Efficacy of a new balloon catheter for internal cardioversion of chronic atrial fibrillation without anaesthesia

Objective—To compare a new internal cardioversion system incorporated into a balloon guided catheter with a conventional two electrode system in patients with atrial fibrillation (AF).
Design—Prospective study.
Patients—74 patients with chronic AF treated by internal cardioversion.
Materials—A 7.5 F balloon catheter with high energy electrode arrays each consisting of six 0.5 cm platinum rings. Brachial vein access enables one electrode array to be placed in the left pulmonary artery (distal pole) and the other at the lateral right atrial wall (proximal pole). The conventional two electrode system consists of 6 F electrodes placed in the proximal left pulmonary artery (anode) and the lower right atrium.
Interventions—Internal cardioversion was performed by shocks delivered in 40 V incremental steps from an external defibrillator. Shocks were applied by the new device to 32 patients (group A) and by the conventional sysytem to 42 patients (group B).
Results—The groups differed with respect to system positioning (9.2 (7.3) v 12.3 (8.1) minutes, p < 0.05) and fluoroscopy times (1.7 (1.0) v 3.3 (2.1) minutes, p < 0.01). Sinus rhythm was restored in 30 patients of group A and in 39 of group B (NS) with mean (SD) energy requirements of 8.4 (3.1) J and 7.2 (3.1) J, respectively (NS).
Conclusions—This new method of internal cardioversion has comparably high primary success rates and low sedation requirements with single and two lead systems.

Keywords: atrial fibrillation;  catheter;  defibrillation;  internal cardioversion     

慢性心房颤动伴左室功能不全患者2种消融策略的对比

目的:探讨慢性心房颤动伴左室功能不全患者最佳导管消融策略.方法:回顾分析47例接受导管消融术的慢性心房颤动伴左室功能小全患者的相关资料,根据消融策略分为环肺静脉电隔离加左房碎裂电位消融组(A组,33例)及单纯环肺静脉电隔离组(B组,14例),对比2组消融的I临床效果及安全性.结果:A、B组消融成功率分别为72.7%及42.9%(P＜0.05),A组发生心脏压塞1例,经心包穿刺引流后获愈.结论:慢性心房颤动伴左室功能不全者采取环肺静脉电隔离加左房碎裂电位消融成功率显著高于采取单纯环肺静脉电隔离策略,可获得较理想的临床效果.     

Safety and efficacy of internal cardioversion of atrial fibrillation in patients with impaired left ventricular systolic function

In patients with structural heart disease and left ventricular ejection fraction <40%, internal cardioversion is a safe and effective method for converting persistent atrial fibrillation. The acute success rate and atrial defibrillation requirement for cardioversion in these patients is comparable to patients with lone atrial fibrillation and structurally normal hearts.     

Effects of left ventricular systolic dysfunction on left atrial appendage and left atrial functions in patients with chronic nonvalvular atrial fibrillation

