Relation between left atrial measurements and thromboembolic risk markers assessed by echocardiography in patients with nonvalvular atrial fibrillation: A cross-sectional study

Background

Left atrium (LA) dilatation has been associated with adverse cardiovascular outcomes in patients with sinus rhythm and atrial fibrillation (AF).

Left atrial deformation imaging with ultrasound based two-dimensional speckle-tracking predicts the rate of recurrence of paroxysmal and persistent atrial fibrillation after successful ablation procedures

Predict AF. Objective: Since predictors of recurrence of atrial fibrillation (AF) after ablation procedures are poorly defined, this prospective study was conducted to assess the value of left atrial (LA) deformation imaging with two‐dimensional speckle‐tracking (2D‐ST) to predict AF recurrences after successful ablation procedures. Methods and results: One hundred and three consecutive patients (age 58.1 ± 16.6 years, 72.8% male) with AF (76 paroxysmal, 27 persistent) and 30 matched controls underwent transthoracic echocardiography and 2D‐ST‐LA‐deformation analysis with assessment of LA‐radial and LA‐longitudinal strain (Sr, Sl), and velocities derived from the apical 4‐ and 2‐chamber views (4CV, 2CV). AF recurrence was assessed during 6 months of follow‐up. For determination of AF‐related LA changes, AF patients were compared to controls and patients with AF recurrences after ablation procedures (n = 30, 29.1%) were compared with patients who maintained sinus rhythm (n = 73, 70.9%). Atrial deformation capabilities were significantly reduced (P < 0.0005) in patients with AF (4CVSl 17.8 ± 13.5%; 4CVSr 22.3 ± 14.9%; 4CV‐velocities 2.53 ± 0.97 seconds) when compared with controls (4CVSl 31.3 ± 12.4%; 4CVSr 30.3 ± 9.1%; 4CV‐velocities 3.48 ± 1.01 cm/s). Independent predictors for AF recurrence after ablation procedures were 2CV‐LA‐global‐strain (Sr, P = 0.03; Sl, P = 0.003), 4CV‐LA‐gobal‐strain (Sr, P = 0.03; Sl, P = 0.02), and regional LA‐septal wall‐Sl (P = 0.008). LA‐global‐strain parameters were superior to regional LA function analysis for the prediction of AF recurrences, with cutoff values (cov), hazard ratios (HR), positive and negative predictive values (PPV, NPV) were: 4CVSl cov, 10.79% (HR 27.8, P < 0.0005; PPV 78.8%, NPV 93.9%), 4CVSr cov, ?16.65% (HR 24.8, P < 0.0005; PPV 69.4%, NPV 96.6%), 2CVSl cov, 12.31% (HR 22.7, P < 0.0005; PPV 75.8%, NPV 95.3%), and 2CVSr cov, ?14.9% (HR 12.9, P < 0.0005; PPV 64.3%, NPV 93.2%). Conclusion: Compared with controls, AF itself seems to decrease LA deformation capabilities. The assessment of global LA strain with 2D‐ST identifies patients with high risk for AF recurrence after ablation procedures. This imaging technique may help to improve therapeutic guiding for patients with AF. (J Cardiovasc Electrophysiol, Vol. 23 p. 247‐255, March 2012.)     

Left atrial stiffness relates to left ventricular diastolic dysfunction and recurrence after pulmonary vein isolation for atrial fibrillation

Left Atrial Stiffness and Atrial Fibrillation . Introduction: An increased left atrial (LA) stiffness reflects the structural remodeling and deterioration of the LA function. This study was designed to estimate LA stiffness by measuring a combination of the strain and LA pressure in patients undergoing pulmonary vein isolation (PVI) of atrial fibrillation (AF) and to evaluate the influence of the LA stiffness on the cardiac function, serum markers, and recurrence of AF after PVI. Methods: In 155 consecutive patients with AF, the brain natriuretic peptide (BNP) and aminoterminal procollagen type III propeptide (PIIIP) plasma levels were measured before the PVI. The difference between the minimum and maximum LA systolic pressures was directly measured by a transseptal puncture. The ratio of the difference in the LA pressures to the peak systolic LA strain evaluated by speckle‐tracking echocardiography was used as an index of the LA stiffness. Results: The calculated LA stiffness index was related to the BNP level (r_s= 0.444, P < 0.001), E/E′ ratio (r_s= 0.444, P < 0.001), LA volume index (r_s= 0.370, P < 0.001), and PIIIP level (r_s= 0.305, P = 0.002). During a mean follow‐up period of 33.8 ± 12.2 months, 45 patients (29%) presented with AF recurrences. A Cox proportional hazard regression analysis showed the LA stiffness index was an independent predictor of recurrence of AF (HR 2.88; 95% CI 1.75 to 4.73, P < 0.001). Conclusions: In patients with AF, the LA stiffness index is related to left ventricular diastolic dysfunction, LA dilatation, and collagen synthesis and may predict AF recurrences after PVI. (J Cardiovasc Electrophysiol, Vol. 22, pp. 999‐1006, September 2011)     

Predictors of arrhythmia recurrence in patients with lone atrial fibrillation.

