Atrial structural remodelling and restoration of atrial contraction after linear ablation for atrial fibrillation.

AIMS: We determined late atrial function following a surgical linear endocardial radiofrequency (RF) ablation procedure that aimed to restore and maintain sinus rhythm (SR) in atrial fibrillation (AF). We tested the hypothesis that successful restoration of SR is accompanied by measurable mechanical atrial function that is at normal or near normal levels. METHODS: Forty-seven patients who underwent the surgical RF procedure at least 6 months previously (median 2.86 years; range: 0.6-4.2 years) were studied using an array of echocardiographic variables. Two patient groups (SR restored [RF-SR], persistent AF [RF-AF]) and an age matched control group were studied. Among the echocardiographic variables measured were left atrial (LA) size and volume, LA active fractional emptying and mitral annular displacement corresponding to atrial contraction (A' velocity) by Doppler tissue imaging. RESULTS: At long term follow up 29/47of patients who underwent the RF procedure were in SR with atrial contraction present echocardiographically. Of the patients initially restored to SR, the proportion remaining in SR at 3 years was 79% (SE 9%). The atrial-emptying fraction was reduced in comparison to that seen in normal controls (27+/-14% vs 46+/-10%). The A' velocity was decreased in the surgical RF cohort vs controls (4.4+/-1.3 vs 9.7+/-1.7cm/s; P=0.0001). Despite LA size preoperatively being similar in both surgical groups, atrial size decreased in those in whom SR was restored (48.6+/-7.6 vs 44.8+/-4.7mm; P=0.0001) but increased in those in whom AF persisted (48.2+/-8.1mm vs 52.3+/-7.8mm; P=0.0001). CONCLUSION: The radial pattern of linear radiofrequency ablation used in the present study resulted in restoration of SR and atrial function. Procedural success was independent of preoperative atrial size. Restoration of SR results in 'reverse' atrial remodelling and improved atrial function. However atrial function remains modestly impaired, either due to the ablation lesions or pre-existing atrial disease.     

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.     

Serial evaluation of left atrial dimension after cardioversion for atrial fibrillation and relation to atrial function

The size of the left atrium is usually increased during atrial fibrillation (AF). The aim of the present study was to evaluate changes in left atrial (LA) dimension after cardioversion for AF, and the relation between LA dimension and atrial function. The initial study population included 171 consecutive patients. Patients who had spontaneous cardioversion to sinus rhythm (56 patients) were compared with patients who had random cardio-version with drugs (50 patients) or direct-current (DC) shock (50 patients). Echocardiographic evaluations included LA size and volume. LA passive and active emptying volumes were calculated, and LA function was assessed. Atrial stunning was observed in 18 patients reverted with DC shock and in 7 patients reverted with drugs. The left atrium was dilated in all patients during AF (48 +/- 5 mm). The size of the left atrium decreased after restoration of sinus rhythm in all patients with spontaneous reversion to sinus rhythm, in 73% of patients reverted with drugs, and in 50% of patients reverted with DC shock. The comparison between patients with a normal mechanical atrial function and patients with reduced atrial function showed that a higher atrial ejection force was associated with a more marked reduction in LA size after restoration of sinus rhythm. A relation between LA volumes and atrial ejection force was observed in the group of patients with depressed atrial mechanical function (r = -0.78; p <0.001). The active emptying fraction was lower, although not significantly, in this group, whereas the conduit volume was increased. Thus, a depressed atrial mechanical function after cardioversion for AF was associated with a persistence of LA dilation.     

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.     

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.     

Pre-treatment with Irbesartan attenuates left atrial stunning after electrical cardioversion of atrial fibrillation.

