vein isolation for atrial fibrillation

Background

Changes in P wave duration (PWD) and P wave area (PWA) have been described following catheter ablation for atrial fibrillation (AF). We hypothesize that video-assisted thoracoscopic pulmonary vein isolation (VATS-PVI) for AF results in decrease of PWD, PWA and P wave dispersion, which may resemble reverse electrical remodeling of the atrium after restoration of sinus rhythm.

Methods

VATS-PVI consisted of PVI and ganglionic plexus ablation in 29 patients (mean age, 59?±?7 years; 23 males; 17 paroxysmal AF) and additional left atrial lesions in patients with persistent AF. PWD and PWA were measured in ECG lead II, aVF and V2 of ECGs during sinus rhythm before, directly after, and 6 months postprocedure. P wave dispersion was derived from the 12 lead ECG.

Results

Prior to VATS-PVI, PWD did not correlate with left atrial size and no difference in left atrial size was found between patients with paroxysmal or persistent AF (p?=?0.27). Following VATS-PVI, PWD initially prolonged in all patients from 115?±?4.6 ms to 131?±?3.6 ms (p?<?0.01) but shortened to 99?±?3.2 ms after 6 months (p?<?0.01). PWA was 5.60?±?0.32 mV*ms at baseline, 6.44?±?0.32 mV*ms post-VATS-PVI (P?=?NS), and 5.40?±?0.28 mV*ms after 6 months (p?=?NS vs. baseline, p?<?0.05 vs. post-VATS-PVI). P wave dispersion decreased in the persistent AF group from baseline 67?±?3.3 to 64?±?2.5 ms post-VATS-PVI (p?=?0.30) and to 61?±?3.4 ms after 6 months (p?<?0.05).

Conclusions

PWD increases significantly directly after successful VATS-PVI in both groups. There was significant decrease in PWD after 6 months. Similarly, P wave dispersion decreased in the persistent group. These changes suggest an immediate procedure related effect, but the later changes may represent reverse electrical atrial remodeling following cessation of AF.     

Incidence of asymptomatic cerebral microthromboembolism after atrial fibrillation ablation guided by complex fractionated atrial electrogram

Cerebral Microthromboembolism After CFAE Ablation . Background: The incidence of cerebral thromboembolism after pulmonary vein isolation (PVI) ranges from 2% to 14%. This study investigated the incidence of cerebral thromboembolism after complex fractionated atrial electrogram (CFAE) ablation with or without PVI. Methods: One hundred consecutive atrial fibrillation (AF) patients (50 paroxysmal and 50 persistent, including 10 longstanding) who underwent CFAE ablation combined with (n = 41, PVI+CFAE group) or without (n = 59, CFAE group) PVI were studied. Coronary angiography (CAG) was conducted with AF ablation in 5 cases in which coronary artery stenosis was suspected on 3D‐computed tomography. PVI was performed before CFAE ablation without circular catheter during AF. After termination of AF, additional ablation was performed to complete PVI with a circular catheter. All patients underwent cerebral magnetic resonance imaging (MRI) including diffusion‐weighted MRI and T2‐weighted MRI the day after ablation. Results: New thromboembolism was detected in 7.0%, and there was no significant difference between the 2 strategies (7.3% in PVI+CFAE group, 6.8% in CFAE group). CHADS2 score (1.6 ± 1.0 vs 0.8 ± 0.9, P < 0.05), left atrial volume (LAV; 83.8 ± 27.1 vs 67.8 ± 21.8, P < 0.05), and left ventricular ejection fraction (LVEF, 53.1 ± 9.2 vs 65.1 ± 9.7, P < 0.01) were significantly different when comparing patients with or without thromboembolism. In multivariate analysis, LVEF (odds ratio [OR], 0.92; 95% confidence interval [CI], 0.84–0.99; P < 0.05) and concomitant CAG (OR 18.82; 95% CI, 1.77–200.00; P < 0.05) were important predictors of new cerebral thromboembolism. Conclusions: The incidence of cerebral microthromboembolism after CFAE ablation was not greater than previous reports in PVI. Cautious management is required during AF ablation, especially in the patients with low LVEF. (J Cardiovasc Electrophysiol, Vol. 23, pp. 567–573, June 2012)     

