Four-year efficacy of cardiac resynchronization therapy on exercise tolerance and disease progression: the importance of performing atrioventricular junction ablation in patients with atrial fibrillation.

OBJECTIVES: The goal of this study was to investigate the effects of cardiac resynchronization therapy (CRT) in heart failure patients with permanent atrial fibrillation (AF) and the role of atrioventricular junction (AVJ) ablation. BACKGROUND: Cardiac resynchronization therapy has been proven effective in heart failure patients with sinus rhythm (SR). However, little is known about the effects of CRT in heart failure patients with permanent AF. METHODS: Efficacy of CRT on ventricular function, exercise performance, and reversal of maladaptive remodeling process was prospectively compared in 48 patients with permanent AF in whom ventricular rate was controlled by drugs, thus resulting in apparently adequate delivery of biventricular pacing (>85% of pacing time), and in 114 permanent AF patients, who had undergone AVJ ablation (100% of resynchronization therapy delivery). The clinical and echocardiographic long-term outcomes of both groups were compared with those of 511 SR patients treated with CRT. RESULTS: Both SR and AF groups showed significant and sustained improvements of all assessed parameters (model p < 0.001 for all parameters). However, within the AF group, only patients who underwent ablation showed a significant increase of ejection fraction (p < 0.001), reverse remodeling effect (p < 0.001), and improved exercise tolerance (p < 0.001); no improvements were observed in AF patients who did not undergo ablation. CONCLUSIONS: Heart failure patients with ventricular conduction disturbance and permanent AF treated with CRT showed large and sustained long-term (up to 4 year) improvements of left ventricular function and functional capacity, similar to patients in SR, only if AVJ ablation was performed.     

Echocardiographic changes and predictors of arrhythmia recurrence after long-term use of the atrial defibrillator

BACKGROUND: The patient-activated atrial defibrillator allows patients to cardiovert themselves from atrial fibrillation soon after the onset of symptoms. The long-term effects of early cardioversion from persistent atrial fibrillation on left ventricular performance and left atrial size are unknown. METHODS: Eighteen patients, mean age 63.4, 83% male, had the Jewel((R)) AF atrial defibrillator implanted for persistent atrial fibrillation only. Transthoracic echocardiography was performed 3-monthly following implant. Parasternal long axis measurements were taken using conventional M-mode techniques. RESULTS: Over follow-up of 28.0+/-9 months, 377 episodes of persistent atrial fibrillation were terminated by patient-activated cardioversion (median 15 per patient). Echocardiographic measurements at implant were; left atrium 44+/-6 mm, left ventricular end-diastolic diameter 49+/-7 mm, left ventricular end-systolic diameter 34+/-7 mm, fractional shortening 33+/-10% and ejection fraction 65+/-17%. After 1 year there had been a significant decrease in mean left atrial size to 41+/-6 mm (P=0.02) and an increase in mean ejection fraction to 73+/-8% (P=0.04). At long-term follow-up however, all parameters reverted to pre-implant levels. Baseline echocardiographic variables did not predict which patients would demonstrate serial increases in sinus rhythm duration between shocks during long-term follow-up. Patients on antiarrhythmic drug therapy however were more likely to demonstrate "sinus rhythm begetting sinus rhythm". CONCLUSIONS: Use of the atrial defibrillator for spontaneous persistent atrial fibrillation is associated with a medium-term (1 year) reduction in left atrial size and an increase in ejection fraction. These changes were not maintained in the long-term. Synergistic therapy with antiarrhythmic drugs may prolong periods of sinus rhythm between arrhythmia recurrences.     

Open heart radio frequency left atrial compartmentation during mitral valve surgery: an alternative to the labyrinth procedure?

