Depletion of atrial natriuretic peptide during longstanding atrial fibrillation.

This review focuses on the relation between atrial fibrillation (AF) and atrial natriuretic peptide (ANP). ANP is produced by the atria secondary to atrial stretch. By causing atrial stretch, acute AF leads to an increase in plasma ANP concentration, which serves to normalize haemodynamics through natriuresis and vasodilation. However, data have been reported suggesting that prolonged AF, by inflicting structural atrial damage, is associated with a reduced capacity by the atria to produce ANP. An inverse relation was thus demonstrated between the duration of AF and plasma ANP concentration. In addition, a reduced ANP response to exercise has been shown to be predictive of unsuccessful cardioversion of AF to sinus rhythm. Finally, ANP has also been shown to predict outcome after a maze operation. Outcome was poor when preoperative plasma ANP concentration was low. Moreover, a high atrial collagen content, as a measure of atrial degeneration, correlated with low ANP. These data indicate that ANP may serve as a marker of atrial integrity, which may help in selecting AF patients for therapeutic interventions.     

Decreased plasma brain natriuretic peptide levels after a successful maze procedure

BACKGROUND AND AIM OF THE STUDY: Previous reports indicate that plasma levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) increase in atrial fibrillation (AF), but decrease after successful direct current (DC) cardioversion. Although the maze procedure is the only curative therapy for AF, the effects on atrial and left ventricular function remain unclear. The study aim was to determine whether plasma ANP and BNP levels decrease after the maze procedure in patients with mitral valve disease. METHODS: Twenty-seven patients either with (n = 23) or without (n = 4) AF underwent mitral valve surgery; of these patients, 13 underwent a maze procedure for chronic AF. Blood samples and echocardiographic data were obtained before and at one year after surgery. RESULTS: Ten patients with AF achieved sinus rhythm (SR) or junctional rhythm after the maze procedure. In patients subjected to mitral valve surgery, mean plasma levels of ANP and BNP were 59.8 +/- 11.9 and 139.2 +/- 53.7 pg/ml, respectively. ANP and BNP plasma levels fell significantly after surgery (to 32.1 +/- 4.1 and 46.7 +/- 10.2 pg/ml, respectively; p = 0.04 and p = 0.004). In patients with successful maze procedure, plasma levels of BNP and left ventricular end-diastolic dimension (LVDd) were significantly decreased by 35.7% and 82.7% compared with preoperative values (BNP, 35.7 +/- 4.9% for SR versus 83.4 +/- 9.6% for AF, p = 0.008; LVDd, 82.7 +/- 3.7% for SR versus 97.0 +/- 3.2% for AF, p = 0.0159). CONCLUSION: A successful maze procedure significantly decreased LVDd and plasma levels of BNP after surgery. These results show that the maze procedure is effective in improving left ventricular diastolic dysfunction for a mid-term period in patients with mitral valve disease.     

Atrial natriuretic peptide level after cardioversion of chronic atrial fibrillation

Heart endocrine studies concerning patients with chronic atrial fibrillation (AF) have become increasingly important. Atrial natriuretic peptide (ANP) is released from atrial myocytes. The increased level of ANP in patients with AF is probably caused by the hemodynamic effect of the arrhythmia. The aim of this study was to explore plasma ANP levels in patients with chronic AF and to describe plasma ANP concentration changes following sinus rhythm (SR) restoration. The study group was comprised of 42 patients, aged between 43 and 76 years with chronic AF (more than 1 month) and a relatively controlled ventricular response (85.8+/-11.3 beats/min). Plasma ANP levels were measured before and 24 h after AF cardioversion. The control group comprised of 11 subjects. All had normal SR without history of AF and were compatible in age, sex and concomitant diseases with the examined group. ANP level values were expressed as mean+/-standard deviation. The mean plasma ANP level in the AF group was significantly higher than in the control group (59.5+/-15.6 vs. 34.3+/-10.2 pg/ml, P<0,001). Electrical or pharmacological cardioversion was performed in 42 patients. SR was successfully restored in 35 patients. Plasma ANP concentrations decreased significantly from baseline values (from 59.4+/-16.6 to 31.4+/-15.0 pg/ml, P<0.001) 24 h after cardioversion in the successful group, while they remained unchanged (60.2+/-10.7 to 59.4+/-10.4 pg/ml, NS) in patients with an unsuccessful cardioversion. CONCLUSION: The mean concentration of ANP in patients with chronic AF was nearly two-times higher than in the control group with sinus rhythm. Conversion to SR was associated with a significant decrease and normalization in plasma ANP concentrations.     