AIMS: The need for antiarrhythmic drugs (AAD) after a first episode of atrial fibrillation (AF) is determined by the probability of recurrence. The aim of this study was to asses the probability of relapse and the predictors of recurrence in patients with idiopathic AF. METHODS AND RESULTS: A cohort of 98 consecutive patients younger than 65 years admitted at the emergency room because of an episode of symptomatic idiopathic (lone) AF was included in this study. On admission, a complete medical history was taken, and an echocardiogram and 24-h Holter monitoring were performed. Patients were seen at 3 and 6 months after the index episode. There were 35 (35.7%) patients with a new-onset AF episode and 63 (64.3%) with a recurrent AF episode. A majority of them were male (71%), with a mean age of 48+/-11 years. Patients with new-onset AF episodes did not receive AAD. At 6 month follow-up, 57% of all patients suffered at least one symptomatic AF relapse. Patients with AF relapses belong more often to the recurrent group vs. new-onset group of AF (65.1 vs. 34.9%, respectively, P = 0.03); they had larger LA diameter indexed for body surface area (BSA) (22.6+/-3.7 vs. 19.8+/-3.2 mm/m(2), P = 0.001), larger left ventricular end-systolic diameter (18.4+/-3.1 vs. 17.2+/-2.5 mm/m(2), P = 0.05) and a tendency towards a higher proportion of atrial tachycardia runs on Holter (66.7 vs. 50%, P = 0.09). Logistic regression analysis showed that the presence of previous episodes of AF (OR: 3.2; 95% CI; 1.0-8.0, P = 0.04) and a larger anteroposterior LA diameter (OR: 1.3; 95% CI; 1.1-1.6, P = 0.001) were independent predictors of AF recurrences at 6 months. CONCLUSIONS: The recurrence rate in lone AF patients is high. The presence of previous episodes and a mildly enlarged anteroposterior LA diameter increase the probability of relapse of lone AF.     

Preprocedural predictors of atrial fibrillation recurrence following pulmonary vein antrum isolation in patients with paroxysmal atrial fibrillation: long-term follow-up results

Predictors of Recurrence after AF Ablation. Introduction: The objective of this study was to identify the simple preprocedural parameters of atrial fibrillation (AF) recurrence following single ablation procedure in patients with paroxysmal AF during long‐term follow‐up period. Methods and Results: Consecutive 474 patients (61 ± 10 years; 364 males, left atrial (LA) diameter 37.6 ± 5.1 mm) with drug‐refractory paroxysmal AF who underwent AF ablation were analyzed. Pulmonary vein antrum isolation (PVAI), cavotricuspid isthmus line creation with bidirectional conduction block, and elimination of all non‐PV triggers of AF were performed in all patients. With a mean follow‐up of 30 ± 13 months after single procedure, 318 patients (67.1%) were in sinus rhythm without any antiarrhythmic drugs. Multivariate analysis using Cox's proportional hazards model, including the age, gender, duration of AF, body mass index, LA size, left ventricular ejection fraction, and presence of hypertension and structural heart disease as variables, demonstrated that LA size was an independent predictor of AF recurrences after PVAI with a 7.2% increase in the probability for every 1 mm increase in LA diameter (P = 0.0007). When the patients were categorized into 3 groups according to the LA diameter, the patients with moderate (40–50 mm) and severe dilatation (>50 mm) had a 1.30‐fold (P = 0.0131) and 2.14‐fold (P = 0.0057) increase, respectively, in the probability of recurrent AF as compared with the patients with normal LA diameter (≤40 mm). Conclusion : In the long‐term follow‐up period, LA size was the best preprocedural predictor of AF recurrence following single ablation procedure in the patients with paroxysmal AF, even in the patients with a relatively small LA. (J Cardiovasc Electrophysiol, Vol. 22, pp. 621‐625, June 2011)     

Assessment of echocardiographic left atrial size: accuracy of M-mode and two-dimensional methods and prediction of diastolic dysfunction