Use of antiarrhythmic drugs during ablation of persistent atrial fibrillation: observations from a large single-centre cohort

Catheter ablation of complex fractionated atrial electrograms (CFAE), also known as defragmentation ablation, may be considered for the treatment of persistent atrial fibrillation (AF) beyond pulmonary vein isolation (PVI). Concomitant antiarrhythmic drug (AAD) therapy is common, but the relevance of AAD administration and its optimal timing during ablation remain unclear. Therefore, we investigated the use and timing of AADs during defragmentation ablation and their possible implications for AF termination and ablation success in a large cohort of patients. Retrospectively, we included 200 consecutive patients (age: 61 ± 12 years, LA diameter: 47 ± 8 mm) with persistent AF (episode duration 47 ± 72 weeks) who underwent de novo ablation including CFAE ablation. In all patients, PVI was performed prior to CFAE ablation. The use and timing of AADs were registered. The follow-ups consisted of Holter ECGs and clinical visits. Termination of AF was achieved in 132 patients (66 %). Intraprocedural AADs were administered in 168/200 patients (84 %) 45 ± 27 min after completion of PVI. Amiodarone was used in the majority of the patients (160/168). The timing of AAD administration was predicted by the atrial fibrillation cycle length (AFCL). At follow-up, 88 patients (46 %) were free from atrial arrhythmia. Multivariate logistic regression analysis revealed that administration of AAD early after PVI, LA size, duration of AF history, sex and AFCL were predictors of AF termination. The administration of AAD and its timing were not predictive of outcome, and age was the sole independent predictor of AF recurrence. The administration of AAD during ablation was common in this large cohort of persistent AF patients. The choice to administer AAD therapy and the timing of the administration during ablation were influenced by AFCL, and these factors did not significantly influence the moderate single procedure success rate in this retrospective analysis.     

Intracardiac Echocardiography Improves Procedural Efficiency During Cryoballoon Ablation for Atrial Fibrillation: A Pilot Study

Intracardiac Echocardiography Guided Cryoballoon Ablation. Background: Cryoballoon ablation is increasingly used for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). This new technique aims to perform PVI safer and faster. However, procedure and fluoroscopy times were similar to conventional RF approaches. We compared ICE plus fluoroscopy versus fluoroscopy alone for anatomical guidance of PVI. Methods: Forty‐three consecutive patients with paroxysmal AF were randomly assigned to ICE plus fluoroscopy (n = 22) versus fluoroscopy alone (n = 21) for guidance of cryoballoon PVI. A “single big balloon” procedure using a 28 mm cryoballoon was performed. The optimal ICE‐guided position of the cryoballoon was assessed by full ostial occlusion and loss of Doppler coded reflow to the left atrium (LA). Any further freezes were ICE‐guided only without use of fluoroscopy or contrast media injection. Results: A total of 171 pulmonary veins could be visualized with ICE. 80% of ICE‐guided freezes were performed with excellent ICE quality. Acute procedural success and AF recurrence rate at 6 months were similar in both groups (AF recurrence: ICE‐guided = 27% vs Fluoroscopy = 33%; P = ns). Patients without ICE guidance had significantly longer procedure (143 ± 27 minutes vs 130 ± 19 minutes; P = 0.05) and fluoroscopy times (42 ± 13 minutes vs 26 ± 10, P = 0.01). The total amount of contrast used during the procedure was significantly lower in patients with ICE guidance (88 ± 31 mL vs 169 ± 38 mL, P < 0.001). Conclusion: Additional ICE guidance appears to be associated with lower fluoroscopy, contrast, and procedure times, with similar efficacy rates. Specifically, ICE allows for better identification of the PV LA junction and more precise anatomically guided cryoballoon ablations. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1202‐1207, November 2010)     