AIMS: Left atrial (LA) stunning, the transient impairment of LA function, is responsible for an increased thrombo-embolic risk after cardioversion of atrial fibrillation (AF). Angiotensin receptor blockers (ARBs) attenuate atrial remodelling in AF and could theoretically influence LA stunning. We studied the effect of Irbesartan on LA stunning. METHODS AND RESULTS: We prospectively assigned 50 patients from the outpatient clinic undergoing electrical cardioversion for AF with duration of >4 weeks, into two matched groups: 25 patients were treated with Irbesartan (228+/-93 mg/day) for at least 2 weeks prior to cardioversion (Irbesartan group); 25 patients did not receive ARBs (control group). The groups did not differ concerning age (64+/-13 vs. 63+/-13 years, respectively), AF duration (20+/-18 vs. 20+/-19 weeks), underlying disease, LA diameter (46+/-7 vs. 47+/-9 mm), left ventricular dimensions, and ejection fraction (47.7+/-11.6 vs. 49.7+/-14.5%). We assessed LA appendage emptying velocities (LAAEV) and LA spontaneous echo contrast (LASEC) by transoesophageal echocardiography before and after cardioversion and at 2 weeks, and the A-wave by transthoracic echocardiography after cardioversion, at 2 and at 4 weeks. LA stunning was significantly attenuated in the Irbesartan group. The reduction of LAAEV immediately after cardioversion was significantly less in the Irbesartan group (LAAEV reduction of 9+/-49% from 28+/-9 cm/s before cardioversion to 25+/-13 cm/s immediately afterwards) than in the control group (reduction of 48+/-20% from 34+/-15 cm/s before cardioversion to 16+/-6 cm/s afterwards) (P = 0.048). New or increased LASEC occurred in eight patients (32%) in the Irbesartan vs. 16 patients (64%) in the control group (P = 0.046). CONCLUSION: Irbesartan significantly attenuates LA stunning after electrical cardioversion of AF. Therefore, ARBs may represent an important pharmacological supplementation in patients being prepared for cardioversion.     

Effect of radiofrequency catheter ablation for atrial fibrillation on left atrial cavity size

Left atrial (LA) remodeling is associated with atrial fibrillation (AF). Radiofrequency catheter ablation offers a good treatment option for AF, with reasonable long-term results. The purpose of the present study was to assess whether LA reverse remodeling occurs after successful catheter ablation. Fifty-seven consecutive patients (45 men; age 53 +/- 8 years) with symptomatic drug-refractory AF were treated with radiofrequency catheter ablation. The patients were divided into 2 groups on the basis of AF recurrence as determined by Holter monitoring and 12-lead electrocardiographic findings at 6 weeks and 3 months of follow-up (sinus rhythm [SR] group, no recurrence; AF group, AF recurrence). At baseline and 3 months of follow-up, 2-dimensional echocardiography was performed to assess LA size and dimensions. Furthermore, LA volumes were measured at end-systole and end-diastole. After 3 months, 39 of 57 patients (68%) maintained SR. At 3 months of follow-up, the LA anteroposterior diameter showed a significant reduction in the SR group (4.5+/- 0.3 vs 4.2 +/- 0.2 cm, p <0.01), and an additional increase was observed in the AF group (4.5+/- 0.3 vs 4.8 +/- 0.3 cm, p <0.05). Furthermore, the LA end-systolic and end-diastolic volumes decreased significantly in the SR group from baseline to follow-up (59 +/- 12 vs 50 +/- 11 ml, p <0.01, and 37 +/- 9 vs 31 +/- 7 ml, p <0.01, respectively). However, a tendency toward an increase in LA volumes was observed in the AF group. In conclusion, the results of this study have demonstrated that LA reverse remodeling occurs after successful radiofrequency catheter ablation for AF.     

Left atrial anatomy and function after conversion from atrial fibrillation in hypertrophic hearts

The aim of the study was to evaluate the influence of left ventricular (LV) hypertrophy on left atrial (LA) electrical and mechanical function after cardioversion atrial fibrillation (A-Fib) of brief duration. Study group A included 100 patients with a first diagnosis of hypertension who had a moderate LV hypertrophy. The patient population included 64 men and 36 women with a mean age of 55 +/-7 years who were hospitalized because of A-Fib and were cardioverted with external DC shock. Control group B included 100 patients without cardiac hypertrophy cardioverted because of lone A-Fib. Atrial function and size were assessed by Doppler echocardiography and the following parameters were measured: transmitral peak A velocity, atrial filling fraction, atrial ejection force, peak E velocity, deceleration time, and isovolumic relaxation time, LA maximal and minimal volume, and LV cardiac mass index. Baseline echocardiography showed that LA diameters and volumes were enlarged in all patients during A-Fib. After the restoration of sinus rhythm LA diameters and volumes decreased and the reduction was more evident in group B compared to group A. LA function as a continuous variable was negatively related to LV mass index (r = -0.77), LA diameter (r = -0.66 and r = -0.69 for the superoinferior diameter), LA maximal volume (r = -0.61) and LA minimal volume (r = -0.55) (all p<0.01). Atrial ejection force as a continuous variable was positively related to age (r =0.78), peak A wave velocity (r =0.71), systolic blood pressure (r =0.51), and IVRT (r =0.41) (all p<0.01). Hypertrophy influenced the recovery of atrial function after cardioversion of A-Fib. Atrial function was reduced in patients with LV hypertrophy even after A-Fib of brief duration.     