Background: Despite the American Society of Echocardiography recommendation to use left atrial volume indexed for body surface area (LAVI) for quantification of left atrial size, a variety of methods are used in clinical practice. Our objectives were to evaluate the accuracy of M‐mode and two‐dimensional (2D) echocardiographic LA size estimates to LAVI and to determine their ability to predict left ventricular diastolic dysfunction. Methods: In 150 consecutive patients, LA diameter (LAD), LA diameter indexed for body surface area (LADI), LA area in the apical two‐ and four‐chamber views (LAA 2c and LAA 4c), biplane area–length LA volume (LAV), and LAVI were obtained. The accuracy of these methods to quantify LA enlargement by LAVI, correlation with clinical parameters, and ability to act as a surrogate for diastolic dysfunction were determined using Pearson correlation coefficients along with univariate and multiple logistic analysis. Results: The true degree of LA size (with LAVI as standard) was identified by LAD in 45%, LADI in 42%, LAA 4c in 43%, and LAA 2c in 41%. All methods showed positive correlation with age, E/E′, mitral regurgitation, and right atrial size and negative correlation with ejection fraction. LAVI was the strongest method to predict any (c = 0.655, P = 0.012) or moderate–severe (P = 0.856 and P < 0.001) diastolic dysfunction. All methods have greater capacity to identify moderate or severe diastolic dysfunction than any degree of diastolic dysfunction alone. Conclusions: One‐dimensional and 2D methods inaccurately quantify LA size and are inferior to LAVI to predict diastolic dysfunction. (Echocardiography 2012;29:379‐384)     

Using traditional measurements of the left atrial diameter to predict the left atrial volume index

BACKGROUND: Left atrial enlargement by echocardiography is associated with adverse cardiovascular outcomes, yet the best method for assessing left atrial size has not been established. We sought to correlate the traditional left atrial diameter (LAD) measured in the parasternal view with the recently characterized left atrial volume index (LAVI). METHODS: 100 routine clinical patients who received a transthoracic echocardiogram for customary indications were studied. The LAD and LAVI were measured in each patient. RESULTS: The mean LAVI was 32.8 milliliters per square meter (ml/m(2)) and the LAD was 46.8 millimeters (mm). LAD > 4.7 centimeters (cm) was predictive of LAVI > 32 ml/m(2) (P < 0.001; OR 17.33; 95% CI = 5.96-50.44). CONCLUSION: LAD > 4.7 cm via the traditional method can be used to indicate left atrial enlargement. However, a LAD < or = 4.7 cm does not correlate well with the LAVI, and in such patients, extreme caution should be employed when using the LAD to estimate cardiac prognosis.     

A systematic review and meta‐analysis of the impact of the left atrial appendage closure on left atrial function

BackgroundLeft atrial (LA) appendage closure (LAAC) is effective in patients with atrial fibrillation who are not candidates for long‐term anticoagulation. However, the impact of LAAC on LA function is unknown. The aim of this study is to evaluate the impact of LAAC on atrial function.MethodsThis meta‐analysis was conducted according to Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines. A search strategy was designed to utilize PubMed/Medline, EMBASE, and Google scholar for studies showing the effect of LAAC on the LA function from inception to November 20, 2021. The standardized mean difference (SMD) was calculated from the means and standard deviations.ResultsOf 247 studies initially identified, 8 studies comprising 260 patients were included in the final analysis. There was a significant increase in LA emptying fraction following LAAC compared with preoperative function (SMD: 0.53; 95% confidence interval [CI]: 0.04–1.01; p = .03; I ² = 75%). In contrast, there were no significant differences in LA volume (SMD: −0.07; 95% CI: −0.82–0.69; p = .86; I ² = 92%) peak atrial longitudinal strain (SMD: 0.50; 95% CI: −0.08–1.08; p = .09; I ² = 89%), peak atrial contraction strain (SMD: 0.38; 95% CI: −0.22–0.99; p = .21; I ² = 81%), strain during atrial contraction (SMD: −0.24; 95% CI: −0.61–0.13; p = .20; I ² = 0%), strain during ventricular systole (SMD: 0.47; 95% CI: −0.32–1.27; p = .24; I ² = 89%), strain during ventricular diastole (SMD: 0.09; 95% CI: −0.32–0.51; p = .66; I ² = 65%).ConclusionLAAC is associated with improvement in the left atrial emptying fraction, but did not significantly influence other parameters.     