OBJECTIVE: It has been claimed that left ventricular (LV) systolic dysfunction impairs left atrial (LA) and left atrial appendage (LAA) functions. In this study, we compared the LA and LAA function parameters in patients with chronic nonvalvular atrial fibrillation (AF) with and without LV systolic dysfunction. METHODS AND RESULTS: The study population consisted of 28 patients with chronic nonvalvularAF. Group I consisted of 12 patients with LV systolic dysfunction (mean age: 61 +/- 14 years; LV ejection fraction: 44 +/- 6%), group II of 16 patients with normal LV systolic function (mean age: 52 +/- 15 years; LV ejection fraction: 65 +/- 3%). LV ejection fraction (EF) was measured by echocardiography utilizing bi-plane area length method.The following LA and LAA transoesophageal echocardiography parameters were obtained: I) LA diameter, 2) LAA ejection velocity, 3) LAA filling velocity, 4) LAA ejection fraction, 5) pulmonary venous (PV) systolic velocity, 6) PV diastolic velocity, 7) PV systolic velocity/diastolic velocity ratio.The left atrium diameter was significantly larger in group I than in group 11 (4.7 +/- 0.7 cm vs. 3.8 +/- 0.6 cm, p < 0.05).The LAA ejection velocity and LAA ejection fraction were significantly lower in group I than in group 11 (22.6 +/- 15.5 cm/s vs 37.5 +/- 11.3 cm/s and 26.9 +/- 20.8% vs. 41.3 +/- 10.9%, p < 0.05 for both comparisons).The PV systolic velocity and PV systolic velocity/diastolic velocity ratio were significantly smaller in group I than in group II (26.2 +/- 14.8 cm/s vs. 51.5 +/- 22 cm/s and 0.7 +/- 0.6 vs. 1.2 +/- 0.5, p < 0.05 for both comparisons).Although decreased LAA filling and PV diastolic velocities were determined in group I, no significant difference existed between groups I and II.Thrombus and/or spontaneous echo contrast (SEC) in the LA and/or LAA were more frequent in group I (75% vs. 18%, p < 0.05). CONCLUSION: These results indicate that LV systolic dysfunction impairs various LA and LA function parameters and is associated with an increased frequency of SEC and/or LA thrombus in patients with chronic nonvalvularAF.     

伊布利特转复老年新发持续性心房颤动合并左心室功能不全患者的临床观察

目的探讨伊布利特转复老年(65岁)新发持续性心房颤动(PAF)合并左心室功能不全(LVD)患者的疗效和安全性。方法选取2014年1月至2017年8月在我院心内科住院的100例老年新发PAF合并LVD患者,按照随机数字表法分为两组:伊布利特组(n=50)采用伊布利特静脉注射转复,首次剂量1 mg,稀释后缓慢注射;胺碘酮组(n=50)采用胺碘酮静脉注射转复,首次剂量150 mg,稀释后缓慢注射。比较两组患者用药后30 min内、60 min内、4 h内、24 h内的转复率,检测用药前及用药后48 h左心室功能指标(LVEDD、LVESD、LVEF及NTproBNP),并记录两组患者转复用药过程中(24 h内)的不良反应。结果伊布利特组患者用药后30 min内、60 min内、4 h内、24 h内PAF转复率均高于胺碘酮组(P0.01或P0.05),伊布利特组患者PAF的平均转复时间短于胺碘酮组(t=-3.232,P=0.002),伊布利特QTc平均恢复时间短于胺碘酮(t=-17.743,P=0.000)。治疗48 h后,两组患者的LVEDD、LVESD、LVEF及NT-proBNP均较治疗前明显改善(P0.01或P0.05),而伊布利特组改善更显著(P0.01或P0.05)。伊布利特组患者短期不良反应发生率低于胺碘酮组(χ~2=4.762,P=0.029),伊布利特组不良反应持续时间短于胺碘酮组(t=-11.622,P=0.000)。结论与胺碘酮相比,伊布利特用于转复老年新发PAF合并LVD起效快,转复率高,左心室功能改善显著,安全性好。     

Long-term outcome in patients with chronic atrial fibrillation after successful internal cardioversion

Internal cardioversion is safe and effective in restoring sinus rhythm, even in patients with persistent AF of prolonged duration. Up to 40% to 50% of patients with AF lasting >1 year but <3 years could be maintained in sinus rhythm using a class III antiarrhythmic drug after successful internal cardioversion, and amiodarone appears to be more effective than sotalol in this patient population.     