老年心血管病患者房颤反复发作的预测

目的　为明确老年心血管疾病患者窦性心律时发生阵发性房颤的危险因素并寻找反复心房颤动发作的预测因子。方法　测量 71例有阵发性房颤发作史的老年心血管疾病患者 (PAF组 )及 73例无阵发性房颤发作史的老年心血管疾病患者 (对照组 )窦性心律时的 12导联ECG ,分别测定最大P波时限 (Pmax)及最小P波时限 (Pmin)并计算其P波离散度 (Pd) ,心脏超声测量左房内径 (LAD)和左室射血分数 (LVEF) ,随访PAF组房颤反复发作情况。结果　PAF组的Pd及Pmax分别为 ( 4 7.0 7± 12 .3 5 )ms和 ( 12 1.2 5± 13 .2 4)ms,较对照组明显延长 (P <0 .0 1) ;PAF组反复房颤发作者 ,Pd≥40ms时相对危险度 3 .3 3 ,Pmax≥ 110ms时相对危险度 2 .48。结论　窦性心律时Pd、Pmax增加是预测老年心血管病患者是否发生房颤及房颤反复发作的有效且无创的临床方法     

Incidence of silent cerebral thromboembolic lesions after atrial fibrillation ablation may change according to technology used: comparison of irrigated radiofrequency, multipolar nonirrigated catheter and cryoballoon

AF Ablation Technologies and Silent Cerebral Ischemic Lesions. Introduction: Silent cerebral ischemic lesions have recently emerged as the most frequent complications after pulmonary vein isolation (PVI). To reduce thromboembolic complications, new types of catheters and energy source have been introduced in clinical practice. The study purpose is to compare the incidence of new silent cerebral ischemic events in patients with paroxysmal atrial fibrillation (PAF) undergoing PVI with different ablation technologies. Methods and Results: One hundred and eight patients (67% men; age 56 ± 9 years) with PAF were enrolled in a consecutive manner to undergo PVI performed with irrigated radiofrequency (RF) catheter (Group 1, 36 patients), multielectrode catheter (PVAC) associated with duty‐cycled RF generator (Group 2, 36 patients) and cryoballoon (Group 3, 36 patients). The protocol included a cerebral magnetic resonance imaging before and after the procedure. After PVI, the following patients showed new silent cerebral ischemic lesions at postprocedural cerebral MRI: 3 patients in Group 1 (8.3%), 14 patients in Group 2 (38.9%), 2 patients in Group 3 (5.6%). PVAC related to higher incidence of silent cerebral ischemic events compared to irrigated RF (P = 0.002) and cryoballoon (P = 0.001), whereas no statistical differences were found between irrigated RF catheter and cryoballoon groups (8.3% vs 5.6%, P = 0.5). At the multivariate analysis, the only independent predictor of new ischemic asymptomatic cerebral lesions after PVI was ablation performed with PVAC (OR 1.48 95% CI 1.19–1.62, P < 0.001). Conclusion: The incidence of silent cerebral lesions after PVI is different depending on technologies used: PVAC increases the risk of 1.48 times compared to irrigated RF and cryoballoon ablation. (J Cardiovasc Electrophysiol, Vol. 22, pp. 961‐968, September 2011)     

High‐Density Mapping of the Sinus Node in Humans: Role of Preferential Pathways and the Effect of Remodeling

