Low-energy internal cardioversion in patients with long-lasting atrial fibrillation refractory to external electrical cardioversion: results and long-term follow-up.

AIM: Low-energy internal cardioversion is a new electrical treatment for patients with persistent atrial fibrillation. This paper evaluates the efficacy and safety of low-energy internal cardioversion in patients with long-lasting atrial fibrillation refractory to external electrical cardioversion, and the clinical outcome of such patients. METHOD AND RESULTS: The study population consisted of 55 patients [32 male, mean age 65 +/- 10 years, 48 (87%) with underlying heart disease] with long-lasting (mean 18 +/- 34 months) atrial fibrillation in whom external cardioversion had failed to restore sinus rhythm. Two custom-made catheters were used: one positioned in the right atrium and one in the coronary sinus or the left pulmonary artery. A standard catheter was inserted into the right ventricular apex to provide R wave synchronization. Sinus rhythm was restored in 52 patients (95%) with a mean defibrillating energy of 6.9 +/- 2.6 J (320 +/- 60 V). No complications were observed. During follow-up (mean 18 +/- 9 months), 16 patients (31%) suffered early recurrence (< or = 1 week) of atrial fibrillation and 20 patients (38%) had late recurrence (> 1 week, mean 3.5 +/- 3.6 months) of atrial fibrillation. Six patients with a late recurrence again underwent cardioversion and five of these maintained sinus rhythm. Therefore, a total of 21/52 patients (40%) were in sinus rhythm at the end of follow-up. No clinical difference was found between patients with and without recurrences. CONCLUSIONS: Low-energy internal cardioversion is a useful means of restoring sinus rhythm in patients with long-lasting atrial fibrillation refractory to external electrical cardioversion. More than one-third of patients maintained sinus rhythm during long-term follow-up.     

A comparison of treatment of atrial fibrillation with low-energy intracardiac cardioversion and conventional external cardioversion

AIM: Low-energy (1 to 15 J), catheter-based intracardiac cardioversionwas compared with transthoracic external cardioversion (360J) in a prospective, cross-over clinical trial. METHODS AND RESULTS: In 187 consecutive patients with chronic atrial fibrillation,over a period of a mean of 10·0±7·3 (SD)months, 217 cardioversion attempts were made. Intracardiac shockswere randomly applied between two 6-F catheters located in eitherthe right atrium and coronary sinus or between the right atriumand left pulmonary artery. When a cardioversion attempt withone method failed, the other method was implemented. After cardioversion,all patients were treated orally with sotalol with a mean dailydose of 174±54 mg. Internal cardioversion was more effective than external cardioversion(65/70=93% vs 92/177 =79%, P<0·01). The mean energyfor successful cardioversion was 5·8±3·2J for the internal and 313±71 J for the external cardioversiongroup. At a mean follow-up of 12·5±6·4months, 48% (38%) of the patients treated with internal (external)cardioversion were in sinus rhythm (P<0·05). In 22 of 25 patients in whom external cardioversion failed,sinus rhythm was restored with internal cardioversion at a meanenergy of 6·5±3·0 J. Overweight patientshad twice the risk of unsuccessful external cardioversion. CONCLUSION: Internal cardioversion is effective in restoring sinus rhythm.It might be indicated in patients in whom external cardioversionhad failed or in whom external cardioversion is assumed to bedifficult or even contraindicated.     

Successful external cardioversion of atrial fibrillation in patients referred to an electrophysiologist for internal cardioversion.