Comparison of left atrial volumes and function by real-time three-dimensional echocardiography in patients having catheter ablation for atrial fibrillation with persistence of sinus rhythm versus recurrent atrial fibrillation three months later

Real-time 3-dimensional echocardiography (RT3DE) can provide a unique combination of accurate left atrial (LA) volume quantification and rapid, automatic assessment of LA function. The aim of the study was to evaluate the changes in LA volumes and function in patients with atrial fibrillation (AF) undergoing radiofrequency catheter ablation (RFCA) using RT3DE; 57 consecutive patients referred for RFCA were studied. Paroxysmal AF was present in 43 patients (75%) and persistent AF in 14 (25%). After a mean follow-up of 7.9 +/- 2.7 months, patients were divided into 2 groups: successful RFCA (SR group) and recurrence of AF (AF group). RT3DE was performed before, within 3 days, and 3 months after RFCA to assess LA volumes (maximum, minimum, and preA) and LA functions (passive, active, and reservoir). A total of 38 patients (67%) had successful RFCA (SR group). Immediately after RFCA, no significant changes in LA volumes and function were observed. After 3 months, a significant reduction in LA volumes (maximum: 26 +/- 8 to 23 +/- 7 ml/m(2), p <0.01) was noted only in the SR group, with a significant improvement in LA active (22 +/- 8% to 33 +/- 9%, p <0.01) and reservoir functions (116 +/- 45% to 152 +/- 54%, p <0.01). Conversely, the AF group showed a trend towards a deterioration of LA volumes and function. In conclusion, in patients who maintain sinus rhythm after RFCA, a significant reverse remodeling and functional improvement of the left atrium is observed using RT3DE.     

心房颤动患者复律前后左心房功能变化的超声研究

目的　探讨心房颤动 ( AF )复律后左心房功能变化的特点。方法　选择 AF病人 96例 ,按心脏节律转复的方式分为自发性复律 ( A)组 2 4例 ,药物复律 ( B)组 40例及直流电复律 ( C)组 3 2例 ;分别应用超声心动图测定其左心房内径和容积 ,计算左心房主动和被动排空容积 ,并评价左心房功能。结果　AF时所有病人的左心房扩大 ,而恢复窦性心律后 A、B及 C组左心房内径降低者分别为 10 0 %、74%及 5 2 %。 62例左心房机械功能正常患者与 3 4例左心房功能降低患者比较有更强的左心房射血力 ( LAEF ) ,这与复律后左心房内径降低有关。左心房功能异常( L AEF<7达因 )患者左心房内径和容积分别与左心房射血力呈负相关 ( r=-0 .72和 -0 .76,P<0 .0 0 1)。左心房主动排空分数降低而管道容积却增加。结论　心房颤动复律后 ,左心房机械功能的延迟恢复与持续存在的的左心房扩大有关     

Factors predicting recurrence of atrial fibrillation after cardioversion

BACKGROUND: Factors predicting the maintenance of sinus rhythm (SR) after cardioversion of atrial fibrillation (AF) have not been well defined. Little is known about the impact of the recovery of the left atrial mechanical function (RLAMF) on AF recurrences. AIM: To identify the clinical and echocardiographic predictors of AF recurrences after cardioversion. METHODS: Of 112 consecutive patients (39 females, 73 males, mean age 62.1+/-10.6 years) with AF who underwent successful electrical or pharmacological cardioversion, 50 maintained SR during 6 month follow-up whereas the remaining 62 had a recurrence of AF. Clinical examination and 2D Doppler echocardiography were performed. From the Doppler mitral flow, RLAMF was evaluated 1, 7, and 21 days after cardioversion. RESULTS: Patients with or without AF recurrence did not differ with respect to age, gender, aetiology, duration of AF, LA size and ejection fraction. In the univariate analysis the lack of RLAMF detected 1 day after cardioversion (relative risk - RR=1.15, p<0.01), functional NYHA class II or III (RR=1.86, p<0.005) and a history of AF episodes (RR=2.02, p相似文献   

