Left atrial radiofrequency ablation during cardiac surgery in patients with atrial fibrillation

Introduction: Intraoperative left atrial radiofrequency (RF) ablation recently has been suggested as an effective surgical treatment for atrial fibrillation (AF). The aim of this study was to verify the outcome of this technique in a controlled multicenter trial. Methods and Results: One hundred three consecutive patients (39 men and 65 women; age 62 ± 11 years) affected by AF underwent cardiac surgery and RF ablation in the left atrium (RF group). The control group consisted of 27 patients (6 men and 21 women; age 64 ± 7 years) with AF who underwent cardiac surgery during the same period and refused RF ablation. Mitral valve disease was present in 89 (86%) and 25 (92%) patients, respectively (P = NS). RF endocardial ablation was performed in order to obtain isolation of both right and left pulmonary veins, a lesion connecting the previous lines, and a lesion connecting the line encircling the left veins to the mitral annulus. Upon discharge from the hospital, sinus rhythm was present in 65 patients (63%) versus 5 patients (18%) in the control group (P < 0.0001). Mean time of cardiopulmonary bypass was longer in the RF group (148 ± 50 min vs 117 ± 30 min, P = 0.013). The complication rate was similar in both groups, but RF ablation‐related complications occurred in 4 RF group patients (3.9%). After a mean follow‐up of 12.5 ± 5 months (range 4–24), 83 (81%) of 102 RF group patients were in stable sinus rhythm versus 3 (11%) of 27 in the control group (P < 0.0001). The success rate was similar among the four surgical centers. Atrial contraction was present in 66 (79.5%) of 83 patients in the RF group in sinus rhythm. Conclusion: Endocardial RF left atrial compartmentalization during cardiac surgery is effective in restoring sinus rhythm in many patients. This technique is easy to perform and reproducible. Rare RF ablation‐related complications can occur. During follow‐up, sinus rhythm persistence is good, and biatrial contraction is preserved in most patients. (J Cardiovasc Electrophysiol, Vol. 14, pp. 1289‐1295, December 2003)     

Identification of pulmonary vein potentials by differential site atrial pacing in patients with paroxysmal atrial fibrillation: enhanced detection by pulmonary vein pacing

INTRODUCTION: Pulmonary vein (PV) isolation may cure paroxysmal atrial fibrillation (PAF); however, identification of PV potentials may be difficult in sinus rhythm. Studies have suggested that atrial pacing may improve the identification of PV potentials. METHODS AND RESULTS: In 25 consecutive patients who underwent PV isolation for PAF, the results of pacing from the distal PV, distal and proximal coronary sinus, and high right atrium compared to sinus rhythm were analyzed to determine the most effective pacing site for identification of PV potentials. The percentage of confirmed PV potentials and the longest interval between atrial and PV potentials in each PV were compared during differential site pacing and sinus rhythm. PV potentials were confirmed in 63 (82%) of 77 PVs that could be mapped during the complete pacing protocol and during sinus rhythm. Distal PV pacing identified significantly more PV potentials (left upper pulmonary vein [LUPV] 100%, left lower pulmonary vein [LLPV] 84%, right upper pulmonary vein [RUPV] 80%, right lower pulmonary vein [RLPV] 53%) compared to other pacing sites and sinus rhythm. Among atrial pacing sites, those ipsilateral to the PV being mapped were the most effective for identifying PV potentials. The intervals between atrial and PV potentials were significantly longer during distal PV pacing than pacing at other sites (LUPV 81.6 +/- 26.2 ms, LLPV 61.4 +/- 26.1 ms, RUPV 59.7 +/- 33.2 ms, RLPV 39.7 +/- 26.7 ms). CONCLUSION: (1) Distal PV pacing was most effective for identifying PV potentials. (2) The interval between atrial and PV potentials was longest during distal PV pacing.     