导管消融治疗持续性心房颤动伴左室功能不全的初步随访

目的评价导管消融治疗持续性心房颤动伴左室功能不全的疗效。方法回顾分析连续10例接受导管消融的持续性心房颤动伴左室功能不全患者,短期随访观察术前、术后心功能的改变。结果9例患者成功完成导管消融术,术前平均左室射血分数(LVEF)0·41±0·01,左室舒张末期内径(LVEDD)56·00±7·21mm,左心房内径(LAD)44·22±5·91mm。术后平均随访2·78±1·78个月,平均LVEF增为0·46±0·06,LVEDD降为53·33±6·42mm,LAD降为42·11±4·65mm,与术前相比差异有统计学意义(P<0·05)。结论在慎重选择病例的基础上,导管消融术治疗持续性心房颤动伴左室功能不全安全、有效。     

导管消融治疗持续性心房颤动伴左室功能不全的临床评价

目的评价导管消融治疗持续性心房颤动（房颤）伴左室功能不全的安全性以及临床疗效。方法心力衰竭（心衰）组为30例持续性房颤伴症状性左室功能不全（左室射血分数≤0.45）患者,对照组为年龄、性别、左房大小和房颤持续时间相匹配的60例无心衰的持续性房颤患者,均接受环肺静脉电隔离联合心房碎裂电位消融治疗房颤。比较两组导管消融手术相关参数及严重并发症发生率。对心衰组术前、术后的左房大小、左室功能及内径进行比较。结果两组病例均完成导管消融术,肺静脉隔离率分别为96.67%及98.33%（P=1.00）。两组间消融时间、X线透视时间和严重并发症发生率差异无统计学意义（202.23±39.03 min比201.87±36.80 min,P=0.97;26.80±7.77 min比27.06±7.16 min,P=0.88;3.3%比3.4%,P=1.00）。随访11±1个月,73%的心衰组患者和78%对照组患者维持窦性心律（P=0.61）,两组中分别有40%和42%患者接受再次消融。与术前相比,术后9个月心衰组患者的左室射血分数增加了7.87%±4.72%,左房内径缩小3.77±4.02 mm,左室舒张末期内径减小6.87±5.32 mm,左室收缩末期内径减小8.93±7.60 mm（P均〈0.05）;维持窦性心律者心功能改善程度高于未能维持窦性心律者。结论包括器质性心脏病者在内,对于持续性房颤合并左室功能不全的患者,环肺静脉电隔离联合心房碎裂电位消融的并发症发生率及消融成功率与无左室功能不全的患者相似。房颤合并左室功能不全的患者经导管消融治疗后,左房、室扩大程度减轻,左室射血分数可得到显著提高。     

Impact of acute left ventricular apical thrombus on cardioversion for atrial fibrillation

Among patients undergoing cardioversion for atrial fibrillation, the presence of left ventricular thrombus is a relatively uncommon and challenging clinical dilemma. While left atrial appendage thrombus is a contraindication to cardioversion, there is paucity of data regarding the safety of cardioversion in with the presence of left ventricular apical thrombus. Also, thrombus characteristics such as protrusion and mobility on echocardiography are known risk factors for systemic embolism. In this article, we present a case highlighting the management of atrial fibrillation in the setting of left ventricular dysfunction, acute heart failure, and echocardiographic evidence of acute left ventricular apical thrombus.     

Waveform optimization for internal cardioversion of atrial fibrillation

Introduction

A novel atrial defibrillator was developed at the Royal Victoria Hospital in collaboration with the Nanotechnology and Integrated Bio-Engineering Centre, University of Ulster. This device is powered by an external pulse of radiofrequency energy and designed to cardiovert using low-tilt monophasic waveform (LTMW) and low-tilt biphasic waveform (LTBW), 12 milliseconds pulse width. This study compared the safety and efficacy of LTMW with LTBW for transvenous cardioversion of atrial fibrillation (AF).

Methods

Patients were anticoagulated with warfarin to maintain International Normalized Ratio between 2 and 3 for 4 weeks prior cardioversion. Warfarin international normalized ratio level was maintained in between 2 and 3 for 4 weeks prior cardioversion. St Jude's defibrillating catheter was positioned in the distal coronary sinus and right atrium and connected to the defibrillator via a junction box. After a test shock using a dummy load, the patient was cardioverted in a step-up progression from 50 to 300 V. Shock success was defined as return of sinus rhythm for 30 seconds or more. If cardioversion was unsuccessful at peak voltage, the patient was crossed over to the other arm of the waveform type and cardioverted at peak voltage.

