P wave dispersion and short-term vs. late atrial fibrillation recurrences after cardioversion

BACKGROUND: P wave dispersion has been previously suggested as a potential tool for predicting the risk of recurrence of atrial fibrillation after electrical cardioversion. We investigated whether different P wave dispersion values are associated with recurrence of atrial fibrillation in the short (< or =1 month after cardioversion) and longer term. METHODS: In 37 patients with long-lasting persistent atrial fibrillation (mean duration 21 +/- 36 months) with (n = 19) or without (n = 18) amiodarone pretreatment as antiarrhythmic prophylaxis, maximum and minimum P wave duration and P wave dispersion were measured 1 min after internal cardioversion. RESULTS: P wave dispersion was lower in patients with amiodarone pretreatment (28.3 +/- 9.5 vs. 21.9 +/- 7.3 ms, P = 0.029). The subgroups of patients with recurrence of atrial fibrillation at 1 month or in the long-term did not differ from the rest of the study sample regarding age, sex, atrial fibrillation duration, left atrial dimensions or ejection fraction. P wave dispersion was significantly higher in patients with short-term atrial fibrillation recurrence (< or = 1 month) than in the rest of the population. Furthermore, P wave dispersion values >25 ms were associated with a higher short-term relapse rate. No significant relation was present in the long-term. CONCLUSIONS: Our results suggest that P wave dispersion analysis immediately after internal cardioversion may help predict short-term recurrences of atrial fibrillation. These findings may be related to different mechanisms and predisposing factors for short-term and late recurrences. The long-term predictive value of serial evaluations of P wave dispersion during follow-up deserves investigation.     

Atrial myocardial deformation properties are temporarily reduced after cardioversion for atrial fibrillation and correlate well with left atrial appendage function.

AIM: This study was conducted to evaluate whether left atrial strain and strain rate correlate well with transesophageal parameters of stunning after atrial fibrillation. METHODS AND RESULTS: Twenty-two consecutive patients with chronic atrial fibrillation >/=3 months and <1 year were enrolled in the study. Transthoracic (TTE) and transesophageal (TEE) echocardiography with color Doppler myocardial imaging were performed before, 1 day after and 10 days after successful cardioversion. Left atrial transthoracic strain (S) and strain rate (SR) from lateral, inferior and anterior atrial walls, left atrial appendage tissue velocities, strain and strain rate values were measured with offline analysis. Left atrial appendage emptying (LAAEV) and filling (LAAFV) velocities were obtained from transesophageal echocardiography. Left atrial transthoracic, and left atrial appendage strain and strain rates were significantly lower following 1 day after cardioversion (TTE S/SR, 5.0 +/- 2.8%/2.3 +/- 1.0; TEE (septal) S/SR, 7.6 +/- 3.6%/1.6 +/- 0.7). There was a good correlation between these parameters and LAAEV (LA systolic strain and LAAEV, r = 0.73, P = 0.007). Left atrial and LAA strain and strain rate values improved over time, and correlated well with LAAEV, measured 10 days after cardioversion. CONCLUSIONS: Transthoracic atrial and TEE LAA strain and strain rate, which are quantitative measures of atrial function, are reduced after cardioversion, and recover subsequently. The good correlation between LAA function and TTE strain and strain rate suggests that TTE atrial parameters may help determine duration of anticoagulation.     

Effect of inotropic stimulation on left atrial appendage function in atrial myopathy of chronic atrial fibrillation

