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.     

Indexed left atrial volume is superior to left atrial diameter in predicting nonvalvular atrial fibrillation recurrence after successful cardioversion: a prospective study

Background: Although indexed left atrial volume (iLAV) is the most accurate measure of left atrial size, it has not been evaluated prospectively as predictor of recurrence of atrial fibrillation (AFib) after successful cardioversion (CV). Methods: We prospectively selected 76 patients (mean age 66.1 ± 13.6 years, 65.8% men) with AFib who underwent successful CV. Baseline clinical and echocardiographic characteristics were obtained before CV. LAV was measured using Simpson's method and indexed to body surface area. All patients were scheduled for follow‐up visit at 1, 6, 12 months, and then annually. A 24‐hour Holter ECG was performed within 6 months and each time the patients reported symptoms suggestive of arrhythmia. Results: The 52 patients (68.4%) with AFib recurrence had larger iLAV (35.5 ± 8.9 mL/m² vs 27.0 ± 6.7 mL/m², P < 0.001). Anteroposterior LA diameter was not associated with AFib relapse (OR 1.08, 95% CI: 0.96–1.21, P = 0.09). Each unit increase in iLAV was associated with a 1.15‐fold increased risk of recurrence (OR 1.15, 95% CI: 1.06–1.25, P < 0.001). In a multivariable model, iLAV remained the only independent predictor of relapse (adjusted OR 1.14, 95% CI: 1.02–1.28, P = 0.02). The area under ROC curves, generated to compare LA diameter, and iLAV as predictors of AFib recurrence were 0.56 (SE 0.07) versus 0.78 (SE 0.05), respectively (P = 0.003). Conclusion: This is the first prospective study to show that larger iLAV, as a more accurate measure of LA remodeling than anteroposterior diameter, is strongly and independently associated with a higher risk of AFib recurrence after CV. (Echocardiography 2012;29:276‐284)     

The optimal technique for electrical cardioversion of atrial fibrillation

The optimal approach to electrical cardioversion of atrial fibrillation includes appropriate patient selection, anticoagulation, careful selection and monitoring of antiarrhythmic therapy, and proper electrical cardioversion technique. The optimal technique requires the use of metal electrodes, with one electrode of at least 8 cm in diameter placed in the anterior position, and the second of 12–13 cm diameter placed posteriorly just below the left scapulae, with generous amounts of the appropriate gel (such as Hewlett-Packard Redux Paste) as the electrode-skin interface and firm pressure to the paddle electrode with the patient in expiration. Thus the anterior-posterior chest diameter is decreased and less air between the electrodes is assured. The initial shock strength should be 200 J. The shock is synchronized with the electrocardiographic QRS complex. This report reviews the justification for these recommendations.     

Effect of atrial fibrillation duration on probability of immediate recurrence after transthoracic cardioversion

INTRODUCTION: An immediate recurrence of atrial fibrillation (IRAF) appears to be more common after early restoration of sinus rhythm with an implantable atrial defibrillator than after elective transthoracic cardioversion, which suggests that the probability of IRAF may be related to the duration of AF. METHODS AND RESULTS: Transthoracic cardioversion was performed 85 +/- 187 days (range 7 minutes to 8 years) after the onset of atrial fibrillation in 315 patients (mean age 61 +/- 13 years). IRAF was defined as a recurrence of AF within 60 seconds after restoration of sinus rhythm. IRAF occurred in 56% of patients when cardioversion was performed within 1 hour of the onset of AF compared with 12% of patients when cardioversion was performed after 24 hours of AF (P < 0.001). The duration of AF was the only independent predictor of IRAF among the clinical variables of age, gender, structural heart disease, antiarrhythmic drug therapy, and cardioversion energy (P < 0.01). CONCLUSION: IRAF is more likely to occur when the duration of AF is <1 hour than when the duration is >24 hours. This observation has clinical implications for the most appropriate timing of cardioversion, particularly in patients who receive device therapy for AF.     

