Improvement in exercise performance after successful cardioversion in patients with persistent atrial fibrillation and symptoms of heart failure

BACKGROUND: Loss of atrial systolic function as well as fast and irregular ventricular response result in the impairment of hemodynamic function in patients with atrial fibrillation (AF). AF is considered to be a less efficient cardiac rhythm than sinus rhythm (SR), and accounts for the symptoms of reduced exercise tolerance, such as fatigue, tiredness or dyspnoea. In more severe cases, the hemodynamic alterations can result in heart failure. AIM: To assess exercise performance before and one month after cardioversion of persistent AF. METHODS: We studied 42 patients with mild to moderate clinically stable heart failure and persistent AF (median duration 7 months) with controlled ventricular rate. They underwent submaximal exercise testing 24 hours before cardioversion and one month after cardioversion. Exercise capacity was determined during symptom-limited exercise testing, according to a modified Bruce protocol with peak VO(2) analysis. RESULTS: Thirty-five (83%) patients were successfully cardioverted to SR. One month after cardioversion 29 patients remained in SR (SR group) while 6 had recurrence of AF, and, together with patients with unsuccessful cardioversion, formed the AF group (n=13). Baseline patient characteristics did not differ between the SR and AF groups. Left ventricular ejection fraction (52.7+/-10.2% vs 56.5+/-9.6%, NS) and exercise tolerance (peak VO(2) 19.85+/-3.5 ml/min/kg vs 22.2+/-3,4 ml/kg/min, NS; and exercise duration 9.5+/-3.4 min vs 10.6+/-2.4 min; NS) were similar in both groups before cardioversion. Successful cardioversion resulted in a mean decrease in resting heart rate of 28 beats/minute (94.7+/-10.3 vs 66.7+/-9.7 beats/min, p<0.05), measured 30 days after cardioversion, and a significant improvement in exercise tolerance in the SR group: exercise duration increased from 9.5+/-3.4 min to 13.7+/-3.2 min, p<0.05; and peak oxygen consumption increased from 19.85+/-3.5 ml/min/kg to 32.2+/-3.6 ml/min/kg, p<0.05. No improvement was observed in the AF group. CONCLUSIONS: Restoration of sinus rhythm in patients with persistent AF is associated with a significant improvement in exercise capacity one month after cardioversion.     

Prevention of atrial fibrillation recurrence by statin therapy in patients with lone atrial fibrillation after successful cardioversion

The aim of this study was to investigate the effect of statin therapy on arrhythmia recurrence in patients with lone atrial fibrillation (AF). From July 1998 to December 1999, 62 patients with lone persistent AF lasting >/=3 months underwent successful external cardioversion. After a mean follow-up of 44 months, 85% had recurrence of AF. The use of statins was associated with a significant decrease in the risk of arrhythmia recurrence after successful cardioversion of AF. The result of this retrospective study demonstrates that the use of statins in patients with lone AF was associated with a significant decrease in the risk of arrhythmia recurrence after successful cardioversion.     

心力衰竭合并心房颤动患者的心脏再同步化治疗

心力衰竭患者中有很大一部分合并心房颤动,这类患者也可存在不同程度的机械不同步运动,心脏再同步化治疗(CRT)可以改善他们的心功能、运动耐量及生活质量。但这些患者容易产生双室起搏不完全,使CRT有效性明显降低。有试验证明房室结消融能提高这类患者CRT的成功率。该文将对心力衰竭合并心房颤动的流行病学特征、病理机制、CRT及房室结消融在CRT中的必要性进行叙述。     

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.     