Atrial fibrillation (AF) leads to remodeling of the left atrium (LA) and left atrial appendage (LAA), resulting in atrial myopathy. Reduced LA and LAA function in chronic AF leads to thrombus formation and spontaneous echo contrast (SEC). The effect of inotropic stimulation on LAA function in patients with chronic AF is unknown. LAA emptying velocity (LAAEV) and maximal LAA area at baseline and after dobutamine were measured by transesophageal echocardiography in 14 subjects in normal sinus rhythm (NSR) and 6 subjects in AF. SEC in the LA was assessed before and after dobutamine. LAAEV increased significantly in both groups. However, the LAAEV at peak dobutamine in patients with AF remained significantly lower than the baseline LAAEV in patients who were in NSR (P = 0.009). Maximal LAA area decreased significantly with dobutamine in both groups, but LAA area at peak dose of dobutamine in patients with AF remained greater than baseline area in those in NSR (P = 0.01). Despite the increase in LAAEV, SEC improved in only two of five patients. We conclude that during AF, the LAA responds to inotropic stimulation with only a modest improvement in function.     

Echocardiographic evaluation of the left atrium and left atrial appendage function in patients with atrial septum aneurysm: implications for thromboembolic complications

BACKGROUND: Our study aimed to assess left atrium (LA) and left atrial appendage (LAA) function in patients with atrial septum aneurysm (ASA) and to relate it to thromboembolic complications. METHODS: The study group comprised 25 patients with isolated ASA (group I) and 17 clinically healthy subjects (control group = group II). Transthoracic and transesophageal echocardiography were performed in all investigated patients. RESULTS: In group I, the following parameters were significantly higher than in the controls: LA minimal dimension (LA (min)) was 2.13 vs. 1.7 cm; LA presystolic dimension (LA (a)) was 2.66 vs. 2.29 cm and LA pre-ejection period/LA ejection time index (PEP/ETLA) was 1.26 vs. 0.41 ( P < 0.05). There were no statistically significant differences between groups as to P wave and PR-interval duration, which were 69 vs. 72 ms and 167 vs. 173 ms, respectively. All LAA parameters were investigated, but LAA minimal areas (LAA (area min)) were higher in the study group than in controls: LAA transversal dimension (LAA (trans)) was 1.89 vs. 1.32 cm; LAA longitudinal dimension (LAA (long)) was 4.24 vs. 3.11 cm; LAA maximal area (LAA (area max)) was 4.35 vs. 3.1 cm (2); LAA ejection fraction (EFLAA) was 56 vs. 33 %; LAA peak emptying (LAAE) was 0.64 vs. 0.41 m/s, and filling velocities (LAAF) was 0.55 vs. 0.42 m/s ( P < 0.05). The results indicate a depression of LA systolic and an enhancement of LAA function in patients with ASA compared with clinically healthy subjects. CONCLUSION: (1) Atrial septum aneurysm impairs left atrium systolic function. (2) In patients with atrial septum aneurysm, left atrium appendage function changes; its systolic as well as a reservoir function improve. (3) The enhancement of LAA function in ASA may be a compensatory mechanism for LA systolic function deterioration. (4) As LAA systolic function is enhanced, it is rather unlikely that LAA is the place of origin of thrombi, which occur relatively frequently (according to the literature) in patients with ASA. The thrombi seem to be formed in the bulging sack of ASA, i.e., in the part of the LA whose systolic function is depressed.     

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     

The effect of conversion type on P wave dispersion in patients with atrial fibrillation

AIM: The aim of this study was to investigate whether conversion type of atrial fibrillation (AF) to sinus rhythm affects the P wave dispersion (PD) in patients with AF. METHODS: Based on conversion type, 95 consecutive patients with AF <3 months were divided into 3 groups: spontaneous cardioversion (SC) (N.=33, mean age: 60.6+/-11.6 years), pharmacologic cardioversion (PC) (N.=32, mean age: 59.2+/-9.6 years) and electrical cardioversion (EC) (N.= 30, mean age: 65.3+/-10.6 years). P wave duration (maximum and minimum) were measured in 12-lead ECG, and PD was calculated. RESULTS: Left atrial diameter and AF duration were significantly higher in EC (43.6+/-4.8 mm and 794.1+/-815.1 h) than SC (38.5+/-3.9 mm and 13.8+/-18.3 h) and PC (40.9+/-4.5 mm and 65.3+/-148.5 h) groups (P<0.01). P maximum was much longer in EC group compared with SC and PC group (121.6+/-9.7, 108.4+/-6.4 and 115.8+/-8.6 ms, P=0.01, respectively). There was a significant difference in PD among SC, PC and EC groups (44.4+/-9.2, 49.5+/-8.7 and 53.5+/-8.8 ms; P=0.005, respectively). PD correlated with AF duration (r=0.36, P=0.03), left atrial diameter (r=0.45, P=0.002) and conversion type (r=0.29, P=0.03). However, there was no significant association between PD and conversion type in multivariate analysis. The prolonged PD resulted from AF duration (P=0.01) and the left atrial size P=0.001). CONCLUSION: This study suggests that conversion type of AF to sinus rhythm has no effect on P wave duration and independent of AF duration and the left atrial diameter.     