The authors report their experience of radiofrequency left atrial compartimentation during open heart mitral valve surgery on 37 patients with a 42 +/- 12 months history of atrial fibrillation. The preoperative left ventricular ejection fraction was 62 +/- 8%; the left atrial diameter was 59 +/- 11 mm. The mean operative time was 245 +/- 60 minutes, which included 19 +/- 5 minutes for the ablation procedure. There were 2 early postoperative deaths and 2 deaths from non-cardiac causes at 3 and 6 months. The left ventricular ejection fraction and left atrial dimension were significantly decreased at the time of hospital discharge (54 +/- 12% and 51 +/- 7 mm respectively) (p < 0.01). After an average follow-up of 1 year, 81% of patients were free of atrial fibrillation: 6 patients had undergone DC cardioversion and 1 had a dual-chamber pacemaker. Patients in sinus rhythm after the ablation were associated with shorter periods of atrial fibrillation and smaller left atrial dimensions postoperatively than those who remained in fibrillation. The authors conclude that radiofrequency compartimentation of the left atrium associated with antiarrhythmic therapy can interrupt atrial fibrillation in 81% of patients at 1 year: the ablation procedure takes only 8% of the operation time. Predictive factors of success of ablation should be defined to determine which patients benefit most from this technique.     

Left ventricular-based cardiac stimulation post AV nodal ablation evaluation (the PAVE study)

BACKGROUND: Chronic right ventricular pacing has been reported to promote cardiac dyssynchrony. The PAVE trial prospectively compared chronic biventricular pacing to right ventricular pacing in patients undergoing ablation of the AV node for management of atrial fibrillation with rapid ventricular rates. METHODS AND RESULTS: One hundred and eighty-four patients requiring AV node ablation were randomized to receive a biventricular pacing system (n = 103) or a right ventricular pacing system (n = 81). The study endpoints were change in the 6-minute hallway walk test, quality of life, and left ventricular ejection fraction. Patient characteristics were similar (64% male; age: 69 +/- 10 years, ejection fraction: 0.46 +/- 0.16; 83%, NYHA Class II or III). At 6 months postablation, patients treated with cardiac resynchronization had a significant improvement in 6-minute walk distance, (31%) above baseline (82.9 +/- 94.7 m), compared to patients receiving right ventricular pacing, (24%) above baseline (61.2 +/- 90.0 m) (P = 0.04). There were no significant differences in the quality-of-life parameters. At 6 months postablation, the ejection fraction in the biventricular group (0.46 +/- 0.13) was significantly greater in comparison to patients receiving right ventricular pacing (0.41 +/- 0.13, P = 0.03). Patients with an ejection fraction 相似文献   

Relationship between efficacy of antiarrhythmic drug therapy and structural remodeling in patients with paroxysmal atrial fibrillation

OBJECTIVES: To evaluate whether the response to antiarrhythmic drug therapy in patients with paroxysmal atrial fibrillation affects the development of structural remodeling in the left atrium and ventricle. METHODS: This study included 230 patients (158 men and 72 women, mean age 67 +/- 11 years) in whom antiarrhythmic drug therapy was attempted for > or = 12 months to maintain sinus rhythm (mean follow-up period 45 +/- 27 months). The patients were divided into three groups according to the response to antiarrhythmic drug therapy: group A consisted of 78 patients without recurrence of atrial fibrillation, group B consisted of 87 patients with recurrence of atrial fibrillation and electrical and/or pharmacological cardioversion to restore sinus rhythm, and group C consisted of 65 patients with permanent conversion despite antiarrhythmic drug therapy. RESULTS: In group A, left atrial dimension (LAD), left ventricular end-diastolic dimension (LVDd), and left ventricular ejection fraction (LVEF) did not change after antiarrhythmic drug therapy. In group B, LAD increased significantly after antiarrhythmic drug therapy (from 32.6 +/- 6.4 to 36.0 +/- 6.5 mm, p < 0.01), Whereas either LVDd or LVEF did not change after antiarrhythmic drug therapy. In group C, LAD increased significantly after antiarrhythmic drug therapy (from 37.3 +/- 7.0 to 40.5 +/- 7.9 mm, p < 0.01) and LVEF was significantly reduced after antiarrhythmic drug therapy (from 69.4 +/- 6.2% to 66.5 +/- 8.9%, p < 0.05). LVDd did not change after antiarrhythmic drug therapy. The plasma concentration of human atrial natriuretic peptide during sinus rhythm at the initiation of antiarrhythmic drug therapy in group A (30.5 +/- 26.7 pg/ml) was significantly lower than those in group B (48.0 +/- 49.7 pg/ml) and group C (49.7 +/- 39.5 pg/ml). CONCLUSIONS: The development of structural remodeling in human myocardium can be prevented with antiarrhythmic drug therapy if sinus rhythm is maintained without recurrence of atrial fibrillation in patients with paroxysmal atrial fibrillation.     