BACKGROUND: Internal cardioversion of atrial fibrillation with direct current energy has become an increasingly employed technique for patients who fail external cardioversion. HYPOTHESIS: The purpose of this study was to determine whether internal cardioversion could be avoided by careful attention to cardioversion technique in a group of patients referred specifically for internal cardioversion after failed external cardioversion by community cardiologists. METHODS: We performed external cardioversion utilizing two operators applying significant pressure to the thorax with up to 360 J prior to the planned internal cardioversion in 20 patients referred for internal cardioversion after failed attempts at external cardioversion. RESULTS: Sixteen patients (80%) were successfully cardioverted and avoided the risk, inconvenience, and cost of internal cardioversion. CONCLUSION: External cardioversion with significant anterior paddle pressure by two operators can decrease the need for internal cardioversion in a significant portion of patients referred to electrophysiologists for internal cardioversion and should be considered prior to an invasive procedure.     

Atrial pacing for suppression of early reinitiation of atrial fibrillation after successful internal cardioversion.

AIMS: To evaluate the efficacy of atrial pacing in the suppression of early reinitiation of atrial fibrillation after successful internal cardioversion. METHODS AND RESULTS: The efficacy of atrial pacing in suppressing early reinitiation of atrial fibrillation was studied in 12 of 45 (29%) patients with early reinitiation of atrial fibrillation after successful cardioversion. These patients were randomized to undergo either repeated defibrillation alone or repeated defibrillation followed by high right atrial pacing at 500 ms in a crossover fashion. In patients with persistent early reinitiation of atrial fibrillation despite atrial pacing at 500 ms and repeated defibrillation, atrial pacing at 300 ms was tested. Lastly, if early reinitiation of atrial fibrillation persisted, administration of intravenous sotalol (1.5 mg. kg(-1)) was tested. Atrial pacing at 500 ms after defibrillation prevented early reinitiation of atrial fibrillation in five of 12 (42%) patients, and was significantly more effective than repeated defibrillation (0/9 patients, 0%, P<0.05). During atrial pacing at 500 ms, the density of atrial premature depolarizations (APDs) was significantly decreased (2.4+/-2.4 APDs. min(-1)vs 16.4+/-9.8 APDs. min(-1), P<0. 05) and the coupling interval of atrial premature depolarization was significantly increased (420+/-32 ms vs 398+/-19 ms, P<0.05) as compared to no pacing. In the remaining seven (58%) patients, atrial pacing at 500 ms failed to prevent early reinitiation of atrial fibrillation, but significantly decreased the density of atrial premature depolarization (3.4+/-2.4 APDs. min(-1)vs 14.2+/-4.8 APDs. min(-1), P<0.05) and delayed the onset of early reinitiation of atrial fibrillation (33+/-17s vs 11+/-11 s, P<0.05). Atrial pacing at 300 ms decreased the coupling interval of atrial premature depolarization as compared to no pacing and during atrial pacing at 500 ms (P<0.05), but without early reinitiation of atrial fibrillation suppression. Administration of intravenous sotalol was effective in preventing early reinitiation of atrial fibrillation in five of seven (71%) patients where pacing failed to suppress early reinitiation of atrial fibrillation. CONCLUSION: The results of this study suggest that atrial pacing can be useful when combined with transvenous defibrillation in patients with early reinitiation of atrial fibrillation.     

Success of serial external electrical cardioversion of persistent atrial fibrillation in maintaining sinus rhythm; a randomized study.

AIMS: The aim of this prospective, randomized study was to determine the efficacy of a serial external electrical cardioversion strategy in maintaining sinus rhythm after 12 months in patients with recurrent persistent atrial fibrillation. METHODS AND RESULTS: Ninety patients with persistent atrial fibrillation lasting more than 72 h but less than 1 year were randomized in a one to one fashion to repetition of up to two electrical cardioversions in the event of relapse of atrial fibrillation detected within 1 month of the previous electrical cardioversion (Group AGG), or to non-treatment of atrial fibrillation relapse (Group CTL). ECGs were scheduled at 6 h, 7 days, and 1 month. Clinical examination and ECGs were repeated during the 6-month and 12-month follow-up examinations. Echocardiography was repeated during the 6-month follow-up examination. Clinical and echocardiographic characteristics were similar in the two groups. All patients were treated with antiarrhythmic drugs before electrical cardioversion and throughout follow-up. After 12 months, sinus rhythm was maintained in 53% of Group AGG patients and in 29% of Group CTL patients (P<0.03). After 6 months, left ventricular ejection fraction had recovered significantly only in Group AGG (56.8 +/- 9.0% at enrollment vs 60.4 +/- 9.4% at 6 months,P <0.001). CONCLUSION: These results demonstrate that an aggressive policy towards persistent atrial fibrillation by means of repetition of electrical cardioversion after early atrial fibrillation recurrence is useful in maintaining sinus rhythm after 12 months.     

