Left atrial electromechanical conduction time predicts atrial fibrillation in patients with mitral stenosis: a 5-year follow-up speckle-tracking echocardiography study

Prolonged left atrial electromechanical conduction time is related with atrial electrical remodeling, and is predictive of the development of atrial fibrillation. The aim of our study was to examine whether left atrial electromechanical conduction time (EMT) and left atrial strain as measured by speckle tracking echocardiography (STE) are predictors for the development of atrial fibrillation (AF) in patients with mitral stenosis (MS) at 5-year follow-up. A total of 81 patients (61% females; mean age 38.1?±?12.1 years) with mild or moderate MS of rheumatic origin according to ACC/AHA guidelines who were in sinus rhythm, and were asymptomatic or have NYHA class 1 symptom were included in the study. AF was searched by 12-lead electrocardiograms or 24-h Holter recordings during follow-up period. Atrial electromechanical conduction time (EMT), peak atrial longitudinal strain (PALS) and peak atrial contraction strain (PACS) were measured by STE. EMTs was defined as the interval between the onset of P-wave to the peak late diastolic longitudinal strain in the basal lateral and septal wall. During the follow-up period of 5 years (mean follow-up duration, 48.2?±?13.3 months), 30 patients (37%) developed AF on standard 12-lead ECG or at their 24-h Holter recording. At follow-up, patients who developed AF were older than patients without AF (42.4?±?11.3 vs. 35.6?±?11.9, p?=?0.014). Mitral valve area (MVA) (1.39?±?0.14 vs. 1.48?±?0.18, p?=?0.03), PALS (13.4?±?4.6 vs. 19?±?5.2, p?<?0.001) and PACS (6?±?2.7 vs. 8.4?±?3.8, p?=?0.004), were lower in patients who developed AF than in patients who did not develop. However, EMTs-Septal (208.2?±?28.4 vs. 180.2?±?38, p?=?0.001), and EMTs-Lateral (247.1?±?27.6 vs. 213.3?±?43.5, p?<?0.001) were longer in patients with AF than in patients without. In multivariate Cox regression analysis, PALS and left atrial EMTs-Lateral were independent predictors for development of AF at follow-up. In patients with mitral stenosis, left atrial strain and electromechanical conduction time in the lateral wall during the long term follow-up period are predictive for the development of atrial fibrillation. Speckle tracking echocardiography is a basic and easily-implemented method based on left atrial parameters which may be helpful for early detection of atrial fibrillation in patients with mitral stenosis.     

Non-pulmonary vein epicardial foci of atrial fibrillation identified in the left atrium after pulmonary vein isolation

BACKGROUND: Pulmonary vein (PV) isolation (PVI) has been demonstrated to be an effective technique for curing atrial fibrillation (AF). AF foci that cannot be isolated by PVI (non-PV foci) can become the cause of AF recurrence. The purpose of this study was to investigate the characteristics of non-PV AF foci. METHODS AND RESULTS: Two hundred consecutive patients with symptomatic AF underwent electrophysiologic studies. In all patients, successful ostial or antral PVI was achieved with a multielectrode basket catheter (MBC). In 45 patients, spontaneous AF was induced even after PVI. In 23 of those patients, 30 AF foci were found in the left atrium (LA) (12 in the PV antrum, and 18 in the LA wall). Twenty-six of those foci were eliminated by focal ablation guided by an MBC. Five of those foci (four in the PV antrum and one in the LA posterior wall) were speculated to be located epicardially because a small potential preceding the LA potential was recorded from the MBC electrodes during AF initiation at the successful ablation site where single large potentials were recorded during sinus rhythm and a longer duration of radiofrequency energy delivery was needed to eliminate them. CONCLUSIONS: MBC mapping with induction of spontaneous AF may be useful for identifying non-PV AF foci in the LA after PVI. In some of those non-PV foci, mainly around the PVI lesions, a few electrophysiologic findings suggesting an epicardial location were observed. This may be a rationale for the efficacy of extensive PV ablation.     

