Outpatient cardioversion of atrial arrhythmias: efficacy,safety, and costs

Background Outpatient direct current (DC) cardioversion is performed routinely, yet scant data support this approach. We studied the efficacy, safety, and costs of outpatient cardioversion. Methods A retrospective analysis of outpatient cardioversions was performed in a 5-year period at an academic medical center in 532 consecutive outpatients with an atrial tachyarrhythmia. The protocol included anticoagulation (international normalized ratio ≥2.0) for ≥4 consecutive weekly draws and then DC cardioversion with the patient under intravenous anesthesia. Arrhythmia symptoms, antiarrhythmic therapy use, and costs were evaluated. Results Ninety percent of patients were discharged in sinus rhythm after cardioversion with a median number of shocks of 1 (range, 1-6) for atrial flutter (n = 113), atrial tachycardia (n = 13), and atrial fibrillation (n = 406). Sixty-seven percent of patients were treated with an antiarrhythmic drug. The complication rate was 2.6%, with 11 unplanned admissions. Thromboemboli occurred only in patients whose anticoagulation deviated from protocol and included chronic hemianopsia starting 4 days after cardioversion, transient right-sided weakness, and cerebral vascular accident 3 days after cardioversion, despite negative results on a transesophageal echocardiogram. Two patients had postcardioversion pulmonary edema. Bradycardia developed in 4 patients; transient pacemaker noncapture after the shock occurred in 4 patients. Transient postshock rhythms also included AV nodal Wenckebach and junctional rhythm. One patient had aspiration pneumonia. The mean cost of cardioversion was $464. Fees for anesthesia ranged from $525 to $650. The anesthetic costs ranged from $2.84 to $21.47. The cardiology fee averaged $501. Conclusion Outpatient cardioversion is a low risk, effective, and economical procedure. (Am Heart J 2003;145:233-8.)     

Rationale and design of a study assessing treatment strategies of atrial fibrillation in patients with heart failure: the Atrial Fibrillation and Congestive Heart Failure (AF-CHF) trial

Background Nonrandomized studies suggest that atrial fibrillation is independently associated with increased mortality in patients with heart failure. Whether restoring and maintaining sinus rhythm will have a beneficial impact on cardiovascular mortality in patients with heart failure has never been tested in an adequately powered randomized trial. Objective The primary objective of the Atrial Fibrillation and Congestive Heart Failure (AF-CHF) trial is to determine whether restoring and maintaining sinus rhythm significantly reduces cardiovascular mortality compared with a rate-control strategy in patients with atrial fibrillation and CHF. Methods AF-CHF is a prospective multicenter trial (109 centers in Canada, United States, South America, Europe, and Israel), that will randomize 1450 patients with CHF with left ventricular ejection fraction ≤35% and atrial fibrillation to 1 of 2 treatment strategies: (1) rhythm control with the use of electrical cardioversion combined with antiarrhythmic drugs (amiodarone or other class III agents), (2) rate control with the use of β-blockers, digoxin, or pacemaker and AV nodal ablation. Cardiovascular mortality is the primary end point and the intention-to-treat approach the primary method of analysis. We anticipate an 18.75% 2-year cardiovascular mortality in the rate control arm with a 25% mortality reduction in the rhythm control group. Results As of August 13, 2002, 334 patients have been enrolled from 68 participating centers. Enrollment is expected to be concluded in May 2003 with a minimum follow-up of 2 years. Conclusion The results of this trial should provide definitive information concerning 2 widely applicable treatment strategies of atrial fibrillation in a large cohort of patients with CHF. (Am Heart J 2002;144:597-607.)     