Predictors for maintenance of sinus rhythm after cardioversion in patients with nonvalvular atrial fibrillation

Recurrence of atrial fibrillation (AF) after cardioversion (CV) to sinus rhythm (SR) is determined by various clinical and echocardiographic parameters. Transesophageal echocardiographic (TEE) parameters have been the focus of clinicians' interests for restoring and maintaining SR. This study determined the clinical, transthoracic, and TEE parameters that predict maintenance of SR in patients with nonvalvular AF after CV. We enrolled 173 patients with nonvalvular AF in the study. TEE could not be performed in 26 patients prior to CV. Twenty-five patients had spontaneously CV prior to TEE. Six patients were excluded because of left atrial (LA) thrombus assessed by TEE. CV was unsuccessful in 6 patients. The remaining 110 consecutive patients (56 men, 54 women, mean age 69 +/- 9 years), who had been successfully cardioverted to SR, were prospectively included in the study. Fifty-seven (52%) patients were still in SR 6 months after CV. Age, gender, the configuration of the fibrillation wave on the electrocardiogram, pulmonary venous diastolic flow, and the presence of diabetes, hypertension, coronary artery disease, mitral annulus calcification, and mitral valve prolapse (MVP) did not predict recurrence. Duration of AF, presence of chronic obstructive pulmonary disease (COPD), LA diameter, left ventricular ejection fraction (EF), left atrial appendage peak flow (LAAPF), LAA ejection fraction (LAAEF), pulmonary venous systolic flow (PVSF), and the presence of LA spontaneous echo contrast (LASEC) predicted recurrence of AF 6 months after CV. In multivariate analysis, LAAEF < 30% was found to be the only independent variable (P < 0.0012) predicting recurrence at 6 months after CV in patients with nonvalvular AF. LAAEF more than 30% had a sensitivity of 75% and a specificity of 88% in predicting maintenance of SR 6 months after CV in patients with nonvalvular AF. In conclusion, TEE variables often used to determine thromboembolic risk also might be used to predict the outcome of CV.     

Internal low energy atrial cardioversion: efficacy and safety in older patients with chronic persistent atrial fibrillation

BACKGROUND: Low-energy internal atrial cardioversion is a relatively new technique based on delivery of intracardiac shocks through transvenous catheters placed into the atria or the vessels. OBJECTIVE: The aim of this study was to assess in older and younger patients with chronic persistent atrial fibrillation (AF) the efficacy and safety of transvenous low-energy internal atrial cardioversion performed without routine administration of sedatives or anesthetics. DESIGN: A prospective longitudinal study. SETTING: A cardiological university hospital. PARTICIPANTS: 82 patients, divided into older (> or = 60 years) (n = 49) and younger (n = 33) subjects. MEASUREMENTS: Atrial defibrillation threshold for internal cardioversion, measured as leading edge voltage (V) and delivered energy (J) of effective shocks, percentage of patients maintaining sinus rhythm at short-term (within 3 days) and at long-term follow-up. METHODS: Patients with chronic persistent AF, treated with oral anticoagulants for at least 3 to 4 weeks, were admitted to hospital. Following a clinical work-up, patients were subjected to low-energy internal atrial cardioversion with shock delivery according to a step-up protocol. RESULTS: Internal cardioversion was effective in restoring sinus rhythm in 90% (44/49) of the older patients and in 94% (31/33) of the younger patients. Shocks were effective at a mean energy between 6 and 8 joules (range 0.9-23) and administration of sedatives or anesthetics was required during the procedure in 22% (11/49) of older and in 48% (16/33) of younger patients (P = .026 at chi-square). No major complications occurred during the procedure. Pharmacological prophylaxis of AF recurrences was instituted immediately following the procedure. During inhospital stay and during the follow-up (mean 12 +/- 9 months for older patients and 15 +/- 10 months for younger patients), AF recurred in 39% (17/44) of older patients and in 16% (5/31) of younger subjects (P = .064 at chi-square). CONCLUSIONS: Internal low energy cardioversion is a very effective procedure for restoring sinus rhythm in patients with AF; it can be performed in older patients, and administration of sedatives or anesthetics can be avoided or minimized in a substantial proportion of subjects. Recurrences of AF in the long term tend to be higher in older subjects and intensive prophylaxis with antiarrhythmic drugs is required.     

