Amiodarone after unsuccessful direct-current cardioversion of persistent atrial fibrillation

AIM: To assess the safety and efficacy of amiodarone used after unsuccessful direct current (DC) cardioversion of persistent atrial fibrillation (AF). METHODS: The study group comprised 67 patients (F/M 26/41; mean age 61.3+/-11.2 years) after unsuccessful DC cardioversion (DCC) of persistent AF (mean arrhythmia duration 212.6+/-135.2 days) in whom another attempt of DCC was intended. Repeat DC cardioversion was performed after loading with oral amiodarone, for a period necessary to achieve a cumulative dose of up to 12.0-16.0 g. Pretreatment was an outpatient procedure. After successful DC cardioversion all study subjects received a maintenance dose of amiodarone, 100-200 mg daily, aimed at preventing AF. The follow-up period was 12 months. RESULTS: Spontaneous conversion to sinus rhythm (SR) during amiodarone pretreatment was observed in 13 pts (19.2%). DCC was performed in 54 pts and SR was restored in 41 of the study pts (76%). Complications occurred in 3 pts, including 1 case of apparent hyperthyroidism and 2 cases of decreased TSH level, and required amiodarone withdrawal. After 12 months, 72.2% of pts maintained SR on low dose (179.2+/-42.1 mg/day) amiodarone. Spontaneous conversion to SR during amiodarone loading was significantly related to long-term SR maintenance after successful DC cardioversion (p<0.013; RR 2.01; 95% CI 1.34-3.03). CONCLUSION: Pretreatment with amiodarone and repeat DC cardioversion results in sinus rhythm restoration in about 80.6% of pts with persistent AF after an initial unsuccessful attempt. Direct-current cardioversion can be performed safely taking standard precautions for patients receiving amiodarone. At 12 months after successful repeated DC cardioversion, more than 72.2% of pts on low-dose amiodarone maintain SR.     

Prevention of recurrences of atrial fibrillation by cardiologists established in general office practice: data from the FAUVE observatory

OBJECTIVES: Analyse the modalities of preventive therapy of recurrences of paroxysmal or persistent atrial fibrillation (AF) with Vaughan-Williams (VW) type IC antiarrhythmics. METHODS: Observational study conducted with 326 French cardiologists established in general office practice, involving on the one hand an opinion survey among the cardiologists and on the other hand a cross-sectional observatory of usual medical practice. Each cardiologist was asked to include two patients aged less than 65 with non-permanent (paroxysmal or persistent) AF without left ventricle dysfunction (LVD) and initiated on treatment with a VW type IC antiarrhythmic after cardioversion to sinus rhythm. RESULTS: The opinion survey among the cardiologists indicates that non-permanent AF constitutes 36.1% of AF cases, of which 57.8% concern LVD-free patients. Most cardiologists (85%) declare to institute a preventive therapy of AF recurrences in 70-100% of these patients after cardioversion to sinus rhythm, with a VW type IC antiarrhythmic in more than 50% of cases. Of the 633 patients included in the FAUVE observatory, mainly men, 409 (64.6%) had paroxysmal AF and 224 (35.4%) had persistent AF. Analysis of therapeutic management shows that both alteration of the previous treatment and the choice of a VW type IC antiarrhythmic are based chiefly on efficacy and on tolerability of the antiarrhythmic therapy. CONCLUSION: VW type IC antiarrhythmics constitute a therapy of choice for the maintenance of sinus rhythm in non-aged and LVD-free patients with non-permanent AF.     

氯沙坦联合胺碘酮对阵发性心房颤动复律及复律后窦性心律维持的影响

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

Maintenance of sinus rhythm and recovery of atrial mechanical function after cardioversion with bepridil or in combination with aprindine in long-lasting persistent atrial fibrillation.