Sinus Node Mapping . Introduction: The area of the functional sinus node complex exceeds that of the anatomical sinus node; however, reasons for this discrepancy are unknown. We aimed to characterize the functional sinus node complex in health and disease with high‐density simultaneous mapping. Methods and Results: Sinus node activity was characterized in 15 reference patients after ablation for supraventricular tachycardia. A further 16 patients were studied following ablation of chronic atrial flutter to determine effects of atrial remodeling. High‐density simultaneous mapping of the sinus node complex was performed using a multi‐electrode array. In reference patients, distance from superior vena cava‐right atrial (SVC‐RA) junction to earliest activation (EA) was 4 ± 4 mm and sinus break‐out (SBO) 9 ± 6 mm. Preferential pathways of conduction were observed between EA and SBO. For patients with flutter, these distances were greater (EA: 15 ± 12 mm, P = 0.003; SBO: 23 ± 11 mm, P < 0.001). Conduction time along preferential pathways was 15 ± 5 ms for reference patients and 23 ± 8 ms for patients with flutter (P = 0.005). Following pacing, distance from SVC–RA junction to EA and SBO lengthened to 13 ± 8 mm (P = 0.006) and 16 ± 10 mm (P = 0.02), respectively, in reference patients, and 19 ± 12 mm (P = 0.045), 28 ± 9 mm (P = 0.02) in patients with flutter. This resulted in caudal shifts in EA and SBO of 10 ± 9 mm and 7 ± 8 mm in reference patients but diminished shifts in patients with flutter; 4 ± 7 mm and 4 ± 6 mm. Conclusion: The functional sinus node complex demonstrates dynamic changes in activation. There are preferential pathways of conduction from sinus node to atrial myocardium. The remodeled atria demonstrate longer conduction times along preferential pathways and a restricted functional sinus node complex. (J Cardiovasc Electrophysiol, Vol. 21, pp. 532‐539, May 2010)     

Atrial Fibrillatory Wall Motion and Degree of Atrial Remodeling in Patients with Atrial Fibrillation: A Tissue Velocity Imaging Study

Introduction: The atrial fibrillation cycle length (AFCL) and the intracardiac atrial electrogram morphology may be used to characterize atrial fibrillation (AF). However, assessment of these parameters requires an invasive electrophysiological study. We assessed clinical and electrophysiological correlates of noninvasive tissue velocity imaging (TVI) of the right and left atrial myocardial fibrillatory wall motion. Methods and Results: We performed an electrophysiological study in 12 patients with AF referred for His bundle ablation. Using atrial electrograms, we determined the AFCL (AFCL‐egm) and electrophysiological AF type. Simultaneously, transthoracic echocardiography was performed. We used the TVI traces to determine the cycle length of the atrial fibrillatory wall motion (AFCL‐tvi) and atrial fibrillatory wall velocities (AFV‐tvi). AFCL‐tvi matched very well with AFCL‐egm (r²= 0.98; P < 0.001), both in the left and right atrium. Patients with permanent AF had shorter AFCL‐tvi (155 ± 15 ms vs 216 ± 23 ms; P < 0.001), higher AFCL‐tvi variability, and lower AFV‐tvi compared to patients with paroxysmal AF. Three electrophysiological AF types were found based on the morphology of the electrograms and these related to specific TVI patterns. Conclusion: TVI of the atrial fibrillatory wall motion may enhance noninvasive characterization of atrial remodeling in patients with atrial fibrillation.     

Incidence and Significance of Early Recurrences Associated with Different Ablation Strategies for AF: A STAR‐AF Substudy

