Early recurrence of atrial fibrillation after external cardioversion

Early recurrence of atrial fibrillation (AF) has been reported to occur in a significant number of patients after internal cardioversion. However, information about early recurrence of AF after external cardioversion has never been reported. The present study was conducted to investigate the clinical and electrophysiological characteristics of early recurrence of AF and its role in failure of cardioversion in patients with chronic AF. METHODS AND RESULTS: The study included 50 consecutive patients, age 69+/-9, with a history of chronic AF for more than 3 months duration and electrical cardioversion. They were divided into two groups according to the presence (group 1) or absence (group 2) of early recurrence of AF. There were 13 (26%) patients in group 1 and 37 (74%) patients in group 2. The age, gender, duration of AF, left ventricular function, left atrial dimension, and underlying heart disease were similar between group 1 and 2. Forty-five patients were successfully converted to sinus rhythm with a mean energy of 158+/-57 . Among those who failed to be converted to sinus rhythm, 4 (80%) belonged to group 1 and 1 (20%) belonged to group 2. The early recurrences of AF were initiated with consecutive APDs; but the numbers of APD in the first 30 seconds after cardioversion were similar between group 1 and 2. However, the coupling interval of the second APD was shorter in group 1 than group 2 (188+/-22 vs 324+/-59 ms, P = 0.003). Nine of the 13 early recurrences were prevented by an increase of shock energy (n = 3) or intravenous amiodarone infusion (n = 6). There were no differences in duration of follow-up, recurrence rate, and time interval to recurrence between group 1 and group 2. Early recurrence of AF occurred in 26% of chronic AF patients who underwent external electrical cardioversion and was a major cause of failure in cardioversion. Early recurrence of AF was initiated by APDs with decreasing coupling intervals and could be prevented with an increase of shock energy or amiodarone.     

Acute reductions in ventricular myocardial tissue velocities after direct current cardioversion of atrial fibrillation.

BACKGROUND: Cardioversion by direct current (DC) and other methods can cause atrial "stunning." There are case reports of acute pulmonary edema after DC cardioversion, but whether acute ventricular dysfunction is a general consequence of DC cardioversion is unknown. We have investigated whether DC cardioversion acutely affects myocardial velocity assessed by Doppler tissue imaging. METHODS: 40 patients (30 with atrial fibrillation and 10 with atrial flutter) undergoing elective DC cardioversion underwent transthoracic echocardiography with Doppler tissue imaging before and immediately after cardioversion, and after follow-up. Peak systolic velocity was derived for 6 ventricular segments using Doppler tissue imaging. RESULTS: Immediately after DC cardioversion of atrial fibrillation, peak systolic velocity decreased in basal lateral (4.3 +/- 2.0-3.3 +/- 1.7 cm/s, P <.001), mitral annulus-septal (3.8 +/- 1.0-3.5 +/- 0.9, P <.05), mitral annulus-lateral (4.9 +/- 1.6-4.1 +/- 1.7, P <.001), and tricuspid annular (7.8 +/- 2.0-7.0 +/- 1.2, P <.03) segments, even though left ventricular ejection fraction was unchanged. In contrast, for the atrial flutter group there were no significant changes in peak systolic velocity in any segment post-DC cardioversion. Follow up studies were performed after sustained in sinus rhythm in both atrial fibrillation and atrial flutter groups. For both groups, increased peak systolic velocity was found in all 6 segments on follow-up (all P <.05). CONCLUSIONS: DC cardioversion causes subclinical, acute reversible reduction in left ventricular peak systolic velocity in patients with atrial fibrillation. The causes of this reduction in myocardial contractile velocity and the circumstances in which acute dysfunction become clinically significant warrant further investigation.     