BACKGROUND: The aim of this study was to evaluate pharmacological cardioversion of long-lasting persistent atrial fibrillation (AF) using bepridil in terms of recovery of atrial mechanical function and maintenance of sinus rhythm. Bepridil alone or in combination with aprindine is effective for termination of persistent AF. METHODS AND RESULTS: The study group comprised 38 consecutive patients (24 men, 58.8+/-9.3 years) with successful conversion of persistent AF lasting >1 month either pharmacologically (Group I) or electrically (Group II). Fast Fourier transform analysis of fibrillation waves was performed and fibrillation cycle length (FCL) was calculated from the peak frequency. In Group I, sinus rhythm was pharmacologically restored in 22 patients after an average 30 days (7-49 days) of bepridil administration, either alone (11) or in combination with oral aprindine (11); they were followed up while using the same drugs. In Group II, electrical conversion restored sinus rhythm in 16 patients, and they were followed up with conventional antiarrhythmic drugs other than bepridil and aprindine. After bepridil treatment FCL increased and became significantly longer in Group I than in Group II (190+/-39 vs 150+/-29 ms, p<0.001). Atrial peak velocity in transmitral flow within the first week after cardioversion was greater in Group I than in Group II (68+/-35 vs 32+/-20 cm/s, p<0.05). By Kaplan-Meier analysis, 83% of Group I patients were free of AF recurrence at the 12-month follow-up, compared with 36% in Group II (p<0.005). CONCLUSIONS: In patients with long-lasting AF, pharmacological conversion with bepridil alone or in combination with aprindine recovered atrial mechanical function better and maintained sinus rhythm longer than electrical conversion.     

Use of enalapril to facilitate sinus rhythm maintenance after external cardioversion of long-standing persistent atrial fibrillation. Results of a prospective and controlled study.

AIMS: This study aimed to assess whether enalapril could improve cardioversion outcome and facilitate sinus rhythm maintenance after conversion of chronic atrial fibrillation (AF). METHODS AND RESULTS: Patients with chronic AF for more than 3 months were assigned to receive either amiodarone (200mg orally 3 times a day; group I: n=75) or the same dosage of amiodarone plus enalapril (10mg twice a day; group II: n=70) 4 weeks before scheduled external cardioversion. The end-point was the time to first recurrence of AF. In 125 patients (86.2%), AF was converted to sinus rhythm. Group II had a trend to a trend to a lower rate of immediate recurrence of AF than group I did (4.3% vs 14.7%, P=0.067). Kaplan-Meier analysis demonstrated a higher probability of group II remaining in sinus rhythm at 4 weeks (84.3% vs 61.3%, P=0.002) and at the median follow-up period of 270 days (74.3% vs 57.3%, P=0.021) than in group II. CONCLUSIONS: The addition of enalapril to amiodarone decreased the rate of immediate and subacute arrhythmia recurrences and facilitated subsequent long-term maintenance of sinus rhythm after cardioversion of persistent AF.     

Use of bepridil in combination with Ic antiarrhythmic agent in converting persistent atrial fibrillation to sinus rhythm.

BACKGROUND: It has been reported that bepridil is as good as amiodarone in converting persistent atrial fibrillation (AF) to sinus rhythm (SR). The conversion effect of bepridil alone is not always satisfactory, however. The efficacy of pharmacological cardioversion by the combination of bepridil and a class Ic antiarrhythmic drug for persistent AF is studied. METHODS AND RESULTS: The participants comprised 37 consecutive patients in whom pharmacological cardioversion was conducted to treat persistent AF (duration 22.5+/-29.6 months). Each patient first received a class Ia or Ic antiarrhythmic drug, then bepridil alone, then a combined therapy of bepridil at 200 mg/day with a class Ic antiarrhythmic drug at a routine dose. Unaccompanied use of any of the antiarrhythmic drugs achieved pharmacological cardioversion in 14 (38%) of the 37 patients (single therapy group), whereas SR was restored by combination of bepridil and a class Ic antiarrhythmic drug in 22 (combined therapy group) of the remaining 23 patients. The duration of AF was significantly longer in the combined therapy group than in the single therapy group (28.3+/-31.0 vs 7.3+/-4.1 months). CONCLUSION: Combined therapy of bepridil and a class Ic antiarrhythmic drug is efficient for pharmacological cardioversion of refractory long-lasting persistent AF.     