Early Recurrence in STAR‐AF. Background: Early recurrences of atrial tachyarrhythmias (ERAT) are common after atrial fibrillation (AF) ablation, and predict late recurrences (LR). We sought to determine the impact of different ablation strategies on ERAT and LR. Methods and Results: The STAR‐AF trial randomized 100  patients with paroxysmal or persistent AF to ablation of complex fractionated electrograms (CFAE) alone, pulmonary vein isolation (PVI) alone, or combined PVI + CFAE. Patients were followed for 12  months. ERAT was defined as any recurrence of AF, atrial tachycardia, or flutter (AT/AFL) >30 seconds during the first 3  months of follow‐up. LR was defined as any recurrence of AF/AT/AFL >30 seconds 3–12  months post. Forty‐nine patients experienced ERAT. The index ablation strategy was the only independent predictor of ERAT on multivariate analysis (HR 2.24 PVI vs PVI + CFAE; and HR 2.65 CFAE vs PVI + CFAE). Fifty‐two patients experienced LR. The presence of ERAT (HR 3.23), the use of antiarrhythmic drug (AAD) in the first 3  months postablation (HR 2.85), and the index ablation strategy were independently associated with LR (HR 3.42 PVI vs PVI + CFAE; HR 4.72 CFAE vs PVI + CFAE). Thirty‐five of 49 (71%) patients with ERAT and 17 (33%) of 51  patients without ERAT had LR (P  < 0.0001). Among patients with ERAT, increased left atrium size (HR 1.08), the use of AAD in the first 3  months postablation (HR 2.86) and the index ablation strategy were independently associated with LR (HR 4.77 PVI vs PVI + CFAE; HR 4.45 CFAE vs PVI + CFAE). Conclusion: ERAT is common following AF ablation and is strongly associated with LR. Although CFAE ablation alone results in higher rates of early and LR, the addition of CFAE to PVI results in increased long‐term success without an increase in ERAT. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1295‐1301, December 2012)     

原发性高血压并发阵发性心房颤动的预测参数探讨

探讨原发性高血压 (EH)患者并发阵发性心房颤动 (PAF)的临床相关无创预测参数。 78例EH患者按有无PAF分为二组 ,对比分析一般临床特征、2 4h动态血压 (ABPM)、标准 12导联心电图 (ECG)、多普勒超声等临床数据 ,多元逐步回归探讨PAF的预测参数。结果 :与无PAF组比较 ,PAF组ABPM显示 2 4h、白昼、夜间收缩压均值偏高(16 0 .1± 8.1vs 14 7.6± 8.6mmHg ,16 9.9± 7.2vs 15 9.8± 7.8mmHg ,14 9.8± 11.1vs 130 .7± 10 .1mmHg ,P均 <0 .0 1) ;ECG最宽P波 (Pmax)、P波离散度 (Pd)偏大 (12 2 .7± 11.7vs 10 8.5± 7.6ms,4 6 .6± 5 .4vs 31.5± 6 .7ms ,P均<0 .0 1) ;多普勒超声提示左房直径 (LA)较大 (48.5± 5 .7vs 37.7± 3.2mm ,P <0 .0 1) ,左室肥厚 (LVH)比例增加 (12 /2 7vs 16 /5 1,P <0 .0 1) ,舒张期二尖瓣流量A波最大速度较小 (36 .4± 6 .7vs 6 1.2± 5 .2cm/s,P <0 .0 1)。多变量回归分析显示夜间收缩压均值、Pd、LVH、LA、A波最大速度均是预测PAF的独立参数。结论 :EH患者夜间收缩压均值、Pd、LVH、LA、A波最大速度是预测PAF的独立参数     

起源于肺静脉的阵发性心房颤动发作初始的电生理特征

目的探讨起源于肺静脉的阵发性心房颤动(简称房颤)在发作初始时的电生理特征。方法记录因阵发性房颤行电生理检查和射频消融术的患者在房颤自发初始时的心内心电图,电生理检查证实起源于肺静脉,分析①房颤发作前10个心动周期的特点及计算平均周长(CL);②诱发房颤或短阵心房激动的房性早搏(简称房早)的配对间期(CI);③早搏指数(PI):即CI/CL。结果共42例患者,由房早诱发房颤85阵(Ⅰ组),诱发短阵心房激动23阵(Ⅱ组)。两组间比较,前者的CI和PI均明显短于后者,分别为(210±62msvs291±65ms,0.36±0.12vs0.48±0.12,P均<0.001)。房颤的诱发方式可分为2类:类型1(ⅠA组)为房颤发作前的10个心动周期相对恒定;类型2(ⅠB组)为房颤发作前的10个心动周期不恒定,表现为长短序列形式。85阵房颤中,ⅠA组有47阵(55%),ⅠB组有38阵(45%)。ⅠA组的CI与ⅠB组的CI无明显差异;ⅠA组的PI较ⅠB组的PI明显缩短(0.33±0.11vs0.39±0.12,P=0.02)。结论起源于肺静脉的阵发性房颤的诱发方式存在周期相对恒定与长短序列两种形式;诱发房颤的房早发生较早。     