The effect of different atrioventricular delays on left atrium and left atrial appendage function in patients with DDD pacemaker

Background: Although it has been known that optimization of atrioventricular delay (AVD) has favorable effect on the left ventricular functions in patients with DDD pacemaker, the effect of different AVDs on left atrium (LA) and left atrial appendage (LAA) functions has not been exactly evaluated. The aim of the present study was to assess the effect of different AVDs on LA and LAA functions in DDD pacemaker implanted patients with atrioventricular block. Methods: Forty‐eight patients with DDD pacemaker were enrolled into the study. Patients were divided into two groups according to the echocardiographic diastolic function: Group I (normal diastolic function) and Group II (diastolic dysfunction). LAA emptying velocity on pulsed wave Doppler and LAA late systolic wave velocity by using tissue Doppler were recorded. Patients were paced for five successive continuous pacing periods of 10 minutes duration using five selective AVDs (80–250 ms). Results: Significant effect on LA and LAA functions has not been observed by the setting of AVD in Group I. However, when the AVD was gradually shortened form 150 ms to 80 ms, LA and LAA functions gradually decreased in Group II patients. When AVD increased to 200 ms, LA and LAA functions were improved. Further increase in AVD resulted in decreased LA and LAA functions. Conclusion: Setting of AVD has not significant effect on the LA and LAA functions in patients with normal diastolic function, but moderate prolongation of AVD in physiological limits improved LA and LAA functions in DDD pacemaker implanted patients with diastolic dysfunction. (Echocardiography 2011;28:626‐632)     

A comparison of P-wave duration and dispersion in patients with short-term and long-term atrial fibrillation

This study compared P-wave duration and dispersion (PD) in patients with short-term (48 hours) atrial fibrillation (AF) after cardioversion. We studied 96 consecutive patients with short-term (group A; n:51, age: 61 +/- 11 years) and long-term AF (group B; n:45, age: 64 +/- 10 years). P-wave measurements were calculated from 12-lead electrocardiogram. There was no difference related to clinical characteristics. Left atrial dimension was significantly higher in group B (P =.003). P maximum (124 +/- 12 vs. 113 +/- 11 ms, P =.001) and PD (57 +/- 8 vs. 49 +/- 9 ms, P =.001) were also significantly longer in group B compared with group A, but P minimum did not. In univariate analysis, PD were related to AF duration (P =.002) and left atrial size (P =.02). This relation remained in multivariate analysis (P =.01, P =.02, respectively). P maximum >112 ms and PD >47 ms had accuracy values of 74% and 83% respectively for separating group B. Our results suggest that P wave duration and dispersion is prolonged in patients with long-term AF compared to short-term AF.     

Relationship between left atrial appendage function and left atrial thrombus in patients with nonvalvular chronic atrial fibrillation and atrial flutter.