Renin-angiotensin system blocker use may be associated with suppression of atrial fibrillation recurrence after pulmonary vein isolation

Introduction: An additional approach may be essential to reduce recurrences of atrial fibrillation (AF) after pulmonary vein isolation (PVI). We examined the efficacy of renin‐angiotensin system blockers (RAS‐B) in suppressing AF recurrences after PVI. Methods and Results: We retrospectively studied 264 consecutive patients (195 male, median age: 63 years) who underwent successful PVI of paroxysmal (n = 94) or persistent AF (n = 170). RAS‐B treatment was performed in 145 patients (angiotensin‐converting enzyme inhibitors; n = 13, angiotensin receptor blockers; n = 129, both; n = 3). Echocardiography was performed before and 3 months after the ablation to examine the occurrence of left atrial structural reverse remodeling (LA‐RR). After a median follow‐up of 195 (interquartile range: 95–316) days, AF recurred in 51 (19.3%) patients. A Cox regression analysis revealed that AF recurrence was significantly lower in the patients with RAS‐B than in those without (hazard ratio [HR] = 0.41 [95% confidence interval (CI): 0.23–0.71], P = 0.002). After a multivariate adjustment for potential confounders, the use of RAS‐B (HR = 0.39 [95% CI: 0.19–0.77], P = 0.007) and type of AF (HR = 0.30 [95% CI: 0.13–0.66], P = 0.003) were the independent predictors for AF recurrence during the entire follow‐up. Although effect of RAS‐B was not significant during the early follow‐up (<3 month), it was the only independent predictor during the late follow‐up (>3 months) (HR = 0.21 [95% CI: 0.08–0.53], P = 0.001). There were no significant differences in LA‐RR occurrence regarding RAS‐B medication. The use of RAS‐B was an independent predictor of late AF recurrences irrespective of an early LA‐RR occurrence. Conclusions: Treatment with RAS‐B significantly reduced the AF recurrence after PVI. This benefit became more prominent 3 months after the PVI. (PACE 2011; 34:296–303)     

Age-related changes in morphology of left atrial appendage in patients with atrial fibrillation

The purpose of this study was to evaluate the relationship between age and frequency of left atrial appendage (LAA) morphology in patients with atrial fibrillation (AF) compared with sinus rhythm (SR). We enrolled 145 AF patients, and 199 SR patients for the control group without any cardiovascular disease. LAA volume index (LAAVi) and morphology were assessed by electrocardiogram-gated computed tomography angiography. LAA morphology was classified into “chicken wing” or “non-chicken wing” according to the previously described classification. There was no significant trend in frequency of non-chicken wing morphology among ages in the SR group (p?=?0.36 for trend), whereas the frequency was negatively related to age in the AF group (p?=?0.002 for trend). In multivariable logistic regression, age?>?65 (odds ratio [OR] 0.42, p?=?0.002) and duration of AF (OR 0.53, p?=?0.010) and LAAVi (OR 0.62, p?=?0.017) were independent factors of non-chicken wing LAA morphology in the AF group. LAA morphology is affected by age, especially in patients with AF. When we utilize non-chicken wing LAA morphology as a stroke risk factor in patients with AF, we should pay attention to their age.     

Intra-procedural imaging of the left atrium and pulmonary veins with rotational angiography: a comparison of anatomy obtained by pre-procedural cardiac computed tomography and trans-thoracic echocardiography

This study evaluated the feasibility and accuracy of three-dimensional rotational angiography (3DRA) to determine the anatomy of the left atrium (LA) and pulmonary veins (PVs) compared with cardiac computed tomography (CCT) and trans-thoracic echocardiography (TTE). One hundred two patients (56.1 ± 9.9 years, 86 males) with an indication for atrial fibrillation ablation were prospectively enrolled. Intra-procedural 3DRA was performed with power injected contrast medium (20 cc/s for 4 s, 240°) in the LA. 3DRA images of the LA and PVs were assessed qualitatively and then compared quantitatively. LA volume measured by 3DRA, CCT and TTE were compared. The majority of 3DRA acquisitions were optimal in delineating the right-side LA–PV (95 % for right superior PV and 96 % for right inferior PV) and left inferior PV anatomy (91 %), whereas it was optimal in only 63 % of left superior PV and 73 % of the LA appendage. The circumferences of PV ostia identified by 3DRA and CCT were correlated in four PVs (r = 0.57 for right superior PV, r = 0.67 for right inferior PV, r = 0.60 for left superior PV, and r = 0.52 for left inferior PV, p < 0.001). The mean LA volume measured by 3DRA (120 ± 32 mL) was greater than that found by CCT (109 ± 35 mL) or TTE (64 ± 23 mL), but the 3DRA LA volume measurements correlated well with those of CCT (r = 0.83, p < 0.001) and TTE (r = 0.69, p < 0.001). Intra-procedural 3DRA provided anatomical accuracy of LA and PVs comparable to those of CCT. However, optimal delineation of the left superior PV and LA appendage was limited. The LA volume determined by 3DRA was well correlated with those of CCT and TTE, despite different absolute values of each.     

