静脉地尔硫治疗快速房颤、房扑的疗效分析

为检验静脉地尔硫艹卓控制房颤、房扑心室率的有效性和安全性，对４７例快速房颤、房扑患者一次静脉注射０．２５ｍｇ／ｋｇ地尔硫艹卓后以５ｍｇ／ｈ～１０ｍｇ／ｈ微泵维持，平均起效时间５．２±２．７ｍｉｎ，总有效率９３．６％，心功能较用药前明显改善（Ｐ＜０．０５），对血压无明显影响，副作用发生率为１０．６％，均不严重。结果提示地尔硫艹卓是一种能迅速、安全、有效控制房颤、房扑患者心室率的药物     

Risk of thromboembolism in acute atrial fibrillation or atrial flutter

Atrial fibrillation (AF) is the most common sustained cardiac dysrhythmia, predominating in the elderly, with stroke as a potentially devastating complication. Prevention of the thromboembolic sequelae from AF remains a central focus of practicing clinicians. Although the risk of thromboembolism in chronic AF is well recognized, less is known about the potential risk of systemic embolism in acute AF. In addition, recent data support the notion of a group at considerable risk of embolism from atrial flutter, an arrhythmia typically believed to bestow little increased risk of thromboembolism. The mechanism of thrombus formation, embolization, and resolution in atrial arrhythmias is not well defined, particularly in that of acute AF or atrial flutter. The traditional concept proposes that atrial thrombus forms only after > 2 days of AF and embolizes by being dislodged from increases in shear forces. This widely accepted concept further holds that newly formed atrial thrombus, in the setting of AF, organizes over a span of 14 days. The results of studies based on observations from transesophageal echocardiography examinations have provided provocative insight into the temporal sequence of atrial thrombus formation, embolization, and resolution in AF or atrial flutter and have expanded the traditional concept of thromboembolism in these atrial dysrhythmias. Namely, left atrial thrombus may form before the onset of AF in the face of sinus rhythm. Conversion to sinus rhythm may increase the thrombogenic milieu of the left atrium. Importantly, atrial thrombus may form in the acute phase of AF. Last, thrombi may require > 14 days to become immobile or to resolve. Findings similar to those of acute AF have been reported in patients with atrial flutter and coexisting cardiac pathology. On the basis of these emerging insights fostered by the use of transesophageal echocardiography, it appears appropriate to consider anticoagulation in patients presenting with acute AF or atrial flutter with coexisting cardiac pathology predisposing to left atrial thrombus.     

肌钙蛋白I在急诊心房颤动和心房扑动患者检测情况分析

目的:回顾性分析心肌标志物肌钙蛋白I(Troponin I,TnI)在急诊科心房颤动和心房扑动(房颤/房扑)患者的检测情况。方法:收集2010年6月至2011年6月,就诊于北京安贞医院急诊科2 190例房颤/房扑患者病例,随机抽取了500例患者的资料进行回顾性分析,分析内容包括肌钙蛋白I检测次数,TnI阳性率和确诊为急性冠状动脉综合征(ACS)的概率。结果:患者至少有1次TnI检测的为86.8%(434/500),其中TnI阳性率为15.7%,诊断为ACS者的概率为5.1%。至少2次检测的患者为41.8%(209/500),其中TnI阳性率为26.8%(56/209),诊断为ACS的占9.6%。结论:在急诊科,房颤/房扑患者有很高的TnI检测率,而急诊患者确诊为ACS仅约5%,提示急诊内科医师需综合评估房颤/房扑患者临床状况后再进行TnI检测,避免临床资源不必要的浪费。     

Incidence of atrial fibrillation post-cavotricuspid isthmus ablation in patients with typical atrial flutter: left-atrial size as an independent predictor of atrial fibrillation recurrence