厄贝沙坦与胺碘酮联合对风湿性心脏病持续性心房颤动转复患者的窦性心律维持作用

目的 研究风湿性心脏病持续性心房颤动(房颤)应用厄贝沙坦联合胺碘酮的窦性心律(窦律)维持作用及复发的危险因素.方法 选择住院准备房颤复律且符合入选标准风湿性心脏病(风心病)瓣膜置换术后持续性房颤患者63例.随机分为对照组(31例)和试验组(32例).对照组给予胺碘酮,试验组用胺碘酮+厄贝沙坦.入选患者转复为窦律后即为试验起始时间,试验终点为转复后12个月.终点事件:症状或无症状房颤首次复发.结果 试验组窦律维持率显著高于对照组(68.7%与41.9%,P＜0.05).治疗12个月后,试验组左心房内径(LAD)显著小于对照组[(48.6±4.6)mm与(51.5±4.2)mm,P＜0.05].风心病持续性房颤复发与LAD(OR 1.242)和是否使用厄贝沙坦(OR 0.226)有关.结论 LAD是风心病持续性房颤复发的危险因素.厄贝沙坦联合胺碘酮在风心病持续性房颤复律后维持窦律的疗效优于单用胺碘酮,并能延缓左心房扩大,防止房颤复发.     

The acute treatment of supraventricular tachycardia with endovenous amiodarone

In the present study we evaluated 35 patients of both sexes, aged 21-84, with newly occurring supraventricular tachyarrhythmias, 19 atrial fibrillation (AF), 6 atrial flutter (FL) and 10 paroxysmal supraventricular tachycardias (PSVT). They were treated with a single amiodarone infusion up to two hours after the restoration of a stable sinus rhythm or to a maximus dose of 2,400 mg (in 24 hours). Plasma amiodarone concentration and QTc were measured at the restoration of sinus rhythm and twelve hours after the amiodarone withdrawal. Amiodarone infusion restored a stable sinus rhythm in all 10 patients of the PSVT group (100%), in 5 of the FL group (83%) and in 16 of the AF group (84%). The average dose needed to stop PSVT was lesser than for AF and FL (M + SE: 473.3 +/- 36.88 vs 1842.1 + 259.6 vs 1548.8 +/- 345.5 mg; p less than 0.001). The average plasma amiodarone concentration at the restoration of sinus rhythm was 2450.4 +/- 175.9 SE ng/ml in all the tachyarrhythmias as a whole without any statistically significant difference among PSVT, FL and AF. Moreover no correlation exists between plasma amiodarone concentrations and the amount of amiodarone infused. QTc showed a statistically significant transient lengthening at the restoration of sinus rhythm, but not twelve hours after amiodarone withdrawal. In conclusion, a single dose of amiodarone is effective and safe in all newly occurring supraventricular tachyarrhythmias, without any important side effect and with a high therapeutic index in pharmacologic cardioversion as alternative treatment to cardioversion.     

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.     

Spectral turbulence analysis of the signal-averaged electrocardiogram of the atrial activation as predictor of recurrence of idiopathic and persistent atrial fibrillation

The frequency domain analysis of the P-wave signal-averaged ECG (P-SAECG) is able to identify patients at risk for lone atrial fibrillation (AF) after cardioversion to sinus rhythm. The terminal portion of the P-wave of right precordial leads on 12-lead ECG is associated with electrical abnormalities in the atria. The aim of this study was to assess the spectral turbulence analysis (STA) of the P-SAECG as a predictor of recurrence of idiopathic AF. STA was performed in 41 patients with 2 or more symptomatic episodes of idiopathic and persistent AF after successful electrical cardioversion and drug-free state (Group A), and in 25 control individuals during sinus rhythm (Group B), matched by age, gender, and P-wave duration. The orientation of the terminal portion (positive or negative) of the Z-lead was assessed as representing right precordial leads potentials. After 6 months follow-up, Group A was divided into two groups according to recurrence: G-A1--at least one recurrence (21 patients), and G-A2--no recurrence (20 patients). Fragmented electrical activity (FEA) was observed in 19 patients of G-A1 and in 2 of G-A2 (odds ratio = 85.5; p<0.001). STA showed 90.5% sensitivity and 90.0% specificity for early recurrence of AF. After 12 months, no patients of G-A2 and 15 of G-A1 developed >3 episodes of persistent AF, being FEA observed in 13 (odds ratio = 14.6, p = 0.002). No episodes of AF were observed in Group B. Average time for recurrence of FEA positive patients (4.3 +/- 0.7 months) was significantly shorter than of G-A2 (7.4+/-0.7 months), and log-rank analysis revealed significant difference of event-free rate over time (p = 0.004). In a logistic regression model FEA, use of amiodarone and a positive terminal portion of the Z-lead of the P-SAECG were independent predictors of recurrence of idiopathic and persistent AF.     