Left atrial deformation as a potent predictor for paroxysmal atrial fibrillation in patients with end-stage renal disease

It is widely known that various factors contribute to left atrial (LA) mechanical dysfunction in patients with end stage renal disease (ESRD). However, the connection between atrial dysfunction and arrhythmic events such as paroxysmal atrial fibrillation (PAF), in this group of patients, remains unclear. The purpose of our study was to evaluate prospectively the association between LA deformation indices and PAF in ESRD patients. 79 patients (41 men, mean age 57?±?17) with ESRD and preserved left ventricular systolic function comprised the study population. All patients underwent a baseline comprehensive echocardiography study and were followed for a mean period of 16?±?5 months. PAF episodes, first and the following events, were reported. LA longitudinal strain reflecting LA reservoir function and LA longitudinal strain rate reflecting LA pump function were specifically evaluated as LA deformation indices of interest, using 2D speckle tracking echocardiography. At the end of follow up period nine patients died. 15 of the rest 70 reported one or more episodes of PAF. LA indexed volumes were significantly higher in patients with PAF (32?±?26 vs. 21.5?±?9 ml/m², p?=?0.002), mean LA strain was significantly reduced (17?±?7 vs. 27?±?9%, p?<?0.001) as well as mean LA stain rate (??1.19?±?0.5 vs. ??1.95?±?0.5 1/s, p?<?0.001). Multivariate analysis showed that LA strain rate when adjusted with age together with PAF history remained the single most significant echocardiographic parameter for PAF prediction. Impaired LA strain and LA strain rate are associated with PAF in ESRD patients. LA strain rate might be a better independent predictor of PAF, compared to standard echocardiographic indices. Further prospective studies are needed to validate its relevance in routine clinical practice.     

Left atrial functional reservoir: predictive value for outcome of catheter ablation in paroxysmal atrial fibrillation

Left arial (LA) function, defined according to conduit, reservoir and booster functions, is closely linked to left ventricular (LV) mechanics, particularly during diastole. Right ventricular pacing (RVP) is thought to impair LA diastolic restoring forces through alteration of ventricular activation. The aim of this study was to determine whether the LA functional reservoir estimated as the change in mean LA ejection fraction (EF) immediately after RVP, and for the second and for the third beats after RVP, predicts clinical outcome in patients with paroxysmal atrial fibrillation (AF) who have undergone catheter ablation (CA). Data from 155 patients with paroxysmal AF (56.0 ± 10.6 years, M:F = 114:41) were analyzed. All patients underwent LA angiography during RVP. LA EFs were measured at the immediate first (LA EF₁), second (LA EF₂) and third beats (LA EF₃) after RVP, using a right anterior oblique 30° view. During follow-up, AF recurred in 35 patients (22.6 %). Mean LA EF₁ was 37.9 ± .8 % in the AF recurrence group and 48.0 ± 8.6 % in the non-recurrence group (P < 0.001). Mean LA EF₂ and LA EF₃ were also lower in the AF recurrence group than in the non-recurrence group (P < 0.001, respectively). Mean percent changes from LA EF₂ to LA EF₃ were ?0.4 ± 3.4 in the AF recurrence group and 5.2 ± 4.9 in the non-recurrence group (P = 0.041). The change in mean EF from LA EF₁ to LA EF₃ in the non-recurrence group was significantly greater than in the recurrence group (P = 0.001). Cox regression analysis showed that predictors of AF recurrence were LA EF₂, LA EF₃ and accompanied obstructive sleep apnea (OSA) (P < 0.001, respectively). Decreased functional LA reservoir (LA EF after RVP) and OSA are significantly related to recurrence of AF following CA in patients with paroxysmal AF.     