Atrial size reduction as a predictor of the success of radiofrequency maze procedure for chronic atrial fibrillation in patients undergoing concomitant valvular surgery

INTRODUCTION: Previous studies showed that the surgical maze procedure can restore sinus rhythm and atrial transport function in patients with chronic atrial fibrillation (AF). However, no previous studies discussed the association of atrial size reduction and the success of sinus conversion by the radiofrequency (RF) maze procedure for chronic AF. METHODS AND RESULTS: A total of 119 chronic AF patients undergoing valvular operations were included in this study. Sixty-one patients received RF and cryoablation to create lesions in both atria to simulate the surgical maze II or III procedure (RF maze II or RF maze III; 13 patients, group 1) or a modified maze pattern (RF maze "IV"; 48 patients, group 2). The other 58 patients who underwent valvular operations alone without the maze procedure served as control (group 3). At 3-month follow-up after operation, sinus rhythm was restored in 73%, 81%, and 11% of patients in groups 1, 2 and 3, respectively. Preoperative left and right atrial sizes were not statistically significant predictors of sinus conversion by the RF maze procedure. However, as a result of postoperative reduction of atrial sizes, postoperative left atrial diameter was significantly smaller in patients who had sinus conversion by the RF maze procedure than in patients who did not regain sinus rhythm (45.0+/-7.0 mm vs 51.0+/-8.0 mm; P = 0.03). Postoperative right atrial area of patients who had sinus conversion by the RF maze procedure also was significantly smaller than that of patients who did not regain sinus rhythm (18.1+/-4.4 cm2 vs 28.5+/-8.2 cm2; P = 0.008). CONCLUSION: Atrial size reduction appears to predict the success of sinus conversion with the RF maze procedure used in conjunction with valvular surgery.     

Limited posterior left atrial cryoablation in patients with chronic atrial fibrillation undergoing valvular heart sugery

OBJECTIVES: We sought to evaluate whether a limited surgical cryoablation of the posterior region of the left atrium was safe and effective in the cure of atrial fibrillation (AF) in patients with associated valvular heart disease. BACKGROUND: Extensive surgical ablation of AF is a complex and risky procedure. The posterior region of the left atrium seems to be important in the initiation and maintenance of AF. METHODS: In 32 patients with chronic AF who underwent heart valve surgery, linear cryolesions connecting the four pulmonary veins and the posterior mitral annulus were performed. Eighteen patients with AF who underwent valvular surgery but refused cryoablation were considered as the control group. RESULTS: Sinus rhythm (SR) was restored in 25 (78%) of 32 patients immediately after the operation. The cryoablation procedure required 20 +/- 4 min. There were no intraoperative and perioperative complications. During the hospital period, one patient died of septicemia. Thirty-one patients reached a minimum of nine months of follow-up. Two deaths occurred but were unrelated to the procedure. Twenty (69%) of 29 patients remained in SR with cryoablation alone, and 26 (90%) of 29 patients with cryoablation, drugs and radiofrequency ablation. Three (10%) of 29 patients remained in chronic AF. Right and left atrial contractility was evident in 24 (92%) of 26 patients in SR. In control group, two deaths occurred, and SR was present in only four (25%) of 16 patients. CONCLUSIONS: Linear cryoablation with lesions connecting the four pulmonary veins and the mitral annulus is effective in restoration and maintenance of SR in patients with heart valve disease and chronic AF. Limited left atrial cryoablation may represent a valid alternative to the maze procedure, reducing myocardial ischemic time and risk of bleeding.     