Left atrial dysfunction is a predictor of postcoronary artery bypass atrial fibrillation: association of left atrial strain and strain rate assessed by speckle tracking

Background: Even though atrial fibrillation (AF) is the most common arrhythmia after coronary artery bypass grafting (CABG), its etiology remains poorly understood. Several factors are linked to postoperative AF (POAF), including advanced age and systemic inflammation. However, left atrial (LA) contractile dysfunction has not been evaluated in the perioperative scenario. Aim: To evaluate LA function through strain and strain rate in patients with coronary artery disease undergoing CABG and its correlation with POAF. Methods: We studied 70 patients undergoing CABG in sinus rhythm at the time of surgery. Preoperative echocardiography with evaluation of LA strain and strain rate by speckle tracking was performed. The occurrence of POAF was evaluated by continuous monitoring. Baseline and postoperative C‐reactive protein (CRP) levels were measured to evaluate systemic inflammation. Results: After 1‐week follow‐up 26% of subjects developed AF. LA strain s wave (LASs) and LA strain rate s (LASRs) and a wave (LASRa) were significantly decreased in patients who developed POAF: LASs (10 ± 1% vs. 24 ± 1%, P < 0.001), LASRs (0.6 ± 0.1 sec^–1 vs. 1.2 ± 0.1 sec^?1, P < 0.001), LASRa (?0.6 ± 0.1 sec^–1 vs. –1.8 ± 0.1 sec^?1, P < 0.001). LASRs, LASRa, age, and LA volume were independent predictors of POAF. CRP at baseline was similar irrespective of POAF development. Conclusions: LA dysfunction, evaluated by strain and strain rate is an independent predictor of POAF and contributes to classic risk factors like age and atrial volume. (Echocardiography 2011;28:1104‐1108)     

C‐Reactive Protein,Left Atrial Volume,and Atrial Fibrillation: A Prospective Study in High‐Risk Elderly

Background: The data regarding the interrelationships of high‐sensitive C‐reactive protein (CRP), left atrial (LA) volume, and atrial fibrillation (AF) are sparse. Additionally, while LA volume has been shown to be useful for prediction of AF in low‐to‐moderate risk populations, its predictive value in clinically high‐risk populations is unknown. Methods: SAFHIRE (Study of Atrial Fibrillation in High Risk Elderly) is an ongoing prospective study of the pathophysiology of first AF in persons aged ≥65 years with ≥2 other AF risk factors [systemic hypertension, proven coronary artery disease, heart failure (HF), diabetes]. Participants are followed annually, and undergo an interview, physical examination, blood work, electrocardiogram, and echocardiogram assessment. Results: Of 800 participants, mean age of 74 ± 6 years, 34 developed first AF over 1.7± 0.9 years. A history of systemic hypertension and proven coronary artery disease was present in 97% and 78%, respectively. CRP was unrelated to LA volume on univariable or multivariable analyses (P > 0.10), and not predictive of first AF on univariable or multivariable models (all P > 0.10). Indexed LA volume was an independent predictor of first AF (unadjusted P< 0.0001; age and sex adjusted P = 0.0006; adjusted for multiple factors, HR 1.3/5 ml per m², 95% CI, 1.09 to 1.48, P = 0.001). Conclusion: In this elderly population at high clinical risk for the development of first AF, CRP was unrelated to LA volume and nonpredictive of first AF, while indexed LA volume was incremental to clinical risk factors for the prediction of first AF. (ECHOCARDIOGRAPHY 2010;27:394‐399)     

Efficacy of adjuvant anterior left atrial ablation during intracardiac echocardiography-guided pulmonary vein antrum isolation for atrial fibrillation

Background: Recent data have shown that the septum and anterior left atrial (LA) wall may contain “rotor” sites required for AF maintenance. However, whether adding ablation of such sites to standard ICE‐guided PVAI improves outcome is not well known. Objective: To determine if adjuvant anterior LA ablation during PVAI improves the cure rate of paroxysmal and permanent AF. Methods: One hundred AF patients (60 paroxysmal, 40 persistent/permanent) undergoing first‐time PVAI were enrolled over three months to receive adjuvant anterior LA ablation (Group I). These patients were compared with 100 randomly selected, matched first‐time PVAI controls from the preceding three months who did not receive adjuvant ablation (Group II). All 200 patients underwent ICE‐guided PVAI during which all four PV antra and SVC were isolated. In group I, a decapolar lasso catheter was used to map the septum and anterior LA wall during AF (induced or spontaneous) for continuous high‐frequency, fractionated electrograms (CFAE). Sites where CFAE were identified were ablated until the local EGM was eliminated. A complete anterior line of block was not a requisite endpoint. Patients were followed up for 12 months. Recurrence was assessed post‐PVAI by symptoms, clinic visits, and Holter at 3, 6, and 12 months. Patients also wore rhythm transmitters for the first 3 months. Recurrence was any AF/AFL >1 min occurring >2 months post‐PVAI. Results: Patients (age 56 ± 11 years, 37% female, EF 53%± 11%) did not differ in baseline characteristics between group I and II by design. Group I patients had longer procedure time (188 ± 45 min vs 162 ± 37 min) and RF duration (57 ± 12 min vs 44 ± 20 min) than group II (P < 0.05 for both). Overall recurrence occurred in 15/100 (15%) in group I and 20/100 (20%) in group II (P = 0.054). Success rates did not differ for paroxysmal patients between group I and II (87% vs 85%, respectively). However, for persistent/permanent patients, group I had a higher success rate compared with group II (82% vs 72%, P = 0.047). Conclusions: Adjuvant anterior LA ablation does not appear to impact procedural outcome in patients with paroxysmal AF but may offer benefit to patients with persistent/permanent AF.     