阵发性心房颤动患者环肺静脉射频消融术后复发的预测因素研究

目的探讨阵发性心房颤动（PAF）患者左心房功能联合B型脑钠肽（BNP）预测环肺静脉射频消融术（CPVA）后复发的意义。 方法选取2017年1月至2018年12月在常州市第一人民医院住院的拟行第一次CPVA术的PAF患者201例。CPVA术前测定患者血液BNP水平;实时三维超声心动图（RT-3DE）获取左心房时间-容积曲线;根据术后3个月动态心电图结果,将PAF患者分为窦性心律组和复发组。应用多因素Logistic回归分析影响CPVA术后PAF复发的独立危险因素;对获得的独立危险因素行预测PAF复发的ROC曲线,比较不同指标的效能。 结果201例PAF患者完成CPVA术,随访中36例（17.9%）复发,复发组BNP高于窦性心律组（P＜0.05）。2组间左心房最大容积指数（LAVImax）、左心房最小容积指数（LAVImin）差异有统计学意义（均P＜0.05）;2组间膨胀指数（EI）、舒张期射血指数（DEI）、被动射血指数（PEI）、主动射血指数（AEI）差异均有统计学意义（均P＜0.05）。多因素Logistic回归分析表明：术前BNP、DEI及PAF病史是PAF复发的独立预测因素（均P＜0.05）。ROC曲线显示：DEI及联合指标（DEI+BNP）预测CPVA术后复发的效能均优于LAVImin（AUC：0.881 vs 0.686、0.901 vs 0.686,均P<0.05）;联合诊断的特异性优于DEI及BNP（89.7% vs 79.4%、89.7% vs 72.7%,均P＜0.05）。 结论CPVA术治疗的PAF患者中,左心房存储功能受损及BNP增高均是CPVA术后PAF复发的独立预测因素,两者联合可提高预测复发的特异度。     

Assessment of left atrial volume and function: a comparative study between echocardiography, magnetic resonance imaging and multi slice computed tomography

Measurement of left atrial (LA) maximal volume (LA(max)) using two-dimensional transthoracic echocardiography (TTE) provides prognostic information in several cardiac diseases. However, the relationship between LA(max) and LA function is poorly understood and TTE is less well suited for measuring dynamic LA volume changes. Conversely, cardiac magnetic resonance imaging (CMR) and multi-slice computed tomography (MSCT) appears more appropriate for such measures. We sought to determine the relationship between LA size assessed with TTE and LA size and function assessed with CMR and MSCT. Fifty-four patients were examined 3 months post myocardial infarction with echocardiography, CMR and MSCT. Left atrial volumes and LA reservoir function were assessed by TTE. LA time-volume curves were determined and LA reservoir function (cyclic change and fractional change), passive emptying function (reservoir volume) and pump function (left atrial ejection fraction-LAEF) were derived using CMR and MSCT. Left atrial fractional change and left atrial ejection fraction (LAEF) determined with CMR and MSCT were unrelated to LA(max) enlargement by echocardiography (P = NS). There was an overall good agreement between CMR and MSCT, with a small to moderate bias in LA(max) (4.9 ± 10.4 ml), CC (3.1 ± 9.1 ml) and reservoir volume (3.4 ± 9.1 ml). TTE underestimates LA(max) with up to 32% compared with CMR and MSCT (P < 0.001). Left atrial function assessed with MSCT and CMR as LA fractional change and LAEF is not significantly related to LA(max) measured by TTE. TTE systematically underestimated LA volumes, whereas there are good agreements between MSCT and CMR for volumetric and functional properties.     

Validation of contrast-enhanced time-resolved magnetic resonance angiography in pre-ablation planning in patients with atrial fibrillation: comparison with traditional technique