Tissue Doppler imaging analysis at pre-cardioversion time predicts recurrent atrial fibrillation: a 12-month follow-up study

Introduction: Tissue Doppler imaging (TDI) has been extensively used in several clinical settings. We aimed to investigate whether TDI can predict recurrent atrial fibrillation (AF).
Methods and Results: Seventy-four consecutive patients (aged 62.6 ± 11.7 years) with AF (>48 hours and <6 months of duration) who underwent successful external electrical direct current cardioversion and 20 healthy individuals were enrolled. Conventional echocardiography and TDI were prospectively performed before cardioversion. Based on a cutoff point of 5.43 cm/sec for the negative systolic wave velocity (NSWV), derived by the normal controls (mean + 2 SD), patients were divided into Group I (36 patients) with a NSWV >5.43 cm/sec and Group II (38 patients) with NSWV ≤5.43 cm/sec. In Group I, 27.8% of patients were in sinus rhythm at 6 months, but had episodes of asymptomatic paroxysmal AF lasting >48 hours; all patients were in AF at 12 months. In Group II, all patients were in sinus rhythm at 12 months. However, those patients presenting with a NSWV less but near to 5 cm/sec had frequent episodes of asymptomatic paroxysmal AF lasting for <48 hours.
Conclusion: One year after successful direct current cardioversion, TDI analysis at pre-cardioversion time may be a useful marker to identify a subgroup of patients with increased risk for AF recurrence.     

胺碘酮联合氯沙坦预防心房颤动复律后复发

目的观察胺碘酮联合氯沙坦治疗阵发性和持续性心房颤动复律后维持窦性心律的疗效。方法80例具有转复窦性心律指征的阵发性和持续性心房颤动患者随机分为两组,单用胺碘酮治疗组（n=40）和胺碘酮＋氯沙坦治疗组（n=40）,12个月后停用胺碘酮,共随访18个月,观察药物对两组患者窦性心律的维持率及心房重构的影响。结果随访第12月和18月,窦性心律维持率在单用胺碘酮治疗组分别为45．9％和35．1％,在胺碘酮＋氯沙坦治疗组分别为79．5％和56．0％;胺碘酮＋氯沙坦组显著高于胺碘酮组（P均〈0．05）。胺碘酮＋氯沙坦组转变为永久性心房颤动患者（8例）显著低于单用胺碘酮治疗组（13例）,（P〈0．05）。左心房直径在单用胺碘酮组治疗前后有显著变化[治疗前（37．7±6．2）mm,治疗18月后时39．2±6．5mm）（P〈0．05）],而胺碘酮＋氯沙坦组无显著改变[治疗前（38．1±5．8）mm,治疗18月后（38．4±6．1）mm]。结论胺碘酮联合氯沙坦能提高心房颤动复律后维持窦性心律的疗效和防止心房结构重构。     

A study of platelet activation in paroxysmal, persistent and permanent atrial fibrillation.