Clinical outcome of very late recurrence of atrial fibrillation after catheter ablation of paroxysmal atrial fibrillation

INTRODUCTION: High recurrence rate is still a major problem associated with ablation of paroxysmal atrial fibrillation (AF). Most of the recurrences occur within 6 months after ablation. The characteristics of very late recurrent AF (>12 months after ablation) have not been reported. METHODS AND RESULTS: Two hundred seven patients with drug-refractory AF underwent successful focal ablation or isolation of AF foci. After the first ablation procedure, Holter monitoring and event recorders were used to evaluate symptomatic recurrent AF. A second ablation procedure was recommended if the antiarrhythmic drugs could not control recurrent AF. During long-term follow-up (mean 30 +/- 11 months, up to 51 months), 70 patients had recurrent AF, including 13 patients (6%) with very late (>12 months) recurrent AF (group 1) and 57 patients (28%) with late (within 12 months after ablation) recurrent AF (group 2). Group 1 patients had a significantly lower incidence of multiple (> or = 2) AF foci (23% vs 63%, P = 0.02) than group 2 patients. In addition, the incidence of antiarrhythmic drugs use (38% vs 84%, P = 0.001) to maintain sinus rhythm after the first episode of recurrent AF was significantly lower in group 1 than group 2 patients, and the incidence of a second intervention procedure (8% vs 35%, P = 0.051) tended to be lower in group 1 than group 2 patients. CONCLUSION: The incidence of very late recurrent AF after ablation of paroxysmal AF is very low, and the clinical outcome of patients with very late recurrent AF is benign.     

Electrophysiologic effects of selective right versus left atrial linear lesions in a canine model of chronic atrial fibrillation

INTRODUCTION: Long linear lesions have been shown to eliminate atrial fibrillation in animal models, but little is known about the electrophysiologic response in one atrium to lesions in the contralateral atrium. METHODS AND RESULTS: Twelve dogs with chronic atrial fibrillation were randomized to either right atrial ablation (n = 4), left atrial ablation first (n = 4), or a sham procedure (n = 4). Simultaneous biatrial endocardial mapping was performed before and after three linear lesions were applied at specific points in either atrium, using an expandable ablation catheter. Atrial fibrillation was reinducible after single atrial ablation in each dog and no longer inducible after biatrial ablation in five dogs. At baseline, the mean atrial fibrillation cycle length was longer on the trabeculated (117+/-15 msec) compared with the smooth right (101+/-16 msec) or left atrium (88+/-10 msec; P < 0.01). Single right and left atrial ablation caused a significant cycle length increase in the ablated atrium. Left atrial ablation increased the cycle length on both the trabeculated (121+/-18 msec vs 137+/-11 msec; P < 0.05) and smooth right atrium (108+/-12 msec vs 124+/-9 msec; P < 0.05). Right atrial ablation, however, had no significant effect on left atrial fibrillation cycle length (82+/-8 msec vs 86+/-7 msec). CONCLUSION: Left atrial linear lesions affect right atrial endocardial activation, whereas right atrial lesions do not affect left atrial activation in a canine model of atrial fibrillation. These findings suggest that the left atrium is the driver during chronic atrial fibrillation in this animal model and may explain the limited success of right atrial ablation alone in human atrial fibrillation.     

Ablation of focal atrial fibrillation

In the past decades management of atrial fibrillation (AF) has been based mainly on drug therapy. New insights into the pathophysiology of AF initiation and maintenance have provided the background for the design of catheter based procedures. The crucial role of the pulmonary veins (PVs) as triggers of AF paved the way for successful mapping and ablation. Electrical isolation of all PVs using the circular mapping approach has been shown to be an effective procedure, with reported success rates around 70 to 80% in most series. Intracardiac echocardiography is a very helpful adjunctive tool to facilitate correct positioning of the circular catheter at the PV-left atrial junction, as well as to monitor energy delivery and assist transseptal left atrial access. PV stenosis is a potential serious complication, occurring in around 2% of cases. It presents mainly with respiratory symptoms, although it is frequently asymptomatic. Spiral computed tomography is a reliable non-invasive method for imaging the PVs and can be used to screen patients for PV stenosis after radiofrequency ablation. In symptomatic patients, PV dilatation and stenting is the preferred treatment approach.The possibility of curing AF represents a major breakthrough in invasive cardiac electrophysiology. Isolation of all PVs is a very solid endpoint for successful ablation and should be pursued in all patients. It seems to be associated with high success rates over long term follow-up. Future refinements in catheter technology should provide simpler and faster procedures and render catheter ablation of AF more widespread and accepted.     