Bolus timing is critical to optimal magnetic resonance angiography (MRA) acquisitions but can be challenging in some patients. Our purpose was to evaluate whether contrast-enhanced time-resolved magnetic resonance angiography (TR-MRA), a dynamic multiphase sequence that does not rely on bolus timing, is a viable alternative method to conventional 3D fast-long angle shot contrast-enhanced magnetic resonance angiography (CE-MRA). Coronal subtracted conventional CE-MRA images in 50 consecutive patients presenting for pre-atrial fibrillation ablation pulmonary venous (PV) mapping were compared with 50 TR-MRA images performed in 50 subsequent patients. The TR-MRA protocol was modified to optimize spatial resolution with slightly reduced temporal resolution (6.1 s scan time). Three experienced readers evaluated each scan’s image quality and relative left atrial (LA) opacification based on a 4-point scale and diagnostic PV visualization in a binary fashion. Additionally, LA signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and PV dimensions were measured for both techniques. TR-MRA had significantly higher overall image quality (3.10?±?0.69 vs. 2.42?±?0.69, p?<?0.0001), and LA opacification scores (3.33?±?0.70 vs. 2.15?±?1.13, p?<?0.0001) compared to CE-MRA. The proportion of diagnostically visualized pulmonary veins was 137/150 (91%) in the CE-MRA group vs. 147/150 (98%) with TR-MRA (p?=?0.010). Both SNR and CNR were higher with TR-MRA vs. CE-MRA (277.9?±?48.9 vs. 106.8?±?41, p?=?0.002 and 100.3?±?41.7 vs. 70.7?±?48.0, p?=?0.002, respectively). Inter-reader variance of individual PV measurements for each of the MR techniques ranged between 0.62 and 1.47 mm and the ICC for vein measurements was higher with TR-MRA (range: 0.62–0.81) compared to CE-MRA (range: 0.47–0.64). TR-MRA, modified to maximize spatial resolution, offers an alternative method for performing high quality MRA examinations in patients with AF. TR-MRA offers greater overall image quality, PV visualization, and similarly reproducible PV measurements compared to traditional CE-MRA, without the challenges of proper bolus timing.     

Relationship between left atrial appendage emptying and left atrial function using cardiac magnetic resonance in patients with atrial fibrillation: comparison with transesophageal echocardiography

To compare cardiac magnetic resonance (CMR) quantifications of left atrium (LA) function and left atrial appendage (LAA) emptying depending on the presence of LA spontaneous echogenic contrast (LA-SEC) on transesophageal echocardiography (TEE) in patients with atrial fibrillation (AF). A total of 48 patients with AF underwent sequential CMR examination and TEE in preparation for catheter ablation. The CMR protocol included cine and velocity encoding (VENC) sequences for evaluation of both LA function and LAA emptying. The peak blood velocity of LAA just before left ventricle systole was defined as the LAA emptying velocity (LAA-EV). Depending on the presence of LA-SEC on TEE, patients were divided into two groups, the SEC group (n?=?15) and the non-SEC group (n?=?33). Mean LAA-EV was significantly greater in the non-SEC group than in the SEC group (54.5?±?24.8 ml/s vs. 26.0?±?22.6 ml/s, P?<?0.01). LAA-EV had a significant positive relationship (P?<?0.05) with LAA backflow velocity, as assessed using TEE. Use of an optimal LAA-EV cutoff value of 35 ml/s to predict LA-SEC yielded a sensitivity of 80.0?%, a specificity of 75.7?%, and positive and negative predictive values of 58.8 and 83.9?%, respectively. Using VENC-CMR, LAA-EV is associated with LA function and can be useful for predicting LA-SEC in patients with AF.     

Predictive Capability of Left Atrial Size Measured by CT,TEE, and TTE for Recurrence of Atrial Fibrillation Following Radiofrequency Catheter Ablation

Background: Recurrence of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA) has been well established and is in part related to left atrial (LA) size. The purpose of this study was to assess the predictive capability of LA diameter (LAD) and LA volume (LAV) by echocardiography and computed tomography (CT) to determine success in patients undergoing RFCA of AF. Methods: Eighty‐eight patients with paroxysmal or persistent AF who had undergone RFCA and had a prior transthoracic echocardiogram (TTE), transesophageal echocardiogram (TEE), and CT were enrolled in the study. TTE LADs and LV ejection fraction as well as TEE LADs and LAVs in three views were recorded. CT LAVs were also recorded. Clinical parameters prior to ablation as well as at 1‐year follow‐up were assessed. Results: A total of 40 (45%) patients with paroxysmal AF and 48 (55%) patients with persistent AF were analyzed. Paroxysmal AF patients had a RFCA success rate of 88% at 1 year with persistent AF patients having a 52% success rate (P < 0.001). A CT‐derived LAV ≥ 117 cc was associated with an odds ratio (OR) for recurrence of 4.8 (95% confidence interval [CI]=[1.4–16.4], P = 0.01) while a LAV ≥130 cc was associated with an OR for recurrence of 22.0 (95% CI =[2.5–191.0], P = 0.005) after adjustment for persistent AF. Conclusions: LA dimensions and AF type are highly predictive of AF recurrence following RFCA. LAV by CT has significant predictive benefit over standard LADs in severely enlarged atria even after adjustment for AF type. (PACE 2010; 532–540)     