Comparison of pulsed-field ablation versus very high power short duration-ablation for pulmonary vein isolation

Background

The newly introduced nonthermal pulsed field ablation (PFA) is a promising technology to achieve fast pulmonary vein isolation (PVI) with high acute success rates and good safety features. However, previous studies have shown that very high power short duration ablation (VHPSD) is also highly effective and fast to achieve PVI with potentially less arrhythmia recurrence compared to conventional radiofrequency ablation. Data comparing PFA to VHPSD-PVI is lacking.

Objective

This study compared procedural and outcome data for PFA-PVI to VHPSD-PVI in patients with paroxysmal or persistent atrial fibrillation (PAF/persAF).

Methods

Consecutive patients undergoing de novo PVI (PFA or VHPSD) were included in this analysis. For PFA-PVI a pentaspline 20 electrode catheter was used. For VHPSD-PVI an enhanced irrigated catheter with a power setting of 70 W/7 s (70 W/5 s at posterior wall) was employed in conjunction with electro-anatomical mapping. All procedures were performed in deep analgo-sedation.

Results

A total of n = 114 patients (n = 57[50%] PFA, n = 17[30%] PAF; n = 40[70%] persAF) were included in this analysis. PVI was successful in all patients. The PFA group revealed a significantly shorter procedure duration (65 ± 17 min vs. 95 ± 23 min, p < 0.01) but longer fluoroscopy time (PFA 15 ± 5 min and VHPSD 12 ± 3 min; p < 0.001). At follow-up after median 125 days (interquartile range: 109–162) n = 46 PFA (80.7%) and n = 44 VHPSD pts (77.2%) were free from atrial arrhythmia after a single procedure (p = 0.819). Two tamponades occurred in the PFA while in VHPSD two pts suffered groin bleedings. One clinically nonsignificant PV stenosis occurred in the VHPSD group.

Conclusion

Pulsed-field ablation and VHPSD-PVI seem to be highly effective and safe to achieve PVI in the setting of PAF and persAF with comparable arrhythmia-free survival. However, procedure duration for PFA PVI is significantly shorter and therefore may be of potential benefit. Compared to PFA VHPSD-PVI might ensure information on left atrial substrate allowing to target concomitant secondary tachycardias.     

阵发性心房颤动肺静脉隔离后诱发房性心律失常的电生理特征分析和长期随访

目的分析阵发性心房颤动(房颤)患者肺静脉隔离术后诱发房性心律失常的电生理学特征和长期随访结果。方法连续纳入2010年2月至2010年10月在北京安贞医院心内科行单纯双侧肺静脉电隔离术并行诱发试验的阵发性房颤患者198例。消融后用冠状窦远端快速起搏(周长以250 ms起始直至心房不应期或180 ms)及静点异丙肾上腺素2~4μg/min,诱发房性心律失常持续大于1 min为诱发阳性。诱发出的心动过速以CARTO引导下的激动标测和拖带标测判定机制并进行针对性消融。所有患者术后随访36个月。结果阵发性房颤患者中有39例(19.7%)诱发出共49种房性心动过速(房速),包括35种规则房速和14种房颤。诱发组左心房内径显著大于未诱发组[(39.5±6.6)mm比(36.7±5.2)mm,P=0.004],而年龄、性别、房颤病史、服用抗心律失常药种类、胺碘酮服用史、结构性心脏病比例和左心室射血分数等差异均无统计学意义。诱发出的规则房速中以大折返最为多见,占28例(80.0%)。按诱发心动过速的起源或消融关键部位发生率依次为二尖瓣环峡部(MI)20种(40.8%),三尖瓣环峡部(CTI)12种(24.5%),肺静脉(PV)6种(12.2%,其中右肺静脉2种、左肺静脉4种)、左心房间隔面4种(8.2%)、上腔静脉3种(6.1%)、左心房顶部1种(2.0%)和其他3种(6.1%)通常用线性消融可终止。随访36个月,诱发组和未诱发组成功率差异无统计学意义(63.9%比60.7%,P=0.592)。结论阵发性房颤肺静脉隔离术后以异丙肾上腺素静点+心房快速起搏诱发的心律失常以MI和CTI依赖最为多见,可被针对性线性消融有效终止,且并不增加远期复发率。     