Pharmakotherapie der supraventrikulären Rhythmusstörungen

Supraventricular tachycardias consist of AV-nodal-reentrant-tachycardias, atrioventricular tachycardias with accessory pathways (WPW-syndrome), atrial tachycardias, atrial fibrillation and atrial flutter. Only specific ECG interpretation with an exact arrhythmia classification offers the way to perform modern differential therapy including drug treatment and also interventional therapy modalities. In atrial fibrillation, drug treatment is still first-line therapy: physicians have to make a decision either to follow the rate or rhythm control concept. In case of rhythm control, drug therapy is tailored to the individual patient taking into account the patients symptomatology, left ventricular ejection fraction and nature and degree of an underlying cardiac disease. Drug refractory symptomatic atrial fibrillation patients should be considered for interventional treatment like pulmonary vein ablation. Recurrent typical right atrial flutter, AV-nodal-reentrant-tachycardia and all forms of atrioventricular tachycardias however are indications for catheter ablation; long-term drug treatment will only be performed in rare cases.     

心脏再同步治疗在心功能不良伴心房颤动患者中的临床疗效分析

目的 探讨心房颤动（房颤）患者经过房室结消融后心脏再同步治疗(CRT)的临床疗效。方法 将80例在本院接受CRT的心功能不良患者按术前心律分为两组：房颤组（15例）、窦性心律组(65例),房颤组患者在CRT治疗同时行房室结消融。房室结消融和CRT术前收集患者基本信息如年龄、性别、心功能（NYHA分级）、病程、糖尿病和高...     

慢性心力衰竭合并持续性心房颤动患者心脏再同步治疗术后房室结消融及药物控制心室率疗效观察

目的观察慢性心力衰竭合并持续性心房颤动（房颤）患者心脏再同步治疗（CRT）的疗效,比较房室结消融术及药物控制心室率两种方法疗效的差异。方法慢性心力衰竭合并持续性房颤患者,符合CRT植入适应证并接受CRT或心脏再同步治疗除颤器（CRT—D）植入术,术后随机分为两组,房室结消融组以及药物治疗组,术后随访观察患者临床症状及心功能改善等情况,比较两组的疗效。结果共人选了26例患者,其中房室结消融组14例,药物控制组12例。术前两组患者间心功能,左心室舒张末期内径（LVEDD）,左心室射血分数（LVEF）及用药等基本情况差异无统计学意义。CRT术后随访结果,房室结消融组双心室起搏比例100％,药物治疗组双心室起搏比例72．0％±9．7％。与药物治疗组相比,房室结消融组LVEDD略有缩小[（61．0±6．9）mm对（62．0±7．8）mm],但差异无统计学意义（P=0．08）,LVEF改善明显（0．41±0．06对0．35±0．04）,差异有统计学意义（P=0．04）,提示房室结消融组疗效更佳。结论对慢性心力衰竭合并持续性房颤患者,CRT可以改善患者心功能,CRT术后行房室结消融可以提高有效的双心室起搏比例,进一步提高CRT疗效。     

Does atrial fibrillation in elderly patients with chronic heart failure limit the efficacy of carvedilol? Suggestions from an observational study.