Long-term results of the maze procedure on left ventricular function for persistent atrial fibrillation associated with mitral valve disease

Although the maze procedure is often performed as a surgical treatment for atrial fibrillation (AF) combined with mitral valve surgery, the long-term efficacy of the maze procedure concerning cardiac function has not been determined. The aim of this study was to assess long-term results of the maze procedure for left ventricular function in patients with persistent AF associated with mitral valve disease. We analyzed 38 patients who underwent the maze procedure for persistent AF and mitral valve surgery. The cardiothoracic ratio on chest X-ray and the left atrial dimension, left ventricular end-diastolic dimension, left ventricular end-systolic dimension and left ventricular ejection fraction on transthoracic echocardiography were evaluated before and 6 years after the maze procedure. Twenty-two patients maintained sinus rhythm (SR group) and 16 patients had recurrence of permanent AF (AF group) after the maze procedure. Preoperative cardiac function and the methods of mitral surgery were similar between the two groups. At the latest follow-up, left ventricular function tended to be better in the SR group than in the AF group. Cardiovascular events occurred more often in the AF group during follow-up (50 vs. 18%, p < 0.05). This retrospective study revealed that maintaining the sinus rhythm after the maze procedure for patients who underwent mitral valve surgery might be important for preserving better long-term left ventricular function and result in fewer cardiovascular events.     

The dubious value of echocardiographic and plasma ANP measurements in predicting outcome of cardioversion in patients with persistent atrial fibrillation

Atrial fibrillation (AF) is a common arrhythmia with important therapeutic and prognostic implications. An attempt to restore sinus rhythm is considered in most patients with AF. The aim of this study was to assess the value of echocardiographic examination and plasma atrial natriuretic peptide (ANP) evaluation in predicting the outcome of cardioversion and maintenance of sinus rhythm in patients with persistent AF. METHODS: Eighty-one consecutive patients, aged 62+/-9 years, with AF of duration 4.7 months were subjected to an echocardiography examination and ANP assessment before cardioversion. The patients were predominantly hypertensive men with moderately enlarged left atrium and ejection fraction of left ventricle of about 50%. All patients were in controlled AF and had normalized blood pressure. In order to predict the outcome of cardioversion, and maintenance of sinus rhythm over a 1 month period, a multivariate logistic regression method was performed using the following variables: left atrial and left ventricular dimensions, left ventricular ejection fraction and plasma ANP levels. RESULTS: Sixty-nine out of the 81 patients were successfully converted to sinus rhythm. At 1 month 57 patients remained in sinus rhythm. There were no statistical differences between sinus rhythm and AF group in baseline ANP levels (59.4 vs 64.2 pg/ml, consecutively), clinical and echocardiographic characteristics. In logistic regression analysis neither baseline echocardiographic variable nor ANP level, predicts successful cardioversion over a 1-month period of observation. CONCLUSION: Echocardiographic data and ANP level should not be included as an important variable when considering patients for cardioversion.     

Results of complex left atrial ablation of long-lasting persistent atrial fibrillation

PURPOSE: The aim of the study was to identify variables associated with successful long-term maintenance of sinus rhythm (SR) after a single ablation of long-lasting persistent atrial fibrillation (AF). METHODS: Complex left atrial (LA) ablation was performed in 100 patients. Restoration of SR by ablation was the desired procedure endpoint. RESULTS: SR was restored by ablation in 38 patients during the first procedure. Following one ablation, 50 patients remained in SR for 31 +/- 14 months. SR maintenance was associated with shorter duration of the persistent AF (median 14 vs. 22 months; P = 0.05), lower proportion of the LA points exhibiting voltage <0.2 mV (median 20% vs. 33%; P = 0.006), and higher proportion of LA points showing voltage >1 mV (median 15% vs. 11%; P = 0.02). CONCLUSION: Among clinical variables, shorter duration of persistent AF and higher voltage recorded around the LA predicted long-term maintenance of SR after single ablation.     