Statin therapy for the prevention of atrial fibrillation trial (SToP AF trial)

Statins for Prevention of Atrial Fibrillation . Background: Inflammation and oxidative stress are associated with atrial fibrillation (AF). Statins have antioxidant and anti‐inflammatory properties. We tested if atorvastatin reduced AF recurrence after DC cardioversion (CV) by modifying systemic oxidative stress and inflammation (NCT00252967). Methods and Results: In a randomized, double‐blinded, placebo‐controlled trial, patients with atrial fibrillation/flutter (AF) were randomized to receive either atorvastatin 80 mg (n = 33) or placebo (n = 31) before CV. Treatment was continued for 12 months or until AF recurred. Serum oxidative stress markers (ratios of oxidized to reduced glutathione and cysteine, derivatives of reactive oxygen species, isoprostanes) and inflammatory markers (high‐sensitivity C‐ reactive protein [hs‐CRP], interleukin‐6 [IL‐6], interleukin‐1β[IL‐1β], tumor necrosis factor alpha [TNFα]) were measured at baseline and on follow‐up. AF recurred in 22 (66.7%) of atorvastatin and 26 (83.9%) of placebo group (P = 0.2). The adjusted hazard ratio of having recurrence on atorvastatin versus on placebo was 0.99 (95% CI: 0.98–1.01, P = 0.3). There was no significant difference in the time to recurrence using Kaplan–Meier survival estimates (median [IR]: 29 [2–145] days versus 22 [7–70] days, P = 0.9). Although no significant effect was seen on oxidative stress, 2 of 4 inflammatory markers, IL‐6 (adjusted OR: 0.59, 95% CI: 0.35–0.97, P = 0.04) and hs‐CRP (adjusted OR: 0.59, 95% CI: 0.37–0.95, P = 0.03) were significantly lowered with atorvastatin. Cholesterol levels significantly decreased with atorvastatin (P = 0.03). Conclusions: High‐dose atorvastatin did not reduce the recurrence of AF after CV. It reduced selective markers of inflammation without affecting systemic oxidative stress. Failure of atorvastatin to prevent AF recurrence may be due to its failure to affect oxidative stress. (J Cardiovasc Electrophysiol, Vol. 22, pp. 414‐419)     

Clinical value of left atrial appendage flow velocity for predicting of cardioversion success in patients with non-valvular atrial fibrillation.

BACKGROUND: Echocardiographic parameters for predicting cardioversion outcome in patients with non-valvular atrial fibrillation are not accurately defined. OBJECTIVE: To evaluate the role of left atrial appendage flow velocity detected by transoesophageal echocardiography for prediction of cardioversion outcome in patients with non-valvular atrial fibrillation enrolled in a prospective. multicentre, international study. METHODS: Four hundred and eight patients (257 males, mean age: 66 +/- 10 years) with non-valvular atrial fibrillation lasting more than 48 h but less than 1 year underwent transthoracic echocardiography and transoesophageal echocardiography before either electrical (n=324) or pharmacological (n=84) cardioversion. RESULTS: Cardioversion was successful in restoring sinus rhythm in 328 (80%) and unsuccessful in 80 patients (20%). Mean left atrial appendage peak emptying flow velocity was significantly higher in patients with successful than in those with unsuccessful cardioversion (32.4 +/- 17.7 vs 23.5 +/- 13.6 cm x s(-1); P<0.0001). At multivariate logistic regression analysis, three parameters proved to be independent predictors of cardioversion success: the atrial fibrillation duration <2 weeks (P=0.011, OR=4.9, CI 95%=1.9-12.7), the mean left atrial appendage flow velocity >31 cm x s(-1) (P=0.0013, OR=2.8, CI 95%=1.5-5.4) and the left atrial diameter <47 mm (P=0.093, OR=2.0, CI 95%=1.2-3.4). These independent predictors of cardioversion success outperformed other univariate predictors such as left ventricular end-diastolic diameter <58 mm, ejection fraction >56% and the absence of left atrial spontaneous echo contrast. CONCLUSION: In patients with non-valvular atrial fibrillation, measurement of the left atrial appendage flow velocity profile by transoesophageal echocardiography before cardioversion provides valuable information for prediction of cardioversion outcome.     