BACKGROUND: No clinical investigation provided any information about a possible influence of atrial fibrillation on the response to beta-blocker therapy in elderly patients with chronic heart failure (CHF). The aim of this study was to observe carvedilol effects in a cohort of patients > 70 years of age with CHF due to left ventricular dysfunction and with chronic atrial fibrillation. METHODS: An observational, 12-month prospective clinical and echocardiographic study was carried out on 240 patients > 70 years of age with heart failure due to systolic dysfunction, 64 of whom with atrial fibrillation. RESULTS: After 1 year of beta-blocker treatment, patients with atrial fibrillation and those in sinus rhythm showed similar benefits, in terms of symptomatic improvement (deltaNYHA -0.44 if atrial fibrillation vs -0.57 if sinus rhythm, p = NS), reduction of events (death + hospitalizations -38 vs -15%), recovery of cardiac function (left ventricular ejection fraction delta +8.8 vs +9.4%, p = NS; left ventricular end-diastolic volume delta -17.2 vs -12.5 ml, p = NS), and reduction in mitral regurgitation (delta -042 vs -0.57, p = NS). No difference was found between the two study groups regarding left ventricular end-diastolic volume reduction (12% in atrial fibrillation patients and 18% in sinus rhythm patients, p = NS) and prevalence of the "reverse remodeling" phenomenon (22 and 21%, respectively, p = NS). CONCLUSIONS: In CHF patients > 70 years of age, beta-adrenergic blockade was shown to be equally effective in improving symptoms and left ventricular geometry and function in patients with atrial fibrillation or in sinus rhythm, without any adjunctive sign of long-term clinical deterioration.     

Prognostic significance of atrial fibrillation in advanced heart failure. A study of 390 patients

BACKGROUND. Atrial fibrillation is common in advanced heart failure, but its prognostic significance is controversial. METHODS AND RESULTS. We evaluated the relation of atrial rhythm to overall survival and sudden death in 390 consecutive advanced heart failure patients. Etiology of heart failure was coronary artery disease in 177 patients (45%) and nonischemic cardiomyopathy or valvular heart disease in 213 patients (55%). Mean left ventricular ejection fraction was 0.19 +/- 0.07. Seventy-five patients (19%) had paroxysmal (26 patients) or chronic (49 patients) atrial fibrillation. Compared with patients with sinus rhythm, patients with atrial fibrillation did not differ in etiology of heart failure, mean pulmonary capillary wedge pressure on therapy, or embolic events but were more likely to be receiving warfarin and antiarrhythmic drugs and had a slightly higher left ventricular ejection fraction. After a mean follow-up of 236 +/- 303 days, 98 patients died: 56 (57%) died suddenly, and 36 (37%) died of progressive heart failure. Actuarial 1-year overall survival was 68%, and sudden death-free survival was 79%. Actuarial survival was significantly worse for atrial fibrillation than for sinus rhythm patients (52% versus 71%, p = 0.0013). Similarly, sudden death-free survival was significantly worse for atrial fibrillation than for sinus rhythm patients (69% versus 82%, p = 0.0013). By Cox proportional hazards model, pulmonary capillary wedge pressure on therapy, left ventricular ejection fraction, coronary artery disease, and atrial fibrillation were independent risk factors for total mortality and sudden death. For patients who had pulmonary capillary wedge pressure of less than 16 mm Hg on therapy, atrial fibrillation was associated with poorer 1-year survival (44% versus 83%, p = 0.00001); however, in the high pulmonary capillary wedge pressure group, atrial fibrillation did not confer an increased risk (58% versus 57%). CONCLUSIONS. Atrial fibrillation is a marker for increased risk of death, especially in heart failure patients who have lower filling pressures on vasodilator and diuretic therapy. Whether aggressive attempts to maintain sinus rhythm will reduce this risk is unknown.     

Atrial fibrillation in the elderly

Atrial fibrillation is the most common arrhythmia in the United States, whose incidence is greatest in the elderly population. This rhythm disorder can be paroxysmal or chronic and is associated with a range of clinical conditions from palpitations and dyspnea to stroke and death. In the elderly the mainstay of treatment of atrial fibrillation should utilize drug therapy. The main goals of drug therapy should be effective rate control to avoid tachycardia-induced cardiomyopathy, anticoagulation to reduce the risk of stroke and thromboembolism, and maintenance of sinus rhythm to prevent adverse atrial remodeling. In those patients in whom effective rate control cannot be achieved, catheter ablation of the atrioventricular node and implantation of a permanent pacemaker should be considered. Catheter ablation of atrial fibrillation by targeting pulmonary venous foci or pulmonary venous isolation currently remains investigational and we advocate its use be limited to symptomatic patients who have failed traditional therapy.     