We hypothesized that the 'residual' thromboembolic risk in therapeutically anticoagulated patients undergoing cardioversion could potentially be related to abnormal haemorheology and platelet activation. To test this hypothesis, we firstly investigated the role of haemorheology and platelet activation in patients with paroxysmal and persistent atrial fibrillation (AF), who were compared with healthy controls and patients with permanent AF. Second, we compared these indices in patients with persistent AF, before and after successful cardioversion. We measured indices of haemorheology (haematocrit, plasma viscosity, and fibrinogen), fibrin D-dimer (an index of thrombogenesis and fibrin turnover) and platelet activation (as assessed by platelet aggregation and plasma levels of beta-thromboglobulin, and soluble P-selectin) in 29 patients with paroxysmal AF, 87 patients with permanent AF and 29 healthy controls in sinus rhythm. The effects of cardioversion were studied in 20 patients with persistent AF, who maintained sinus rhythm at 2 months follow-up. Plasma levels of beta-thromboglobulin (P = 0.03) and fibrin D-dimer (P = 0.001) were higher in patients with AF, when compared with controls; the highest levels were seen in those with permanent AF (Tukey's test, < 0.05). Plasma viscosity was significantly higher in the patients with paroxysmal AF compared with healthy controls (P = 0.02). Plasma soluble P-selectin levels and platelet aggregation responses to all four platelet agonists (adenosine diphosphate, collagen, epinephrine and thrombin) in patients with paroxysmal AF and permanent AF were similar to controls. Plasma fibrinogen, viscosity and other markers of platelet activation (including platelet aggregation) were not significantly different in patients with paroxysmal AF, during episodes of AF and sinus rhythm (P = not significant), although mean haematocrit was significantly higher during the episodes of AF compared with episodes of sinus rhythm (P = 0.03). Among the patients with persistent AF who remained in sinus rhythm at 2 months following successful cardioversion, there was a significant decrease in the plasma levels of soluble P-selectin at 2 weeks and 2 months, when compared with baseline (pre-cardioversion) levels (P < 0.001). Haemorheology and platelet aggregation response to agonists did not change significantly, except for a transient increase in platelet aggregation response to collagen at 2 weeks (P = 0.045). In conclusion. abnormal haemostatic and platelet activation in patients with permanent AF are not consistently observed in patients with paroxysmal and persistent AF. Abnormal haemorheology appears to play an important role in patients with paroxysmal AF, especially during the paroxysms of AF. Cardioversion of persistent AF to sinus rhythm appears to decrease the platelet activation, but whether this translates into a beneficial reduction in thromboembolic risk requires further study.     

Intravenous amiodarone for cardioversion of recent-onset atrial fibrillation

BACKGROUND: Atrial fibrillation (AF) is one of the most common causes of hospital admission, with a prevalence of up to 5% of the population, increasing with advancing age. Emergency direct current cardioversion is the therapy of choice when arrhythmia leads to hemodynamic compromise, but in patients who are hemodynamically stable, antiarrhythmic drugs are usually given to restore sinus rhythm. HYPOTHESIS: The study was undertaken to assess the efficacy of intravenous amiodarone in cardioversion of recent-onset paroxysmal atrial fibrillation (AF). No standard antiarrhythmic therapy has been accepted for pharmacologic cardioversion of AF. Amiodarone seems to be a promising candidate, but only few randomized trials are available and the results are inconsistent. METHODS: In all, 160 patients with AF lasting < 24 h were randomly assigned (2:1 fashion) to the amiodarone group (n = 106) receiving 5 mg/kg as a 30 min intravenous (i.v.) infusion, followed by i.v. infusion of 10 mg/kg during 20 h diluted in 1000 ml of 10% glucose with 20 IU of rapid-action insulin, 80 mEq of potassium chloride, and 8 g of magnesium sulphate (GIKM), or to the control group (n = 54) receiving 1000 ml of GIKM alone. Treatment was continued up to 20 h independent of sinus rhythm restoration. RESULTS: Sinus rhythm was restored 20 h after initiation of therapy in 88 (83%) patients in the amiodarone group and in 24 (44%) patients in the control group (p < 0.0001). The difference between efficacy of the two treatment modalities became significant already after 8 h of therapy (53 vs. 14 patients with sinus rhythm, respectively, p < 0.05). The mean dose of amiodarone administered until sinus rhythm restoration was 740 +/- 296 mg. The presence and the type of underlying heart disease did not influence the conversion rate in either group. In two patients (1.8%) treated with amiodarone, the return of sinus rhythm was preceded by asystole. CONCLUSION: Amiodarone is effective in the termination of AF lasting < 24 h. It may be particularly useful in patients with organic heart disease in whom class I antiarrhythmic agents may be contraindicated. During treatment, the heart rhythm should be monitored continuously.     