冷冻球囊消融与射频消融对阵发性心房颤动患者心房重构的影响

目的:比较冷冻球囊消融(CBA)与射频消融(RFA)对阵发性心房颤动(房颤)患者心房重构的影响.方法:本研究选取在2014年5月-2017年5月于郑州大学第一附属医院因阵发性房颤行CBA或RFA治疗的患者.所有患者均于术前、术后半年、1年、2年和3年时行12导联心电图或24 h动态心电图和超声心动图检查.左心房电重构通...     

峡部依赖性心房扑动对心房颤动发作的影响

目的观察导管射频消融治疗峡部依赖性心房扑动(房扑)对心房颤动(房颤)发作的影响,进一步探讨房扑和房颤的关系。方法86例房扑患者,其体表心电图均提示典型房扑,男性54例、女性32例,年龄50.0±15.6(11～74)岁,病程5.6±6.4(0.1～30)年。将所有患者分成A、B两组,A组为房扑合并房颤患者,共25例;B组为不合并房颤患者,共61例;其中A组同时合并房室结折返性心动过速(AVNRT)3例,房室折返性心动过速(AVRT)4例,阵发性房性心动过速(PAT)10例;B组合并房室结折返性心动过速5例,房室折返性心动过速7例。对峡部依赖性房扑者,线性消融下腔静脉—三尖瓣环峡部致双向传导阻滞;房室折返性心动过速者行旁道消融术;房室结折返性心动过速者行慢径改良术,阵发性房速术中持续或可诱发,予以射频消融。平均随访27.1±14.1(6～63)月。结果A组25例患者中,术后68%(17/25)患者不再发作房颤;其余8例仍有房颤发作,其中1例为术前同时合并房室折返性心动过速,5例为合并阵发性房速。61例术前不合并房颤者,术后随访中有16.4%(10/61)新发房颤。86例患者中,6例因病态窦房结综合征行起搏器植入术,随访未诉心悸、胸闷,心电图为窦性心律与起搏心律交替出现。结论房扑可能与房颤具有共同的发生基质,也可以是房颤的触发因素,成功消融房扑后可以阻止房颤的发生。但房颤发生机制多样,消融峡部依赖性房扑,仍会发生房颤,术前合并房颤或房速者是最强的预测因子。     

Induction of atrial fibrillation in mice by rapid transesophageal atrial pacing

Objective: Atrial fibrillation (AF) as an “indicator arrhythmia” for enhanced atrial vulnerability in mouse hearts has not yet been systematically examined. We therefore evaluated a transesophageal rapid atrial stimulation protocol for the induction of AF in C57Bl/6 mice. Methods: 40 C57Bl/6 mice (19 female and 21 male; 5.2 ± 2.1 months; 18 – 27 g) were examined by closed chest transesophageal atrial stimulation. Baseline ECG and electrophysiological parameters, AF-inducing stimulation cycle length (CL) and AF duration were analyzed. Results: The surface ECG demonstrated a significantly faster heart rate in female mice (R-R: 138.7 ± 19.9 ms versus 150.5 ± 15.7 ms, P < 0.05). AF was inducible in 90 % of the population and not inducible in 4 mice, all female (21 % in this subgroup). Mean induction CL was 27.4 ± 7.3 ms. Mean AF duration was 26.9 ± 42.6 s before spontaneous termination. In a subgroup of 4 female and 4 male mice (mean age 7.5 months), successive testing of AF induction showed a range of higher susceptibility to AF at stimulus amplitudes of 3.0 – 4.0 mA and stimulation CLs between 15 – 25 ms. AF induction was observed to be constantly reproducible in the individual animals. No correlation to pacing stimulus length and amplitude was found. Conclusions: This study demonstrates that it is possible to reproducibly induce self-terminating AF and supraventricular arrhythmias in mice by transesophageal atrial burst stimulation. The presented method allowing serial testings of the same animal can be a useful tool in further investigations with transgenic mice and might be helpful in the characterization of underlying genetic or molecular mechanisms of AF. Received: 26 April 2002, Returned for revision: 21 May 2002, Revision received: 17 June 2002, Accepted: 24 June 2002 Correspondence to: J. W. Schrickel, MD     