Assessment of upgrading to biventricular pacing in patients with right ventricular pacing and congestive heart failure after atrioventricular junctional ablation for chronic atrial fibrillation.

AIMS: Effects of cardiac resynchronization therapy (CRT) in patients with right ventricular pacing and congestive heart failure (CHF) have only been reported in limited series. CRT in patients with atrial fibrillation remains controversial. Patients with AV junctional ablation offer a unique opportunity to study the effects of CRT in patients with right ventricular pacing combined with atrial fibrillation. The aims of the present study were to evaluate the effects of upgrading to biventricular pacing patients with CHF, permanent atrial fibrillation, and prior ablation of the atrioventricular (AV) junction followed by conventional right ventricular pacing. METHODS AND RESULTS: We studied 16 consecutive patients with permanent atrial fibrillation treated by AV junctional ablation. After a mean follow-up of 20+/-19 months (6 weeks to 5 years) they were successfully upgraded to biventricular pacing for severe CHF. Parameters were prospectively evaluated at baseline and at 6 months. The 14 surviving patients at 6 months demonstrated significant improvement (P<0.02) in New York Heart Association class but the exercise test parameters remained unchanged. Cardiothoracic ratio decreased by 5% (P=0.04), end-systolic diameter by 8% (P=0.001), end-diastolic diameter by 4% (P=0.08), systolic pulmonary artery pressure by 17% (P<0.0001) and mitral regurgitation area by 40% (P<0.05). Ejection fraction increased by 17% (P=0.11) and fractional shortening by 24% (P=0.01). CONCLUSION: CRT improves left ventricular performance and functional status in patients with permanent atrial fibrillation and prior remote right ventricular pacing.     

心脏再同步化治疗慢性心衰的临床观察

目的观察心脏再同步化治疗(CRT)慢性心力衰竭(CHF)患者的临床疗效。方法选择2008年1月至2009年8月行CRT的患者32例,其中12例植入再同步心脏转复除颤器(CRT-D)。32例中30例为窦性心律,2例为房颤心律。随访21.5±6.2个月,观察患者NYHA心功能分级、QRS波时限、左室射血分数(LVEF)、左室舒张末内径(LVEDD)、6分钟步行距离(6MWD)、因心功不全住院时间等。结果 32例植入CRT(D)患者中,有24例临床症状明显改善,心功分级降低,LVEF和6MWD增加,QRS波时限、LVEDD减少,因心功不全住院时间明显减少约24.5%(p<0.05)。8例患者心功能没有明显改善,但因心功不全住院时间减少约8.3%(p<0.05)。4例患者记录到室性心律失常事件(12.5%),2例室速经抗心动过速起搏(ATP)有效转复,2例患者因室颤而放电,均成功转复,CRT-D均能有效识别和转复。结论 CRT可明显改善CHF患者的心功能,提高生活质量,缓解临床症状,植入CRT-D可有效预防心源性猝死(SCD)。     

Left atrial size reduction improves the sinus rhythm conversion rate after radiofrequency ablation for continuous atrial fibrillation in patients undergoing concomitant cardiac surgery