Longstanding atrial fibrillation causes depletion of atrial natriuretic peptide in patients with advanced congestive heart failure

BACKGROUND: Congestive heart failure (CHF) is characterized by neurohormonal activation, including increased plasma concentrations of atrial natriuretic peptide (ANP) and N-terminal ANP (N-ANP). Onset of atrial fibrillation (AF) further increases these peptides, but it may be hypothesized that concentrations decrease during longstanding AF due to inherent atrial degeneration. AIM: We sought to investigate the relation between neurohormonal activation in patients with CHF and the duration of concomitant AF. METHODS: The study group comprised 60 patients (age 70 +/- 8 years) with advanced CHF due to left ventricular systolic dysfunction (left ventricular ejection fraction (LVEF) < 0.35) and chronic AF (duration 21 (1-340) months). Plasma neurohormone concentrations were measured, and multiple regression analysis was performed to identify their clinical predictors. RESULTS: Median plasma neurohormone concentrations were: ANP 113 pmol/l, N-ANP 1187 pmol/l, norepinephrine 496 pg/ml, renin 127 micro units/l, aldosterone 128 pg/ml and endothelin 8.1 pg/ml. Norepinephrine, renin, aldosterone and endothelin were not significantly related to the duration of AF. In contrast, ANP decreased along with the duration of AF (P = 0.03), while the same trend was observed for N-ANP (P = 0.10). However, for these peptides a first order interaction with LVEF was present, which was not observed in the other neurohormones. In patients with LVEF > 0.25 ANP and N-ANP increased along with the duration of AF, whereas in patients with LVEF < or = 0.25 an inverse relation between ANP (P = 0.02) and N-ANP (P = 0.04) and the duration of AF was present, longer-standing AF being associated with lower concentrations. CONCLUSION: In patients with advanced CHF with low LVEF plasma ANP and N-ANP concentrations decrease during longstanding AF. This finding agrees with the concept that longstanding AF leads to impaired ability of the atria to produce these neurohormones due to inherent degenerative changes.     

Plasma concentration of atrial natriuretic peptide is related to the duration of atrial fibrillation in patients with advanced heart failure

BACKGROUND: Plasma concentration of atrial natriuretic peptide (ANP) is elevated in patients with atrial fibrillation (AF) and in patients with chronic heart failure (CHF).Aim. To assess ANP level in patients with permanent AF and advanced CHF. METHODS: The study group consisted of 41 patients (27 males, mean age 62+/-8 years) with AF of a mean duration of 8.8 months. Twenty six (63%) patients were in NYHA class II, and 15 (37%) - in NYHA class III or IV. All patients underwent clinical and echocardiographic evaluation as well as ANP plasma concentration assessment. Multiple regression analysis was used to identify factors which determine ANP plasma concentration. RESULTS: Mean ANP plasma concentration was 52.4+/-22.7 pg/ml in the whole study group; 38.6+/-10.8 pg/ml in NYHA class II patients and 74.9+/-18.7 pg/ml in NYHA class III-IV subjects (p<0.0001). Among echocardiographic parameters, patients with NYHA class III or IV had significantly lower left ventricular ejection fraction and greater left atrial volume than patients with NYHA class II (32% versus 56%, p<0.0001 and 101.0+/-23.8 cm(3) versus 83.4+/-16.1 cm(3), p<0.006, respectively). Multiple regression analysis revealed a significant negative correlation between AF duration and ANP level (p=0.0013) in a group of patients with NYHA class III or IV and identified AF duration as an independent predictor of ANP plasma concentration in this group of patients. CONCLUSIONS: ANP plasma concentration in patients with persistent AF and advanced CHF is determined by AF duration - the longer the AF duration the lower the ANP level.     

The left atrial function index: a rhythm independent marker of atrial function.