Introduction: Atrial fibrillation and atrial flutter often coexist. The long-term occurrence of atrial fibrillation in patients presenting with atrial flutter alone is unknown. We report the long-term follow-up in patients who underwent cavotricuspid isthmus ablation for treatment of lone atrial flutter.
Methods and Results: Between January 1997 and June 2002, 632 patients underwent cavotricuspid isthmus ablation for the treatment of typical atrial flutter at the Cleveland Clinic Foundation. Three hundred sixty-three patients were included in this study and followed for a mean duration of 39 ± 11 months. The mean duration of atrial flutter symptoms was 12 ± 5 months. Mean left-atrial size and left-ventricular ejection fraction were 4.2 ± 0.8 cm and 47 ± 13%, respectively. After a mean follow-up time of 39 ± 11 months, 13% (48 of 363) of the patients remained in sinus rhythm. Five percent (18 of 363) of patients experienced recurrence of atrial flutter only. Sixty-eight percent (246 of 363) experienced the onset of atrial fibrillation and 14% (51 of 363) experienced recurrence of atrial flutter and the new onset of atrial fibrillation. Overall, 82% (297 of 363) of the patients experienced new onset of drug refractory atrial fibrillation. Left-atrial size was a predictor of atrial fibrillation recurrence post-atrial flutter ablation.
Conclusion: At long-term follow-up, approximately 82% of patients post-cavotricuspid isthmus ablation for atrial flutter developed drug refractory atrial fibrillation. This finding suggests that elimination of atrial flutter might delay, but does not prevent, atrial fibrillation. Evidence suggests both arrhythmias may share common triggers and such patients may derive a better long-term benefit from anatomical ablative treatment of atrial fibrillation as well.     

Transthoracic echocardiography for precardioversion screening during atrial flutter/fibrillation in young patients

BACKGROUND: Transthoracic echocardiography (TTE) is reliable for detection of thrombi in the left ventricle and right atrium, but not in the left atrial appendage. Therefore, transesophageal echocardiography (TEE) is routinely performed in adults prior to electric cardioversion for atrial flutter/fibrillation (AFF). Whether young survivors of congenital heart disease repair with AFF need routine TEE prior to electric cardioversion is unknown. HYPOTHESIS: Electric cardioversion for AFF is safe in survivors of congenital heart disease repair/palliation if an intracardiac thrombus is not suspected on TTE imaging. METHODS: This study reports the outcome of patients in a pediatric tertiary care cardiac unit where electric cardioversion was performed if no intracardiac thrombus was suspected on TTE. We performed a retrospective chart review of all patients treated with electric cardioversion for AFF at Children's Hospital of Michigan during 1997-2002. RESULTS: Of 35 patients who presented with 110 episodes of AFF requiring electric cardioversion during the study duration, 32 (age 3 months-49 years, median age 20.5 years, 104 AFF episodes) had previously undergone palliative surgery or repair of their congenital heart disease. Of these 32 patients, 18 were survivors of a Fontan palliation (for a single-ventricle variant) and the remaining 14 were survivors of other defects and repairs (septal defects, valve replacements, and tetralogy of Fallot). During 81% of the episodes, patients were receiving aspirin, warfarin, or heparin for anticoagulation at presentation. Transthoracic echocardiography was performed in 74 AFF episodes; of these, 10 TTE studies were suspicious for atrial thrombi. Transesophageal echocardiography confirmed the presence of a thrombus in 3 of these 10 patients. These patients received warfarin for 2 weeks and then underwent electric cardioversion. No thromboembolic events occurred immediately after or on follow-up in any patient. CONCLUSIONS: These findings suggest that TTE may be an effective imaging tool for precardioversion screening in young patients with AFF.     

Catheter ablation of atrial flutter due to amiodarone therapy for paroxysmal atrial fibrillation.