BACKGROUND: Radiofrequency (RF) ablation can effectively restore sinus rhythm in the majority of patients with continuous atrial fibrillation (AF). However, no previous randomized studies have discussed the association of left atrial size reduction and the improvement of sinus rhythm conversion rate after radiofrequency ablation for continuous AF. METHODS: This prospective randomized study included 46 patients with continuous AF and cardiac disease. Twenty patients underwent cardiac surgery and radiofrequency ablation (group I). The other 26 patients underwent cardiac surgery and RF ablation combined with left atrial size reduction (group II). The patients were followed for one year postoperatively. Rhythm, neurological complications, and left atrial size were evaluated. RESULTS: At the one-year follow-up sinus rhythm was restored in 61.1 % of patients in group I and 77.3 % of patients in group II. LA diameter, evaluated by echocardiography, was reduced from 60 +/- 15 mm to 55 +/- 8 mm in group I and from 69 +/- 19 mm to 51 +/- 8 mm in group II. One case of stroke was observed postoperatively in each group. In group I one patient suffered a transient ischemic attack. Two patients in each group received transvenous permanent pacemaker implantation. CONCLUSION: Left atrial size reduction improves sinus rhythm conversion rate after RF ablation for continuous atrial fibrillation in patients undergoing concomitant cardiac surgery.     

Effect of percutaneous transvenous mitral commissurotomy for the preservation of sinus rhythm in patients with mitral stenosis

OBJECTIVES: Atrial fibrillation is frequently associated with mitral stenosis and is considered to be an unfavorable factor for the long-term prognosis. The efficacy of percutaneous transvenous mitral commissurotomy(PTMC) was examined for the preservation of sinus rhythm in patients with mitral stenosis after PTMC. METHODS: Long-term clinical data after PTMC were obtained from 71 patients who had undergone PTMC from March 1989 to September 1999. Eighteen patients in sinus rhythm before PTMC were divided into two groups: the SR group(n = 5) who remained in sinus rhythm, and the Af group(n = 13) who showed change from sinus rhythm to persistent or paroxysmal atrial fibrillation after PTMC. RESULTS: Age, sex, mitral valve area(1.4 +/- 0.3 vs 1.2 +/- 0.3 cm2), mean mitral pressure gradient(14.3 +/- 5.5 vs 12.6 +/- 5.9 mmHg), mean left atrial pressure(15.9 +/- 7.6 vs 19.0 +/- 7.7 mmHg), left ventricular end-diastolic pressure(7.5 +/- 2.8 vs 9.3 +/- 3.9 mmHg), left ventricular end-diastolic volume index(77 +/- 13 vs 82 +/- 14 ml/m2), left ventricular ejection fraction(60 +/- 6% vs 55 +/- 4%) and cardiac output(5.1 +/- 0.4 vs 4.9 +/- 0.8 l/m2) before PTMC were not different between the two groups. Changes in mean mitral pressure gradient, mean left atrial pressure and cardiac output immediately after PTMC were not different statistically. Mitral valve area immediately after PTMC was significantly greater in the SR group compared to the Af group(2.3 +/- 0.3 vs 1.8 +/- 0.3 cm2, p < 0.05). The change in mitral valve area was also greater in the SR group(1.0 +/- 0.2 vs 0.6 +/- 0.4 cm2, p < 0.05), but there was no statistical difference in the percentage change of mitral valve area between before and immediately after PTMC(SR group 78 +/- 35% vs Af group 50 +/- 35%). End-diastolic pressure, end-diastolic volume index and ejection fraction immediately after PTMC were not statistically different. CONCLUSIONS: The final mitral valve area immediately after PTMC in the patients with mitral stenosis in sinus rhythm, but not the changes of mean mitral pressure gradient, mean left atrial pressure or cardiac output, is important for the maintenance of sinus rhythm.     

Effects of rhythm regularization and rate control in improving left ventricular function in atrial fibrillation patients undergoing atrioventricular nodal ablation