Left atrial volume: predictor of atrial fibrillation in patients with degenerative mitral regurgitation

BACKGROUND AND AIM OF THE STUDY: In patients with mitral regurgitation (MR) due to degenerative mitral valve prolapse (MVP), preoperative atrial fibrillation (AF) has been identified as an independent predictor of survival after surgery for MR. Thus, the determinants of preoperative AF may have critical implications to evaluate the timing of mitral valve repair. The study aim was to investigate the role of left atrial (LA) volume in predicting preoperative AF in patients with severe MR due to degenerative MVP. METHODS: Sixty-six patients with severe degenerative MR (regurgitant volume > or =60 ml, regurgitant fraction > or =50%, effective regurgitant orifice area > or =0.4 cm(2)) in sinus rhythm (SR) at diagnosis and conservatively managed were eligible for the study. Complete two-dimensional (2-D) echocardiographic and Doppler measurements, including the measurement of maximum LA volume, were performed in all patients. RESULTS: During follow up under conservative management (18.1+/-4.8 months), eight patients (12%) experienced conversion to AF, and 58 remained in SR. The mean LA dimension was 4.0+/-0.5 cm in patients with SR, and 5.1+/-0.8 cm in those who developed AF (p <0.0001). The mean LA volume and LA volume index (indexed to body surface area) were 95 +/-23 ml and 60+/-14 ml/m(2) respectively in patients with SR, and 166+/-66 ml and 104+/-42 ml/m(2) respectively in those who developed AF (both p <0.0001). The optimal cut-off value for LA volume to predict AF conversion was 117.5 ml (sensitivity 88%, specificity 83%), and for LA volume index was 75 ml/m(2) (sensitivity 88%, specificity 88%). CONCLUSION: LA volume measurement should be considered in patients with degenerative severe MR diagnosed in SR. A LA volume index > or =75 ml/m(2) reflects the risk of subsequent AF, and patients should be closely monitored.     

Right atrial appendage thrombosis in atrial fibrillation: its frequency and its clinical predictors

This study assesses the incidence of right atrial (RA) chamber and appendage thrombosis in patients with atrial fibrillation (AF) in relation to RA appendage morphology and function. Transthoracic and multiplane transesophageal echocardiography were performed in 102 patients with AF to assess the incidence of RA and left atrial (LA) thrombi and spontaneous echo contrast. Both right and left ventricular sizes, atrial chamber and appendage sizes and function were measured. Twenty-two patients in sinus rhythm served as the control group (SR). Complete visualization of the RA appendage was feasible in 90 patients with AF. Patients with AF had lower tricuspid annular excursion (p = 0.008) and larger RA chamber area (p = 0.0001) than patients in SR. In addition, RA appendage areas were larger (p <0.05) and RA ejection fraction and peak emptying velocities (both p <0.0001) were lower in patients with AF patients than in those in SR. Equivalent differences were found for the LA appendage. Six thrombi were found in the RA appendage and 11 thrombi in the LA appendage in AF patients. Spontaneous echo contrast was found in 57% and 66% in the right atrium and in the left atrium, respectively. AF patients with RA appendage thrombi had a larger RA area (p = 0.0001), and lower RA appendage ejection fraction and emptying velocities (both p = 0.0001) than patients without thrombi. Spontaneous echo contrast was detected in all patients with thrombi. Spontaneous echo contrast was the only independent predictor of RA (p = 0.03) and LA appendage thrombosis (p = 0.036). In conclusion, multiplane transesophageal echocardiography allows the assessment of RA appendage morphology and function. RA spontaneous echo contrast is the only independent predictor of RA appendage thrombosis.     

Ibutilide: efficacy and safety in atrial fibrillation and atrial flutter in a general cardiology practice.