Prediction of maintenance of sinus rhythm after electrical cardioversion of atrial fibrillation by non-deterministic modelling.

AIMS: Atrial fibrillation (AF) is the most common rhythm disorder. Because of the high recurrence rate of AF after cardioversion and because of potential side effects of electrical cardioversion, it is clinically important to predict persistence of sinus rhythm after electrical cardioversion before it is attempted. The aim of our study was the development of a mathematical model by "genetic" programming (GP), a non-deterministic modelling technique, which would predict maintenance of sinus rhythm after electrical cardioversion of persistent AF. PATIENTS AND METHODS: Ninety-seven patients with persistent AF lasting more than 48h, undergoing the first attempt at transthoracic cardioversion were included in this prospective study. Persistence of AF before the cardioversion attempt, amiodarone treatment, left atrial dimension, mean, standard deviation and approximate entropy of ECG R-R intervals were collected. The data of 53 patients were randomly selected from the database and used for GP modelling; the other 44 data sets were used for model testing. RESULTS: In 23 patients sinus rhythm persisted at 3 months. In the other 21 patients sinus rhythm was not achieved or its duration was less than 3 months. The model developed by GP failed to predict maintenance of sinus rhythm at 3 months in one patient and in six patients falsely predicted maintenance of sinus rhythm. Positive and negative likelihood ratios of the model for testing data were 4.32 and 0.05, respectively. Using this model 15 of 21 (71.4%) cardioversions not resulting in sinus rhythm at 3 months would have been avoided, whereas 22 of 23 (95.6%) cardioversions resulting in sinus rhythm at 3 months would have been administered. CONCLUSION: This model developed by GP, including clinical data, ECG data from the time-domain and nonlinear dynamics can predict maintenance of sinus rhythm. Further research is needed to explore its utility in the present or an expanded form.     

Amiodarone in restoration and maintenance of sinus rhythm in patients with chronic atrial fibrillation after unsuccessful direct-current cardioversion