Prediction of the efficacy of pulmonary vein isolation for the treatment of atrial fibrillation by the signal-averaged P-wave duration

BACKGROUND: The noninvasive methods for predicting a successful pulmonary vein isolation (PVI) have not been well described. The aim of this study was to assess the usefulness of the P-wave signal-averaged electrocardiogram (P-SAECG) in predicting the chance of a successful PVI in patients with atrial fibrillation (AF). METHODS: A P-SAECG was recorded before (pre), 1 day after, and 3-4 months after the PVI in 51 AF patients (41, paroxysmal AF; 10, persistent AF). Three-dimensional electroanatomic mapping (3D-EAM) of the right and left atria and left PVs was performed before PVI in 10 patients to analyze the biatrial conduction time (BAT). RESULTS: Fifteen patients suffered from AF recurrences 3 months or more after the PVI. The pre-filtered P-wave duration (FPD) was significantly longer in patients with recurrence than in those without (166.8 +/- 14.8 ms vs 145.9 +/- 12.6 ms, P < 0.0001). In both patient groups, PVI shortened the FPD, which continued for 3-4 months. Multivariate analysis revealed that a pre-FPD >150 ms was a powerful predictor for recurrence, but persistent AF, the left atrial dimension, and structural heart disease were not predictors for recurrence. 3D-EAM showed that the delayed activation point was located within the left PVs and the BAT was identical to the pre-FPD. CONCLUSIONS: The pre-FPD may strongly reflect atrial dysfunction, and thus may be useful for predicting a successful PVI. Shortening of the FPD after the PVI and similar FPD and BAT values suggest that the last component of the FPD represents the activation of the left PVs.     

Assessment of left atrial volume by contrast enhanced magnetic resonance angiography.

Left atrial (LA) volume is associated with cardiovascular morbidity, particularly atrial fibrillation. Contrast-enhanced magnetic resonance angiography (CE-MRA) visualizes the LA, but the validity of LA volume measurements using this technique has not been evaluated. We performed CE-MRA and cine magnetic resonance (MR) in 18 consecutive patients referred for CE-MRA prior to atrial fibrillation ablation. The CE-MRA LA volumes were compared to cine MR LA volumes at the maximal LA size and at LA end-diastole using linear regression and limits of agreement analysis. The mean cine MR LA volume was 118 +/- 39 mL at maximal LA size and 91 +/- 38 mL at LA end-diastole. Left atrial volume determined by CE-MRA was 93 +/- 38 mL. Although the CE-MRA LA volume had a strong correlation with the maximal cine MR LA volume (R2 = 0.86, p < 0.001), the 95% limits of agreement were relatively wide (-54 to 3 mL). The cine MR LA end-diastolic and CE-MRA LA volumes were more closely correlated (R2 = 0.98, p < 0.001) with narrow 95% limits of agreement (-8 to 11 mL). The CE-MRA LA volumes correspond most closely to LA end-diastolic cine MR LA volumes and may be a useful measure of LA size.     

A novel predictive model for late recurrence after catheter ablation for atrial fibrillation using left appendage volume measured by cardiac computed tomography

Larger left atrial appendage (LAA) volume is associated with a higher risk of late recurrence (LR) in patients undergoing radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF). However, it is unclear whether LAA volume predicts LR, independent of established risk factors. We sought to evaluate the value of LAA volume in predicting LR after RFCA for AF and to develop a score prediction model including LAA volume for these patients. We retrospectively studied 992 patients who underwent RFCA for AF and cardiac computed tomography before RFCA at a single center. At 3 years after RFCA, 362 patients (36.5?%) experienced recurrence. The multivariate Cox regression model showed that age?≥?75 years (10 points), non-paroxysmal AF (9 points), diabetes mellitus (4 points), left atrial volume index (1 point per 10 ml/m² rounded to the nearest integer), and the second (4.7 to < 7 ml/m²; 4 points) and third (≥?7 ml/m²; 5 points) tertiles of the LAA volume index were independent risk factors LR. The above-mentioned risk factors were included in the integrated score model, and the C-index of the proposed score model was 0.715 (95?% confidence interval [CI] 0.679–0.752). LAA volume is an independent predictor of LR and the predictive model including LAA volume showed good discrimination power. These findings provide evidence for the inclusion of LAA volume in the risk stratification for AF recurrence in patients undergoing RFCA for AF.