BACKGROUND: Published experience with ibutilide (IB) in randomized clinical trials reveals that conversion to sinus rhythm (SR) occurs in 31% of patients with atrial fibrillation (AF) and in 63% of patients with atrial flutter. HYPOTHESIS: The study was undertaken to test the efficacy and safety of IB in patients with AF and with atrial flutter and to compare them with those reported in previous studies. METHODS: In a general cardiology practice, 54 consecutive patients with AF or atrial flutter, no contraindication to IB, and a normal QTc interval, were treated with intravenous IB (0.4-2.0 mg). Duration of arrhythmia, left atrial (LA) size, ejection fraction (EF), time to conversion, QTc interval, and adverse drug events were determined. Patients were observed for a minimum of 6 h. Successful cardioversion was defined as arrhythmia termination within 6 h. RESULTS: Twenty-four of 34 (70.6%) patients with AF and 15 of 20 (75%) patients with atrial flutter converted to SR. Conversion of AF to SR was more likely to occur if duration of AF was approximately 96 h compared with > 96 h (81 vs. 17%, respectively; p = 0.006). The mean time to arrhythmia termination was 68.8 min. Left atrial size, determined by echocardiogram, was 44 +/- 13 mm in 43 patients. Patients with LA size approximately 45 mm had a conversion rate of 55% in both AF and flutter, compared with a conversion rate of 72% in patients with LA size < 45 mm. Ejection fraction was not a predictor of drug success. The QTc intervals were significantly prolonged after IB administration, with a mean change of 47.1 ms for successfully treated patients. Sustained polymorphic ventricular tachycardia occurred in one patient within 1 min of IB infusion, requiring electrical cardioversion to SR. This patient's serum electrolytes and QTc interval were normal prior to IB infusion; however, the QTc increased by 160 ms (from 387 to 547 ms) during drug infusion. No systemic or pulmonary emboli occurred. CONCLUSION: The efficacy of IB for conversion of AF to SR in this prospective observational study was considerably better than previously reported. Duration of AF remains an important predictor of conversion to SR. Complications are rare and without long-term adverse effects.     

Prognostic predictors of sinus rhythm control by amiodarone and electrical cardioversion in patients undergoing percutaneous transluminal mitral valvuloplasty for rheumatic atrial fibrillation.

BACKGROUND: Conversion to sinus rhythm (SR) is rarely attempted in patients with rheumatic atrial fibrillation (AF) because the length of AF duration and the dilation of left atrium (LA) make maintenance of SR difficult. In this study, predictors of the successful maintenance of SR with amiodarone and electrical cardioversion in rheumatic AF patients receiving percutaneous transluminal mitral valvuloplasty (PTMV) were identified. METHODS AND RESULTS: This study included 23 consecutive patients undergoing PTMV for rheumatic AF (6 men, 53+/-11 years; AF duration 25 +/-24 months; LA diameter 44+/-6 mm; mitral valve area (MV) 1.1+/-0.2 cm(2)). Electrical cardioversion was required for the successful conversion to SR in all patients regardless of whether they had received amiodarone (400 mg/day) 2 months before PTMV (n=8) or 2 months after (n=15). After cardioversion, all patients received amiodarone 200 mg/day. With a follow-up period of 35+/-8 months, 14 patients (61%) remained in SR. A greater reduction in LA size (-4+/-3 mm vs 1+/-1 mm; p=0.004) and an greater increase in MV area (0.8+/-0.4 cm(2) vs 0.5+/-0.2 cm(2); p=0.01) by PTMV, not AF duration, were found to be the independent predictors for patients with successful maintenance of SR as compared with patients with recurrence of AF. CONCLUSION: In rheumatic AF patients receiving PTMV, the successful maintenance of SR with amiodarone and electrical cardioversion can be predicted by the degree to which LA size is reduced and MV area is increased.     

Left atrial reservoir function as a potent marker for first atrial fibrillation or flutter in persons > or = 65 years of age