Cerebral thromboembolism after direct current cardioversion for pure atrial flutter

The need for prophylactic anticoagulation before electrical cardioversion for atrial arrhythmias is clearly established in the case of atrial fibrillation. By contrast, such prophylaxis is not a current standard of care before cardioversion for pure atrial flutter, since this arrythmia seems not to increase the risk of postcardioversion embolism. We present a patient who developed two cerebral embolisms 24 h after electrical cardioversion for pure atrial flutter. To our knowledge, this observation has not been previously reported. Received: 2 February 1996 Accepted: 24 October 1996     

心房颤动直流电复律前后左心房功能变化的超声心动图研究

目的评价体外直流电复律对心房颤动(房颤)患者复律后左心房大小和容量的影响以及左心房大小与功能的关系。方法随机选择房颤患者68例,按心脏复律的方式分为直流电复律组36例,药物复律组32例,应用超声心动图测定其左房内径和容积,计算左房主动、被动排空容积及左房射血力。分析左房内径和容积变化与左房收缩功能的关系。结果房颤时所有患者的左房扩大,而恢复窦性心律后直流电复律组和药物复律组的左房上下径显著降低(P<0.05或P<0.001)。直流电复律与药物复律组比较,左房最大和最小容积显著增大(P<0.001或P<0.01)。左房机械功能正常患者与25例左房机械功能异常患者比较有较强的左房射血力;左心房机械功能降低的患者左心房内径和容积分别与左心房射血力呈负相关(r=-0.73和-0.78,P<0.001),而且左心房主动排空分数降低,管道容积却增加。结论体外直流电复律后许多患者出现左心房功能降低,心房收缩功能延迟恢复与持续的左房扩大有关;而药物复律患者的左房射血力较强与恢复窦性心律后左房容积明显降低有关。     

Left atrial appendage-flow velocity predicts cardioversion success in atrial fibrillation

Restoration of sinus rhythm by electrical cardioversion is a therapeutic option in appropriately selected patients with atrial fibrillation. It is important to determine predictors of electrical cardioversion outcome in patients with atrial fibrillation. Predictive value of clinical and conventional echocardiographic parameters for predicting cardioversion outcome is limited. The role of left atrial appendage (LAA) function, which may reflect left atrial contractile function, for prediction of cardioversion outcome remains unclear. We conducted a single center prospective study to evaluate the role of LAA function for prediction of cardioversion success in patients with atrial fibrillation. One hundred sixty three patients with atrial fibrillation underwent transthoracic and transesophageal echocardiography (TEE) before electrical cardioversion. LAA functions, including LAA peak flow velocity, LAA area and LAA ejection fraction, were examined. Cardioversion was successful in 133 patients and unsuccessful in 30 patients. Mean LAA peak emptying flow velocity was significantly higher in the patients with successful cardioversion than in those with unsuccessful cardioversion (0.34 +/- 0.14 vs 0.27 +/- 0.1 m/sec; p = 0.013). At multivariate logistic regression analysis, only LAA flow velocity (> 0.28 m/sec, odds ratio = 2.8 ; p = 0.03) proved to be an independent predictor of cardioversion success. LAA area (p = 0.18) and LAA ejection fraction (p = 0.52) were not different between successful and unsuccessful cardioversion groups. Therefore, measurement of LAA flow velocity provides valuable information for prediction of cardioversion outcome in patients with atrial fibrillation before TEE guided cardioversion.     

两种不同电复律方式转复持续性房颤的比较

目的研究前—前位置复律与前—后位置复律对持续性房颤患者的复律成功率及安全性的比较。方法选择2004-01~2005-11于我院心内科住院的持续性房颤患者71例,分别进行前—前位置复律与前—后位置复律,观察各组的复律成功率及成功转复为窦性心律所需的电击次数、总用电量以及复律后12 h血清心肌酶的变化。结果前—前位置复律与前—后位置复律成功率比较差异无显著性(67.6%vs 75.7%,P>0.05),但前—后位置复律具有比前—前位置复律更少的放电次数和总用电量(放电次数:1.8±0.8次vs 2.2±0.7次,P<0.05;总用电量:291.9±197.7 J vs 388.2±193.5 J,P<0.05)。两组间心肌酶学改变无差别,肌酸激酶的水平增加,而其同功酶仍在正常范围内。肌酸激酶水平随着复律电量的增加而升高。结论前—前位置复律与前—后位置复律对持续性房颤患者的复律成功率相同,但后者在放电次数和总用电量上优于前者,两者在对心脏的损伤方面同样安全。     

A practical guide to external direct current cardioversion

Cardioversion is a procedure used to convert a tachyarrhythmia to normal sinus rhythm by applying a synchronised electric shock. This can be carried out on an elective or urgent basis. The purpose of this article is to provide the reader with a greater understanding of external direct current (DC) cardioversion by exploring some of the theoretical and practical issues associated with the procedure.     