     

阵发性房颤环肺静脉电隔离术前后左房结构和功能的研究

目的经胸超声心动图(TTE)和经食道超声心动图(TEE)联合应用对阵发性房颤患者肺静脉前庭电隔离术前后左房、左心耳结构和功能的评价。方法46例阵发性房颤患者和16例正常对照组接受TTE和TEE检查,测量左房内径指数(LADI)、左房面积指数(LAAI)、左房容积指数(LAVI)、左房射血力(LA-EF)、左心耳内径指数(LAADI)、左心耳最大面积指数(LAAmaxI)、左心耳最小面积指数(LAAminI)、左心耳射血分数(LAA-EF)、左心耳最大排空血流速度(LAA-P)和左心耳最大充盈血流速度(LAA-F)及有无血栓征象。41例确诊无左心房及左心耳血栓的患者行肺静脉前庭电隔离术。术后6个月以上对其中39例患者随访行TTE和TEE复查。结果肺静脉前庭电隔离术组、术后随访组与正常对照组间左房结构、功能均有显著差异(P<0.05～P<0.01)。三组间左心耳的结构和功能亦均有显著差异(P<0.05～P<0.01)。阵发性房颤患者左房、左心耳结构与其功能的变化呈线性负相关。结论TTE和TEE联合应用为评价阵发性房颤患者左房的结构、功能以及肺静脉前庭电隔离术前病例的筛选、术后疗效的评估提供重要信息。     

Evaluation of left atrial appendage function and thrombi in patients with atrial fibrillation: from transthoracic to real time 3D transesophageal echocardiography

The detection of embolic sources in patients with atrial fibrillation (AF) is important to guide anticoagulant therapy. Two-dimensional transesophageal echocardiography (TEE) is the gold standard to study left atrial appendage (LAA) anatomy and morphology, despite some false-positive diagnosis. We hypothesized that real time 3D TEE (RT3DTEE) is superior to 2DTEE in detecting and/or excluding LAA thrombi. We studied 93 patients with non-valvular AF (60 males, age?=?67.1?±?14.2 years) referred for electric cardioversion with transthoracic, 2DTEE and RT3DTEE. Before cardioversion, TTE allowed a confident measurement of emptying velocity of LAA (LAAeV) only in 59/93 patients (63%). On the contrary a good quality TEE LAAeV was obtained in all patients with 49/93 (53%) dysfunctional LAA (LAAeV?<?40 cm/s). A subgroup of 5 patients (7.2% of the 69 effective cardioversion) presented a persistent dysfunction after cardioversion (with LAAeV values of <40 cm/s on the TEE post-CV). TEE allowed to observe a bilobed shape in 45 patients (48.4%) and three lobes in 22 patients (23.7%). In addition, besides to several additional findings, 2DTEE managed to detect thrombi with certainty in 8/93 patients (8.6%). In other 5 cases with diagnostic doubts for thrombi with 2DTEE (5/93 patients: 5.4%), the addition of the RT3DTEE mode allowed to discriminate with certainty the presence of just pectinate muscles in 4 patients RT3DTEE in patients with AF at risk of embolism is feasible, accurate and showed an additional diagnostic capability in the differential diagnosis of selected cases with suspected LAA thrombi.     

Reconstructing and Registering Three-Dimensional Rotational Angiogram of Left Atrium during Ablation of Atrial Fibrillation