AIMS: Antiarrhythmic drug treatment for atrial fibrillation can cause atrial flutter-like arrhythmias. The aim of this study was to clarify the effect of catheter ablation of the tricuspid annulus-vena cava inferior isthmus on amiodarone-induced atrial flutter and to determine the incidence of atrial fibrillation after catheter ablation of amiodarone-induced atrial flutter in comparison to regular typical flutter. METHODS AND RESULTS: Among 92 consecutive patients with typical atrial flutter who underwent isthmus ablation 28 patients had atrial flutter without a history of previous atrial fibrillation (group I), 10 patients had atrial flutter following the initiation of amiodarone therapy for paroxysmal atrial fibrillation (group II) and 54 patients had atrial flutter and atrial fibrillation (group III). Atrial cycle length during atrial flutter in amiodarone-treated patients (group II) (277+/-24 ms) was significantly longer as compared to the cycle length of atrial flutter in group I (247+/-33 ms) and group III patients (235+/-28 ms). The rate of successful transient entrainment and overdrive stimulation to sinus rhythm was not different between patients with (60%) or without amiodarone therapy (group I: 71%, group III: 53%). Successful isthmus ablation with bidirectional conduction block eliminating right atrial flutter was achieved in 90% of amiodarone-treated patients and 93% of patients without amiodarone therapy. In the amiodarone-treated patient group atrial conduction times during pacing in sinus rhythm were significantly prolonged by 20-30% before and after ablation in all regions of the reentrant circuit. During a mean follow-up of 8+/-3 months post-ablation, atrial fibrillation recurred in two of 10 patients on continued amiodarone therapy after successful isthmus ablation. Thus, successful catheter ablation of atrial flutter due to amiodarone therapy was associated with a markedly lower recurrence rate of paroxysmal atrial fibrillation (20%) as compared to patients with atrial flutter plus preexisting paroxysmal atrial fibrillation (76%) and was similar to the outcome of patients with successful atrial flutter ablation without preexisting atrial fibrillation (25%). CONCLUSION: These data suggest that isthmus ablation with bidirectional block and continuation of amiodarone therapy is an effective therapy for the treatment of atrial flutter due to amiodarone therapy for paroxysmal atrial fibrillation.     

Cardiac troponin T does not increase after electrical cardioversion for atrial fibrillation or atrial flutter

Objective—To determine whether cardiac troponin T increases after electrical cardioversion in patients with atrial fibrillation or atrial flutter.
Design—Serum creatine kinase (CK), creatine kinase-MB (CKMB), and cardiac troponin T were measured before, 24 hours, and 48 hours after cardioversion in 15 patients with atrial fibrillation or atrial flutter.
Results—12 of the 15 patients (80%) were successfully cardioverted to sinus rhythm. The median number of shocks was three (range one to six), the median cumulative energy 710 J (50 to 1430 J), and the median peak energy 300 J (50 to 360 J). Total CK increased from a baseline median concentration of 92 (45 to 259) to 1324 (96 to 6660) U/l at 24 hours and 1529 (120 to 4774) U/l at 48 hours after cardioversion. There was a small increase in CKMB but the ratio of CKMB to CK did not increase. There was no increase in cardiac troponin T in any patient.
Conclusions—Following electrical cardioversion of atrial fibrillation or atrial flutter, cardiac troponin T remains unchanged despite a large rise in total CK, indicating that the CK is derived from skeletal muscle and that myocardial injury does not occur. If cardiac troponin T is increased after cardioversion for atrial arrhythmias then other causes of myocardial damage should be sought.

Keywords: atrial fibrillation; atrial flutter; cardioversion; troponin T     

射频消融治疗老年房扑房颤患者疗效及安全性的评价

目的展望射频消融治疗老年房扑房颤患者的前景，评价其安全性及疗效。方法回顾3年来在北京大学第一医院进行射频消融的年龄在60～82岁的房扑房颤患者的病例。结果46名患者中1例因不能耐受未能继续消融治疗；20例房扑患者全部消融成功，成功率100％，随访1～30个月无复发；25例房颤患者消融肺静脉78条，以肺静脉电位消失为标准，成功率96％，随访1～30个月，5例复发，成功率80．0％。5例复发患者药物控制心室率；1例出现急性心脏压塞，治疗后好转。将该组并发症的发生率与同期在北京大学第一医院因阵发性室上性心动过速行射频消融的年龄16～60岁组并发症的发生率进行比较，差异无显著性。结论射频消融因其安全性、有效性，对老年患者可明显减少药物副作用，提高生活质量，可成为无禁忌房扑房颤患者的一线治疗方案。     