Background: When direct-current (DC) cardioversion is used, sinus rhythm can be restored, at least temporarily, in 80–90% of patients with atrial fibrillation. However, there is a small but significant group of patients with chronic atrial fibrillation in whom DC cardioversion has failed to restore sinus rhythm. The value of antiarrhythmic drug pretreatment before DC cardioversion is still controversial. Hypothesis: The aim of our study was to assess (1) the effecti veness of repeat DC cardioversion in patients with chronic atrial fibrillation after pretreatment with amiodarone, and (2) the efficacy of amiodarone in maintaining sinus rhythm after repeat cardioversion. Methods: Forty-nine patients with chronic atrial fibrillation after ineffective DC cardioversion were included in the study. Repeat DC cardioversion was performed after loading with oral amiodarone, 10–15 mg/kg body weight/day for a period necessary to achieve the cumulative dose of over 6.0 g. Results: Spontaneous conversion to sinus rhythm during amiodarone pretreatment was achieved in 9 of 49 patients (18%). Direct-current cardioversion was performed in 39 patients and sinus rhythm was achieved in 23 of these patients (59%). Mean heart rate decreased from 95 beats/min before to 68 beats/min after DC cardioversion (p<0.001). Systolic blood pressure significantly (p<0.05) decreased from 126 ± 23 to 108 ± 25 mmHg. Complications occurring in four patients just after electroconversion were well tolerated and of short duration. After 12 months, 52% of patients maintained sinus rhythm on low dose (200 mg/day) amiodarone therapy. Conclusion: Pretreatment with amiodarone and repeat DC cardioversion allows for restoration of sinus rhythm in about 65% of patients with chronic atrial fibrillation after first ineffective DC cardioversion. Direct-current cardioversion can be performed safely with the use of standard precautions in patients who are receiving amiodarone. At 12 months' follow-up, more than 50% of patients maintain sinus rhythm on low-dose amiodarone after successful repeat cardioversion.     

心房颤动电转复后左心耳顿抑的预测因子

目的研究非瓣膜病心房颤动(房颤)患者中,心脏电转复后左心耳顿抑的危险因素与预测因子.方法 68例房颤电转复成功患者,分为左心耳顿抑组与对照组,通过单因素及多元逐步逻辑回归分析,将临床和超声影像学指标作为待选变量,对电转复后左心耳顿抑的危险因素进行研究.结果单因素分析发现,左心耳顿抑组与对照组间差异有统计学意义的指标有房颤持续时间[(10.6±15.6)周vs(22.0±20.1)周,P＜0.05]、左心房内径[(43.8±7.7)mm vs(48.5±6.2)mm,P＜0.01)]、左心房排空分数[(0.32±0.08)vs(0.27±0.09),P＜0.05]、左心室射血分数[(0.50±0.06)vs(0.46±0.06),P＜0.01]、最大复律能量[(96.8±65.8)J vs(156.8±100.8)J,P＜0.01]、累积转复能量[(146.8±142.6)J vs(290.5±242.1)J,P＜0.01]和电转复次数[(1.7±0.9)次vs(2.4±1.2)次,P＜0.05].多元逐步逻辑回归分析发现,房颤持续时间(β＝0.105,P＜0.01)、左心房内径(β＝0.196,P＜0.01)、左心室射血分数(β＝-20.549,P＜0.01)、转复累积能量(β＝0.004,P＜0.05)是左心耳顿抑的独立危险因素.结论房颤持续时间、左心房内径、左心室射血分数和累积复律能量是房颤电转复后左心耳顿抑的独立预测因子.     

Propafenone versus disopyramide for maintenance of sinus rhythm after electrical cardioversion of chronic atrial fibrillation: A randomized,double-blind study

Summary Safety and efficacy of propafenone and disopyramide for long-term maintenance of sinus rhythm after electrical cardioversion was studied in 56 patients with chronic altrial fibrillation (median arrhythmia duration, 5 months). After cardioversion, patients were randomly assigned to receive double-blind propafenone 300 mg tid (25 patients) or disopyramide 250 mg tid (31 patients). Downward dose adjustment was allowed in case of intolerable side effects. The endpoints were arrhythmia recurrence; and side effects not amenable to dose reduction. For patients randomized to propafenone (mean dose, 878±65 mg/day), 66% [95% confidence interval [(CI) 46–85%] and 55% (95% CI, 34–76%) remained in sinus rhythm at 3 and 6 months, respectively (Kaplan-Meier method). Similar figures were found with disopyramide (mean dose, 704±81 mg/day): 71% (95% CI, 54–87%) and 67% (95% CI, 50–84%) at 3 and 6 months, respectively (p=NS). In the patients with a relapse of atrial fibrillation, the ventricular rate while still using the prophylactic agents did not increase significantly compared with precardioversion. However, one patient on disopyramide had an excessively high relapse heart rate (170 vs. 100 beats/min). Side effects were more frequent on disopyramide. Side effects necessitating drug discontinuation occurred in 12 patients: 4 patients (16%) on propafenone and 8 (26%) on disopyramide. Severe adverse effects occurred in two patients, who developed heart failure while on disopyramide. There were no proarrhythmic events or deaths. Thus, propafenone and disopyramide are equally effective for maintaining sinus rhythm after cardioversion of atrial fibrillation. Propafenone is, however, better tolerated than disopyramide, which may cause heart failure.     