The aim of this prospective study was to evaluate the incremental value of left atrial (LA) function for the prediction of risk for first atrial fibrillation (AF) or atrial flutter. Maximum and minimum LA volumes were quantitated by echocardiography in 574 adults (mean age 74 +/- 6 years, 52% men) without a history or evidence of atrial arrhythmia. During a mean follow-up period of 1.9 +/- 1.2 years, 30 subjects (5.2%) developed electrocardiographically confirmed AF or atrial flutter. Subjects with new AF or atrial flutter had lower LA reservoir function, as measured by total LA emptying fraction (38% vs 49%, p <0.0001) and higher maximum LA volumes (47 vs 40 ml/m(2), p = 0.005). An increase in age-adjusted risk for AF or atrial flutter was evident when the cohort was stratified according to medians of LA emptying fraction (< or =49%: hazard ratio 6.5, p = 0.001) and LA volume (> or =38 ml/m(2): hazard ratio 2.0, p = 0.07), with the risk being highest for subjects with concomitant LA emptying fractions < or =49% and LA volume > or =38 ml/m(2) (hazard ratio 9.3, p = 0.003). LA emptying fraction (p = 0.002) was associated with risk for first AF or atrial flutter after adjusting for baseline clinical risk factors for AF or atrial flutter, left ventricular ejection fraction, diastolic function grade, and LA volume. In conclusion, reduced LA reservoir function markedly increases the propensity for first AF or atrial flutter, independent of LA volume, left ventricular function, and clinical risk factors.     

High-sensitivity C-reactive protein is predictive of successful cardioversion for atrial fibrillation and maintenance of sinus rhythm after conversion

BACKGROUNDS: Cardioversion for atrial fibrillation (AF) is the most effective treatment for the restoration of sinus rhythm (SR). Recently, an elevated level of hs-CRP has been shown to be associated with AF burden, suggesting that inflammation increases the propensity for persistence of AF. We examined whether the level of high-sensitivity C-reactive protein (hs-CRP) was predictive of the outcome of cardioversion for AF. METHODS AND RESULTS: One hundred and six patients with a history of symptomatic AF lasting > or =1 day (age 63+/-14 years, mean+/-S.D.) underwent cardioversion. Echocardiography and hs-CRP assay were performed immediately prior to cardioversion. SR was restored in 84 patients (79%). By using selected cutoff values, multiple discriminant analysis revealed significant associations between successful cardioversion and a shorter duration of AF (AF duration< or =36 days, odds ratio (OR), 0.98; 95% confidence interval (CI), 0.97-0.99), smaller left atrial diameter (left atrial diameter< or =40 mm, OR 0.82, 95% CI 0.71-0.94), better-preserved left ventricular ejection fraction (left ventricular ejection fraction> or =60%, OR 0.92, 95% CI 0.86-0.99), and lower hs-CRP level (hs-CRP< or =0.12 mg/dL, OR 0.33, 95% CI 0.21-0.51). During a follow-up period of 140+/-144 days, AF recurred in 64 patients (76%). By using a cutoff value of hs-CRP> or =0.06 mg/dL, Cox proportional-hazards regression model found that only hs-CRP level was an independent predictor of AF recurrence (OR 5.30, 95% CI 2.46-11.5) after adjustment for coexisting cardiovascular risks. When patients were divided by the hs-CRP level of 0.06 mg/dL, percentage of maintenance of SR below and above the cutoff was 53% and 4%, respectively (log-rank test, p<0.0001). CONCLUSIONS: hs-CRP level determined prior to cardioversion represents an independent predictor of both successful cardioversion for AF and the maintenance of SR after conversion.     

Echocardiographic Parameters for Predicting Maintenance of Sinus Rhythm After Internal Atrial Defibrillation

Chronic atrial fibrillation (AF), which is refractory to external electrical direct current shock and/or pharmacologic cardioversion, may be successfully cardioverted using internal atrial defibrillation. To avoid unnecessary procedures, it is important to be able to predict which patients will revert to AF. Thirty-eight patients with chronic AF underwent successful internal atrial defibrillation and were followed for 6 months after restoration of sinus rhythm. Left atrial (LA) diameter, left ventricular ejection fraction, maximum LA appendage area, and peak emptying velocities of the LA appendage were analyzed to determine which of these factors were associated with recurrence of AF. Forty-nine percent of patients had a recurrence of AF within 6 months following internal atrial defibrillation. The preprocedural ejection fraction (mean ± SD 59 + 14% vs 57 + 13%, p = 0.63), LA diameter (4.2 ± 0.6 cm vs 4.5 ± 0.6 cm, p = 0.16), and LA appendage area (5.0 ± 1.5 cm² vs 5.8 ± 1.5 cm², p = 0.13) did not differ significantly between patients who maintained sinus rhythm and those who had recurrence of AF. Peak emptying velocities of the LA appendage before cardioversion were significantly lower in patients with recurrence of AF compared with patients who maintained sinus rhythm (0.26 ± 0.1 m/s vs 0.49 ± 0.17 m/s, p = 0.001). A peak emptying velocity <0.36 had a sensitivity of 82% and a specificity of 83% for predicting recurrence of AF.     