Lack of prevention of heart failure by serial electrical cardioversion in patients with persistent atrial fibrillation

OBJECTIVE—To investigate the occurrence of heart failure complications, and to identify variables that predict heart failure in patients with (recurrent) persistent atrial fibrillation, treated aggressively with serial electrical cardioversion and antiarrhythmic drugs to maintain sinus rhythm.DESIGN—Non-randomised controlled trial; cohort; case series; mean (SD) follow up duration 3.4 (1.6) years.SETTING—Tertiary care centre.SUBJECTS—Consecutive sampling of 342 patients with persistent atrial fibrillation (defined as > 24 hours duration) considered eligible for electrical cardioversion.INTERVENTIONS—Serial electrical cardioversions and serial antiarrhythmic drug treatment, after identification and treatment of underlying cardiovascular disease.MAIN OUTCOME MEASURES—heart failure complications: development or progression of heart failure requiring the institution or addition of drug treatment, hospital admission, or death from heart failure.RESULTS—Development or progression of heart failure occurred in 38 patients (11%), and 22 patients (6%) died from heart failure. These complications were related to the presence of coronary artery disease (p < 0.001, risk ratio 3.2, 95% confidence interval (CI) 1.6 to 6.5), rheumatic heart disease (p < 0.001, risk ratio 5.0, 95% CI 2.4 to 10.2), cardiomyopathy (p < 0.001, risk ratio 5.0, 95% CI 2.0 to 12.4), atrial fibrillation for < 3 months (p = 0.04, risk ratio 2.0, 95% CI 1.0 to 3.7), and poor exercise tolerance (New York Heart Association class III at inclusion, p < 0.001, risk ratio 3.5, 95% CI 1.9 to 6.7). No heart failure complications were observed in patients with lone atrial fibrillation.CONCLUSIONS—Aggressive serial electrical cardioversion does not prevent heart failure complications in patients with persistent atrial fibrillation. These complications are predominantly observed in patients with more severe underlying cardiovascular disease. Randomised comparison with rate control treatment is needed to define the optimal treatment for persistent atrial fibrillation in relation to heart failure.     

Prediction of successful cardioversion and maintenance of sinus rhythm in patients with lone atrial fibrillation

OBJECTIVE: We aimed to prospectively investigate the predictive value of echocardiographic parameters for the prediction of successful cardioversion and long-term sinus rhythm (SR) maintenance in patients who have experienced a lone episode of atrial fibrillation (AF). MEASUREMENTS AND RESULTS: Clinical and echocardiographic data, including mean left atrial appendage (LAA) peak flow velocity and mitral annulus motion, were analyzed in 78 consecutive patients (mean [+/- SD] age, 59.3 +/- 9.3 years) with AF lasting > 48 h and < 6 months. Sixty-one patients (78%) underwent successful external electrical cardioversion, while the remaining remained in AF. At the 1-year follow-up, of the 61 patients who had successfully been converted to SR, 24 (39.3%) remained in SR. For predicting the success of the cardioversion, we used a model consisting of two variables. LAA flow velocity (> 20 cm/s) and left ventricular (LV) fractional shortening (> 30%) appear to be quite strong, yielding 83.3% correct results. For predicting the maintenance of SR, we used a model consisting of two variables. The absence of the early systolic abnormal mitral annulus motion and LAA flow velocity (> 20 cm/s) appears to be quite strong, yielding 84.6% correct results. LAA flow velocity only marginally enters the model, and, if removed, little predictive value is lost (dropping to 83.3%). Removing the early systolic abnormal mitral annulus motion variable, the prediction value drops significantly to 70.5%. CONCLUSION: LAA flow velocity combined with LV fractional shortening can predict the success of the conversion of AF to SR. Additionally, LAA flow velocity, combined with the analysis of mitral annulus motion before cardioversion, can predict the long-term maintenance of SR.     

心房颤动合并心力衰竭的非药物治疗

心房颤动和心力衰竭是两个互相促进、发生、发展的疾病,在同一患者中常常同时存在.对于这类患者房颤的最佳处理仍存在争议,抗心律失常药物疗效有限且不良反应明显,本文主要介绍心房颤动合并心力衰竭的非药物治疗.     