AIMS: This study evaluates a simple echocardiographic rhythm independent expression of left atrial (LA) function, 'the left atrial function index' (LAFI). BACKGROUND: Quantitation of LA function is challenging and often established parameters including peak A are limited to sinus rhythm (SR). We hypothesized that atrial function could be characterized independent of rhythm by combining analogues of LA volume, reservoir function and LV stroke volume. METHODS: Seventy-two patients with chronic atrial fibrillation (CAF) were followed for six months post cardioversion (CV). Thirty-seven age matched healthy subjects were controls. The LAFI = LAEF x LVOT-VTI/LAESVI (LAEF = LA emptying fraction, LAESVI = maximal LA volume indexed to BSA, LVOT-VTI = outflow tract velocity time integral). RESULTS: The LAFI pre-CV in the CAF group was depressed vs controls (0.10 +/- 0.05 vs 0.54 +/- 0.17; P = 0.0001). Post-CV, LAFI was lower in persistent AF than in those restored to SR (AF vs SR: 0.08 +/- 0.03 vs 0.15 +/- 0.08; P = 0.0001), improved progressively in SR and was unchanged when AF persisted. CONCLUSION: The LAFI, a simple, rhythm independent expression of atrial function, appears sensitive to differences between individuals in AF and those restored to SR and justifies clinical and investigative applications.     

心房颤动病史和心房大小与射频迷宫术疗效的关系

报道风湿性心脏病 (RHD)慢性心房颤动 (AF) 6 6例射频迷宫手术治疗AF的结果 ,通过探讨病史长短和左房大小对射频迷宫手术疗效的影响 ,试述心房重构对AF治疗的影响。手术后恢复窦性心律 (恢复组 )患者和未恢复窦性心律 (未恢复组 )患者AF病史长短和左房大小有显著差异 (3.84± 3.2 4vs 11.13± 8.74年 ,6 6 .17± 9.88vs81.83± 12 .85mm ,P均 <0 .0 1)。AF病史越长手术效果越差 ,AF病史 >3年的患者AF转复率明显低于AF病史 <3年者(72 .5 %vs 96 .2 % ,P <0 .0 1) ;左房越大手术效果越差 ,左房最大直径 >70mm患者AF转复率明显低于 <70mm的患者 (6 1.5 %vs 95 % ,P <0 .0 1)。AF病史长短和左房大小明显影响射频迷宫手术的疗效 ,这可能是心房重构给AF治疗带来的不利影响     

144例心脏瓣膜病合并心房颤动外科手术同期行单极冲洗射频消融改良迷宫术的疗效

目的分析本院心脏瓣膜病伴发心房颤动(简称房颤)的患者外科手术同期行单极冲洗射频消融改良迷宫术MazeⅢ型手术疗效。方法调查2007年11月至2010年8月收治的心脏瓣膜病合并房颤患者在心内直视手术下同期行单极冲洗射频消融改良迷宫术MazeⅢ型手术,观察随访6个月时的心律情况,根据节律分为窦性心律(简称窦律)组和非窦律组,分析影响术后转律的原因。结果 144例入选,2例安置永久起搏器,1例因瓣周漏而行二次手术。出院时窦律88例(61.11%),房颤39例(27.08%),随访6个月窦律88例(61.11%),房颤25例(17.36%)。窦律组左房小于非窦律组,房颤时间短于非窦律组。左房内径≥6.5 cm者,可达龙的转复率高于非可达龙组(53.8%vs 28.6%,P<0.05)。结论心脏病伴发房颤的病人,在心脏外科手术中同期行单极冲洗射频消融改良迷宫术,对窦律的恢复仍不失为一种安全有效的方法。术前左房内径大小及房颤持续时间是房颤转复的主要危险因素,可达龙在一定程度上可提高大左房(≥6.5 cm)的转复成功率。     