Double-dose external cardioversion for refractory unstable atrial fibrillation in the ED

A 45-year-old man with dilated cardiomyopathy, atrial fibrillation, and hypertension presented to the emergency department with palpitations and shortness of breath for 2 days after running out of his medications. An electrocardiogram disclosed atrial fibrillation with rapid ventricular response. The patient was hemodynamically unstable and failed multiple cardioversion attempts up to 360 J. A second defibrillator was then attached and the patient successfully cardioverted once both defibrillators were set to their maximum levels, thus delivering a total of 720 J. Double-dose external cardioversion with 2 defibrillators is an important alternative method that the emergency physician should be aware of when treating refractory atrial fibrillation in the hemodynamically unstable patient.     

Doppler sonographic evaluation of left atrial function after cardioversion of atrial fibrillation.

Restoration of sinus rhythm is not always followed by immediate return of effective atrial contraction. Left atrial mechanical function can be assessed by Doppler echocardiography; in the present study we measured the atrial ejection force, which is a noninvasive Doppler-derived parameter that measures the strength of atrial contraction.The aim of the present study was to evaluate the influence of clinical and echocardiographic parameters: duration and cause of atrial fibrillation, different modality of cardioversion, and left atrial size with respect to the delay in the return of effective atrial contraction after cardioversion. Seventy patients were randomly chosen to undergo cardioversion by either direct current shock or intravenously administered procainamide hydrochloride. The 52 patients who had sinus rhythm restored underwent a complete Doppler echocardiographic examination 1 h after the restoration of sinus rhythm and after 1 day, 7 days, and 1 month. The relation between clinical variables and atrial ejection force was tested. Atrial ejection force was greater immediately and 24 h after cardioversion in patients who underwent pharmacologic therapy compared to patients treated with direct current shock (11.3+/-3 versus 5+/-2.9 dynes; P<0.001). In both groups atrial ejection force increased over time. The mode of cardioversion was significantly associated with recovery of left atrial mechanical function by day 1 in univariate and multivariate analysis (odds ratio, 0.14; 95% confidence interval, 0.02-1.2). The other variable associated with the delay in the recovery of atrial function was a dilated left atrium (odds ratio, 0.16; 95% confidence interval, 0.12-1.6). Atrial ejection force is a noninvasive parameter that can be easily measured after cardioversion and gives accurate information about the recovery of left atrial mechanical function. The recovery of left atrial function was influenced by the mode of cardioversion and left atrial size.     

Influence of diabetes on the maintenance of sinus rhythm after a successful direct current cardioversion in patients with atrial fibrillation

AIM: To determine independent risk factors for recurrence of atrial fibrillation (AF) after a successful direct current (DC) cardioversion in patients with and without diabetes. DESIGN: We retrospectively analysed the outcome in patients recently diagnosed with persistent AF. METHODS: Of 364 patients included, 289 had a successful direct current (DC) cardioversion. We compared 42 (14.5%) patients known to have diabetes to 247 (85.5%) without. Patients were reviewed in outpatient clinic with assessment of heart rhythm clinically and by electrocardiogram. Median follow-up after DC cardioversion was 74 days [interquartile range (IQR) 69-78 days]. RESULTS: When reviewed in outpatient clinic, only 63.7% (185 of 289) were still in sinus rhythm (SR). Of the group without diabetes, 66.8% (165 of 247) remained in SR vs. 45.2% (19 of 42) of the group with diabetes (P = 0.005). Binary logistic regression analysis showed duration of AF (P < 0.0001) and the presence of diabetes (P = 0.019) have been independent risk factors for recurrence of AF. DISCUSSION: Presence of diabetes and the longer duration of AF were independent risk factors for the recurrence of AF after a successful DC cardioversion.     