The relationship between the left atrial appendage (LAA) function, as assessed by transesophageal echocardiography, and the incidence of left atrial thrombus was evaluated in 62 patients with nonvalvular chronic atrial fibrillation (AF; n=50) and atrial flutter (AFL; n=12). It was hypothesized that in both AF and AFL not only the LAA flow velocity (LAAFV), but also the frequency of the LAA movement (the LAA flow time, LAAFT) is a major contributing factor to thrombus formation. LAAFT was defined as the average duration of LAA flow with emptying and filling waves. The patients with AF were divided into 2 groups: lone AF (n=14) and non-lone AF (n=36). LAA thrombus was found in 6 patients with none-lone AF. LAAFV was lower and LAAFT was shorter in patients with thrombus as compared with patients without thrombus (12.0+/-2.2 cm/s vs 24.1+/-10.6 cm/s, 68.7+/-1.5 ms vs 72.9+/-3.3 ms, p<0.01, respectively). Patients with AFL had higher LAAFV and longer LAAFT than those with chronic AF. The present data suggest that, in addition to LAAFV, LAAFT characterized LAA function and might serve as a predictor of thrombus formation in chronic AF. With respect to LAA function, patients with lone AF or AFL are at low risk for thrombus formation.     

Reverse atrial electrical remodelling following atrial defibrillation as determined by signal-averaged ECG

BACKGROUND: Following successful cardioversion for atrial fibrillation (AF), the rate of early recurrence remains high. Analysis of the signal-averaged electrocardiogram of the P wave has been proposed as a noninvasive method of predicting those at risk of recurrence. PURPOSE: To determine the change in signal-averaged P wave duration (SAPWD) following cardioversion from AF, and to determine whether SAPWD is associated with the risk of recurrence. METHODS: SAPWD was determined in 76 patients immediately following successful electrical cardioversion and three days later. Patients were then followed clinically for one year. RESULTS: Recurrent AF was observed in 32 of 76 patients at 90 days following cardioversion. There was no difference in SAPWD immediately following cardioversion (158+/-28 ms versus 164+/-31 ms, P=NS) or three days following cardioversion (152+/-24 ms versus 158+/-36 ms, P=0.4) in patients with and without recurrent AF. There was, however, a significant decrease in the SAPWD during the first three days following cardioversion in the patients who remained in sinus rhythm (158+/-28 ms initially versus 152+/-24 ms on day three, P=0.009). Among the patients with recurrent AF, the decrease was smaller and not statistically significant (161+/-30 ms versus 158+/-36 ms, P=0.3). CONCLUSION: Shortening of the SAPWD occurs following atrial defibrillation in patients who maintain sinus rhythm at 90 days. This provides evidence for reverse atrial electrical remodelling and its association with the maintenance of sinus rhythm.     

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。     

Recurrence of atrial fibrillation after internal cardioversion of persistent atrial fibrillation: prognostic importance of electrophysiologic parameters.

BACKGROUND: The purpose of this study was to determine whether the extent of atrial electrical remodeling affects the recurrence of atrial fibrillation (AF) after cardioversion of persistent AF (PAF). METHODS AND RESULTS: Internal atrial cardioversion was performed in 47 patients with PAF. The right atrial monophasic action potential duration (RA-MAPD) at pacing cycle lengths (PCLs) of 800-300 ms and P wave signal-averaged electrocardiogram were recorded after cardioversion. Bepridil (150-200 mg/day) and carvedilol (10 mg/day) were administered to all patients after cardioversion. Of the 47 patients, 20 had recurrent AF within 3 months. No relation was observed between age, left atrial dimension, left ventricular ejection fraction, and AF recurrence. The AF duration was significantly longer (p<0.05) and RA-MAPD at PCLs of 800 to 300 ms were significantly shorter (p<0.05) in patients with AF recurrence than in those without recurrence. The mean slope of the RA-MAPD for PCLs between 600 and 300 ms did not differ between the patients with and without AF recurrence. The filtered P-wave duration (FPD) was significantly longer in the patients with AF recurrence than in those without (p<0.05). Multivariate analysis also showed that the RA-MAPD at a PCL of 300 ms and FPD were predictors of AF recurrence (RAMAPD: p=0.038; FPD: p=0.052). CONCLUSION: These results suggest that electrical remodeling related to the repolarization and depolarization may be the main contributors to early AF recurrence after cardioversion under the administration of bepridil and carvedilol.     