Results

Thirty patients were randomized equally to LTBW and LTMW (15 each). Seven out of 15 patients (46%) cardioverted to sinus rhythm with LTBW, and 1 (6%) of 15, with LTMW (P = .035). Including crossover patients, 14 patients (46%) converted to sinus rhythm. After crossover, 4 patients were cardioverted with LTBW and 2 with LTMW. Overall mean voltage, current, and energy used for cardioversion were 270.53 ± 35.96 V, 3.68 ± 0.80 A, and 9.12 ± 3.73 J, respectively, and intracardiac impedance was 70.82 ± 13.46 Ω. For patients who were successfully cardioverted, mean voltage, current, energy, and intracardiac impedance were 268.28 ± 42.41 V, 3.52 ± 0.63 A, 8.51 ± 3.16 J, and 73.92 ± 12.01 Ω. There were no major adverse complications during the study. Cardiac markers measured postcardioversion were unremarkable.

Conclusion

Low-tilt biphasic waveform was more efficacious for low-energy transvenous cardioversion of AF. A significant proportion of patients were successfully cardioverted to sinus rhythm with low energy. Radiofrequency-powered defibrillation can be safely used for transvenous cardioversion of AF.     

阵发性房颤患者血栓前状态与左室舒张功能不全的关联

目的：探讨阵发性房颤患者血栓前状态与左室舒张功能障碍之间的关系.方法：在198例新发的尚无临床相关心血管疾病的阵发性房颤患者中,测定血浆纤维蛋白原、D-二聚体水平,并常规进行超声心动图和组织多普勒成像（TDI）检查.结果：常规超声心动图和TDI共检测到105例有左心室舒张功能障碍.单因素分析显示,与舒张功能正常者比较,左室舒张功能障碍者年龄偏大[（56±9）岁比（59±12）岁],BMI更高[（27.4±4.6）kg/m2比（29.0±4.9） kg/m2],糖尿病（10.8％比26.7％）、吸烟（20.4％比24.8％）比例较高,血浆纤维蛋白原[（2.95±0.41） mg/dl比（4.29±0.62） mg/dl]和D-二聚体水平[（0.38±0.06） ng/ml比（0.65±0.10） ng/ml]也较高,均有显著差异（P＜0.05～＜0.01）;多元回归分析显示,超声心动图检测出的舒张功能不全独立于其他协变量,而与血浆纤维蛋白原、D-二聚体水平相关（r=0.365～0.421,P均＜0.001）.结论：血浆纤维蛋白原水平升高及血栓前状态与无临床相关心血管原发病的阵发性房颤患者的左心室舒张功能障碍相关,并可增加舒张性心力衰竭的风险.     

Impact of catheter ablation for atrial fibrillation in patients with heart failure and left ventricular systolic dysfunction

Introduction and AimsCatheter ablation has been shown to improve left ventricular (LV) ejection fraction (LVEF) in patients with atrial fibrillation (AF) and heart failure (HF). Our aim was to assess the impact of AF ablation on the outcome of patients with HF and LV systolic dysfunction.MethodsWe performed a retrospective observational cohort study of all patients with HF and LVEF <50% and with no apparent cause for systolic dysfunction other than AF who underwent catheter ablation in a tertiary referral center between July 2016 and November 2018. The primary endpoint was a ≥5% improvement in LVEF. Secondary endpoints included improvement in New York Heart Association (NYHA) class and reduction in LV end-diastolic diameter (LVEDD) and left atrial diameter (LAD).ResultsOf 153 patients who underwent AF ablation in this period, 22 (77% male, median age 61 [IQR 54-64] years) fulfilled the inclusion criteria. Median follow-up was 11.1 months (IQR 6.1-19.0). After ablation, median LVEF increased from 40% (IQR 33-41) to 58% (IQR 55-62) (p<0.01), mean NYHA class improved from 2.35±0.49 to 1.3±0.47 (p<0.001), and median LAD and LVEDD decreased from 48.0 (IQR 43.5-51.5) mm to 44 (IQR 40-49) mm (p<0.01) and from 61.0 (IQR 54.0-64.8) mm to 55.0 (52.2-58.0) mm (p<0.01), respectively.ConclusionIn patients with HF and LV systolic dysfunction, AF ablation is associated not only with improved functional status but also with favorable structural remodeling, including improvement in LVEF and decreases in LAD and LVEDD.     