非瓣膜病心房颤动或心房扑动患者应用不同起始剂量华法林对INR达标速度的影响

目的观察我国非瓣膜病心房颤动（NVAF）或心房扑动（AFL）患者应用不同起始剂量华法林时,国际标准化比值（INR）首次达标和稳定的时间及出血并发症的发生率等,以进一步了解中国人应用国产华法林的最佳起始剂量。方法人选84例,随机分入起始剂量3．125mg组（第1组）,起始5mg,2d后改为3．125mg组（第2组）和起始5mg治疗组（第3组）。于治疗第3、4、5、7、9天测定INR,根据INR调整华法林剂量,直到INR稳定于1．8～3．0,随访1个月。结果第3组比第1、2组提早达标并稳定,第1、2组差异无统计学意义。3组均无明显出血及血栓栓塞事件,INR增高发生率差异无统计学意义。结论对于中国NVAF或AFL患者,以5mg为初始剂量应用华法林能使INR安全、迅速、有效地达标并稳定。服药3次后即于第4天起测INR是安全的。     

Incidence and clinical significance of transformation of atrial fibrillation to atrial flutter in patients undergoing long-term antiarrhythmic drug treatment.

AIMS: To investigate the rate of transformation of atrial fibrillation to atrial flutter in patients taking antiarrhythmic drugs for the prophylaxis of atrial fibrillation, we retrospectively analysed data from 305 consecutive patients with paroxysmal atrial fibrillation (155 male; mean age 63 +/- 11 years) treated with ventricular rate controlling drugs, antiarrhythmic drugs, or without drugs. METHODS AND RESULTS: At a mean follow-up of 9 months (range 1-24) all patients experienced recurrence of arrhythmia: 48 (14.6%, Group A) suffered Type 1 atrial flutter, and 257 (85.4%, Group B) atrial fibrillation. The relative rate of recurrence of atrial flutter vs atrial fibrillation was similar in patients without treatment or with ventricular rate controlling drugs (from 6.8% to 14.6%, P=ns). However, recurrence was higher (25%) in patients administered antiarrhythmic drug therapy. The relative risk in these patients was 3.02 times greater, compared with patients without treatment, or treated with rate controlling drugs (P<0.001). There were no differences between groups concerning the baseline clinical characteristics and the clinical consequences of the recurrence; patients with atrial flutter had a lower rate of conversion to sinus rhythm (42% vs 64%) and a higher rate of hospital admission (69% vs 36%) compared with those with atrial fibrillation. Six patients (8.5%) experienced 1:1 atrioventricular conduction during atrial flutter with a ventricular rate of 240-280 beats x min(-1). CONCLUSION: Our data suggest that the use of antiarrhythmic drugs for the prophylaxis of atrial fibrillation is associated with a threefold increase in the probability of Type 1 atrial flutter recurrence, as opposed to atrial fibrillation, which may have important clinical consequences, but which did not in our study.     

Mechanism of propensity to atrial fibrillation in patients undergoing isthmus ablation for typical atrial flutter

Mechanism of propensity to atrial fibrillation. BACKGROUND: Patients undergoing isthmus ablation for atrial flutter (AFL) may reveal postablation atrial fibrillation (AF). The electrophysiological mechanism is unclear. In patients with idiopathic AF, enhanced spatial dispersion of right atrial refractoriness was the substrate for the initiation of AF. We hypothesize that dispersion of right atrial refractoriness in patients undergoing AFL ablation is the major cause of postablation AF. METHODS: Consecutive patients (n=42) undergoing isthmus ablation for typical AFL were included. Twelve right atrial unipolar electrograms were recorded. Inducibility of AF was assessed by a pacing protocol, starting with one extrastimulus, followed by more aggressive pacing until AF was induced. Mean fibrillatory intervals were used to assess local refractoriness of each recording site. Spatial dispersion of right atrial refractoriness was calculated as the coefficient of dispersion (CD-value: standard deviation of the mean of all local mean fibrillatory intervals as a percentage of the overall mean fibrillatory interval). A CD-value of 3.0 or less was defined as normal, whereas CD-value greater than 3.0 was considered enhanced dispersion. PES and refractoriness analysis were followed by isthmus ablation. RESULTS: Of the 42 patients, 29 had CD-value of 3.0 or less. In these 29 patients, AF was induced with 1 extrastimulus in only 1 patient, with 2 extrastimuli in 4 patients and burst pacing was required to induce AF in 24 of these 29 patients. Prior to the procedure, 5 of 29 patients had AF episodes, after ablation 6 of 29 patients. Of the 42 patients, 13 had CD-value greater than 3.0, AF was induced with a single extrastimulus in 11 patients, with 2 extrastimuli in the remaining 2 patients. Of the 13 patients, 11 had AF episodes both before and after ablation (P<0.001). CONCLUSION: Enhanced spatial dispersion of right atrial refractoriness may be the substrate for propensity to AF in patients with AFL. The substrate was associated with enhanced inducibility of atrial fibrillation.     

