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

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

厄贝沙坦预防阵发性心房颤动复发作用的观察

目的探讨厄贝沙坦预防心房颤动复发的作用。方法将78例阵发性心房颤动患者随机分为口服胺碘酮组(甲组)和口服胺碘酮加厄贝沙坦组(乙组)各39例,观察窦性心律的维持情况。结果甲、乙两组随访时间分别为304.5±120.6天和272.7±107.4天,差异无显著性意义(P>0.05),窦性心律的维持率分别为56.41%和76.31%,差异有显著性意义(P<0.05)。结论厄贝沙坦可预防心房颤动的复发。     

Long-short sequence may predict immediate recurrence of atrial fibrillation after external cardioversion.

AIM: We thought, that analysis of surface electrocardiograms recorded immediately after electrical external cardioversion (EC) might enlighten the mechanisms responsible for immediate recurrence of atrial fibrillation (AF) and especially to test whether atrial ectopic beats (PAC) with long-short (LS) sequence are related to the recurrence of arrhythmia after cardioversion in patients with chronic AF. METHODS AND RESULTS: One hundred and thirty-seven patients (mean age 57+/-7 years) undergoing EC for chronic AF entered the study. Evaluation of the patients included clinical history, physical examination, ECG, routine laboratory tests, and transthoracic echocardiography. The cardioversion was performed with monophasic waveform shock and immediately after successful EC, 1 min of recording of the ECG lead II was analysed. One hundred and twenty patients (87%) of 137 patients enrolled in the study had had successful EC and 33 (27%) of them experienced immediate recurrence of AF within 1 min (Group I) and 87 patients had no arrhythmia recurrence (Group II). In group I in 24 patients (73%) recurrence of AF was initiated by PAC with LS sequence. In only 12 of 87 (13%) patients who did not experience immediate recurrence of AF (Group II) PACs were recorded. CONCLUSIONS: Atrial ectopic beats (PACs) with LS sequence, being responsible for AF relapse in about 70% of patients, might predict early re-initiation of arrhythmia after EC. Electrocardiograms, recorded immediately after EC, are a potentially feasible approach in establishing the patterns of AF relapse that may be useful in the management of AF recurrence.     

胺碘酮对阵发性心房颤动射频消融术后复发的影响

心房颤动（房颤）是临床上最常见的心律失常,虽然迂10年来房颤的导管消融发展迅速,消融方法日渐完善,但术后仍存在较高的复发率。近年的研究表明房颤消融术后与期应用抗心律失常药物可以降低早期的房颤复发率^[1],任能否降低房颤的远期复发率仍存在争议心^[2-3]。本研究的目创是探讨胺碘酮对阵发性房颤患者导管消融术后近期和远剪复发率的影响。     

Predictors of atrial fibrillation recurrence in patients with long-lasting atrial fibrillation

BACKGROUND:

Limited data are available on the predictors of atrial fibrillation (AF) recurrence in patients with chronic AF.

OBJECTIVES:

To evaluate potential clinical, echocardiographic and electrophysiological predictors of AF recurrence after internal cardioversion for long-lasting AF.

METHODS:

A total of 99 consecutive patients (63 men and 36 women, mean age 63.33±9.27 years) with long-standing AF (52.42±72.02 months) underwent internal cardioversion with a catheter that consisted of two defibrillating coils. Shocks were delivered according to a step-up protocol. Clinical follow-up and electrocardiographic recordings were performed on a monthly basis for a 12-month period or whenever patients experienced symptoms suggestive of recurrent AF.

RESULTS:

Ninety-three patients (93.94%) underwent a successful uncomplicated cardioversion, with a mean atrial defibrillation threshold of 10.69±6.76 J. Immediate reinitiation of AF was observed in 15 patients (15.78%) of whom a repeated cardioversion restored sinus rhythm in 13 cases. Early recurrence of AF (within one week) was observed in 12 of 93 patients (12.90%). At the end of the 12-month follow-up period, during which seven patients were lost, 42 of the 86 remaining patients (48.84%) were still in sinus rhythm. Multivariate regression analysis showed that left atrial diameter (OR 1.126, 95% CI 1.015 to 1.249; P=0.025) and mitral A wave velocity (OR 0.972, 95% CI 0.945 to 0.999; P=0.044) were significant and independent predictors of AF recurrence, whereas age, left ventricular ejection fraction and AF cycle length were not predictive of arrhythmia recurrence.

CONCLUSION:

The present study showed that the left atrial diameter and mitral A wave velocity are the only variables associated with AF recurrence after successful cardioversion.     