Transient manifestation of left ventricular diastolic dysfunction following ablation in patients with paroxysmal atrial fibrillation

Background

In patients with atrial fibrillation, ablation decreases left atrial (LA) compliance, which may lead to left ventricular (LV) diastolic dysfunction. We aimed to examine serial changes in LV diastolic function after 2 ablation procedures and their related factors in patients with paroxysmal atrial fibrillation (PAF).

Hypothesis

LV diastolic function is different after 2 ablation procedures.

Methods

We enrolled 132 patients with PAF (76 males, mean age 67 years; cryoballoon [CB] ablation/radiofrequency [RF] ablation 60/72) who underwent a single ablation procedure. The transthoracic echocardiographic parameters were obtained before, 3 days after, and 6 months after ablation.

Results

The afterload‐related index of LV diastolic function, Ed/Ea = E/e' / (0.9 × systolic blood pressure), increased significantly at 3 days after ablation, especially after CB ablation (P <0.05), although no differences were observed in age, sex, LA size, LV size, and E/e' before ablation between CB ablation and RF ablation. Creatine kinase release after ablation was significantly higher in CB ablation than in RF ablation (P <0.001). The increment of Ed/Ea after CB ablation was positively correlated with LV ejection fraction (LVEF) before ablation (r =0.416; P <0.05). The elderly (age ≥ 75 years), females, and patients with hypertension were more likely to show impaired LV diastolic function transiently after 3 days of ablation, but the diastolic index was restored to baseline level after 6 months.

Conclusions

The increased Ed/Ea after CB ablation represented transient manifestation of underlying LV diastolic dysfunction in PAF patients with preserved LVEF with older age, female sex, and a history of hypertension.     

Meta-analysis of the effectiveness and safety of catheter ablation of atrial fibrillation in patients with versus without left ventricular systolic dysfunction

Catheter ablation is a promising therapy for atrial fibrillation (AF), but its utility in patients with left ventricular systolic dysfunction (LVSD) is uncertain. The objectives of this study were to perform a systematic review and meta-analysis of randomized and observational studies comparing the rates of recurrent AF, atrial tachycardia (AT), and complications after AF catheter ablation in those with versus without LVSD and to summarize the impact of catheter ablation on the left ventricular ejection fraction. Seven observational studies and 1 randomized trial were included (total n = 1,851). Follow-up ranged from 6 to 27 months. In those with LVSD, 28% to 55% were free of AF or AT on follow-up after 1 AF catheter ablation, increasing to 64% to 96% after a mean of 1.4 procedures. The relative risk for recurrent AF or AT in those with versus without LVSD was 1.5 (95% confidence interval 1.2 to 1.8, p <0.001) after 1 procedure and 1.2 (95% confidence interval 0.9 to 1.5, p = 0.2) after multiple procedures. No difference in complications was observed in patients with (3.5%) versus without (2.5%) heart failure (p = 0.55). After catheter ablation, those with LVSD experienced a pooled absolute improvement in the left ventricular ejection fraction of 0.11 (95% confidence interval 0.07 to 0.14, p <0.001). In conclusion, patients with and without LVSD had similar risk for recurrent AF or AT after catheter ablation, but repeat procedures were required more often in those with LVSD. Significant improvements in left ventricular ejection fractions after ablation were observed in those with LVSD. Randomized trials are needed given the limitations of present data.