心房颤动复律后维持窦性心律影响因素的临床分析

目的探讨心房颤动（Af）复律后维持窦性心律的影响因素。方法选择2006年～2008年首次诊断Af（发病时间〈3个月）经药物或直流电成功转复窦性心律的住院患者98例。随访6个月后Af未复发者为维持窦性心律组（A组）52例,Af复发者（B组）46例。回顾性对比分析两组的临床特征、心电图指标、超声心动图（UCG）参数及相互关系,探讨A组的独立预测因子及诊断价值。结果 6个月随访后,52例（占53%）仍维持窦性心律,46例Af复发,半数以上复发在复律后2周内。两组间在性别、年龄、基础心脏病、β受体阻断剂使用、复律方式、左心室射血分数（LVEF）等差异无统计学意义。B组与A组相比,复律前Af持续时间（28.7±26.3d对1.3±1.4d,P〈0.01）、P波最大时间（Pmax）（P〈0.01）和P波离散度（Pd）（52±12ms对40±10ms,P〈0.01）、左心房直径（LAD）（47±4mm对41±3mm,P〈0.01）和左房自发性声学显影（P〈0.01）差异有统计学意义;但是两组间P波最小时间（Pmin）差异无显著性。多元回归分析显示：Af持续时间〈7d（OR=2.61）、LAD〈45mm（OR=2.10）和Pd〈47ms（OR=3.72）是复律后维持窦性心律的独立预测因子,准确性分别为82%、83%和86%。Pmax和左房无自发性声学显影仅是单因素影响因子。结论复律前Af持续时间、左房大小和Pd是预测Af复律后维持窦性心律的重要因素。     

心房颤动患者外周血造血祖细胞的变化及其意义

目的 观察心房颤动(房颤)患者外周血中造血祖细胞(HPCs)及血浆心钠素(ANP)、基质细胞衍生因子-1α(SDF-1α)的改变及其意义. 方法 永久性房颤患者30例(永久性房颤组),阵发性房颤患者28例(阵发性房颤组),窦性心律心脏病患者30例(窦性心律组).应用流式细胞仪测定所有患者外周血CD34抗原阳性(CD34+)HPCs水平,放射免疫法测定其血浆中ANP水平,酶联免疫吸附测定法检测其血浆SDF-1α水平.分别于每组中随机抽取10例患者,分离外周血HPCs并进行细胞培养,应用碱性磷酸酶抗碱性磷酸酶法检测培养后HPCs的ANP表达. 结果 (1)永久性房颤组外周血CD34+HPCs水平明显高于阵发性房颤组(P＜0.05)及窦性心律组(P＜0.05);阵发性房颤组外周血CD34+HPCs水平与窦性心律组差异无统计学意义(P＞0.05).(2)永久性房颤组血浆ANP水平和SDF-1α水平均明显高于阵发性房颤组及窦性心律组(均为P＜0.05);阵发性房颤组血浆ANP及SDF-1α水平与窦性心律组差异无统计学意义(均为P＞0.05).(3)血浆ANP及SDF-1α与外周血CD34+HPCs均有明显正相关(r=0.783,P＜0.01;r=0.427,P＜0.01).(4)外周血HPCs经过3 d的培养,永久性房颤组外周血中部分HPCs有ANP表达,而阵发性房颤组及窦性心律对照组HPCs无ANP表达. 结论 永久性房颤患者外周血CD34+HPCs升高,血浆ANP及SDF-1α水平也相应增高,并且其外周血HPCs具有向心房肌细胞分化的趋势.     

Chronic atrial fibrillation ablation impact on endocrine and mechanical cardiac functions.

AIMS: Assess the impact of persistent/permanent atrial fibrillation (AF) ablation on endocrine and mechanical cardiac functions. METHODS AND RESULTS: In all, 43 patients (40 males, 53 +/- 12 years) undergoing persistent/permanent AF ablation had atrial (ANP) and brain natriuretic peptide (BNP) measurements before day 1, 3, and 3 months after ablation. In the same period of time transthoracic echocardiography was performed. With a mean radiofrequency delivery of 98 +/- 29 min, sinus rhythm (SR) was restored in 30 patients (70%) without DC shock. ANP decreased significantly (P < 0.001) with restoration of SR and then increased until day 3 post ablation without reaching the level observed during AF. At 3 months, ANP was significantly lower than day 3 reaching normal value in 28 (65%) patients and being <7 pg/mL in 4 (9%). The BNP followed the same trend with normal BNP level in 23 (53%) patients at 3 months. Identifiable atrial filling waves on the pulsed Doppler transmitral recordings performed between day 2 and day 4 after the procedure were seen in 18 patients (42%). At 3 months, 39 (95%) of the patients with SR during echocardiography had a significant A wave. CONCLUSION: SR following persistent/permanent AF ablation is associated with a dramatic decrease in natriuretic peptides. At 3 months, despite relatively extensive atrial ablation, endocrine and mechanical cardiac functions are significantly improved.     