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

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

Stunning of the left atrium after pharmacological cardioversion of atrial fibrillation

INTRODUCTION: Stunning of the left atrium and atrial appendage is a well known but not fully clarified phenomenon observed during the cardioversion of atrial fibrillation regardless of the cardioversion method attempted. AIM: To assess the effects of propafenone and amiodarone on left atrium and left atrial appendage contractility. METHODS: Forty patients with paroxysmal atrial fibrillation (20 females, 20 males), aged 60-83 (mean 72.0+/-10.1) years, were enrolled into the study. Half of these patients had sinus rhythm restored by the administration of oral propafenone (150-300 mg) and the remaining 20 patients were treated with intravenous amiodarone (150-450 mg). The control group consisted of 20 patients (10 females, 10 males) aged 52-78 (mean 61.2+/-9.3) years with sinus rhythm and no history of atrial fibrillation. All the patients had a transthoracic (TTE) and transesophageal (TEE) echocardiography performed while still in the AF, before drug administration and 1 hour after sinus rhythm restoration. RESULTS: All haemodynamic parameters of the left atrium measured after the sinus rhythm restoration were significantly worse when compared with the control group. Left atrial fractional shortening and total atrial fraction were significantly lower after propafenone than amiodarone (8.6+/-3.6% vs 11.7+/-5.5%, p<0.05; and LA FC 16.2+/-5.3% vs 23.3 (+/-6.3)% respectively, p<0.05). Doppler echocardiographic parameters included in the analysis such as mitral flow and superior left pulmonary vein flow were significantly lower in the sinus rhythm restoration group than in the control group. Among them the end-diastolic mitral flow velocity amplitude and flow velocity integral as well as the maximum pulmonary retrograde velocity were significantly worse in the group treated with propafenone than in patients receiving amiodarone. All the atrial appendage Doppler velocity parameters were significantly reduced after the sinus rhythm restoration in both groups. In the patients treated with propafenone, values of these parameters were significantly decreased compared with the patients receiving amiodarone. CONCLUSIONS: Successful pharmacological cardioversion of atrial fibrillation causes the left atrium and left atrial appendage contractility impairment similar to that observed with other methods of the sinus rhythm restoration. Following the AF cardioversion the level of left atrial stunning is higher in the patients treated with propafenone than in subjects receiving amiodarone.     

Time to Cardioversion of Recurrent Atrial Arrhythmias After Catheter Ablation of Atrial Fibrillation and Long‐Term Clinical Outcome

Introduction: It is unclear whether early restoration of sinus rhythm in patients with persistent atrial arrhythmias after catheter ablation of atrial fibrillation (AF) facilitates reverse atrial remodeling and promotes long‐term maintenance of sinus rhythm. The purpose of this study was to determine the relationship between the time to restoration of sinus rhythm after a recurrence of an atrial arrhythmia and long‐term maintenance of sinus rhythm after radiofrequency catheter ablation of AF. Methods and Results: Radiofrequency catheter ablation was performed in 384 consecutive patients (age 60 ± 9 years) for paroxysmal (215 patients) or persistent AF (169 patients). Transthoracic cardioversion was performed in all 93 patients (24%) who presented with a persistent atrial arrhythmia: AF (n = 74) or atrial flutter (n = 19) at a mean of 51 ± 53 days from the recurrence of atrial arrhythmia and 88 ± 72 days from the ablation procedure. At a mean of 16 ± 10 months after the ablation procedure, 25 of 93 patients (27%) who underwent cardioversion were in sinus rhythm without antiarrhythmic therapy. Among the 46 patients who underwent cardioversion at ≤30 days after the recurrence, 23 (50%) were in sinus rhythm without antiarrhythmic therapy. On multivariate analysis of clinical variables, time to cardioversion within 30 days after the onset of atrial arrhythmia was the only independent predictor of maintenance of sinus rhythm in the absence of antiarrhythmic drug therapy after a single ablation procedure (OR 22.5; 95% CI 4.87–103.88, P < 0.001). Conclusion: Freedom from AF/flutter is achieved in approximately 50% of patients who undergo cardioversion within 30 days of a persistent atrial arrhythmia after catheter ablation of AF.     