Background: Three-dimensional (3D) image of left atrium (LA) can greatly facilitate ablation of atrial fibrillation (AF). Reconstructing method using computed tomography (CT) has certain limitations. The 3D image of LA can be intraprocedurally reconstructed by a rotational angiography technique.
Methods: Forty-six patients undergoing AF ablation were included in this study. Preprocedural CT imaging and intraprocedural reconstructing 3D rotational angiogram (3DRA) of LA were performed in all the patients. Rapid ventricular pacing (RVP, 300 ms) was used to inhibit the drainage of atrium. During RVP, contrast medium was injected into the LA, and rotational angiography was performed. The 3DRA was reconstructed and was registered with the live fluoroscopy. The 3DRA was evaluated in comparison to the CT image. In the navigation of the registered 3DRA, the ablation of AF was performed.
Results: Forty-four 3DRAs (95.7%) were successfully reconstructed and registered with the live fluoroscopy. The LA anatomy was delineated in the 3DRA in comparison to a CT image. AF ablation was successfully performed in the 44 patients in the navigation of the registered 3DRA. There were good correlations in the PV ostial diameter and the LA volume as assessed by 3DRA in comparison to a CT image (r >= 0.87). The radiation exposure in rotational angiography was substantially less than that in CT scanning (2.7 ± 0.9 mSv vs. 24.9 ± 3.1 mSv, P < 0.001).
Conclusions: It is feasible to reconstruct and register the 3DRA with live fluoroscopy using the RVP method during the ablation of AF.     

Periprocedural 3D imaging of the left atrium and esophagus: comparison of different protocols of 3D rotational angiography of the left atrium and esophagus in group of 547 consecutive patients undergoing catheter ablation of the complex atrial arrhythmias

A new method in creating 3D models of the left atrium (LA) and esophagus before catheter ablation of atrial arrhythmias is 3D rotational angiography (3DRA) of the LA. The purpose of this retrospective study was to test various acquisition protocols of the 3DRA and attempt to define the parameters influencing the success of the protocols. From August 2010 to November 2014, 3DRA of the LA using the Philips Allura FD 10 X-ray system was performed in 547 consecutive patients using right atrial and left atrial protocols. Visualization of the esophagus was performed after oral administration of a contrast agent. Patients were monitored for success (creation of a useful 3D models) and evaluated for a number of parameters affecting the success of 3DRA. The success of the RA protocol was 88.89?% with and 91.91?% without esophagus imaging. The success of the LA protocol was 97.42?% with and 94.54?% without esophagus imaging. The only factor reducing the success of the RA protocol was BMI; the LA protocol was not influenced by any factor. Ventricular fibrillation induced in two patients was successfully treated with defibrillation. 3DRA of the LA is a reliable method that supports catheter ablation of complex atrial arrhythmias. The LA protocol with esophagus imaging was significantly more reliable than the RA protocol; the other protocols were comparable. The RA protocol may be negatively affected by high BMI. Simultaneous imaging of the esophagus is safe and feasible, and the LA protocol can be recommended.     

The effects of pulmonary vein isolation on the dominant frequency and organization of coronary sinus electrical activity during permanent atrial fibrillation

BACKGROUND: Pulmonary vein isolation (PVI) has been shown to suppress atrial fibrillation (AF). We examined the effects of PVI on disorganization and dominant frequencies (DF) in patients with permanent AF. METHODS AND RESULTS: Twenty-eight patients with permanent AF (>6 months) who failed > or =1 antiarrhythmic drugs (AAD) and > or =2 cardioversions (CV) with AF reversion <30 minutes after CV were included. PVI and isolation of DFs in pulmonary veins (PVs) was performed during AF. Fast Fourier transformations of atrial electrograms were performed. Disorganization index (DI) was defined as the percentage of time spent in type III AF during 1-minute continuous recordings. The temporal stability and reproducibility of DIs from the same sites were verified over time prior to ablation. Highly disorganized AF activity concentrated in the posterior left atrium (PLA) including sites at the left atrial (PV-LA) junction (55.7% of sites in PLA, 32.9% in septum, and 11.4% in other sites). DF and DI from the coronary sinus (CS) before and after PVI were analyzed. PVI reduced the DI (14.3 +/- 25.0% before PVI vs 4.6 +/- 8.6% after PVI; P < 0.02). There was significant reduction of DI in 26 of 28 patients. The DF remained unchanged (5.6 +/- 1.3 Hz before PVI vs 5.9 +/- 0.9 Hz after PVI; P = 0.31). After a follow-up of 30 +/- 11 months, 15 (54%) of patients are free of symptomatic AF, 3 (10%) in sinus rhythm on AAD, 5 (18%) with paroxysmal AF, 4 (14%) in chronic AF, and 1 (4%) with atypical flutter. CONCLUSIONS: In the vast majority of patients with chronic AF, PVI reduces AF disorganization without affecting the DF as measured in the CS.