Preoperative atrial size predicts the success of radiofrequency maze procedure for permanent atrial fibrillation in patients undergoing concomitant valvular surgery

BACKGROUND: The radiofrequency (RF) maze procedure can effectively restore sinus rhythm and atrial transport function in the majority of patients with permanent atrial fibrillation (AF) and mitral valve disease. No previous study has described a cutoff value of preoperative atrial size determined by the discriminant analysis in predicting the success of sinus conversion by the RF maze procedure for permanent AF in patients with mitral valve disease. METHODS AND RESULTS: This study included 81 patients with permanent AF and mitral valve disease who underwent the RF maze IV procedure while undergoing concomitant valvular operations. There was one surgical death (1.2%). Another patient died of acute necrotizing pancreatitis 13 months later. Two patients (2.5%) developed sick sinus syndrome and received transvenous permanent pacemaker implantation. In the remaining 77 patients, there were 38 men and 39 women, with a mean (+/- SD) age of 51 +/- 11 years. At a mean follow-up time of 38 months, 65 patients (84.4%) had persistent sinus conversion that had been accomplished by the RF maze procedure (group 1), and 12 patients (15.6%) did not regain sinus rhythm (group 2). We evaluated the preoperative variables between the two groups. Univariate analysis demonstrated that the preoperative left atrial area and the left atrial diameter of group 1 patients were significantly smaller than those of group 2 patients. Group 1 had significantly fewer patients associated with tricuspid valve disease than did group 2. By multiple stepwise logistic regression analysis, only the preoperative left atrial area was an independent determinant of sinus conversion by the RF maze procedure (odds ratio, 0.961; 95% confidence interval, 0.935 to 0.988; p < 0.005). Linear discriminant analysis demonstrated that the sensitivity and specificity of the cutoff value of 56.25 cm(2) of the preoperative left atrial area in predicting the sinus conversion by the RF maze procedure were 50.0% and 86.2%, respectively, and the positive and negative predictive values were 40.0% and 90.3%, respectively. CONCLUSION: The preoperative left atrial area is an independent determinant of sinus conversion by the RF maze procedure for patients with permanent AF and mitral valve disease.     

Effect of maze procedure in patients with atrial fibrillation undergoing valve replacement

BACKGROUND AND AIMS OF THE STUDY: The study aim was to elucidate the impact of the maze procedure on late outcome after valve replacement. METHODS: Between 1992 and 2000, 241 patients underwent the maze procedure combined with valve replacement. Patients were allocated to three groups: aortic valve replacement (AVR/maze, n = 16); mitral valve replacement (MVR/maze, n = 148); and combined aortic and mitral valve replacement (DVR/maze, n = 77). RESULTS: Mean follow up was 3.9 +/- 2.3 years. Hospital mortality was 0% in the AVR/maze group, 2.0% (n = 3) in the MVR/maze group, and 3.9% (n = 3) in the DVR/maze group. Elimination of atrial fibrillation (AF) at discharge was achieved in 74.3-75.9% of cases. Freedom from recurrence of AF/atrial flutter was 71.2% in the AVR/maze group, 68.2% in the MVR/maze group, and 64.0% in the DVR/maze group at five-year follow up. By multivariate analysis, risk factors for recurrence of AF/atrial flutter included preoperative enlarged left atrial dimension >70 mm, decreased postoperative fractional shortening <30%, and absence of postoperative left atrial contraction. Freedom from stroke was 93.6% in patients who achieved regular rhythm (normal sinus rhythm or junctional rhythm), and 80.9% in those with recurrence of AF at five years after surgery (p = 0.03). CONCLUSION: The combined maze procedure and valve replacement is safe and effective in selected patients. Restoration of regular rhythm significantly reduced the incidence of late stroke.     