Pulmonary edema after extensive radiofrequency ablation for atrial fibrillation

Background: More extensive ablation strategies for the treatment of atrial fibrillation (AF) have increased success rates but are associated with new and sometimes serious complications. We describe a new complication after extensive radiofrequency (RF) ablation in the left atrium (LA) for persistent AF.
Methods and Results: Electroanatomic guided circumferential ablation around both ipsilateral pulmonary veins (PV) was performed with the endpoint of complete conduction block. When necessary, supplementary RF applications were added, including ablation of complex fractionated potentials and/or isolation of other thoracic veins and/or linear left atrial lesions. RF energy was delivered via an irrigated tip catheter with a maximum power of 30–35 W. Four out of 120 patients undergoing extensive RF ablation for persistent AF (including two patients with additional LA substrate modification) developed dyspnea, bilateral pulmonary edema, and signs of a systemic inflammatory response syndrome (SIRS) (rise in body temperature, leukocyte count, and C-reactive protein (CRP levels) 18–48 hours after the procedure. There were no signs of PV stenosis, focal lung injury, left ventricular dysfunction, circulatory failure, or infection. All patients had complete recovery with supportive therapy within 3–4 days after the onset of symptoms.
Conclusions: Extensive LA radiofrequency ablation bears the risk of a severe pulmonary edema. Although the precise mechanism is elusive, clinical features point toward a systemic inflammatory response.     

Radiofrequency and cryoballoon ablation improve cognitive function in patients with atrial fibrillation

Atrial fibrillation is considered to be the most common arrhythmia in the clinic, and it gradually increases with age. In recent years, there has been increasing evidence that atrial fibrillation may exacerbate the progression of cognitive dysfunction. The current guidelines recommend ablation for drug-refractory atrial fibrillation.We aimed to prospectively analyze changes in cognitive function in patients with atrial fibrillation following treatment using different ablation methods.A total of 139 patients, with non-valvular atrial fibrillation, were included in the study. The patients were divided into the drug therapy (n = 41) and catheter ablation (n = 98) groups, with the catheter ablation group further subdivided into radiofrequency ablation (n = 68) and cryoballoon (CY) ablation (n = 30). We evaluated cognitive function at baseline, 3- and 12-months follow-up using the Telephone Interview for Cognitive Status-modified (TICS-m) test, then analyzed differences in cognitive function between the drug therapy and catheter ablation groups, to reveal the effect of the different ablation methods.We observed a significantly higher TICS-m score (39.56 ± 3.198) in the catheter ablation group at 12-month follow-up (P < .001), than the drug treatment group was. Additionally, we found no statistically significant differences in TICS-m scores between the radiofrequency ablation and CY groups at 3- and 12-month postoperatively (P > .05), although the two subgroups showed statistically significant cognitive function (P < .001).Overall, these findings indicated that radiofrequency and CY ablation improve cognitive function in patients with atrial fibrillation.     

The effect of left atrial remodeling after cryoballoon ablation and radiofrequency ablation for paroxysmal atrial fibrillation