Dofetilide reduces the frequency of ventricular arrhythmias and implantable cardioverter defibrillator therapies

Dofetilide Reduces VT/VF and ICD Therapies . Background: Patients with an implanted cardioverter defibrillator (ICD) and ventricular arrhythmias leading to ICD therapies have poor clinical outcomes and quality of life. Antiarrhythmic agents and catheter ablation are needed to control these arrhythmias. Dofetilide has only been approved for the treatment of atrial fibrillation. The role of dofetilide in the control of ventricular arrhythmias in patients with an ICD has not been established. Objective: Evaluate the safety and efficacy of dofetilide in a consecutive group of patients with an ICD and recurrent ventricular tachycardia (VT) and/ or ventricular fibrillation (VF) after other antiarrhythmic drugs have failed to suppress these arrhythmias. Methods: We studied 30 patients (age 59 ± 11; 5 women) with symptomatic VT or VF and ICDs for secondary prevention of sudden cardiac death. These patients had an average of 1.8 ± 4.5 episodes of VT/VF per month despite antiarrhymic therapy. Twenty‐one patients (70%) had recurrent appropriate ICD therapies prior to initiation of dofetilide, and 9 (30%) VTs below the programmed detection rate of the ICD. Twenty‐three patients (77%) had coronary artery disease. Mean ejection fraction was 30 ± 14% and 26/30 (87%) had congestive heart failure. All patients had previously failed 2 ± 1 antiarrhythmic drugs including amiodarone (n = 19) and sotalol (n = 10). Results: During the first month of treatment, 25 patients (83%) had complete suppression of VT/VF and of the 21 patients with ICD therapies 16 (76%) had no therapies during the first month of treatment. During a follow‐up period of 32 ± 32 months, dofetilide reduced the monthly episodes of VT/VF from 1.8 ± 4.5 to 1.0 ± 3.5 (P = 0.006). Monthly ICD therapies decreased from 0.9 ± 1.4 to 0.4 ± 1.7 (P = 0.037). In 9 patients that presented with slow VTs under the ICD detection zone, dofetilide reduced monthly VT/VF episodes from 0.7 ± 0.6 to 0.1 ± 0.1 (P = 0.01) and 6 (67%) had no further ICD therapies. Dofetilide was discontinued in 13 patients (43%) after 24 ± 30 months due to failure to control VT/VF (n = 7), placement of a left ventricular assist device (n = 3), catheter ablation (n = 1), heart transplantation (n = 1), and left ventricular restoration surgery (n = 1). There were 7 documented deaths (2 patients died suddenly; 3 patients of progressive heart failure; and 2 of non‐cardiac causes). Conclusions: In patients with an ICD and ventricular arrhythmias, dofetilide decreases the frequency of VT/VF and ICD therapies even when other antiarrhythmic agents, including amiodarone, have previously been ineffective. Recurrences still occur in some patients requiring catheter ablation, mechanical support, or heart transplantation. (J Cardiovasc Electrophysiol, Vol. 23 p. 296‐301, March 2012.)     