心房颤动复律后左房大小和左房功能的研究

目的 观察心房颤动转复前后左房大小、左房收缩功能的改变及两者的关系。方法 94例房颤患者中34例自发转复为窦律。60例被随机分为药物转复31例,直流电转复29例。所有患者房颤转复前后采用多谱勒超声心动图测定左房腔径、容量和A峰速度以评价左房大小和收缩功能。结果 转复后,左房腔径和容量均显著缩小（P＜0．01）,A峰速度显著增快（P＜0．01）,但电转复患者发生上述改变所需的时间相对较长。结论 房颤可使左房发生腔径扩大、收缩功能下降的改变。转复窦律后,上述改变可迅速逆转,但电转复因对心肌的损伤作用,而使上述逆转延迟发生。     

Incidence of early adverse events surrounding direct current cardioversion of persistent atrial fibrillation. A cohort study of practices

AIMS: To establish the incidence of early adverse events surrounding direct current (DC) cardioversion of persistent atrial fibrillation in an unselected patient cohort and to describe and analyse these complications. METHODS: Prospective study over a three-month period (February, March and April 2000). Outcome measures included all serious adverse events during the hospitalisation for DC cardioversion. Six hundred and eighty-four DC cardioversion were performed on 659 patients. RESULTS: The rate of adverse events was 4.4% including 1.3% bradycardia, 0.3% ventricular arrhythmia, 0.3% QT increase, 1% serious haemorrhages, 0.4% death and 1.2% miscellaneous adverse events. CONCLUSION: The perceived tolerance to DC cardioversion in atrial fibrillation should be amended with the 4.4% serious early adverse events.     

体外电复律治疗房颤对植入左心耳封堵器患者的影响

目的：探讨植入左心耳封堵器的房颤患者接受体外电复律治疗的可行性和安全性。方法：选取2016年5月至2019年12月北京医院收治的经皮成功植入左心耳封堵器患者51例，其中接受体外电复律治疗7例（13.7%），观察电复律对装置的影响及相关不良事件。结果：51例患者中，接受电复律治疗的7例（13.7%）患者未发生封堵器移位或脱落，围手术期未发生严重不良事件。结论：植入左心耳封堵器的房颤患者接受体外电复律治疗是安全、可行的。     

The prognostic significance of atrial arrhythmias recorded early after cardioversion for atrial fibrillation

In a substantial number of patients, AF recurs after successful electrical cardioversion. The purpose of this study was to investigate if the atrial arrhythmias recorded immediately after cardioversion are associated with the risk of recurrence of the arrhythmia and to compare the prognostic significance of this parameter with that of other established risk factors. In a series of 71 patients, the risk factors for recurrence of AF during the first year after successful electrical cardioversion were analyzed. A new parameter that was investigated was the frequency of atrial premature beats and the presence of runs of supraventricular tachycardia in the Holter recording started immediately after the cardioversion. Age, left atrial size, left ventricular systolic function, duration of the arrhythmia before cardioversion, underlying cardiac disease, or medication taken were not found to be predictive of recurrence of the arrhythmia. However, the natural logarithm of the number of atrial premature complexes per hour of the Holter recording in the 37 patients in whom AF recurred was higher compared to that of the 34 patients who maintained sinus rhythm (P < 0.0005). The same was true if only the first 6 hours of the recording were analyzed (P < 0.0005). There was a trend for more frequent arrhythmia recurrence if runs of supraventricular tachycardia were present. The finding of > 10 atrial premature complexes per hour in the recording had a relative risk of 2.57 (1.51-4.37), a positive predictive accuracy of 76.5%, and a negative predictive accuracy of 70.3% for subsequent arrhythmia recurrence. We can conclude that frequent (> 10/hour) atrial premature complexes in the Holter recording after electrical cardioversion for AF is a significant risk factor for recurrence of the arrhythmia.