BackgroundCryoballoon ablation (CBA) and radiofrequency ablation (RFA) are the most common procedures used to treat refractory atrial fibrillation (AF) and are performed through pulmonary vein isolation (PVI). Studies have shown that CBA can approximately match the therapeutic effects of RFA against AF. However, few studies have investigated the difference between CBA and RFA of the effects on left atrial remodeling for paroxysmal AF.ObjectiveAtrial remodeling is considered pivotal to the occurrence and development of AF, therefore we sought to assess the influence of atrial remodeling in patients with paroxysmal AF after CBA and RFA in this study.MethodsIn this nonrandomized retrospective observational study, we enrolled 328 consecutive patients who underwent CBA or RFA for refractory paroxysmal AF in May 2014 to May 2017 in our hospital. After propensity score matching, 96 patients were included in the CBA group, and 96 were included in the RFA group. Patients were asked to undergo a 12‐lead electrocardiogram, a 24‐h Holter monitor, and an echocardiogram and to provide their clinical history and symptoms at 6 months and 1, 2, and 3 years postprocedurally. Electrical remodeling of the left atrium was assessed by P wave dispersion (Pdis); structural remodeling was assessed by the left atrium diameter (LAD) and left atrial volume index (LAVI) during scheduled visits.ResultsAs of January 2020, compared with baseline, at 1 year, 2 years, and 3 years after ablation, the average changes in Pdis (∆Pdis), LAD (∆LAD), and LAVI (∆LAVI) were significant in both the CBA and RFA groups. Six months after ablation, ∆Pdis, ∆LAD, and ∆LAVI were greater in the CBA group than in the RFA group. There was no significant difference between the two groups in AF/flutter recurrence, but the AF/flutter‐free survival time of CBA group may be longer than RFA group after 2 years after ablation. A higher ∆Pdis, ∆LAD, or ∆LAVI at 1 year after ablation may increase AF/flutter‐free survival.ConclusionsAlthough CBA and RFA are both effective in left atrial electrical and structural reverse‐remodeling in paroxysmal AF, CBA may outperform RFA for both purposes 6 months after ablation. However, during long‐term follow‐up, there was no significant intergroup difference.     

Mechanistic significance of intermittent pulmonary vein tachycardia in patients with atrial fibrillation

INTRODUCTION: The significance of intermittent tachycardia within a pulmonary vein (PV) during an episode of atrial fibrillation (AF) is unclear. The aim of this study was to determine the role that intermittent PV tachycardias play in AF. METHODS AND RESULTS: In 56 patients with AF, segmental ostial ablation guided by PV potentials was performed to isolate the PVs. The characteristics of intermittent PV tachycardias and the inducibility of AF before and after PV isolation were analyzed prospectively. During AF, a PV tachycardia (mean cycle length 130 +/- 30 msec) with exit block to the left atrium was present in 93% of left superior, 80% of left inferior, 73% of right superior, and 7% of right inferior PVs. The site of shortest cycle length during AF alternated between the PVs and left atrium 1 to 13 times per minute. Complete isolation was achieved in 168 (94%) of 178 targeted PVs. In 99% of PVs, tachycardia resolved upon isolation. AF was persistent before and after PV isolation in 100% and 27% of patients, respectively (P < 0.001). CONCLUSION: Intermittent bursts of tachycardia are observed within multiple PVs during persistent AF in a majority of patients. After PV isolation, PV tachycardias almost always resolve, and AF is less likely to be inducible or persistent. These observations suggest a dynamic interplay between the atria and PVs, with intermittent bursts of PV tachycardia being dependent on left atrial input and with the probability of persistent AF diminishing when PV tachycardias are eliminated by PV isolation.     

Acute effects of left atrial radiofrequency ablation on atrial fibrillation

INTRODUCTION: Acutely, when left atrial ablation is performed during atrial fibrillation (AF), the AF may persist and require cardioversion, or it may convert to sinus rhythm or to atrial tachycardia/flutter. The prevalence of these acute outcomes has not been described. METHODS AND RESULTS: Left atrial ablation, usually including encirclement of the pulmonary veins, was performed during AF in 144 patients with drug-refractory AF. Conversion to sinus rhythm occurred in 19 patients (13%), to left atrial tachycardia in 6 (4%), and to atrial flutter in 6 (4%). In the 6 patients with a focal atrial tachycardia, the mean cycle length was 294 +/- 45 ms. The tachycardia arose in the left atrial roof in 3 patients, the left atrial appendage in 2, and the anterior left atrium in 1. In 3 of 6 patients, the focal atrial tachycardia originated in an area that displayed a relatively short cycle length during AF. In 6 patients, AF converted to macroreentrant atrial flutter with a mean cycle length of 253 +/- 47 ms, involving the mitral isthmus in 5 patients and the septum in 1 patient. All atrial tachycardias and flutters were successfully ablated with 1 to 15 applications of radiofrequency energy. CONCLUSION: When left atrial ablation is performed during AF, the AF may convert to atrial tachycardia or flutter in approximately 10% of patients. Focal atrial tachycardias that occur during ablation of AF may be attributable to driving mechanisms that persist after AF has been eliminated, whereas atrial flutter results from incomplete ablation lines.     