Effects of verapamil and ibutilide on atrial fibrillation and postfibrillation atrial refractoriness

INTRODUCTION: Early recurrence of atrial fibrillation (AF) after cardioversion may be related to shortening of the atrial effective refractory period (ERP). This study compared the effects of verapamil and ibutilide on AF cycle length (AFCL), atrial ERP, and susceptibility to recurrent AF. METHODS AND RESULTS: In 33 adults, the atrial ERP was measured at basic drive CLs of 350 and 500 msec before and after a brief episode of pacing-induced AF. During AF, verapamil, ibutilide, or saline was infused in 11 patients each. Shortening of the post-AF atrial ERP was attenuated by verapamil and prevented by ibutilide. AFCL shortened by 32+/-21 msec in the verapamil group (P < 0.01), prolonged by 44+/-14 msec in the ibutilide group (P < 0.001), and did not change in the control group. AF converted to sinus rhythm within 10 minutes less often after verapamil (0%) than after ibutilide (82%) or than in the control group (73%). Post-AF, AF lasting > 10 minutes was induced more often in the verapamil group than in the ibutilide group (26% vs 0%; P = 0.01). Another 10 patients received verapamil or ibutilide in the absence of AF. Atrial ERP was unchanged after verapamil and prolonged after ibutilide. CONCLUSION: Verapamil shortens AFCL and impedes the conversion of induced AF, whereas ibutilide prolongs AFCL and does not impede the early conversion of induced AF. Ibutilide is more effective than verapamil in preventing pos     

Effect of verapamil on prevention of atrial fibrillation in patients implanted with an implantable atrial defibrillator.

BACKGROUND: The role of verapamil in the prevention of atrial fibrillation (AF) in patients with recurrent AF is unknown. HYPOTHESIS: The aim of this study was to evaluate the effect of verapamil on the prevention of AF in patients implanted with an implantable atrial defibrillator (IAD). METHODS: The effects of verapamil (240 mg/day) on the total duration of AF, number of AF recurrences, and number of cardioversions were prospectively evaluated in a randomized, crossover fashion over an 8-week period in 11 patients (9 men, 2 women; mean age: 60 +/- 6 years) implanted with an IAD. RESULTS: Implantable atrial defibrillators successfully converted 13 of 14 (93%) spontaneous episodes of AF. There was no significant difference in the efficacy of cardioversion (86 vs. 100%, p = 0.8), the total duration of AF (173 +/- 198 vs. 270 +/- 241 h, p = 0.5), the number of AF episodes (8.5 +/- 9.0 vs. 9.3 +/- 10.2, p = 0.3), and the number of cardioversions (1.7 +/- 2.4 vs. 1.8 +/- 2.1 p = 0.7) with or without treatment with verapamil. CONCLUSIONS: The results of the present study suggest that treatment with verapamil has no significant effect on the prevention of AF in patients treated with an LAD.     

左旋氨氯地平对阵发性房颤并高血压患者房颤的影响

目的观察左旋氨氯地平对阵发性房颤并高血压患者P波离散度（Pd）、左房内径、高敏C反应蛋白（hs—CRP）水平、房颤发作情况的影响。方法将阵发性房颤并高血压患者100例随机分为治疗组（50例）和对照组（50例）。降压药物治疗组给予左旋氨氯地平,对照组给予坎地沙坦,随访1年,观察治疗前后Pd、左房内径、hs—CRP水平及房颤发作情况。结果至随访结束,在长期应用胺碘酮的患者中,对照组房颤复发17例,占81．0％,治疗组房颤复发22例,占95．7％,两组之间差异无统计学意义（x^2=1．122,P〉0．05）。未长期应用胺碘酮的患者,对照组、治疗组在7-12个月时房颤发作次数均较治疗前减少（t=2．823,P〈0．01;t=2．655,P〈0．05）,但两组之间差异无统计学意义（t=0．594,P〉0．05）。与治疗前比较,对照组、治疗组的Pd、左房内径、hs—CRP均降低（t=4．025-13．546,P〈0．01）,治疗后两组之间Pd、左房内径、hs—CRP比较,差异无统计学意义（t=1．234-1．514,P〉0．05）。结论左旋氨氯地平可减少阵发性房颤并高血压患者房颤的复发,降低Pd、左房内径和hs—CRP水平,其效果与坎地沙坦没有差异。     