Transoesophageal low-energy cardioversion of atrial fibrillation. Results with the oesophageal-right atrial lead configuration.

BACKGROUND: Low energy internal cardioversion is a safe and effective procedure to restore sinus rhythm in patients with atrial fibrillation refractory to external cardioversion. However the procedure is invasive and fluoroscopy is mandatory.Aim of the study To assess the efficacy, safety and tolerability of a new simplified procedure of low energy internal cardioversion. METHODS: Twenty-five consecutive patients (19 males and 6 females) with persistent atrial fibrillation were submitted to low energy internal cardioversion using a step-up protocol (in steps of 50 V, starting from 300 V). A large surface area lead (cathode) was positioned in the oesophagus, 45 cm from the nasal orifice. A second large surface area lead (anode) was positioned in the right atrium. A quadripolar lead was positioned at the right ventricular apex to achieve ventricular synchronization and back-up pacing. Oesophageal endoscopy was performed within 24 h of the end of the procedure and repeated after 48 h, if injury to the oesophageal mucosa had occurred. RESULTS: Sinus rhythm was restored in 23 patients (92%) with a mean delivered energy of 15.74 J (range 5-27) and a mean impedance of 48 Omega. In two patients, endoscopy revealed that small burns had occurred in the oesophageal mucosa. Such lesions spontaneously healed after 48 h. CONCLUSIONS: This new technique of performing low energy internal cardioversion is effective and safe and avoids the positioning of a lead in the coronary sinus or in the left pulmonary artery, thereby simplifying the procedure.     

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     

Long-short sequence may predict immediate recurrence of atrial fibrillation after external cardioversion.

AIM: We thought, that analysis of surface electrocardiograms recorded immediately after electrical external cardioversion (EC) might enlighten the mechanisms responsible for immediate recurrence of atrial fibrillation (AF) and especially to test whether atrial ectopic beats (PAC) with long-short (LS) sequence are related to the recurrence of arrhythmia after cardioversion in patients with chronic AF. METHODS AND RESULTS: One hundred and thirty-seven patients (mean age 57+/-7 years) undergoing EC for chronic AF entered the study. Evaluation of the patients included clinical history, physical examination, ECG, routine laboratory tests, and transthoracic echocardiography. The cardioversion was performed with monophasic waveform shock and immediately after successful EC, 1 min of recording of the ECG lead II was analysed. One hundred and twenty patients (87%) of 137 patients enrolled in the study had had successful EC and 33 (27%) of them experienced immediate recurrence of AF within 1 min (Group I) and 87 patients had no arrhythmia recurrence (Group II). In group I in 24 patients (73%) recurrence of AF was initiated by PAC with LS sequence. In only 12 of 87 (13%) patients who did not experience immediate recurrence of AF (Group II) PACs were recorded. CONCLUSIONS: Atrial ectopic beats (PACs) with LS sequence, being responsible for AF relapse in about 70% of patients, might predict early re-initiation of arrhythmia after EC. Electrocardiograms, recorded immediately after EC, are a potentially feasible approach in establishing the patterns of AF relapse that may be useful in the management of AF recurrence.     