Effect of low-dose amiodarone on atrial fibrillation or flutter in Japanese patients with heart failure.

The efficacy and safety of amiodarone in the management of atrial fibrillation (AF) or flutter in 108 Japanese patients with heart failure was retrospectively examined. Thirty-four (41%) of the 82 patients who were in sinus rhythm after 1 month of amiodarone administration had their first recurrence, 70% of cases occurring within 1 year of initiation. The cumulative rates of maintenance of sinus rhythm were 0.68, 0.55, and 0.47 at 1, 3, and 5 years, respectively. Amiodarone was more effective in maintaining sinus rhythm in patients with paroxysmal AF or flutter than in those with the persistent form (p<0.05). The cumulative rates for cases that remained in permanent AF were 0.04, 0.11, and 0.14 at 1, 3, and 5 years, respectively. Apart from suppressing AF, the mean heart rate during Holter monitoring was significantly decreased with amiodarone therapy in cases of permanent AF. Adverse effects requiring the discontinuation of amiodarone therapy occurred in 16% of patients. Low-dose amiodarone therapy may prevent AF or flutter in Japanese patients with heart failure.     

A randomized comparison of external and internal cardioversion of chronic atrial fibrillation.

BACKGROUND. Delivery of shocks within the right atrium has been reported to be more effective than conventional external shocks in converting atrial fibrillation (AF), but these two cardioversion techniques have never been compared prospectively. The purpose of this study was to compare the efficacies of external and internal cardioversion in patients with chronic AF unresponsive to prior attempts at electrical and/or pharmacological cardioversion. Low-dose amiodarone was used in all patients after cardioversion to suppress recurrences of AF. METHODS AND RESULTS. One hundred twelve patients with AF of at least 1 month in duration were randomly assigned to undergo external cardioversion with 300-360-J shocks or internal cardioversion with 200-300-J shocks delivered through a standard electrode catheter within the right atrium. The patients were treated with amiodarone (200 mg/day 5-7 days/week) for 1 month before electrical cardioversion and afterward if the cardioversion was successful. The patients were evaluated at regular intervals during 1 year of follow-up. The efficacy of internal cardioversion was significantly greater than that of external cardioversion (91% versus 67%, p = 0.002). The only variable that was associated with the outcome of cardioversion was body weight. Among patients in whom sinus rhythm was restored, AF recurred as often after internal and external cardioversion; at 1 year of follow-up, 37% of patients in whom external or internal cardioversion had been effective were still in sinus rhythm. Patients who had undergone an attempt at electrical cardioversion before entry into this study were less likely to remain in sinus rhythm after cardioversion. The only complications of cardioversion were one instance of cerebral thromboembolism after external cardioversion and one instance of transient pulmonary edema after internal cardioversion. Therapy with amiodarone was discontinued because of an adverse drug effect in only three patients. CONCLUSIONS. Internal cardioversion is more effective than external cardioversion in restoring sinus rhythm and is as safe as external cardioversion in patients with chronic AF. The recurrence rate of AF is the same after both types of cardioversion. If conventional electrical cardioversion is ineffective, internal cardioversion should be attempted. The combination of low-dose amiodarone and external or internal cardioversion may result in maintaining sinus rhythm long-term in patients with refractory AF.     

Long-term outcome in patients with chronic atrial fibrillation after successful internal cardioversion

Internal cardioversion is safe and effective in restoring sinus rhythm, even in patients with persistent AF of prolonged duration. Up to 40% to 50% of patients with AF lasting >1 year but <3 years could be maintained in sinus rhythm using a class III antiarrhythmic drug after successful internal cardioversion, and amiodarone appears to be more effective than sotalol in this patient population.