Effect of electrical cardioversion on 1‐year outcomes in patients with early recurrence after catheter ablation for atrial fibrillation

BackgroundAtrial fibrillation (AF) recurrence is common in the 3‐month blanking‐period after catheter ablation, during which electrical cardioversion (ECV) is usually performed to restore sinus rhythm. Whether ECV can affect the clinical outcome of post‐ablation AF patients is inconsistent, however. We aimed to explore the 1‐year effect of ECV on AF recurrence and rehospitalization in patients experienced recurrence within 3‐month after AF catheter ablation.MethodsPatients who experienced recurrence within 3‐month after AF catheter ablation procedure were enrolled from the China Atrial Fibrillation Registry (China‐AF). A 1:3 Propensity score matching (PSM) method was applying to adjust the confounders between patients who had been treated by ECV or not. Logistic regression models were conducted to evaluate the association of ECV with 1‐year AF recurrence and rehospitalization.ResultsIn this study, 2961 patients experienced AF recurrence within 3‐month after the procedure, and 282 of them underwent successful ECV, 2155 patients did not undergo ECV. One‐year AF recurrence rates were 56.4% in ECV group versus 65.4% in non‐ECV group (p = .003), and were 55.9% versus 65.9%, respectively, after PSM (adjusted odds ratio [OR] 0.66; 95% confidence interval (CI): 0.49–0.88, p = .005). However, the difference of 1‐year rehospitalization rates between two groups were not statistically significant before (ECV group: 23.7% vs. non‐ECV group: 22.3%, p = .595) and after PSM (ECV group: 24.4% vs. non‐ECV group: 21.6%, adjusted OR1.14; 95% CI 0.81–1.62, p = .451).ConclusionsSuccessful ECV was associated with lower rate of one‐year recurrence in patients with early recurrent AF after catheter ablation.     

Factors predicting success rate and recurrence of atrial fibrillation after first electrical cardioversion in patients with persistent atrial fibrillation

BACKGROUND: The recurrence rate of atrial fibrillation (AF) after elective cardioversion is high. HYPOTHESIS: The study aimed to identify clinical predictors for successful electrical cardioversion and maintenance of sinus rhythm after a first electrical cardioversion in patients with persistent AF without concomitant antiarrhythmic drugs of class I and III. METHODS: Consecutive outpatients (n = 166) with persistent AF for > 1 month, scheduled for elective cardioversion, were prospectively included in the study. A clinical investigation, echocardiographic assay, and Holter electrocardiogram (ECG) before and ECG 4 weeks after cardioversion, were performed in all patients. RESULTS: The mean age of the patients was 68 years (range 45-83) and duration of AF was 5 (1-48) months. Sinus rhythm was established in 124 (75%) patients. In multivariate analysis, only duration of AF < 6 months (p < 0.04, odds ratio [OR] 2.2, 95% confidence interval [CI] 1.1 to 4.7) and patients weight (p < 0.03, OR 2.3, 95% CI 1.1 to 4.8 for weight < 80 kg) were identified as independent predictors of successful cardioversion. At 4 weeks after cardioversion, only 46 (37%) of 124 patients maintained sinus rhythm. Independent factors for maintenance of sinus rhythm, in multivariate analysis, were AF <3 months (p < 0.04, OR 2.5, 95% CI 1.1 to 5.6), treatment with beta blockers (p < 0.00001, OR 7.0, 95% CI 3.0 to 16.3) or verapamil/diltiazem (p < 0.04, OR 3.6, 95% CI 1.1 to 12.1), and right atrial dimension < 37 mm (p < 0.02, OR 5.9, 95% CI 1.4 to 25.4). CONCLUSIONS: In patients with persistent AF, the patient's weight and the duration of AF are independent predictors for a successful cardioversion. Short duration of AF, treatment with beta blockers or verapamil/diltiazem, and right atrial area/dimension are independent predictors for maintenance of sinus rhythm.     

Clinical evaluation of a policy of early repeated internal cardioversion for recurrence of atrial fibrillation