Atrial stunning: basics and clinical considerations

Conversion of atrial fibrillation and flutter to sinus rhythm results in a transient mechanical dysfunction of atrium and atrial appendage, termed atrial stunning. Atrial stunning has been reported with all modes of conversion of atrial fibrillation and flutter to sinus rhythm including both transthoracic and low energy internal electrical, pharmacological, and spontaneous cardioversion, and conversion by overdrive pacing and by radiofrequency ablation. Atrial stunning is a function of the underlying arrhythmia becoming apparent at the restoration of sinus rhythm, not the function of the mode of conversion, and does not develop after the unsuccessful attempts of cardioversion or the delivery of electric current to the heart during rhythms other than atrial fibrillation or flutter. Tachycardia-induced atrial cardiomyopathy, cytosolic calcium accumulation, and atrial hibernation are the suggested mechanisms of atrial stunning. Atrial stunning is at maximum immediately after cardioversion and improves progressively with a complete resolution within a few minutes to 4-6 weeks depending on the duration of the preceding atrial fibrillation, atrial size, and structural heart disease. Atrial stunning causes postcardioversion thromboembolism despite restoration of sinus rhythm. Duration of anticoagulation therapy after successful cardioversion should depend on the duration of atrial stunning. Lack of improvement in cardiac output and functional recovery of patients immediately after cardioversion is attributed to the atrial stunning. Verapamil, acetylstrophenathidine, isoproterenol, and dofetilide have been reported to protect from atrial stunning in animal and small human studies. Right atrium stunning is less marked and improves earlier than that of left atrium, resulting in a differential atrial stunning explaining the rare occurrence of pulmonary edema after cardioversion.     

高敏C反应蛋白与心房顿抑关系的临床研究

目的探讨高敏C反应蛋白（hsCRP）与心房顿抑的关系。方法将冠脉造影排除冠心病的患者分为慢性房颤组68例和窦律组103例。将房颤患者进行复律。比较房颤组复律前与窦律组、以及复律前后血浆hsCRP水平。结果房颤组患者复律前较窦律患者hsCRP升高，分别为（6．3±1．2）mg／L和（2．3±0．4）mg／L；复律后hsCRP为（13．6±3．7）mg／L，较复律前升高。结论慢性房颤患者hsCRP升高，且hsCRP与心房顿抑相关，是心房顿抑的独立预测因子。     

Serial evaluation of left atrial dimension after cardioversion for atrial fibrillation and relation to atrial function

The size of the left atrium is usually increased during atrial fibrillation (AF). The aim of the present study was to evaluate changes in left atrial (LA) dimension after cardioversion for AF, and the relation between LA dimension and atrial function. The initial study population included 171 consecutive patients. Patients who had spontaneous cardioversion to sinus rhythm (56 patients) were compared with patients who had random cardio-version with drugs (50 patients) or direct-current (DC) shock (50 patients). Echocardiographic evaluations included LA size and volume. LA passive and active emptying volumes were calculated, and LA function was assessed. Atrial stunning was observed in 18 patients reverted with DC shock and in 7 patients reverted with drugs. The left atrium was dilated in all patients during AF (48 +/- 5 mm). The size of the left atrium decreased after restoration of sinus rhythm in all patients with spontaneous reversion to sinus rhythm, in 73% of patients reverted with drugs, and in 50% of patients reverted with DC shock. The comparison between patients with a normal mechanical atrial function and patients with reduced atrial function showed that a higher atrial ejection force was associated with a more marked reduction in LA size after restoration of sinus rhythm. A relation between LA volumes and atrial ejection force was observed in the group of patients with depressed atrial mechanical function (r = -0.78; p <0.001). The active emptying fraction was lower, although not significantly, in this group, whereas the conduit volume was increased. Thus, a depressed atrial mechanical function after cardioversion for AF was associated with a persistence of LA dilation.     

Left atrial “stunning” following radiofrequency catheter ablation of chronic atrial flutter