Midterm results of left atrial bipolar radiofrequency ablation combined with a mitral valve procedure in persistent atrial fibrillation

Introduction

The aim of the study was to assess the midterm results of left atrial bipolar radiofrequency ablation combined with a mitral valve procedure in patients with mitral valve disease and persistent atrial fibrillation.

Methods

Between October 2006 and July 2009, 95 patients with mitral valve disease and persistent atrial fibrillation underwent a mitral valve procedure and left atrial bipolar radiofrequency ablation. The postoperative data of the combined procedure were collected at the time of discharge and at one, three, six and 12 months after the operation.

Results

Hospital mortality rate was 6.3% (six patients). Normal sinus rhythm was achieved in 77.2% of patients during the early postoperative period in hospital, and in 73.3, 72.0 and 75% of patients at three, six and 12 months postoperatively, respectively. Patients were followed up for a mean duration of 14.02 ± 5.71 months (range: 6–19 months). During this midterm follow-up period, nine patients had late recurrence of atrial fibrillation. No risk factor was identified for late recurrence of atrial fibrillation.

Conclusion

Our midterm follow-up results suggest that the addition of left atrial bipolar radiofrequency ablation to mitral valve surgery is an effective and safe procedure to restore sinus rhythm in patients with chronic atrial fibrillation.     

Effect of radiofrequency ablation of atrial flutter on the natural history of subsequent atrial arrhythmias

Introduction: Patients with atrial flutter (AFL) treated medically are at high risk for subsequent development of atrial fibrillation (AF). Whether curative radiofrequency ablation of AFL can modify the natural history of arrhythmia progression is not clear. We aimed to determine whether ablation of AFL decreases the subsequent development of AF in patients without previous AF. Methods and Results: Patients with AFL as the sole atrial arrhythmia were selected from patients who underwent successful AFL ablation at Mayo Clinic between 1997 and 2003 (N = 137). The cohort was divided by presence (n = 50) or absence (n = 87) of structural heart disease. A control group comprised 59 patients with AFL and no history of paroxysmal AF, who received only medical therapy. Occurrence of AF after AFL ablation was compared among study groups and controls. Symptomatic AF occurred in 49 patients during 5 years of follow‐up after AFL ablation, with similar frequency in both study groups. The cumulative probability of paroxysmal and chronic AF was similar in controls and each study group. By multivariate analysis, the AFL ablation procedure carries significant risk of AF occurrence during follow‐up. Fifty patients discontinued antiarrhythmic drugs after AFL ablation, and the rate of cardioversions decreased. Conclusion: Successful ablation of AFL does not improve the natural history of atrial arrhythmia progression; postablation AF is frequent. This suggests that AFL may be initiated by bursts of AF and that in the absence of AFL substrate the AF continues to progress.     

Prevention of paroxysmal atrial fibrillation in patients with sinus bradycardia: role of right atrial linear ablation and pacing site