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.     

Relation of fibrillatory wave amplitude with hemostatic abnormality and left atrial appendage dysfunction in patients with chronic nonrheumatic atrial fibrillation

Large left atrium (LA) and LA appendage (LAA) dysfunction are known to relate to cardiogenic thromboembolism, so the present study investigated the relation of the atrial fibrillatory wave (F wave) amplitude to hemostatic markers and LAA function. Transthoracic and transesophageal echocardiographic studies were performed in 82 consecutive patients with chronic, nonrheumatic atrial fibrillation (AF). Patients were divided into 2 groups according to F wave amplitude in lead V1 on the 12-lead ECG: coarse AF (the greatest amplitude of F wave > or =1 mm, n=44) and fine AF (<1 mm, n=38). Plasma levels of thrombin-antithrombin III complex, D-dimer, platelet factor 4 and beta-thromboglobulin were determined. Compared with patients with coarse AF, those with fine AF had lower LAA peak flow velocity (p<0.05) and higher prevalence of embolic cerebral infarction (50% vs 27%, p<0.05). Platelet activity did not differ between the 2 groups; however, plasma levels of thrombin-antithrombin III complex and D-dimer were significantly higher in patients with fine AF than in those with coarse AF (p<0.05). Multiple logistic regression analysis showed that fine AF was independently associated with cerebral embolism. Therefore, the presence of fine F wave in V1 would be a useful marker of LAA dysfunction and hypercoagulability, and indicate a risk for cerebral embolism in patients with chronic, nonrheumatic AF.     

Right atrial appendage function in patients with chronic nonvalvular atrial fibrillation

To assess right atrial appendage (RAA) flow and its possible relationship to left atrial appendage (LAA) flow in chronic nonvalvular atrial fibrillation (AF), transesophageal echocardiography (TEE) was performed in 26 patients with chronic nonvalvular AF (group I). For the purpose of comparison, an additional group of 27 patients with chronic valvular AF due to mitral stenosis (group II) was analyzed. The clinically estimated duration of AF in group I was significantly longer than that of group II (8.7+/-3.4 versus 2.7+/-1.1 years). Although right atrial size and RAA maximal area were larger in group I than those in group II, left atrial size was larger in group II than that in group I. Group II had larger LAA maximal areas than group I, but this difference did not reach statistical significance. The two groups were not different with respect to the RAA or LAA emptying velocities. Significant correlations were observed between echocardiographic parameters of the two atria in patients with nonvalvular AF (r range, 0.4 to 0.7). In contrast, in patients with valvular AF, no correlation was observed between the echocardiographic parameters of the two atria (appendage emptying velocity, r = 0.38, p = 0.051; atrial size, r = -0.03, p = 0.89; maximal appendage area, r = 0.07, p = 0.75, respectively). There were no significant differences in the presence of right and left atrial spontaneous echo contrast and thrombus between the groups. All of the right and left atrial thrombi were confined to their respective appendages and were found in the atria with spontaneous echo contrast. Both RAA and LAA thrombi were present in one patient. In conclusion, our findings suggest that AF could affect both atria equally in nonvalvular AF, in contrast to valvular AF. Therefore, the assessment of RAA function as well as LAA may be important in patients with chronic nonvalvular AF.     