Echocardiographic assessment of left atrial function for prediction of efficacy of catheter ablation for atrial fibrillation

Proper selection for catheter ablation (CA) for atrial fibrillation (AF) is still an issue. Echocardiographic assessment of left atrium (LA) is complex and challenging. Speckle tracking echocardiography (STE) with recent standardized LA deformation analysis allows for the quantitative assessment of various LA function parameters. We aimed to assess the value of detailed evaluations of LA function using STE in patients with non-valvular AF without structural heart disease to predict the outcomes after CA for AF. Secondary aim was to analyze the prediction of CA efficacy in patients with normal LA dimension in baseline echocardiography.We studied with transthoracic and transesophageal echocardiography 82 patients (58% males, mean age 57.3 ± 9.5 years) with non-valvular paroxysmal AF without structural heart disease scheduled for CA. Peak longitudinal LA strain (LAS) and strain rate (LASR) during the reservoir (r), conduit (cd) and contraction (ct) phases were measured by STE before the procedure. Patients were followed for 1 year using serial 4 to 7 day Holter ECG monitoring.Complete freedom from any AF recurrence was achieved in 44 (54%) patients. All patients had normal left ventricular systolic and diastolic function and 53 (65%) of them had not enlarged LA. In the multivariable logistic regression analysis, global left atrial reservoir strain (LASr) was identified as an independent predictor of CA efficacy (OR [95% CI]: 1.35 [1.17–1.55], P < .0001). The opportunity of CA success was 135 fold higher for each 1% increase in global LASr.The receiver operating characteristic (ROC) analysis identified global LASr and left atrial conduit strain (LAScd) as the most powerful parameters for predicting of CA outcome with an area under the curve of 0.896 and 0.860, respectively, in the whole study group, and 0.922 and 0.938, respectively, in patients with not enlarged LA.In patients with paroxysmal AF and normal standard echocardiographic assessment, parameters reflecting LA compliance - reservoir and conduit strain, are independent and strong predictors of CA outcome.     

Substrate modification by pulmonary vein isolation and left atrial linear ablation in patients with persistent atrial fibrillation: its impact on complex-fractionated atrial electrograms

PV and Linear Ablation for CFAEs . Introduction: Linear ablations in the left atrium (LA), in addition to pulmonary vein (PV) isolation, have been demonstrated to be an effective ablation strategy in patients with persistent atrial fibrillation (PsAF). This study investigated the impact of LA linear ablation on the complex‐fractionated atrial electrograms (CFAEs) of PsAF patients. Methods and Results: A total of 40 consecutive PsAF patients (age: 54 ± 10 years, 39 males) who underwent catheter ablation were enrolled in this study. Linear ablation of both roofline between the right and left superior PVs and the mitral isthmus line joining from the mitral annulus to the left inferior PV were performed following PV isolation during AF. High‐density automated CFAE mapping was performed using the NAVX, and maps were obtained 3 times during the procedure (prior to ablation, after PV isolation, and after linear ablations) and were compared. PsAF was terminated by ablation in 13 of 40 patients. The mean total LA surface area and baseline CFAEs area were 120.8 ± 23.6 and 88.0 ± 23.5 cm² (74.2%), respectively. After PV isolation and linear ablations in the LA, the area of CFAEs area was reduced to 71.6 ± 22.6 cm² (58.7%) (P < 0.001) and 44.9 ± 23.0 cm² (39.2%) (P < 0.001), respectively. The LA linear ablations resulted in a significant reduction of the CFAEs area percentage in the region remote from ablation sites (from 56.3 ± 20.6 cm² (59.6%) to 40.4 ± 16.5 cm² (42.9%), P < 0.0001). Conclusion: Both PV isolation and LA linear ablations diminished the CFAEs in PsAF patients, suggesting substrate modification by PV and linear ablations. (J Cardiovasc Electrophysiol, Vol. 23, pp. 962‐970, September 2012)     

Quinidine for Pharmacological Cardioversion of Atrial Fibrillation: A Retrospective Analysis in 501 Consecutive Patients