INTRODUCTION: Right atrial linear lesions (RALL), either alone or in combination with antiarrhythmic drug therapy, may modify the substrate for maintenance of atrial fibrillation (AF). The aim of this prospective randomized study was to determine whether RALL provides additional benefit to right atrial appendage pacing (RAAP) and/or interatrial septum pacing (IASP) and drug therapy in patients with symptomatic paroxysmal AF and sinus bradycardia requiring permanent atrial pacing. METHODS AND RESULTS: Sixty-four patients (33 men and 31 women, mean age 73 +/- 10 years) completed the 6-month follow-up. Patients were randomized to either RALL (n = 33) or non-right atrial linear lesions (NRALL), and then to either IASP (n = 32) or RAAP (n = 32). Fifteen RALL patients were paced at the IAS and 18 at the RAA. Seventeen NRALL patients were paced at the IAS and 14 at the RAA. No statistical difference was observed with regard to the mean atrial tachyarrhythmia (AT) burden between NRALL (84 +/- 169 min/day) and RALL patients (202 +/- 219 min/day). Mean AT burden was significantly lower in the IASP group (70 +/- 150 min/day) than in RAAP group (219 +/- 317 min/day; P < 0.016). In the RALL group, the mean AT burden was 99 +/- 180 min/day in the IASP patients and 288 +/- 372 min/day in the RAAP patients (P < 0.046). In the NRALL group, no statistical difference in the mean AT burden was observed between IASP patients (46 +/- 117 min/day) and RAAP patients (130 +/- 211 min/day). CONCLUSION: The results of the present study indicate that RALL did not provide any additional therapeutic benefit to combined antiarrhythmic drug therapy and septal or nonseptal atrial pacing in patients with sinus bradycardia and paroxysmal AF.     

左心耳电隔离在持续性心房颤动治疗中的研究进展

肺静脉隔离是心房颤动(房颤)导管消融的基石,对于阵发性房颤有良好效果,但在持续性房颤中的效果则不尽人意.肺静脉隔离以外的辅助消融策略有助于提高持续性房颤的手术成功率.左心耳不仅是心腔内血栓的常见起源,还是导致快速性房性心律失常发生或维持的因素,因而左心耳电隔离成为持续性房颤辅助消融策略之一,研究表明其可能有助于提高持续...     

射频消融联合左心耳封堵术治疗心房纤颤17例回顾性分析

目的探讨心房颤动"一站式"手术的有效性和安全性。方法回顾性分析临床17例心房纤颤患者通过射频消融联合左心耳封堵"一站式"手术治疗后的临床资料。结果手术后出现肺部感染2例(11.76%),一过性交界性逸搏心律2例(11.76%),食管瘘1例(5.89%),术后3个月经食道超声心动图复查发现,封堵器表面血栓形成1例(5.89%),术后6个月随访无卒中、出血及死亡患者,1例患者心房颤动复发,继续抗凝治疗,其他患者均改为阿司匹林或氯吡格雷单联抗栓治疗。结论对于卒中高危且有抗凝禁忌的非瓣膜性心房颤动患者,射频消融联合左心耳封堵"一站式"手术是可行的、安全的、有效的。     

Inducibility of paroxysmal atrial fibrillation by isoproterenol and its relation to the mode of onset of atrial fibrillation

Background: Isoproterenol has been used to assess inducibility during catheter ablation for paroxysmal PAF. However, no studies have determined the sensitivity and specificity of isoproterenol for the induction of AF. It also is not clear whether isoproterenol is equally effective in inducing AF in the clinical subtypes of vagotonic, adrenergic, and random AF.
Objective: To determine the sensitivity and specificity of isoproterenol for the induction of atrial fibrillation (AF).
Methods: Isoproterenol was infused at 5, 10, 15, and 20 μg/min at 2-minute intervals or until AF was induced in 20 control subjects with no history of AF and in 80 patients with PAF.
Results: Among the 20 control subjects, AF was induced by isoproterenol in one patient (5%). Among the 80 patients with PAF, persistent AF was induced in 67 patients (84%, P < 0.001). Isoproterenol induced AF in 15 of 17 patients (88%) with vagotonic AF, 11 of 11 patients (100%) with adrenergic AF, and 41 of 52 patients (79%) with random episodes of AF (P = 0.2). The yield of AF was 11% (9/80) after 5 μg/min, 28% (22/80) after 10 μg/min, 51% (40/78) after 15 μg/min, and 88% (67/76) after 20 μg/min of isoproterenol (P < 0.01). Isoproterenol had to be discontinued in four patients (5%) before reaching the maximum dose due to reversible chest pain or systolic blood pressure <85 mmHg.
Conclusions: Isoproterenol at infusion rates up to 20 μg/min has a high sensitivity (88%) and specificity (95%) for induction of AF in patients with PAF, regardless of whether the clinical subtype is vagotonic, adrenergic, or random.