心房颤动电复律的相关因素

目的分析影响心房颤动电复律成功的因素。方法根据房颤患者62例电复律是否成功,分为复律成功组和失败组。比较两组在性别、年龄、并发冠心病、高血压病和瓣膜性心脏病、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。CRP检测:所有患者于入院后/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）。结果与转复成功组比较,转复失败组年龄大（P<0.05）,左心房内径大（P<0.05）,并发瓣膜性病变比例高（P<0.05）,房颤持续时间长（P<0.05）,hs-CRP水平高（P<0.05）。经多因素分析,hs-CRP水平OR为2.1（95%CI1.4-3.2,P<0.01）、左房直径OR为1.8（95%CI1.2-2.2,P<0.01）和房颤持续时间OR为2.8（95%CI1.6-4.0,P<0.01）。结论hs-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。     

氯沙坦联合胺碘酮对阵发性心房颤动复律及复律后窦性心律维持的影响

目的 了解氯沙坦联合胺碘酮对阵发性心房颤动的复律效果及复律后窦性心律维持的影响.方法 2003年1月至2005年10月将解放军421医院心内科86例非瓣膜病阵发性心房颤动患者分为胺碘酮治疗组和氯沙坦 胺碘酮治疗组,观察治疗24 h,3 d和7 d时心房颤动的转复情况.在心房颤动复律后,继续药物治疗并随访观察1年,评价两组窦性心律的维持效果.结果 胺碘酮组44例心房颤动患者治疗24 h,3 d和7 d心房颤动的转复率分别为65.90%,75.00%和86.36%,氯沙坦 胺碘酮治疗组的转复率为66.66%,80.95%和95.23%.两组在7 d时心房颤动的转复率差异有显著性意义(P＜0.05).随访1年时两组窦性心律的维持率分别为71.05%和87.50%(P＜0.05),两组左房内径分别为(37.45±1.44)mm和(35.83±1.38)mm(P＜0.05).结论 氯沙坦联合胺碘酮对阵发性心房颤动的复律及复律后窦性心律维持均优于单用胺碘酮治疗,可能与氯沙坦抑制肾素-血管紧张素系统,降低心脏负荷,抑制心房电及结构重构有关.     

Maintenance of sinus rhythm after electrical cardioversion for recurrent atrial fibrillation following mitral valve surgery with or without associated radiofrequency ablation

Background

This study reports the outcomes of patients who underwent electrical cardioversion for atrial fibrillation recurrence following mitral valve surgery and associated radiofrequency ablation compared to those who did not undergo concomitant atrial fibrillation ablation.

Methods

The population consisted of 116 patients with persistent/long-standing persistent AF who underwent mitral valve surgery with (Group A, n = 54) or without (Group B, n = 62) associated radiofrequency ablation between January 2007 and January 2011 at three institutions and who subsequently underwent cardioversion for persistent atrial fibrillation within 12 months of their initial procedure.

Results

The mean follow-up duration was 30.7 ± 9.4 months. Of the 104 patients with acute restoration of SR 42 (40.3%) had AF recurrence. The average time to recurrence after cardioversion was 7.3 ± 4.2 days. Recurrence was significantly lower in patients undergoing ablation surgery (21.4%) than in those undergoing no ablation surgery (78.6%, p < 0.001). Non-performed ablation procedure (p < 0.001), time from surgery ≥ 88 days and left atrial dimensions ≥ 45.5 mm before cardioversion (both, p = 0.005) were multivariable predictors of atrial fibrillation recurrence. In Group B the use of amiodarone was inversely correlated with recurrence of AF (p < 0.001). This correlation was not significant (r = − 0.02, p = 0.85) in Group A.

Conclusions

Electrical cardioversion for recurrent AF showed better results and stable recovery of sinus rhythm in patients undergoing concomitant surgical ablation during mitral valve surgery. This might be attributable to substrate modification caused by surgical lesions. Amiodarone improved the ECV-success rate only in patients with no associate ablation. Further larger randomized studies are necessary to confirm our findings.     

Segmental atrial contraction in patients restored to sinus rhythm after cardioversion for chronic atrial fibrillation: a colour Doppler tissue imaging study.