Objectives. This study examined the effect of radiofrequency ablation (RFA) on left atrial (LA) and left atrial appendage (LAA) function in humans with chronic atrial flutter (AFL).Background. Atrial stunning and the development of spontaneous echocardiographic contrast (SEC) is a consequence of electrical cardioversion of AFL to sinus rhythm. This phenomenon has been termed “stunning” and is associated with thrombus formation and embolic stroke. Radiofrequency ablation is now considered to be definitive treatment for chronic AFL, but whether this procedure is complicated by LA stunning is unknown.Methods. Fifteen patients with chronic AFL undergoing curative RFA underwent transesophageal echocardiography to evaluate LA and LAA function and SEC before and immediately, 30 minutes and 3 weeks after RFA. To control for possible direct effects of RFA on atrial function, seven patients undergoing RFA for paroxysmal AFL were also studied. In this group, RF energy was delivered in sinus rhythm and echocardiographic parameters were assessed before and immediately and 30 minutes following RFA.Results. Chronic AFL: Mean arrhythmia duration was 17.2 ± 13.3 months. Twelve patients (80%) developed SEC following RF energy application and reversion to sinus rhythm. LAA velocities decreased significantly from 54.0 ± 14.2 cm/s in AFL to 18.0 ± 7.1 cm/s in sinus rhythm after arrhythmia termination (p < 0.01). These changes persisted for 30 minutes. Following 3 weeks of sustained sinus rhythm, significant improvements in LAA velocities (68.9 ± 23.6 vs. 18.0 ± 7.1 cm/s, p < 0.01) and mitral A-wave velocities (49.8 ± 10.3 vs. 13.4 ± 11.2 cm/s, p < 0.01) were evident and SEC had resolved in all patients. Paroxysmal AFL: Radiofrequency energy delivered in sinus rhythm had no significant effect on any of the above indexes of LA or LAA function and no patient developed SEC following RFA.Conclusions. Radiofrequency ablation of chronic AFL is associated with significant LA stunning and the development of SEC. Left atrial stunning is not secondary to the RF energy application itself. Sustained sinus rhythm for 3 weeks leads to resolution of these acute phenomena. Left atrial stunning occurs in the absence of direct current shock or antiarrhythmic drugs, suggesting that its mechanism may be a function of the preceding arrhythmia rather than the mode of reversion.     

Baseline characteristics of patients with atrial fibrillation: the AFFIRM Study

Background Although anticoagulation therapy is accepted for most patients with atrial fibrillation, 2 different strategies exist for management of the cardiac rhythm: atrial fibrillation is allowed to persist while the ventricular rate is controlled; and atrial fibrillation is converted, and an attempt is made to maintain sinus rhythm. Methods The Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) Study was a randomized clinical trial that compared these 2 strategies. We report the baseline characteristics of the patients enrolled in the AFFIRM Study. Results More than 7400 patients at more than 200 North American hospitals and clinics qualified for enrollment in the AFFIRM Study. A total of 4060 patients were enrolled in the AFFIRM Study. The average age of patients enrolled was 70 years, with 39% female and 89% white. Hypertension was present in 71%. Coronary artery disease was present in 38%. Echocardiography was performed in 3311 patients, and results showed normal ventricular function in 68% and normal left atrial size in 33%. Most patients with recurrent episodes had symptoms with atrial fibrillation. Approximately one third of patients were enrolled with a first episode of atrial fibrillation. Conclusion The AFFIRM Study enrolled 4060 predominantly elderly patients with atrial fibrillation to compare ventricular rate control with rhythm control. The patients in the AFFIRM Study were representative of patients at high risk for complications from atrial fibrillation, which indicates that the results of this large clinical trial will be relevant to patient care. (Am Heart J 2002;143:991-1001.)     

非瓣膜性心房颤动复律后左心房收缩功能改变与心房肌细胞凋亡的关系

目的:研究非瓣膜性心房颤动患者复律后左房收缩功能改变与心房肌细胞凋亡之间的关系。方法:超声观察27例患者(病例组)经药物复律后第1、15、30天时的二尖瓣血流并与15例窦性心律者(对照组)作比较,TUNEL法了解受检者的心房肌细胞凋亡指数。结果:病例组患者复律后15d的房缩期二尖瓣峰速血流、速度积分显著增大,且此后的2周内渐渐增大,而同期的左室舒张早中期血流蜂速、速度积分减小。与对照组相比,病例组心房肌细胞凋亡指数增高[(7.68±1.08)%:(2.16±0.59)%,P<0.05],而复律后第30天时房缩期二尖瓣血流仍较对照组显著减小(P<0.05)。相关分析显示:心房颤动患者心房肌细胞凋亡指数与30d内房缩期二尖瓣峰速血流变化率及速度积分变化率之间呈良好负相关(r=-0.58或-0.52,P<0.05)。结论:心房颤动患者恢复窦性心律后左房收缩功能的改变与其心房肌细胞凋亡有相关性,后者可能在一定程度上参与了影响患者复律后左房功能恢复的过程。     