Impact of left atrial size reduction on chronic atrial fibrillation in mitral valve surgery

BACKGROUND AND AIM OF THE STUDY: Left atrial enlargement is a risk factor for the development of atrial fibrillation (AF). Large atrial size increases thromboembolic risk and reduces the success rate of cardioversion. The study aim was to evaluate if left atrial size reduction affects cardiac rhythm in patients with chronic AF undergoing mitral valve surgery. METHODS: Twenty-seven patients were analyzed prospectively. The left atrial incision was extended to the left inferior pulmonary vein. Left atrial size reduction was achieved by closure of the left atrial appendage from inside with a double running suture. The same suture plicated the left lateral atrial wall to the roof of the left pulmonary vein inflow and the inferior atrial wall. The atrial septum was plicated by placing stitches of the closing suture line across the fossa ovalis. Rhythm, neurological complications, cardioversion, anticoagulation and anti-arrhythmic medication were evaluated at one year postoperatively and at recent follow up (mean 40 +/- 15 months). RESULTS: At discharge, five patients (19%) were in sinus rhythm (SR). At one year postoperatively, SR was restored in 17 patients (63%), but five (19%) reported episodes of arrhythmia and AF persisted in 10 (37%). At recent follow up, four patients had died and three were lost to follow up. Among 20 patients examined, 13 (65%) had SR but six reported episodes of arrhythmia and AF persisted in seven (35%). LA diameter was significantly reduced, from 60.2 +/- 9.8 mm preoperatively to 44.5 +/- 7.0 mm at one year after surgery. CONCLUSION: The addition of left atrial size reduction to mitral valve surgery is technically simple, and was effective in 63% of patients with chronic AF, restoring predominant SR. In order to influence pathogenetic factors other than size, additional ablative steps may further increase the SR conversion rate. Size reduction may also improve the outcome of other ablative approaches.     

Concomitant recovery of atrial mechanical and endocrine function after cardioversion in patients with persistent atrial fibrillation

OBJECTIVES: The purpose of this study was to evaluate left atrial mechanical function recovery and plasma atrial natriuretic peptide (ANP) release following successful cardioversion of persistent atrial fibrillation (AF). BACKGROUND: Atrial fibrillation is characterized by functional deterioration, loss of atrial contraction, and elevation of plasma ANP levels. The response of ANP release toward atrial mechanical function after cardioversion of AF has not been fully examined. METHODS: We examined 29 patients with successfully cardioverted persistent AF in whom sinus rhythm was maintained for at least 30 days after cardioversion. We assessed mechanical function of the left atrium at 24 h and 7 and 30 days after cardioversion and evaluated plasma ANP level at the same time. Atrial mechanical function was assessed during echocardiographic examination by means of the peak velocity of the transmitral A-wave, early transmitral to atrial flow velocity ratio, and atrial filling fraction (AFF). The plasma ANP level was determined by the radioimmunoassay method. RESULTS: Plasma ANP levels were significantly reduced from 59.4 +/- 16.6 pg/ml to 31.1 +/- 9.2 pg/ml at 24 h after successful cardioversion. Within 30 days, we noted progressive improvement of atrial systolic function (increase in AFF from 21% to 31%, p < 0.05). At the same time, plasma ANP levels gradually increased from 31.1 +/- 9.2 pg/ml at 24 h to 36.9 +/- 12.8 pg/ml on day 30 following cardioversion (p < 0.05). CONCLUSIONS: Plasma ANP levels significantly decreased in patients with persistent AF after successful cardioversion. In the 30 days after cardioversion, gradual elevation of plasma ANP concentration was observed concomitantly with an increase of AFF. Plasma ANP release after successful cardioversion of persistent AF might be due to recovery of atrial mechanical function.