心脏再同步化治疗顽固性心力衰竭合并心房颤动

目的总结心脏再同步化治疗(CRT)合并心房颤动(房颤)的心力衰竭(心衰)的疗效,分析这类患者CRT反应的可能原因。方法 2003年3月至2007年3月接受CRT合并房颤的难治性心衰患者5例,4例为扩张型心肌病,1例为缺血性心肌病,NYHA心功能Ⅲ～Ⅳ级。4例经冠状窦途径成功置入左室电极,1例冠状窦途径失败后行右室双部位起搏(流出道间隔部和心尖部)。结果术后平均随访(12±13)个月,所有患者术后临床症状均有不同程度的改善,NYHA分级提高0+～2级;生活质量和活动耐力均有改善。平均双室起搏比例(90±9)%,其中第2、4、5例术后频发室性早搏,平均双室起搏比例偏低(77%～83%)。第2例加用胺碘酮后比例由83%升至95%,NYHA分级提高2级。5例患者先后于术后1～33个月死亡,直接死亡原因为室性心律失常者2例,心衰恶化者3例。结论 CRT同样可以使合并持续性房颤的难治性心衰患者受益,可以提高生活质量、活动耐力。保证完全的双室起搏是合并房颤的心衰患者对CRT反应的关键因素之一。合并房颤的难治性心衰患者可能更需要在严重心衰早期积极地选择CRT。部分合并房颤的难治性心衰患者,在行CRT同时应考虑植入除颤器。     

Cardiac resynchronization therapy in patients with heart failure and atrial fibrillation: importance of new-onset atrial fibrillation and total atrial conduction time

Aims: Cardiac resynchronization therapy (CRT) is an established therapyfor patients with heart failure and sinus rhythm (SR), but itsvalue in atrial fibrillation (AF) remains unclear. Furthermore,response to CRT may be difficult to predict in these patients.The aim of our study was to investigate whether predictors forCRT success differ between patients with AF and SR and to studythe influence of present or developing AF on response to CRT. Methods and results: We examined consecutive patients in whom CRT was implanted disregardingthe atrial rhythm. Atrial fibrillation was defined as eithercurrent or earlier AF, response to CRT was defined as a decreasein the left ventricular end-systolic volume of 10% after 6 months.Total atrial conduction time (TACT), a measure to predict therisk of developing AF, was determined by echocardiography. Weincluded 114 patients, of whom 56 (49%) were known with AF (23current AF and 33 earlier AF). The other 58 patients had nohistory of AF. After 6 months, response in current and earlierAF and that in SR patients was comparable (56, 58 and 55%, respectively).In AF patients, multivariate analysis revealed a shorter TACTat baseline [odds ratio (OR) 16.7 (1.5–185.3), P = 0.02]and an interventricular mechanical delay (IVMD) >40 ms [OR10.4 (1.0–110.9), P = 0.05] as predictors for response.Non-responders more frequently suffered from new-onset AF (P= 0.02). Conclusion: Failure to CRT is associated with new-onset AF. Total atrialactivation time may be a parameter to predict response in AFpatients.     

Brain natriuretic peptide predicts successful cardioversion in patients with atrial fibrillation and maintenance of sinus rhythm

BACKGROUND: Brain natriuretic peptide (BNP) is released from the heart by hemodynamically induced muscle stretch. Patients with atrial fibrillation have higher levels of BNP than those in sinus rhythm. OBJECTIVE: To assess the usefulness of BNP as a predictor of successful cardioversion in patients with persistent atrial fibrillation and subsequent maintenance of sinus rhythm. SUBJECTS AND METHODS: Twenty patients undergoing cardioversion for persistent atrial fibrillation were enrolled. BNP levels were measured before electric cardioversion, and 30 min and two weeks after cardioversion. Baseline echocardiograms and 12-lead electrocardiograms were obtained from all patients. Patients with valvular disease, previous mitral valve surgery or significant left ventricular dysfunction were excluded. RESULTS: The mean BNP level and the mean heart rate were significantly higher before cardioversion than 30 min after (197+/-132 pg/mL versus 164+/-143 pg/mL, P=0.02, and 77+/-17 beats/min versus 57+/-12 beats/min, P=0.0007, respectively). Patients who reverted back to atrial fibrillation after two weeks had a baseline BNP of 293+/-106 pg/mL, while those who remained in sinus rhythm for two weeks had a lower baseline BNP of 163+/-122 pg/mL (P=0.02). CONCLUSION: In patients with persistent atrial fibrillation, BNP levels are associated with successful cardioversion and maintenance of sinus rhythm two weeks after cardioversion.