OBJECTIVES: To assess the relative contributions of rate control and rhythm regularization to left ventricular function in atrial fibrillation (AF) patients undergoing atrioventricular nodal ablation. This was performed by assessing the effect of ventricular rhythm regularization on left ventricular function during AF, and the effect of varying heart rate on left ventricular function after ablation. PATIENTS AND METHODS: Eleven patients with continuous AF and V/VI-R pacemakers undergoing therapeutic atrioventricular nodal ablation were studied. Preablation patients underwent two 30 min observation periods in a randomized, blinded fashion during which they were either in baseline AF (pacer set to default V/VI 50/min) or being paced using a rhythm stabilizing algorithm (RSA) designed to regularize rhythm without changing baseline ventricular rate. Six weeks after ablation, patients were again observed during the two following 30 min periods: pacing at a low clinically indicated rate (69+/-9 beats/min), and pacing at the rapid, mean preablation rate. During all observation periods, left ventricular function was measured continuously using a nuclear vest that provided validated measures of heart rate, ejection fraction, and normalized end-systolic volume (ESV) and end-diastolic (EDV) volume. RESULTS: Before ablation, RSA successfully regularized rhythm, decreasing the coefficient of variation of interbeat intervals 20+/-5% to 10+/-4% (P<0.001). The heart rate with RSA (105+/-19 beats/min) was not significantly different from the baseline AF rate (102+/-21 beats/min). Increased rhythm regularity achieved by RSA significantly improved left ventricular function, decreasing ESV from 62+/-12 units to 57+/-11 units (P=0.03), and increasing the ejection fraction from 31+/-11% to 36+/-11% (P=0.03). After ablation, at the clinically indicated low pacing rate of 69+/-9 beats/min, a much greater improvement in ejection fraction was observed, increasing to 44+/-13% (P=0.005 compared with preablation). However, rapid regular pacing at the mean preablation rate of 110+/-18 beats/min eradicated this improvement, decreasing the ejection fraction to 31+/-8% (P=0.003), and increasing ESV from 53+/-13 units to 62+/-8 units (P=0.006). CONCLUSIONS: Rhythm regularity achieved by a regularizing pacing algorithm can significantly, albeit modestly, improve left ventricular function in AF. However, more marked improvements in left ventricular function seen after ablation are primarily due to rate reduction alone.     

Left ventricular mechanics during right ventricular apical or left ventricular-based pacing in patients with chronic atrial fibrillation after atrioventricular junction ablation

OBJECTIVES: The aim of the study was to evaluate whether left ventricular (LV) mechanics are better under LV-based pacing than under right ventricular (RV) apical pacing in patients with permanent atrial fibrillation (AF) after atrioventricular junction (AVJ) ablation. BACKGROUND: "Ablate and pace" is an acceptable therapy for drug-refractory AF. However, the RV apical stimulation commonly used seems to interfere with the beneficial hemodynamic effect of regularization of heart rhythm. METHODS: The study included 12 patients (5 men, mean age 62 +/- 8.3 years), 6 with impaired and 6 with normal LV systolic function. All of them had a biventricular pacemaker system implanted and underwent atrioventricular node ablation for drug-refractory chronic AF. Using a conductance catheter, we analyzed LV pressure-volume loops during routine coronary angiography in order to evaluate short-term changes in LV mechanics during RV apical and LV-based (LV free wall or biventricular) pacing. RESULTS: Compared with RV pacing, LV-based pacing significantly improved the indexes of LV systolic function (i.e., end-systolic pressure and volume, cardiac index, stroke work, preload recruitable stroke work, maximal rate of rise of LV pressure [dP/dt(max)], LV ejection fraction, and end-systolic elastance). The LV diastolic filling indexes, end-diastolic pressure and volume, were better during LV-based pacing, whereas LV diastolic function indexes, -dP/dt(max), passive diastolic chamber stiffness, and time constant of LV isovolumic relaxation showed no clear change. CONCLUSIONS: In the short term, LV-based pacing is superior to RV apical pacing in terms of contractile function and LV filling after AVJ ablation for drug-refractory AF.     