Increased P-wave dispersion predicts recurrent atrial fibrillation after cardioversion

Atrial fibrillation (AF) will recur in a number of patients treated with cardioversion. Being able to identify reliable risk factors would be useful for making management decisions. P-wave dispersion (PWD) is an electrocardiographic measurement, which reflects a disparity in atrial conduction. P-wave dispersion has been shown to be increased in patients with paroxysmal AF. This pilot study aims to determine the role of PWD in predicting AF recurrence in patients who underwent elective cardioversion. Forty-five patients who were successfully cardioverted for persistent AF were included for study. Eighteen patients had a PWD greater than 80 ms; of these 13 had AF recurrence. Of the 25 patients with PWD less than 80 milliseconds, 12 had recurrent AF. P-wave dispersion values greater than 80 milliseconds were found more frequently in patients with AF recurrence (P = .05), supporting the use of this parameter in predicting return of AF. Larger studies are needed for further evaluation.     

Clinical value of left atrial appendage flow for prediction of long-term sinus rhythm maintenance in patients with nonvalvular atrial fibrillation

OBJECTIVES: This study evaluated the role of various clinical and echocardiographic parameters, including the left atrial appendage (LAA) anterograde flow velocity, for prediction of the long-term preservation of sinus rhythm (SR) in patients with successful cardioversion (CV) of nonvalvular atrial fibrillation (AF). BACKGROUND: Echocardiographic parameters for assessing long-term SR maintenance after successful CV of nonvalvular AF are not accurately defined. METHODS: Clinical, transthoracic echocardiographic and transesophageal echocardiographic (TEE) data--measured in AF lasting >48 h--of 186 consecutive patients (116 men, mean age: 65 +/- 9 years) with successful CV (electrical or pharmacologic) were analyzed for assessment of one-year maintenance of SR. RESULTS: At one-year follow-up, 91 of 186 (49%) patients who underwent successful CV continued to have SR. Mean LAA peak emptying flow velocity was higher in patients remaining in SR for one year than in those with AF relapse (41.7 +/- 20.2 cm/s vs. 27.7 +/- 17.0 cm/s; p < 0.001). On multivariate logistic regression analysis, only the mean LAA peak emptying velocity >40 cm/s (p = 0.0001; chi(2): 23.9, odds ratio [OR] = 5.2, confidence interval [CI] 95% = 2.7 to 10.1) and the use of preventive antiarrhythmic drug treatment (p = 0.0398; chi(2): 4.2; OR = 2.0, CI 95% = 1.0 to 3.8) predicted the continuous preservation of SR during one year, outperforming other univariate predictors such as absence of left atrial spontaneous echocardiographic contrast during TEE, the left atrial parasternal diameter <44 mm, left ventricular ejection fraction >46% and AF duration <1 week before CV. The negative and positive predictive values of the mean LAA peak emptying velocity >40 cm/s for assessing preservation of SR were 66% (CI 95% = 56.9 to 74.2) and 73% (CI 95% = 62.4 to 83.3), respectively. CONCLUSIONS: In TEE-guided management of nonvalvular AF, high LAA flow velocity identifies patients with greater likelihood to remain in SR for one year after successful CV. Low LAA velocity is of limited value in identifying patients who will relapse into AF.     

Prediction of atrial fibrillation recurrence after cardioversion by P wave signal-averaged electrocardiography.

The purpose of this report was to determine prospectively whether P wave signal-averaged electrocardiography (ECG) is useful for the prediction of recurrences of atrial fibrillation after cardioversion. The P wave signal-averaged ECG was recorded in 73 patients after successful cardioversion. Duration of the filtered P wave and the root mean square voltages for the last 20 ms of the P wave were calculated. In addition to signal-averaged ECG P wave analysis, all patients were evaluated by echocardiography. During 6 months follow-up period recurrence of atrial fibrillation was observed in 31 (42.5%) patients and in 42 (57.5%) patients sinus rhythm was maintained. There was no difference in gender, age, presence of organic heart disease, left atrial diameter, left ventricular ejection fraction, use of antiarrhythmic drug, and duration of atrial fibrillation (P>0.05). The filtered P-wave duration was longer and the root mean square voltages for the last 20 ms of the P wave was lower in patients with recurrence of atrial fibrillation than in patients who maintained sinus rhythm (138.3+/-12.5 ms vs. 112.4+/-11.8 ms, P = 0.001; 1.9+/-0.7 microV vs. 2.5+/-0.6 microV, P = 0.001). A filtered P-wave duration > or =128 ms associated with a root mean square voltage for the last 20 ms of the P wave < or =2.1 microV had a sensitivity of 70% and specificity of 76% for the detection of patients with recurrence of atrial fibrillation after successful cardioversion of atrial fibrillation. We found that the likelihood of recurrence of atrial fibrillation after cardioversion was increased 4.31-fold (95% confidence interval 2.08-9.83) if these parameters were used. These results suggest that P wave signal-averaged ECG could be useful to identify patients at risk for recurrence of atrial fibrillation after cardioversion.     