The Effect of Exercise to P Wave Dispersion and Its Evaluation as a Predictor of Atrial Fibrillation

Aim: Prolongation of P wave time and increase of its dispersion as an independent predictor of atrial fibrillation. In patients with paroxysmal atrial fibrillation (PAF) as in healthy people, exercise augments sympathetic activity and therefore can cause the development of atrial fibrillation. The aim of this study is to evaluate the effect of exercise on P wave dispersion and to predict the development of atrial fibrillation. Methods: One hundred and ninety‐eight patients (93 women, 105 men, mean age: 59.05 ± 11.01 years ) having the diagnosis of PAF were included in the study. The left atrial diameter of all these patients was more than 4.0 cm. One hundred and fifty‐five patients (72 females, 83 males, mean age: 58.41 ± 10.79 years ), with left atrial diameter more than 4.0 cm and without PAF were taken as control group. Symptom limited exercise test with modified Bruce protocol was performed on all patients. Rest, maximum exercise and recovery, and first, third, and fifth‐minute 12‐derivation ECG was taken in all patients. The velocity of ECG was adjusted to 50 mm/s; shortest and largest P wave durations were measured and P wave dispersion was calculated. Results: The mean left atrial diameter was 4.41 ± 0.58 cm in PAF patients and 4.38 ± 0.48 cm in control group. No differences were found between PAF patients with the controls in exercise time (10.38 ± 2.93 vs 10.81 ± 2.75 minutes ); METs (6.98 ± 1.72 vs 7.28 ± 1.75 minutes ); resting heart rate (79.13 ± 14.86 vs 79.69 ± 10.43 bpm ); peak heart rate (146.83 ± 23.21 vs 146.94 ± 16.13 bpm ). Maximum exercise P wave duration and P wave dispersion were greater than the rest measurements in PAF group (respectively P < 0.0001 and P = 0.0004 ). Conclusion: In PAF patients, P wave dispersion is significantly longer at rest, maximum exercise and recovery time than in a control group without PAF.     

Atrial electrical and structural changes associated with longstanding hypertension in humans: implications for the substrate for atrial fibrillation

Atrial Remodeling in Human Hypertension Introduction: Hypertension (HT) is the most common modifiable risk factor for atrial fibrillation (AF), yet little is known of the atrial effects of chronic HT in humans. We aimed to characterize the electrophysiologic (EP) and electroanatomic (EA) remodeling of the right atrium (RA) in patients with chronically treated systemic HT and left ventricular hypertrophy (LVH) without a history of AF. Methods and Results: Twenty patients with (systolic BP 145 ± 10 mmHg) and without (BP 119 ± 11 mmHg, P < 0.01) systemic HT underwent detailed conventional EP and EA voltage and activation mapping. We measured RA refractoriness at the coronary sinus and high septum at cycle lengths (CLs) 600 and 450 ms, and RA conduction velocities, activation times, and voltages at a global and regional level at CLs 600 ms and 300 ms. HT was associated with slowing of global (73 ± 17 cm/s vs 96 ± 12 cm/s in controls, P < 0.01) and regional conduction velocity particularly in the posterior RA (70 ± 17 cm/s vs 96 ± 12 cm/s in controls, P < 0.01) at the crista terminalis (fractionation and double potentials in HT 72%± 4 vs 43%± 23 in controls, P = 0.04). Mean RA voltage was similar between the 2 groups, however HT was associated with an increase in areas of low voltage (<0.5 mV; HT 13% vs controls 9%, P = 0.04). Sustained AF was induced in 30% HT patients and no controls. Conclusion: Chronically treated systemic HT with LVH is accompanied by atrial remodeling characterized by: (i) global conduction slowing, (ii) regional conduction delay particularly at the crista terminalis, and (iii) increased AF inducibility. These changes may in part be responsible for the increased propensity to AF associated with systemic HT. (J Cardiovasc Electrophysiol, Vol. 22, pp. 1317‐1324, December 2011)