A population-based study of mortality among patients with atrial fibrillation or flutter

PURPOSE: To determine the mortality associated with atrial flutter and atrial fibrillation in the general population. SUBJECTS AND METHODS: Using the Marshfield Epidemiologic Study Area, a database that captures nearly all medical care and deaths among its 58,820 residents, we identified patients diagnosed with atrial flutter or atrial fibrillation from July 1, 1991, through June 30, 1995. Patients were followed prospectively and compared with a group of controls without these arrhythmias. RESULTS: A total of 4775 person-years of follow-up were completed in 577 patients and 577 controls. Compared with controls, mortality among patients with atrial fibrillation or flutter was nearly 7.8-fold higher at 6 months (95% confidence interval [CI]: 4.1 to 15) and 2.5-fold higher (95% CI: 2.0 to 3.1; P < 0.0001) at the last follow-up (mean [+/- SD] of 3.6 +/- 2.3 years; range, 1 day to 7.3 years). At 6 months, mortality among patients with atrial flutter alone was somewhat greater than in controls and less than one third that of those with atrial fibrillation (with or without atrial flutter) (P = 0.02). At the last follow-up, however, mortality was greater among patients with atrial flutter (hazard ratio [HR] = 1.7; 95% CI: 1.2 to 2.6; P = 0.007), atrial fibrillation (HR = 2.4; 95% CI: 1.9 to 3.1; P < 0.0001), or both atrial arrhythmias (HR = 2.5; 95% CI: 1.9 to 3.3; P < 0.0001) when compared with controls in models that adjusted for cardiovascular risk factors. CONCLUSION: In the general population, both atrial flutter and atrial fibrillation are independent predictors of increased late mortality. The relatively benign course during the 6-month period after the initial diagnosis of atrial flutter suggests that early diagnosis and treatment of these patients may improve their long-term survival.     

三尖瓣峡部消融对心房颤动导管消融术后复发的影响

目的:评估三尖瓣峡部消融对伴有典型心房扑动(房扑)和不伴典型房扑发作的心房颤动(房颤)患者术后复发的影响.方法:连续入选房颤射频消融治疗患者113例,根据有无典型房扑分为三尖瓣峡部消融组(CTI组)和未行三尖瓣峡部消融组(Non-CTI组),比较临床特征及手术特点,并随访术后典型房扑和房颤发生率.结果:Non-CTI组左房内径更大,持续性和永久性房颤的比例、左房线性消融的比例更高.而CTI组射频消融时间较Non-CTI组更长.术后典型房扑和房颤发生率2组无显著区别.结论:无典型房扑发作的房颤患者,不行三尖瓣峡部消融,不会升高术后典型房扑发生率和房颤复发率,同时射频消融时间缩短.     

Celivarone for maintenance of sinus rhythm and conversion of atrial fibrillation/flutter