Anticoagulation Therapy in Patients With Heart Failure Due to Systolic Dysfunction and Sinus Rhythm: Analysis of REDINSCOR Registry

INTRODUCTION AND OBJECTIVES: In patients with heart failure, left ventricular ejection fraction ≤35% and sinus rhythm without conditions such as atrial fibrillation, thrombus or history of thromboembolic events, the use of anticoagulation is controversial. Our objective was to evaluate the anticoagulation strategy in these patients, variables associated with its use, and its effects on various cardiovascular events. METHODS: Of the patients included in the REDINSCOR registry with left ventricular ejection fraction ≤35% and sinus rhythm without other anticoagulation indications (including patients with heart failure from 19 Spanish centres), we compared those who received this treatment with the remaining patients. RESULTS: Between 2007 and 2010, 2263 patients were included, of whom 902 had left ventricular ejection fraction ≤35% and sinus rhythm. Of these, 237 (26%) were receiving anticoagulation therapy. Variables associated with this treatment were a lower left ventricular ejection fraction, ischemic etiology, advanced functional class, wider QRS, larger left atrial diameter, and hospitalization. After 21(11-32) months of median follow-up, there were no significant differences in total mortality (14% versus 12.5%) or stroke (0.8% versus 0.9%). A propensity score adjusted multivariate analysis showed a reduction in a combined end-point including cardiac death, heart transplantation, coronary revascularization, and cardiovascular hospitalization (hazard ratio: 0.74; 95% confidence interval, 0.56-0.97; P=.03) in patients receiving anticoagulation therapy. No information regarding bleeding was collected in the follow-up. CONCLUSIONS: In a large and contemporary series of patients with heart failure, left ventricular ejection fraction ≤35% and sinus rhythm, 26% received anticoagulation therapy. This was not associated with lower mortality or stroke incidence, although there was a reduction in major cardiac events. Full English text available from:www.revespcardiol.org.     

Hemodynamic abnormalities in the left atrial appendage in patients with paroxysmal atrial fibrillation, with special reference to albumin-contrast echocardiographic aspects

AIM: We assessed the prolonged dysfunction of the left atrial appendage caused by paroxysmal atrial fibrillation. METHODS AND RESULTS: Transesophageal echocardiography with intravenous albumin-microspheres (Albunex, 0.2 ml/kg) was performed in 100 consecutive patients (44 patients in sinus rhythm without previous paroxysmal atrial fibrillation: 13 patients in sinus rhythm who had had previous episodes of paroxysmal atrial fibrillation; and 43 patients with sustained atrial fibrillation). We compared the left atrial appendage ejection fraction and degree of opacification in the left atrial appendage with Albunex in the groups. Patients with previous paroxysmal atrial fibrillation had lower left atrial appendage ejection fractions than patients in sinus rhythm without paroxysmal atrial fibrillation (33 +/- 14 vs. 47 +/- 14%, p < 0.001). More than half of the patients (7/13 [54%]) with previous paroxysmal atrial fibrillation showed delayed and incomplete opacification of the left atrial appendage with Albunex. CONCLUSION: We conclude that paroxysmal atrial fibrillation causes left atrial appendage stunning, at least in some patients.     

递进式射频消融逆转伴持续性心房颤动“扩张型心肌病”20例的疗效

目的评价递进式射频消融对于心脏扩大的持续性心房颤动的临床效果。方法20例心脏扩大的持续性心房颤动患者接受在接触式三维标测系统(CARTO)指导下的递进式射频消融治疗,术中尽量终止心房颤动。手术6个月后进行随访,比较患者术前及术后的症状、左心房前后径、左心室舒张末内径、左心室收缩末内径、左心室射血分数。结果 (1)术中有40%的患者在消融过程中直接转复为窦性心律,其余经过电复律后转为窦性心律;(2)术后有15%的患者为阵发性心房扑动,85%的患者维持窦性心律;(3)术后患者症状明显好转,左心房前后径、左心室舒张末内径、左心室收缩末内径纽约心脏协会(NYHA)心功能分级较术前明显好转,差异有统计学意义(P<0.01);左心室射血分数较术前提高,差异有统计学意义(45.00%±15.00%vs.36.50%±19.50%,P<0.05)。结论对于高度选择性的伴有心脏扩大的持续性心房颤动患者进行递进式射频消融治疗是安全的,术后大部分患者可以维持窦性心律,同时心腔发生了逆重构,左心室收缩功能得以改善,心功能不全症状好转。