Impact of atrial fibrillation duration on postcardioversion recurrence

BACKGROUND: "Begetting," a mechanistic tenet of atrial fibrillation (AF), stipulates that the rate of recurrence of AF after cardioversion is proportional to the preceding arrhythmia duration. However, recent reports suggest that, for brief durations, the incidence of early recurrence of AF (ERAF) is inversely proportional to duration. These reports were based on potentially biased data. OBJECTIVES: We performed a prospective study to examine the impact of AF duration on postcardioversion recurrence. METHODS: Forty-four patients underwent placement of an implantable cardioverter-defibrillator (ICD) capable of delivering patient-elicited AF cardioversion shocks. Subsequently, in the ambulatory setting, the timing of shocks in relationship to perceived AF onset was randomly assigned within individuals to early (as soon as possible) or delayed (1 day later). RESULTS: During a follow-up averaging 199 days per patient, a total of 61 AF episodes among 17 patients occurred for which a patient-elicited cardioversion shock was delivered. Twenty-three shocks were delivered using early protocol (mean 6.8 hours after AF onset), and 38 shocks were delivered using delayed protocol (mean 34.7 hours after AF onset). The incidence of ERAF was significantly lower using the delayed protocol. CONCLUSION: A strategy of approximately 24-hour delay in cardioversion shock timing decreased the incidence of ERAF, relative to a shock delivered within a few hours of AF onset. This observation has important mechanistic and therapeutic implications.     

Fatal ventricular fibrillation following verapamil in Wolff-Parkinson-White syndrome with atrial fibrillation

A 29-year-old man with Wolff-Parkinson-White syndrome and atrial fibrillation developed fatal ventricular fibrillation shortly after receiving intravenous verapamil. The patient presented with an irregular pulse of 190. A total of 23 mg of verapamil was administered in small intravenous doses over 35 minutes. The ventricular rate accelerated as verapamil was administered, and fatal ventricular fibrillation followed. Three theoretical mechanisms by which verapamil may enhance conduction of atrial fibrillation in Wolff-Parkinson-White syndrome, predisposing to ventricular fibrillation, are mentioned.     

典型心房扑动对心房颤动导管消融复发的影响

目的 评价典型心房扑动(房扑)对心房颤动(房颤)导管消融复发的影响.方法 120例药物治疗无效的阵发性房颤患者在三维电解剖标测系统和肺静脉环状标测电极导管联合指导下行环肺静脉电隔离.其中17例(14.2%)合并典型房扑(房扑组,其余作为对照组),行三尖瓣环峡部消融,三尖瓣环峡部消融终点为三尖瓣环峡部双向阻滞.房颤复发定义为导管消融3个月后发生房性快速心律失常.结果 房扑组房颤病程(9.8±10.7)年,长于对照组(5.9±6.3)年,差异有统计学意义(P=0.036).房扑组与对照组相比,年龄、性别、合并器质性心脏病、左心房直径、左心室射血分数差异无统计学意义.随访91～401(237±79)d,房扑组房颤复发率为47.1%,对照组房颤复发率为12.6%,两组间差异有统计学意义(P=0.001).经校正年龄、房颤病程、合并器质性心脏病、左心房直径等因素,Cox多因素分析发现消融术前合并房扑是房颤复发的独立危险因素(危险比3.52,95%可信区间1.32～9.34,P=0.012).结论 典型房扑可能增加房颤导管消融术后房颤的复发,房颤导管消融前应对患者是否合并典型房扑进行认真评价.     

睡眠时长对心房颤动患者射频消融术后复发的影响

目的:探讨不同睡眠时长(SD)对心房颤动患者射频消融术后复发的影响。方法:入选2017年2月至2017年10月,在北京安贞医院首次接受导管射频消融治疗的432例心房颤动患者,定期随访并收集患者的睡眠时长、心电图、24 h动态心电图及超声心动图等资料。根据术后第6个月的睡眠时长,将患者分为三组:睡眠时长不足组(SD≤6 h)、睡眠时长正常组(6SD8 h)、睡眠时长过多组(SD≥8 h)。结果:随访至术后第6个月, 330例患者维持窦性心律,97例患者复发,4例患者失访,1例患者死亡。睡眠时长正常组患者的窦性心律维持率明显高于睡眠时长不足组和睡眠时长过多组(85.9%vs. 60.7%vs. 69.5%,P0.001)。多因素Cox回归分析显示左心房内径(HR=1.060, 95%CI:1.004～1.118)、睡眠时长不足(HR=2.643, 95%CI:1.540～4.535)及睡眠时长过多(HR=1.920, 95%CI:1.120～3.290)是消融术后心房颤动复发的独立危险因素。结论:睡眠时长不足或过多是心房颤动患者射频消融术后复发的危险因素。     