Celivarone in Atrial Fibrillation/Atrial Flutter. Introduction: Celivarone, a new noniodinated benzofuran derivative pharmacologically related to dronedarone and amiodarone, has been shown to have antiarrhythmic properties at a molecular level. The purpose of the 2 trials presented here (MAIA and CORYFEE) was to assess celivarone efficacy in the maintenance of sinus rhythm postcardioversion and for the conversion of atrial fibrillation (AF)/atrial flutter (AFL). Methods and Results: In the MAIA trial, 673 patients with AF/AFL recently converted to sinus rhythm were randomly assigned to receive 50, 100, 200, or 300 mg once‐daily dosing of celivarone; 200 mg daily of amiodarone preceded by a loading dose of 600 mg for 10 days; or placebo. At 3 months’ follow up, no significant difference was observed in time to AF/AFL relapse among the various celivarone groups and placebo. However, fewer symptomatic AF/AFL recurrences were observed in the lower‐dose celivarone groups (26.6% for celivarone 50 mg [P = 0.022] and 25.2% for celivarone 100 mg [P = 0.018] vs 40.5% for placebo at 90 days). Fewer adverse events were observed with the use of celivarone and placebo than amiodarone. In the CORYFEE study, 150 patients with AF/AFL were randomly assigned to once‐daily celivarone dosing of 300 or 600 mg, or placebo, for a 2‐day treatment period. There was no significant difference in the rate of spontaneous conversion to sinus rhythm between the treatment and control groups. Conclusions: In these studies, celivarone does not appear to be efficacious in the maintenance of sinus rhythm in AF/AFL patients or for the conversion of AF/AFL patients. (J Cardiovasc Electrophysiol, Vol. 23, pp. 462‐472, May 2012)     

Detection of paroxysmal atrial fibrillation or flutter in patients with acute ischemic stroke or transient ischemic attack by Holter monitoring

Background and purpose

Paroxysmal atrial fibrillation and flutter are strong risk factors for stroke. Due to high recurrence rate of ischemic events and given the benefit of oral anticoagulation over antiplatelet drugs, it is important to identify this arrhythmia. Unfortunately, paroxysmal AF or flutter is asymptomatic in majority and therefore, difficult to detect.

Methods

Consecutive patients presenting with symptoms of acute ischemic stroke or transient ischemic attack were included. All patients free of AF or flutter on presentation underwent 24 h Holter monitoring within 7 days of admission.

Results

Overall, fifty two (52) patients (mean age 59.51 ± 13.45 years) with acute stroke (80.8%) and TIA (19.8%) underwent 24 h Holter monitoring. Paroxysmal AF was detected in 3 cases (5.8%), all 3 patients had acute stroke and were older than age 60 years. Type of stroke was the only factor which was associated with greater risk of having paroxysmal AF or flutter, AF accounted for 50% cases (2 out of 4) of clinically suspected cardio embolic stroke.

Conclusion

Screening consecutive patients with ischemic stroke with routine Holter monitoring will identify new atrial fibrillation/flutter in approximately one in 17 patients. Older age and type of stroke are strongly associated with increased risk. By carefully selecting the patients, the detection rates could be further increased.     

Evaluation of an individualized strategy of cavotricuspid isthmus ablation as an adjunct to atrial fibrillation ablation

Objectives: To evaluate supplementary cavotricuspid isthmus (CTI) ablation as an adjunct to atrial fibrillation (AF) ablation in selected patients.
Background: It is unclear whether routine CTI ablation is beneficial in all patients undergoing AF ablation.
Methods and Results: In patients undergoing AF ablation, additional CTI block was created only for those with typical atrial flutter (Afl) before or during the ablation. Out of 188 consecutive patients (108 male, 56 ± 9 years), 75 underwent CTI ablation (Group CTI+) and left atrial (LA) ablation (circular mapping-guided extensive pulmonary vein isolation in all and linear LA ablation when required), while 113 underwent LA ablation alone (Group CTI−). Group CTI+ patients had smaller LA and less frequently persistent/permanent AF and linear LA ablation. Over a follow-up of 30 ± 10 months, complications (4% vs 5%, P = NS), typical Afl occurrence (1.3% and 2.6%, P = NS) and AF recurrence (25% and 28%, P = NS) were similar. Atypical Afl was more common in Group CTI− (4 vs 14%, P = 0.026). Eighty-two percent and 79% of patients in Groups CTI+ and CTI−, respectively, remained arrhythmia free in stable sinus rhythm without antiarrhythmic drug treatment (P = NS).
Conclusions: Avoiding supplementary CTI ablation in AF ablation patients without evidence of typical flutter does not result in a higher incidence of typical Afl. Despite more persistent/permanent AF and larger LA in patients without evidence of typical flutter, a strategy of selective supplementary ablation resulted in similar and low AF recurrence rates in the group without CTI ablation compared with the group with CTI ablation.