AIMS: There is little known about segmental atrial function in patients with atrial arrhythmias. We evaluated segmental atrial contractility using colour Doppler tissue imaging (CDTI) in patients with chronic atrial fibrillation (CAF) who were successfully restored and maintained in sinus rhythm (SR). METHODS AND RESULTS: We compared the segmental atrial contractility in 39 CAF patients who were successfully cardioverted and maintained in SR for 6 months. Follow up echocardiograms were performed at baseline, 1 week, 1 month and 6 months and compared to a normal age matched cohort (n = 34). Using CDTI, mean peak velocities of atrial contraction were measured from annular, mid and superior segments of lateral and septal walls of the left atrium and right atrium in the apical four-chamber view. Segmental velocities from the posterior and anterior walls of the left atrium were measured from the apical two-chamber view. Segmental left atrial velocities improved over time in the CAF group, with the majority of the recovery occurring in the first month, but failed to normalise even at 6 months. In comparison, the right atrial velocities in the AF group had normalised at 1 month. CONCLUSION: Patients with CAF have persistent segmental left atrial dysfunction even 6 months after restoration and maintenance of SR, though right atrial velocities appear to normalise. This differential recovery indicates that left atrial function remains subnormal in patients with CAF despite maintenance of SR, suggesting underlying atrial myopathy or fibrosis as a consequence of CAF.     

External cardioversion of atrial fibrillation: comparison of biphasic vs monophasic waveform shocks.

AIMS: It is well established in transthoracic ventricular defibrillation that biphasic truncated waveform shocks are associated with superior defibrillation efficacy when compared with damped sine wave monophasic waveform shocks. The aim of this study was to explore whether biphasic waveform shocks were superior to monophasic waveform shocks for external cardioversion of atrial fibrillation (AF). METHODS AND RESULTS: Fifty-seven patients in whom cardioversion of AF was indicated were randomized in this prospective study, to transthoracic cardioversion with either monophasic damped sine waveform shocks or biphasic impedance compensating waveform shocks. In the group randomized to monophasic waveform shocks (27 patients), a first shock of 150 J was delivered, followed (if necessary) by a 360 J shock. In the biphasic waveform group (30 patients), the first shock had an energy of 150 J and (if necessary) a second 150 J was delivered. All shocks were delivered in the anterolateral chest pad position. Sinus rhythm was restored in 16 patients (51%) with the first monophasic shock and in 27 patients (86%) with the first biphasic shock. The difference was statistically significant (P=0.02). After the second shock, sinus rhythm was obtained in a total of 24 patients (88%) with monophasic shocks and in 28 patients (93%) with biphasic shocks. No complication was observed in either group and cardiac enzymes (CK, CKmb, troponin I, myoglobin) did not show any significant changes. CONCLUSION: This study suggests that at the same energy level of 150 J, biphasic impedance compensating waveform shocks are superior to monophasic damped sine waveform shocks cardioversion of atrial fibrillation.     

胺碘酮用于心房颤动心律转复后维持窦性心律的远期疗效观察

评价胺碘酮对８１例慢性心房颤动患者转复后长期维持窦性心律的有效性和安全性。胺碘酮负荷量６００ｍｇ／ｄ１～２周、４００ｍｇ／ｄ１～２周，继以维持量２１５±５０ｍｇ／ｄ，服药１～２周后行电转复。９例（９／７６，１１．８４％）在胺碘酮负荷量期间转为窦性心律，７２例电转复为窦性心律，平均随访１４．５个月（０．５～９２个月）．胺碘酮维持窦性心律半年有效率７１．６％（５８／８１），１年有效率６３．０％（５１／８１），副反应发生率１１．１％（９／８１）．未见严重毒副反应，逻辑回归分析显示心功能分级为维持窦性心律的负性因素，胺碘酮为慢性心房颤动转复后维持窦性心律的有效药物，用量以较小为宜。