INTRODUCTION: The clinical value of cardioversion (CV) of persistent atrial fibrillation (AF) is limited by the high rate of early AF recurrence, which may be related to the persistence of atrial electrical remodeling. We examined the hypothesis that the likelihood of maintaining sinus rhythm after CV of persistent AF is significantly enhanced by a policy of early repeated CV. METHODS AND RESULTS: Fifty-nine patients with persistent AF underwent internal CV (CV 1). Those patients cardioverted were monitored with daily transtelephonic ECG. In the event of AF recurrence, these patients were admitted rapidly for repeat CV (CV 2) and, if further recurrence occurred, a third CV (CV 3) was performed. Daily ECG monitoring was continued until 1 month of sinus rhythm was maintained or a total of three CVs were performed. Of the 59 patients undergoing CV 1, 43 were discharged in sinus rhythm and 29 subsequently had AF recurrence during monitoring. Twenty-three of these underwent CV 2 and 11 of these underwent CV 3. Of those having repeated CVs, only 4 patients maintained sinus rhythm for 1 month (3 after CV 2 and 1 after CV 3). The remaining patients had repeated AF recurrence during the monitoring period. Mean time from AF recurrence to CV 2 was 20+/-13 hours and from AF recurrence to CV 3 was 13+/-7.2 hours. Atrial effective refractory periods increased from 189+/-16 msec at CV 1 to 215+/-18 msec at CV 3 (P < 0.05), indicating reversal of atrial electrical remodeling during this period. CONCLUSION: A policy of early repeated CVs for AF recurrence has very limited clinical value despite evidence of reversal of atrial electrical remodeling. The time between AF recurrence and repeat CV may need to be reduced further if such a policy is to succeed.     

Plasma levels of NT-pro-BNP in patients with atrial fibrillation before and after electrical cardioversion

Summary Objective Plasma levels of brain natriuretic peptide (BNP) have been examined in studies on patients with persistent atrial fibrillation, both before and after electrical cardioversion. Studied patients often showed a comorbidity with congestive heart failure, which complicates interpretation of measured BNP values as a natriuretic peptide. The aim of this study was to examine plasma levels of N-terminal fragment pro-brain natriuretic peptide (NT-pro-BNP), which is the more stable but inactive cleavage product of pro-BNP in patients with atrial fibrillation, but normal left ventricular ejection fraction, before and after electrical cardioversion. Patients and methods NT-pro-BNP plasma levels of 34 consecutive patients were measured before, shortly after and 11 days after electrical cardioversion. All patients showed a normal ejection fraction after echocardiographic or laevocardiographic criteria. Results At baseline, all patients showed elevated NT-pro-BNP compared to a healthy control group (1086 vs. 66.9 pg/ml, p<0.001). After a mean follow-up time of 11 days in patients with persistent restored sinusrhythm, NT-pro-BNP decreased from 1071 pg/ml at baseline to 300 pg/ml (p<0.001). In contrast, patients with recurrence of atrial fibrillation showed increased levels from 1570.5 pg/ml at baseline to 1991 pg/ml (p=0.13; n.s.). Recurrence of atrial fibrillation was independent from height of NT-pro-BNP levels at baseline (p=0.23). Conclusions Atrial fibrillation in patients with a normal left ventricular ejection fraction is associated with elevated NT-pro-BNP plasma levels, which decrease when a persistent sinus-rhythm can be restored by electrical cardioversion. On the other hand, NT-pro-BNP seems to increase (n.s.) when recurrence of atrial fibrillation occurs. Finally, NT-pro-BNP is no valid predictor for long-term success of sinus-rhythm restoration by electrical cardioversion.      

Impact of biphasic electrical cardioversion of atrial fibrillation on early recurrent atrial fibrillation and shock efficacy

INTRODUCTION: Early recurrent atrial fibrillation (ERAF) after external cardioversion of atrial fibrillation (AF) occurs in 12% to 26% of patients. Whether biphasic cardioversion has an impact on the incidence of ERAF after cardioversion of AF is unclear. METHODS AND RESULTS: Consecutive patients (n = 216, mean age 66 years, 71% male, 88% with structural cardiovascular disease or hypertension) underwent cardioversion with a biphasic (Bi) or monophasic (Mo) shock waveform in randomized fashion. Energies used were 120-150-200-200 Ws (Bi) or 200-300-360-360 Ws (Mo). The two study groups (Bi vs Mo) did not differ with regard to age, sex, body mass index, underlying cardiovascular disease, left atrial diameter, left ventricular ejection fraction, duration of AF fibrillation, and antiarrhythmic drug therapy. Mean delivered energy was significantly lower in the Bi group (Bi: 186 +/- 143 Ws vs Mo: 324 +/- 227 Ws; P < 0.001). Overall incidence of ERAF (AF relapse within 1 minute after successful cardioversion) was 8.9% and showed no difference between the two groups (Bi: 8.1% vs Mo: 9.7%, P = NS). Cardioversion was successful in 95.4% of patients. The success rate was comparable in both groups (Bi: 94.3% vs Mo 96.8%; P = NS). First shock efficacy did not differ between Bi and Mo (76.4% vs 67.7%; P = NS). Mean number of shocks were 1.4 shocks per patient in both groups. CONCLUSION: Biphasic cardioversion allows comparable success rates with significantly lower energies. However, the incidence of ERAF is not influenced by biphasic cardioversion. With the energies used, biphasic and monophasic shock waveforms are comparable with regard to first shock and cumulative shock efficacy.     