Effect of atorvastatin on the recurrence rates of atrial fibrillation after electrical cardioversion

To study the effect of atorvastatin on recurrence of atrial fibrillation (AF) after electrical cardioversion (EC), 48 patients with AF lasting 48 hours who were scheduled for EC were randomized to the atorvastatin (group I) and control (group II) groups. Six patients in group I (25%) and 2 patients in group II (8.3%) had spontaneous conversion before EC (p >0.05). The end point was the recurrence of AF during 3 months of follow-up. Eighteen patients in group I (12.5%) and 11 patients in group II (45.8%) had recurrence (p = 0.01, log-rank test). With the Cox proportional model, the predictors of recurrence included a body mass index of 25 to 30 kg/m2 (relative risk [RR] 0.07, 95% confidence interval [CI] 0.008 to 0.59), body mass index > or = 30 kg/m2 (RR 0.24, 95% CI 0.08 to 0.72), AF duration of > or = 3 months (RR 0.28, 95% CI 0.09 to 0.83), diabetes mellitus (RR 0.34, 95% CI 0.12 to 0.98), and left atrial diameter of > or = 45 mm (RR 0.23, 95% CI 0.07 to 0.74). Atorvastatin was associated with a significantly reduced risk of developing AF (unadjusted RR 0.23, 95% CI 0.064 to 0.82, p = 0.024). This association remained significant after adjustment for these predictors (adjusted RR 0.19, 95% CI 0.052 to 0.72, p = 0.01). High-sensitivity C-reactive protein levels at baseline were not different between the 2 groups (p = 0.92). Although the high-sensitivity C-reactive protein levels decreased significantly 48 hours after EC compared with the baseline levels in group I (2.82 +/- 1.46 vs 2.56 +/- 1.3 mg/dl, p = 0.02), no significant change occurred in group II (2.87 +/- 0.8 vs 2.84 +/- 0.8 mg/dl, p = 0.09). In conclusion, atorvastatin decreased the recurrence rate of AF after EC.     

Effect of valsartan and ramipril on atrial fibrillation recurrence and P-wave dispersion in hypertensive patients with recurrent symptomatic lone atrial fibrillation

BackgroundThis study compared the effect of antihypertensive treatment with valsartan or ramipril on atrial fibrillation (AF) recurrence, on P-wave dispersion, (PWD) and on serum procollagen type I carboxy terminal peptide (PIP).MethodsA total of 369 mild hypertensive (systolic blood pressure (SBP) >140 and/or 90 < diastolic blood pressure (DBP) < 110 mm Hg) outpatients in sinus rhythm but with at least two episodes of AF in the previous 6 months were randomized to valsartan (n = 122), ramipril (n = 124), or amlodipine (n = 123) for 1 year. Clinic blood pressure (BP) and a 24-h electrocardiogram (ECG) were evaluated monthly. Patients were asked to report any episode of symptomatic AF and to perform an ECG as early as possible. PWD and serum PIP levels were evaluated before and after each treatment period.ResultsSBP and DBP were significantly reduced by the three treatments (P < 0.001). A total of 46 (47.4%) patients treated with amlodipine had a recurrence of AF as did 26 (27.9%) patients treated with ramipril (P < 0.01 vs. amlodipine) and 16 (16.1%) patients treated with valsartan (P < 0.01 vs. amlodipine and P < 0.05 vs. ramipril). The Kaplan-Meyer analysis showed a significant reduction of AF episodes in the valsartan group (P = 0.005 log-rank test) as well as in the ramipril group (P = 0.021), even if at a lesser degree. PWD values were significantly reduced by ramipril (-4.2 ms, P < 0.05) and even more by valsartan (-11.2 ms, P < 0.01), the difference being significant (P < 0.01). Serum PIP levels were reduced by ramipril (-49.7 mug, P < 0.001) and valsartan (-49.3 mug, P < 0.001).ConclusionsDespite similar BP lowering, valsartan and ramipril were more effective than amlodipine in preventing new episodes of AF, but the effect of valsartan was greater than that of ramipril. This could be related to the greater PWD reduction observed with valsartan.American Journal of Hypertension (2008). doi:10.1038/ajh.2008.217American Journal of Hypertension (2008); 21, 9, 1034-1039. doi 10.1038/ajh.2008.217.