Transesophageal atrial pacing using a pill electrode for the termination of atrial flutter

To determine the efficacy of transesophageal rapid atrial pacing with a "pill-electrode" for the termination of atrial flutter, we studied 14 consecutive unselected patients presenting with atrial flutter of various etiologies. The bipolar pill-electrode (interelectrode distance 13 mm) was introduced orally without sedation. Of 14 pacing attempts, atrial capture was obtained in 13 (93 percent), and sustained alteration in rhythm (atrial fibrillation, sinus rhythm or type 2 flutter) in 12 (86 percent). Normal sinus rhythm occurred in six (43 percent), in all of whom it was preceded by transient atrial fibrillation. There was no difference in baseline flutter rates, pacing rates for atrial capture, or duration of flutter between patients reverting to sinus rhythm and those remaining in flutter or converting to atrial fibrillation. Pacing was well tolerated in all but one subject. Thus, esophageal pacing with the pill-electrode was simple to perform, well-tolerated and highly successful for atrial capture in patients with atrial flutter. Although it had a lower success rate than DC cardioversion in producing sinus rhythm, the simplicity of application makes it a useful initial alternative, particularly in patients in whom cardioversion may be hazardous.     

Effect of low-dose isoproterenol infusion on left atrial appendage function soon after cardioversion of chronic atrial tachyarrhythmias

BACKGROUND: Cardioversion of chronic atrial fibrillation or atrial flutter to sinus rhythm is often associated with transient atrial mechanical dysfunction, i.e. 'atrial stunning', which may increase the risk of subsequent thromboembolic events. We hypothesized that, because of its positive inotropic action, a low-dose isoproterenol infusion might improve postcardioversion atrial mechanical function. METHOD: Eighteen patients (15 male, three female; 12 atrial fibrillation, six atrial flutter; mean age 65+/-10 years) exhibiting atrial postcardioversion stunning were included in the study. Isoproterenol was infused for 10 min at a dose sufficient to increase the heart rate by about 10%. Using transesophageal echocardiography, both the left atrial appendage emptying/filling flow velocity and function (fractional area change) were examined at baseline, before isoproterenol (immediately after cardioversion) and after isoproterenol. RESULTS: With infusion of 0.005-0.008 microg/kg/min isoproterenol, heart rate increased by 11.1+/-2.9%, and left atrial appendage emptying velocity, which was diminished following cardioversion, increased significantly (P<0.001) (baseline, before and after isoproterenol: 41.1+/-18.0, 20.3+/-8.5 and 27.3+/-9.6 cm/s, respectively). No major complications were associated with isoproterenol infusion. CONCLUSIONS: Short-term infusion of low-dose isoproterenol improved atrial function after cardioversion of chronic atrial fibrillation and atrial flutter.     

Failure of rapid atrial pacing in the conversion of atrial flutter

Rapid atrial pacing, at rates of 150 to 600/min with stimulus strength up to 15 ma, was attempted in 15 patients with atrial flutter. In 13 of the patients, atrial capture was achieved with changes in both atrial and ventricular rates. In 7 of these, flutter resumed upon cessation of pacing. In the other 6, rapid atrial pacing produced atrial fibrillation which persisted until cardioversion. In 2 patients, atrial capture could not be obtained because of increased atrial refractoriness secondary to flutter. Thus, rapid atrial pacing was ineffective in converting atrial flutter to normal sinus rhythm in all 15 patients. This was in contrast to direct-current cardioversion which was successful in 12 of the patients, in all of whom stable sinus rhythm developed. The 3 patients who did not undergo cardioversion subsequently experienced spontaneous conversion to sinus rhythm. These results suggest that rapid atrial pacing has little place in the management of atrial flutter.     

Stunning of the Left Atrium after Conversion of Atrial Fibrillation: Predictor for Maintenance of Sinus Rhythm?