Predictors for maintenance of sinus rhythm after cardioversion in patients with nonvalvular atrial fibrillation

Recurrence of atrial fibrillation (AF) after cardioversion (CV) to sinus rhythm (SR) is determined by various clinical and echocardiographic parameters. Transesophageal echocardiographic (TEE) parameters have been the focus of clinicians' interests for restoring and maintaining SR. This study determined the clinical, transthoracic, and TEE parameters that predict maintenance of SR in patients with nonvalvular AF after CV. We enrolled 173 patients with nonvalvular AF in the study. TEE could not be performed in 26 patients prior to CV. Twenty-five patients had spontaneously CV prior to TEE. Six patients were excluded because of left atrial (LA) thrombus assessed by TEE. CV was unsuccessful in 6 patients. The remaining 110 consecutive patients (56 men, 54 women, mean age 69 +/- 9 years), who had been successfully cardioverted to SR, were prospectively included in the study. Fifty-seven (52%) patients were still in SR 6 months after CV. Age, gender, the configuration of the fibrillation wave on the electrocardiogram, pulmonary venous diastolic flow, and the presence of diabetes, hypertension, coronary artery disease, mitral annulus calcification, and mitral valve prolapse (MVP) did not predict recurrence. Duration of AF, presence of chronic obstructive pulmonary disease (COPD), LA diameter, left ventricular ejection fraction (EF), left atrial appendage peak flow (LAAPF), LAA ejection fraction (LAAEF), pulmonary venous systolic flow (PVSF), and the presence of LA spontaneous echo contrast (LASEC) predicted recurrence of AF 6 months after CV. In multivariate analysis, LAAEF < 30% was found to be the only independent variable (P < 0.0012) predicting recurrence at 6 months after CV in patients with nonvalvular AF. LAAEF more than 30% had a sensitivity of 75% and a specificity of 88% in predicting maintenance of SR 6 months after CV in patients with nonvalvular AF. In conclusion, TEE variables often used to determine thromboembolic risk also might be used to predict the outcome of CV.     

In patients with chronic atrial fibrillation and left ventricular systolic dysfunction, restoration of sinus rhythm confers substantial benefit.

STUDY OBJECTIVES: To evaluate the benefit of sinus rhythm (SR) restoration in patients with chronic controlled atrial fibrillation (AF) and left ventricular systolic dysfunction (LVSD). DESIGN: Prospective case-control study on the short-term outcome (6 to 9 months) of clinical and echocardiographic variables following attempted cardioversion. SETTING: Outpatient clinic of a university hospital. PATIENTS: Fifteen men and 5 women, ranging in age from 40 to 76 years, who had chronic controlled (mean [+/- SD] ventricular rate, 82 +/- 10 beats/min) AF and left ventricular fractional shortening (LVFS) of < 28% at baseline. Control was provided by retrospective paired echocardiographic examinations of six AF patients, plus the study cases with potentially unsuccessful cardioversion or early recurrence of AF. INTERVENTIONS: Attempt to restore SR with amiodarone or electrical countershock. Measurements and results: Conversion was attained in 17 patients, but AF recurred early in 4 patients, 3 of whom had proven ischemic LVSD. In the 13 patients with sustained SR, LVFS increased from 20 +/- 4% to 31 +/- 6% (p < 0.0001). In contrast, no changes were detected in the control group (n = 13). This improvement was paralleled by decreases in left ventricular (LV) end-diastolic dimension (from 55 +/- 7 to 51 +/- 6 mm; p = 0.014), LV mass (from 181 +/- 28 to 159 +/- 37 g; p = 0.015), and left atrial diameter (from 45 +/- 9 mm to 42 +/- 7; p = 0.003). A marked decrease in heart rate (from 82 +/- 9 to 64 +/- 5 beats/min; p < 0.0001) and a reduction in New York Heart Association functional class (from 2.3 +/- 0.9 to 1.2 +/- 0.4; p = 0.0007) also were observed in patients with sustained SR but not among subjects in the control group. CONCLUSIONS: Even when adequate control of the ventricular rate has been achieved, the LV function of patients with chronic AF greatly improves after restoration and maintenance of SR.