Background: Although quinidine has been used to terminate atrial fibrillation (AFib) for a long time, it has been recently classified to be used as a third‐line‐drug for cardioversion. However, these recommendations are based on a few small studies, and there are no data available of a larger modern patient population undergoing pharmacological cardioversion of AFib. Therefore, we evaluated the safety of quinidine for cardioversion of paroxysmal AFib in patients after cardiac surgery and coronary intervention. Methods: In 501 consecutive patients (66 ± 9 years, 32% women), 200–400 mg of quinidine were administered every 6 hours until cardioversion or for a maximum of 48 hours. Patients were included with QT interval ≤450 ms, ejection fraction (EF) ≥35%, and plasma potassium >4.3 mEq/L. Exclusion criteria were: unstable angina, myocardial infarction <3 months, and advanced congestive heart failure. Patients received verapamil, beta‐blockers, or digitalis to slow down ventricular rate <100 bpm. Results: Quinidine therapy did not have to be stopped due to adverse drug reactions (ADR), and no significant QTc interval prolongation (Bazett and Fridericia correction) and no life‐threatening ventricular arrhythmia occurred. Mean quinidine dose was 617 ± 520 mg and 92% of the patients received verapamil or beta‐blocker to decrease ventricular rate. Cardioversion was successful in 84% of patients. All ADRs were minor and transient. Multivariate analysis revealed female gender (OR 2.62, CI 1.61–4.26, P < 0.001) and EF 45–54% (OR 1.97, CI 1.15–3.36, P = 0.013) as independent risk factors for ADRs. Conclusions: Quinidine for pharmacological cardioversion of AFib is safe and well tolerated in this subset of patients.     

Different patterns of atrial remodeling after catheter ablation of chronic atrial fibrillation

Atrial Substrate Remodeling After Chronic AF Ablation . Background: Multiple remodeling patterns have been observed after catheter ablation of atrial fibrillation (AF). Objective: We aimed to clarify the electrical/structural properties associated with recurrences after ablation of chronic AF. Methods: After a stepwise ablation procedure in 120 consecutive patients with persistent/long‐lasting persistent AF, 36 had a recurrence of AF (Group 1/Group 2: recurrence with paroxysmal/persistent AF, n = 16/20). Results: During the first procedure, the left atrial (LA) bipolar voltage did not differ between the 2 groups, and the LA volume was smaller in Group 1 than in Group 2 and it was the only factor predicting the recurrent types (P = 0.009, OR = 1.04). In the second procedure, the bipolar voltage of the global left atrium increased (1.33 ± 0.11 mV vs 1.76 ± 0.16 mV, P = 0.001) in Group 1 and decreased (1.31 ± 0.14 mV vs 0.90 ± 0.12 mV, P = 0.01) in Group 2, when compared with that of the first procedure. The LA low‐voltage area (<0.5 mV) decreased in Group 1, and increased in Group 2. The LA volume (90 ± 8 cm³ vs 72 ± 8 cm³, P = 0.002) decreased in the second procedure in Group 1. It remained the same in Group 2. The right atrial substrates did not change between the procedures. After a follow‐up of 27 ± 3 months, all patients in Group 1 and 14 patients in Group 2 remained in sinus rhythm (P = 0.02). Conclusion: A better outcome with reverse electrical and structural remodeling occurred after the ablation of chronic AF when the recurrence was paroxysmal AF. Progressive electrical remodeling without any structural remodeling developed in those with a recurrence involving persistent AF. (J Cardiovasc Electrophysiol, Vol. 22, pp. 385‐393)     

Long-term prognostic significance of left atrial volume in acute myocardial infarction

OBJECTIVES: The aim of this study was to evaluate the significance of increased left atrial (LA) volume determined within the first 48 h of admission as a long-term predictor of outcome in patients with acute myocardial infarction (MI). BACKGROUND: The LA volume reflects left ventricular (LV) diastolic properties. Whereas other LV Doppler diastolic characteristics are influenced by acute changes in LV function, LA volume is stable and reflects diastolic properties before MI. METHODS: Clinical and echocardiographic parameters were prospectively collected in 395 consecutive patients with acute MI. Patients with LA volume index (LAVI) >32 ml/m(2) (normal + 2 standard deviations) were compared with those with LAVI <==32 ml/m(2). Independent clinical and echocardiographic prognostic risk factors for five years' mortality were determined by the Cox proportional hazard model. RESULTS: Left atrial volume index >32 ml/m(2) was found in 63 patients (19%) who had a higher incidence of congestive heart failure on admission (24% vs. 12%, p < 0.01), a higher incidence of mitral regurgitation, increased LV dimensions, and reduced LV ejection fraction when compared with patients with LAVI <==32 ml/m(2). Their five-year mortality rate was 34.5% versus 14.2% (p < 0.001). Significant independent risk predictors of five years' mortality were age (10 years) (odds ratio [OR] 1.45; 95% confidence interval [CI]1.14 to 1.86), Killip class >/=2 on admission (OR 2.30; 95% CI 1.29 to 4.09), LAVI >32 ml/m(2) (OR 2.22; 95% CI 1.25 to 3.96), diabetes (OR 1.94; 95% CI 1.15 to 3.28), and LV restrictive filling pattern (OR 1.89; 95% CI 1.09 to 3.31). CONCLUSIONS: In patients with acute MI, increased LA volume, determined within the first 48 h of admission, is an independent predictor of five-year mortality with incremental prognostic information to clinical and echocardiographic data.     