非瓣膜病心房颤动患者电转复前后左心耳功能的经食管超声心动图研究

目的阐明左心耳功能对非瓣膜病心房颤动（ＮＶＡＦ）患者电转复成功率的预测价值,且对电转复后左心耳收缩功能恢复过程进行观察。方法应用经食管超声心动图对６０例ＮＶＡＦ患者电转复前及转复后２４小时、３天和１周左心耳血流频谱模式、峰值血流速度（ＬＡＡＰＥＶ）及左房自发显影的检测。结果（１）电转复前左心耳ＬＡＡＰＥＶ≥２０ｃｍ／ｓ者,转复成功率为７５％;反之,ＬＡＡＰＥＶ＜２０ｃｍ／ｓ,成功率为３０％;（２）电转复后左心耳血流频谱变成规则收缩与舒张的频谱模式,ＬＡＡＰＥＶ为２３±１０ｃｍ／ｓ,低于转复前３０±１２ｃｍ／ｓ（Ｐ＜０００１）;转复后左房新出现自发显影者８例,自发显影密度增加者１１例。结论ＮＶＡＦ患者电转复前左心耳收缩功能与窦性心律的维持高度相关;转复后左心耳“顿抑”,出现了血栓易于形成的条件,故对此类患者电转复后应给予足够的抗凝治疗,预防左房与左心耳血栓形成。     

Left atrial appendage flow in nonrheumatic atrial fibrillation : relationship with pulmonary venous flow and ECG fibrillatory wave amplitude

OBJECTIVE: This study was conducted (1) to examine the relationship between left atrial appendage (LAA) flow velocity and pulmonary venous flow (PVF) variables during nonrheumatic atrial fibrillation (AF), and (2) to determine whether a reduction in LAA flow is reflected by the fibrillatory wave amplitude on the surface ECG. BACKGROUND: Although LAA Doppler echocardiographic signals provide information regarding the velocity and direction of flow only for a localized narrow sample, systolic PVF represents in part the global left atrial function, mainly relaxation. Controversy exists about whether the amplitude of fibrillatory waves recorded on the surface ECG correlates with LAA flow velocity during AF. MEASUREMENTS AND RESULTS: Thirty-three patients (20 men, 13 women; mean [+/- SD] age, 61 +/- 11 years) with nonrheumatic AF undergoing transthoracic and transesophageal echocardiography were studied. A correlation between LAA flow velocity and systolic PVF variables (peak systolic velocity, R: = 0.450, p = 0.009; velocity-time integral of systolic flow, R = 0.491, p = 0.004; systolic fraction of PVF, R: = 0.627, p < 0.0001) was observed. Patients with a low LAA flow profile (< 25 cm/s) had a reduced systolic PVF. Longer AF duration and the occurrence of moderate mitral regurgitation were related to reduced LAA flow. AF was subdivided into coarse (peak-to-peak fibrillatory amplitude > or = 1 mm) or fine (< 1 mm) in standard ECG lead V1. There was no association between the coarseness of AF and the LAA flow profile. CONCLUSION: In patients with nonrheumatic AF, a reduction in LAA flow velocity correlates with a reduction in systolic PVF. These hemodynamic changes are not reflected by the ECG fibrillatory wave amplitude.