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.     

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.     

高敏C反应蛋白对心房颤动患者电复律后再发的预测

目的通过检测患者血清高敏C反应蛋白(hs-CRP)水平,探讨其对非瓣膜性心房颤动(房颤)患者电复律后再发的预测价值。方法非瓣膜性持续性房颤经电复律的患者126例,男性73例,女性53例,平均年龄(64±10)岁,在电复律前,测定hs-CRP,依据hs-CRP水平将患者分为3组,低水平组41例,hs-CRP<2.0 mg/L,中等水平组47例,hs-CRP 2.0~3.0 mg/L,高水平组38例,hs-CRP>3.0 mg/L。随访6个月,复查24 h动态心电图,观察房颤的复发情况。结果3组在年龄、房颤时间、左心房大小、心功能方面比较差异无统计学意义(P>0.05)。6个月随访时,低水平组房颤的复发率7.3%,远低于中等水平组的21.3%和高水平组的36.8%,差异有统计学意义(P<0.001),中等水平组房颤的复发率低于高水平组(P<0.05),Cox回归分析显示,hs-CRP水平与电复律后,房颤再发呈显著正相关(OR=3.22,95%CI:1.58~13.41)。结论非瓣膜性持续性房颤电复律后,hs-CRP水平与房颤的中期再发有关,hs-CRP可以作为房颤电复律后再发的独立预测因子。     

血糖水平对阵发性心房颤动患者电复律的影响

目的:探讨随机血糖水平对阵发性心房颤动(房颤)患者电复律的影响.方法:116例阵发性房颤患者(房颤发作时间＜24 h),根据入院时随机血糖水平分为3组:A组(58例,血糖＜7.8 mmol/L)、B组(35例,血糖7.8～10.9 mmol/L)及C组(23例,血糖≥11.0 mmol/L),同时查各组患者糖化血红蛋白(HbA1c),给予同步直流电复律(双向波100～200 J).结果:A组转复窦性心律的成功率最高(56例,96.6％),与C组(18例,78.5％)比较,差异有统计学意义(P＜0.01);C组不仅转复成功率最低,而且左房内径和HbA1c均明显高于A、B组(P＜0.05).结论:当阵发性房颤患者随机血糖≥11.0 mmol/L时,电转复成功率明显降低.     

电复律前后超敏C-反应蛋白浓度与远期心房颤动复发的关系

目的探讨电复律前、后高敏C反应蛋白（highsensitivityreactivepmtein,hs-CRP）浓度与远期心房颤动（房颤）复发之间的关系。方法选择确诊为持续性房颤而进行电复律治疗有效的患者102例为研究对象。复律前及复律后第1、3、7及28天检测所有患者hs-CRP浓度、12导联心电图及动态心电网,随访时间为24个月。根据房颤是否复发分为两组：窦律维持组（67例）及房颤复发组（35例）,并对两组相关资料进行比较分析。结果两组除心房内径比较差异有统计学意义（P〈0．05）外,其他基础临床资料比较,差异无统计学意义（P〉0．05）。复律前房颤复发组的hs-CRP浓度显著高于窦律维持组,差异有统计学意义[（16．1±5．4）mg／L vs（11．2±4．2）mg／L,P〈0．05]。复律后第1天两组的hs-CRP浓度下降幅度比较,差异无统计学意义（P〉0．05）。复律后第3、7、28天,窦律维持组hs-CRP浓度与复律前相比显著性下降,差异有统计学意义（P〈0．05）;房颤复发组有下降,但差异无统计学意义（P〉0．05）。Cox多元回归分析结果显示,左心房内径（OR=1．11,95％CI：1．01～1．18）、基线hs-CRP浓度（OR=1．39,95％CI：1．20～3．40）及复律后第3天的hs-CRP浓度（OR=1．13,95％CI：0．92～2．36）与房颤复发呈正相关。结论复律前、后hs-CRP浓度对远期房颤复发均具有预测价值。     