Interatrial Mechanical Dyssynchrony Worsened Atrial Mechanical Function in Sinus Node Disease With or Without Paroxysmal Atrial Fibrillation

Introduction: Atrial electromechanical dysfunction might contribute to the development of atrial fibrillation (AF) in patients with sinus node disease (SND). The aim of this study was to investigate the prevalence and impact of atrial mechanical dyssynchrony on atrial function in SND patients with or without paroxysmal AF. Methods: We performed echocardiographic examination with tissue Doppler imaging in 30 SND patients with (n = 11) or without (n = 19) paroxysmal AF who received dual‐chamber pacemakers. Tissue Doppler indexes included atrial contraction velocities (Va) and timing events (Ta) were measured at midleft atrial (LA) and right atrial (RA) wall. Intraatrial synchronicity was defined by the standard deviation and maximum time delay of Ta among 6 segments of LA (septal/lateral/inferior/anterior/posterior/anterospetal). Interatrial synchronicity was defined by time delay between Ta from RA and LA free wall. Results: There were no differences in age, P‐wave duration, left ventricular ejection fraction, LA volume, and ejection fraction between with or without AF. Patients with paroxysmal AF had lower mitral inflow A velocity (70 ± 19 vs 91 ± 17 cm/s, P = 0.005), LA active empting fraction (24 ± 14 vs 36 ± 13%, P = 0.027), mean Va of LA (2.6 ± 0.9 vs 3.4 ± 0.9 cm/s, P = 0.028), and greater interatrial synchronicity (33 ± 25 vs 12 ± 19 ms, P = 0.022) than those without AF. Furthermore, a lower mitral inflow A velocity (Odd ratio [OR]= 1.12, 95% Confidence interval [CI] 1.01–1.24, P = 0.025) and prolonged interatrial dyssynchrony (OR = 1.08, 95% CI 1.01–1.16, P = 0.020) were independent predictors for the presence of AF in SND patients. Conclusion: SND patients with paroxysmal AF had reduced regional and global active LA mechanical contraction and increased interatrial dyssychrony as compared with those without AF. These findings suggest that abnormal atrial electromechanical properties are associated with AF in SND patients.     

环肺静脉隔离术对阵发性心房颤动患者左心房大小和功能的影响

目的:探讨环肺静脉隔离术对阵发性心房颤动(Af)患者左心房大小和功能的影响。方法:28例阵发性Af患者择期行环肺静脉隔离术,根据Af复发与否分为复发组(5例)和未复发组(23例);同期选择窦性心律患者30例作为对照组。应用超声心动图对所有患者在窦性心律下于术前、术后24h、1个月和3个月时测量左心房最大容积(LAVmax)、左心房最小容积(LAVmin)、二尖瓣环晚期运动峰值速度(A峰)、肺静脉收缩期波(S峰)、舒张期波(D峰)、心房血流逆向波(PVa峰),并计算左心房射血分数(LAEF)。结果:①左心房大小:复发组和未复发组患者消融术前LAVmax和LAVmin均较对照组增加(均P<0.05),在术后24hLAVmin均增加(均P<0.01),LAVmax无明显变化;未复发组术后1个月时LAVmax、LAVmin均减小至正常(均P<0.05),术后3个月时未再进一步减小,而复发组术后1个月和3个月恢复至术前大小。②左心房功能:复发组和未复发组消融术前LAEF和A峰值均较对照组降低(均P<0.05),术后24h左心房功能指标均较术前明显降低(均P<0.05);术后1个月时复发组和未复发组左心房功能指标较术后24h均明显增加(均P<0.01),2组PVa峰、S峰和D峰值均恢复至术前正常水平(均P<0.05),LAEF和A峰在未复发组增加至正常水平(P<0.05),而在复发组仅恢复至术前水平;术后3个月时左心房功能指标较术后1个月时均未再有明显变化。结论:环肺静脉隔离术可以逆转阵发性Af造成的左心房大小和功能异常,而且长期对左心房大小和功能无负面影响。