Recurrence of atrial fibrillation (AF) after cardioversion (CV) to sinus rhythm (SR) is determined by various clinical and echocardiographic parameters. The aim of this study was to determine the value of mitral inflow A-wave velocity, performed at 24 hours after CV in estimation of AF recurrence. The study group consisted of 187 consecutive patients with nonvalvular atrial fibrillation, who had been cardioverted to SR from 1998 to 2000. Transthoracic echocardiography was performed in all cases recruited for the study 24 hours after CV. Left atrial (LA) diameter, left ventricular ejection fraction, and mitral inflow A-wave velocity were measured. The patients were evaluated in five groups according to their recurrence time (<30 days, 31-90 days, 91-180 days, 181-365 days, and >365 days). Maintenance of SR was determined to have a negative linear correlation with age (r =-0.97, P = 0.006), LA diameter (r =-0.93, P = 0.02), and AF duration (r =-0.93, P = 0.02), while having a positive linear correlation with mitral inflow A-wave velocity (r = 0.96, P = 0.008). In the maintenance of sinus rhythm, age, LA diameter, and AF duration were not affected from the method of CV, while mitral inflow A-wave velocity was found to be affected with the method of CV. No relationship was determined between mitral inflow A-wave velocity and the maintenance of sinus rhythm in those performed electrical cardioversion, while frequency of recurrence was found to be higher in those with slow mitral inflow A-wave velocity who were performed pharmacological cardioversion (r = 0.89, P = 0.004). In conclusion, age, duration of AF, LA diameter, and the mitral inflow A-wave velocity can be used to predict the maintenance of SR after CV.     

Pre-treatment with Irbesartan attenuates left atrial stunning after electrical cardioversion of atrial fibrillation.

AIMS: Left atrial (LA) stunning, the transient impairment of LA function, is responsible for an increased thrombo-embolic risk after cardioversion of atrial fibrillation (AF). Angiotensin receptor blockers (ARBs) attenuate atrial remodelling in AF and could theoretically influence LA stunning. We studied the effect of Irbesartan on LA stunning. METHODS AND RESULTS: We prospectively assigned 50 patients from the outpatient clinic undergoing electrical cardioversion for AF with duration of >4 weeks, into two matched groups: 25 patients were treated with Irbesartan (228+/-93 mg/day) for at least 2 weeks prior to cardioversion (Irbesartan group); 25 patients did not receive ARBs (control group). The groups did not differ concerning age (64+/-13 vs. 63+/-13 years, respectively), AF duration (20+/-18 vs. 20+/-19 weeks), underlying disease, LA diameter (46+/-7 vs. 47+/-9 mm), left ventricular dimensions, and ejection fraction (47.7+/-11.6 vs. 49.7+/-14.5%). We assessed LA appendage emptying velocities (LAAEV) and LA spontaneous echo contrast (LASEC) by transoesophageal echocardiography before and after cardioversion and at 2 weeks, and the A-wave by transthoracic echocardiography after cardioversion, at 2 and at 4 weeks. LA stunning was significantly attenuated in the Irbesartan group. The reduction of LAAEV immediately after cardioversion was significantly less in the Irbesartan group (LAAEV reduction of 9+/-49% from 28+/-9 cm/s before cardioversion to 25+/-13 cm/s immediately afterwards) than in the control group (reduction of 48+/-20% from 34+/-15 cm/s before cardioversion to 16+/-6 cm/s afterwards) (P = 0.048). New or increased LASEC occurred in eight patients (32%) in the Irbesartan vs. 16 patients (64%) in the control group (P = 0.046). CONCLUSION: Irbesartan significantly attenuates LA stunning after electrical cardioversion of AF. Therefore, ARBs may represent an important pharmacological supplementation in patients being prepared for cardioversion.     

Relapse and mortality following cardioversion of new-onset vs. recurrent atrial fibrillation and atrial flutter in the elderly.