Burden and timing of premature atrial contractions after electrical cardioversion of persistent atrial fibrillation do not predict its recurrence

BACKGROUND: The heart is susceptible to recurrence of atrial fibrillation (AF) during the period immediately following conversion to sinus rhythm (SR). It is less clear whether various onset or trigger mechanisms can predict AF recurrence after direct current (DC) cardioversion of persistent AF. METHODS: In this study, 172 patients (117 men), mean age 69 +/- 11 y, and with persistent AF underwent elective electrical cardioversion. A detailed analysis was made of the heart rhythm and potential AF trigger mechanisms based on 5 min electrocardiogram (ECG) recordings after conversion. RESULTS: Of 151 patients discharged in SR, 45 (30%) had a recurrence of AF within 1 wk. Premature atrial contractions (PACs) were the most common potential trigger, occurring on an average of 3/min. They were equally frequent in patients with and without immediate and early reinitiation of AF, and in patients with and without AF recurrence at the 1-wk follow-up visit. Other trigger mechanisms were too infrequent to allow conclusions. CONCLUSION: Premature atrial contractions were the most common potential trigger mechanism occurring immediately after cardioversion in patients with persistent AF. However, they neither predicted immediate and/or early reinitiations, nor recurrences during the first wk after cardioversion.     

Reversal of electrical remodeling after cardioversion of persistent atrial fibrillation

INTRODUCTION: In animals, atrial fibrillation results in reversible atrial electrical remodeling manifested as shortening of the atrial effective refractory period, slowing of intra-atrial conduction, and prolongation of sinus node recovery time. There is limited information on changes in these parameters after cardioversion in patients with persistent atrial fibrillation. METHODS AND RESULTS: Thirty-eight patients who had been in atrial fibrillation for 1 to 12 months underwent electrophysiologic testing 10 minutes and 1 hour after cardioversion. At 1 week, 19 patients still in sinus rhythm returned for repeat testing. Reverse remodeling of the effective refractory period was not uniform across the three atrial sites tested. At the lateral right atrium, there was a highly significant increase in the effective refractory period between 10 minutes and 1 hour after cardioversion (drive cycle length 400 ms: 204 +/- 17 ms vs 211 +/- 20 ms, drive cycle length 550 ms: 213 +/- 18 ms vs 219 +/- 23 ms, P < 0.001). The effective refractory period at the coronary sinus and distal coronary sinus did not change in the first hour but had increased by 1 week. The corrected sinus node recovery time did not change in the first hour but was shorter at 1 week (606 +/- 311 ms vs 408 +/- 160 ms, P = 0.009). P wave duration also was shorter at 1 week (135 +/- 18 ms vs 129 +/- 13 ms, P = 0.04) consistent with increasing atrial conduction velocity. CONCLUSION: The atrial effective refractory period increases, sinus node function improves, and atrial conduction velocity goes up in the first week after cardioversion of long-standing atrial fibrillation in humans. Reverse electrical remodeling of the effective refractory period occurs at different rates in different regions of the atrium.     

心房颤动导管消融术后早期复发的直流电复律临床分析

目的对心房颤动(简称房颤)导管消融术后1个月内复发行直流电复律的患者的临床特征进行前瞻性研究。方法丙泊酚镇静、禁食状态下,单向波同步电复律,电极板置于心尖-胸骨旁右侧,能量依次采用300,360,360J。结果共入选23例患者,年龄58±13岁,房颤病史6.8±5.0年,左房直径41.9±9.8mm,左室射血分数0.58±0.11。复发心律失常中12例为心房扑动,10例为房颤,1例为房性心动过速。共进行27次电复律,19次(70.4%)即刻复律成功,其中15次1次放电复律成功。1例复律后出现窦性心动过缓伴交界心律,1例丙泊酚镇静时出现呼吸暂停。随访8.5±3.7个月,52.2%的患者为窦性心律。即刻复律成功组其远期成功率为64.7%,即刻复律失败的远期均不成功,两组间有显著性差异(P=0.014)。1次放电即可成功者远期成功率为69.2%,需要多次放电的患者远期成功率为20.0%,两组间有显著性差异(P=0.036)。结论直流电复律可安全有效地用于房颤导管消融术后早期复发的患者,即刻电复律成功是远期成功的预测因素,复律时需要多次放电的远期成功率低。     

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.