AIMS: Trials of rate control vs. rhythm control for atrial fibrillation or flutter included few patients with new-onset arrhythmia. Our objective was to assess the relapse rate and the effect of the relapse of new-onset atrial arrhythmias on mortality after direct-current cardioversion (DCCV). METHODS AND RESULTS: A cohort of 351 patients with atrial fibrillation (new onset in 179) and 126 patients with atrial flutter (new onset in 78) was followed-up after DCCV. Cox proportional hazard models were used. Median age was 74.6 years. Mean follow-up for relapse was 7.7 months; for death, 29.4 months. Patients with new-onset atrial flutter [adjusted hazard ratio (HR) = 1] were more likely to maintain sinus rhythm than the patients with recurrent atrial flutter (adjusted HR = 2.5, P < 0.01), new-onset atrial fibrillation (adjusted HR = 2.4, P < 0.01), or recurrent atrial fibrillation (adjusted HR = 2.7, P < 0.01). Patients with new-onset atrial fibrillation were as likely to have relapses as patients with recurrent atrial fibrillation or flutter. Relapse of atrial arrhythmia after DCCV was associated with increased mortality (adjusted HR= 3.1, P < 0.01). CONCLUSION: DCCV is more successful in maintaining sinus rhythm in patients with new-onset atrial flutter than in patients with new-onset atrial fibrillation. Relapse of atrial arrhythmia after cardioversion is associated with increased mortality.     

Atrial stunning: determinants and cellular mechanisms

Background

Atrial stunning is a transient depression of atrial and atrial-appendage mechanical function after successful cardioversion of atrial fibrillation compared with its precardioversion state.

Method

Atrial stunning associated with different methods of cardioversion of atrial fibrillation and the determinants and cellular mechanisms of atrial stunning were elaborated by thoroughly examining the studies on the subject identified through a comprehensive literature search.

Results and conclusion

Atrial stunning has been reported with all methods of cardioversion of atrial fibrillation, including transthoracic electrical, low-energy internal electrical, pharmacological, and spontaneous. It is a function of the underlying atrial fibrillation becoming apparent at the restoration of sinus rhythm, regardless of the method used for conversion. Unsuccessful cardioversion does not result in atrial stunning. The duration of the preceding atrial fibrillation, atrial size, and underlying structural heart disease are the determinants of atrial stunning. A shorter duration of atrial fibrillation and smaller atrial diameters are associated with a relatively less severe stunning, lasting for a shorter duration. Atrial stunning after cardioversion of atrial fibrillation of <1 week usually resolves within 24 hours, and atrial stunning after cardioversion of chronic atrial fibrillation usually resolves within 4 weeks. Tachycardia-induced atrial cardiomyopathy, atrial cytosolic calcium alterations with down-regulation of the L-type Ca2+ channels and up-regulation of the Na+/Ca2+ exchanger, atrial hibernation with myocyte dedifferentiation and myolysis, and atrial fibrosis are the suggested mechanisms underlying atrial stunning. Atrial stunning determines the risk of postcardioversion thrombus formation in atria and atrial appendages, the duration of postcardioversion anticoagulation therapy, the recovery of the atrial contribution to the ventricular function, and the functional recovery of the patients after successful cardioversion of atrial fibrillation.     

Atrial stunning as predictor of early relapse into atrial fibrillation after cardioversion

Although the high rate of success after cardioversion, less than 50% of patients maintain sinus rhythm for the first year. In view for the high percentage of relapse into atrial fibrillation, it is interesting to analyze the relationship between atrial stunning after cardioversion and relapse into atrial fibrillation. Thus, we evaluated 101 patients with atrial fibrillation and successful cardioversion. Atrial mechanical function was assessed by measures of transmitral peak A wave velocity, determined before and weekly after cardioversion during 1 month. Fifty-five percent of patient relapse into atrial fibrillation during follow-up. No significant differences were found in clinical and echocardiographic variables between the group with and without relapse. However, the group of patients who relapsed into atrial fibrillation showed a lower peak A wave velocity immediately after cardioversion than patients who maintain in sinus rhythm at month (0.44 ± 0.27 vs. 0.60 ± 0.38 m/s p < 0.01). Impaired atrial function improves during the first 14 days after cardioversion.     

心房颤动患者复律前后左心房功能变化的超声研究

目的　探讨心房颤动 ( AF )复律后左心房功能变化的特点。方法　选择 AF病人 96例 ,按心脏节律转复的方式分为自发性复律 ( A)组 2 4例 ,药物复律 ( B)组 40例及直流电复律 ( C)组 3 2例 ;分别应用超声心动图测定其左心房内径和容积 ,计算左心房主动和被动排空容积 ,并评价左心房功能。结果　AF时所有病人的左心房扩大 ,而恢复窦性心律后 A、B及 C组左心房内径降低者分别为 10 0 %、74%及 5 2 %。 62例左心房机械功能正常患者与 3 4例左心房功能降低患者比较有更强的左心房射血力 ( LAEF ) ,这与复律后左心房内径降低有关。左心房功能异常( L AEF<7达因 )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 .72和 -0 .76,P<0 .0 0 1)。左心房主动排空分数降低而管道容积却增加。结论　心房颤动复律后 ,左心房机械功能的延迟恢复与持续存在的的左心房扩大有关     

Successful intracardiac electrical conversion of atrial flutter in patients with complex congenital heart disease

Sixteen patients presenting on 21 occasions with atrial flutter in association with complex congenital heart disease were treated by intracardiac stimulation techniques combined with activation mapping. Nineteen episodes of atrial flutter were successfully converted to sinus rhythm. In the remaining two episodes atrial fibrillation was induced with spontaneous conversion to sinus rhythm within 12 hours in one episode and immediate DC cardioversion to sinus rhythm in the other. Intracardiac stimulation techniques were highly successful in this group and allowed reliable conversion to sinus rhythm without general anaesthesia and high energy cardioversion. In patients with atrial flutter associated with congenital heart disease intracardiac stimulation techniques should be tried first.     

Drug and electrical therapy of supraventricular tachyarrhythmias

This article reviews current pharmacological and electrical approaches to the restoration of sinus rhythm in patients who suffer from atrial fibrillation and atrial flutter. Spontaneous conversion to sinus rhythm occurs in a high proportion of atrial fibrillation of < 24 h duration. Among patients presenting with atrial fibrillation, which was clinically estimated to have lasted < 48 h, the likelihood of cardioversion-related clinical thromboembolism is low, which supports the current practice of early cardioversion without anticoagulation. Antiarrhythmic drugs effective in terminating atrial fibrillation of short duration are those which possess class IA, IC and III properties. Electrical transthoracic cardioversion by using different electrode positions and additional pressure over the electrodes during shock delivery is a highly effective and well-tolerated method in restoration of sinus rhythm even in patients under conscious sedation. Immediate spontaneous reinitiation of atrial fibrillation can occur in a significant proportion of patients undergoing electrical cardioversion and can be reduced after a pretreatment with antiarrhythmic drugs. In patients with failed external cardioversion, internal low energy cardioversion offers an effective option for restoring sinus rhythm. After cardioversion in a high proportion of patients antiarrhythmic drugs are necessary to prevent atrial fibrillation from recurring. A serial cardioversion approach can prevent the evolution of permanent atrial fibrillation in a subgroup of patients. Overdrive atrial pacing is an effective and minimally invasive procedure for termination of atrial flutter. The acute administration of class IA, IC and III antiarrhythmic drugs increases the success rate of this method in restoring sinus rhythm.     

Successful intracardiac electrical conversion of atrial flutter in patients with complex congenital heart disease.

Sixteen patients presenting on 21 occasions with atrial flutter in association with complex congenital heart disease were treated by intracardiac stimulation techniques combined with activation mapping. Nineteen episodes of atrial flutter were successfully converted to sinus rhythm. In the remaining two episodes atrial fibrillation was induced with spontaneous conversion to sinus rhythm within 12 hours in one episode and immediate DC cardioversion to sinus rhythm in the other. Intracardiac stimulation techniques were highly successful in this group and allowed reliable conversion to sinus rhythm without general anaesthesia and high energy cardioversion. In patients with atrial flutter associated with congenital heart disease intracardiac stimulation techniques should be tried first.