Prediction of cardiovascular outcomes with left atrial size: is volume superior to area or diameter?

OBJECTIVES: We sought to compare left atrial (LA) volume to LA area and diameter for the prediction of adverse cardiovascular outcomes. BACKGROUND: The incremental value of LA volume compared with LA area or diameter as a cardiovascular risk marker has not been evaluated prospectively for patients with sinus rhythm or atrial fibrillation (AF). METHODS: Left atrial size was assessed with biplane LA volume, four-chamber LA area, and M-mode dimension for 423 patients (mean age 71 +/- 8 years, 56% men) who were prospectively followed for development of first AF, congestive heart failure, stroke, transient ischemic attack, myocardial infarction, coronary revascularization, and cardiovascular death. RESULTS: Of the 317 subjects in sinus rhythm at baseline, 62 had 90 new events during a mean follow-up of 3.5 +/- 2.3 years. All three LA size parameters were independently predictive of combined outcomes (all p < 0.0001). The overall performance for the prediction of cardiovascular events was greatest for LA volume (area under the receiver operator characteristic curve: indexed LA volume 0.71; LA area 0.64; LA diameter 0.59). A graded association between the degree of LA enlargement and risk of cardiovascular events was only evident for indexed LA volume. For subjects with AF, there was no association between LA size and cardiovascular events. CONCLUSIONS: Left atrial volume is a more robust marker of cardiovascular events than LA area or diameter in subjects with sinus rhythm. The predictive utility of LA size for cardiovascular events in AF was poor, irrespective of the method of LA size quantitation.     

Does Left Atrial Volume and Pulmonary Venous Anatomy Predict the Outcome of Catheter Ablation of Atrial Fibrillation?

Introduction: Preprocedural factors may be helpful in selecting patients with atrial fibrillation (AF) for treatment with catheter ablation and in making an assumption regarding their prognosis. The aims of this study were to investigate whether left atrial (LA) volume and pulmonary venous (PV) anatomy, evaluated by computed tomography (CT) prior to ablation, will predict AF recurrence following catheter ablation.
Methods and Results: We included 146 patients (mean age 57 ± 11 years, 83% male) with symptomatic AF (55% paroxysmal, 18% persistent, 27% long-standing persistent). All patients underwent CT scanning prior to catheter ablation to evaluate LA volume and PV anatomy. Circumferential PV isolation was performed guided by Cartomerge electroanatomical mapping. The outcome was defined as complete success, improvement, or failure.
After a mean follow-up of 19 ±7 months, complete success was achieved in 59 patients (40%), and 38 patients (26%) demonstrated improvement. LA volume was found to be an independent predictor of AF recurrence with an adjusted OR of 1.14 for every 10-mL increase in volume (95% CI 1.00–1.29, P = 0.047). PV variations were equally distributed among the different outcomes of the ablation procedure, and therefore univariate analysis did not identify PV anatomy as a predictor of outcome.
Conclusion: LA volume is an independent predictor of AF recurrence after catheter ablation. Additionally, PV anatomy did not have any effect on the outcome. These findings suggest that an assessment of LA volume may be incorporated into the preprocedural evaluation of patients being considered for AF ablation.     

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)     

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)     

Formula to estimate left atrial volume using antero-posterior diameter in patients with catheter ablation of atrial fibrillation

In patients undergoing atrial fibrillation (AF) ablation, an enlarged left atrium (LA) is a predictor of procedural failure as well as AF recurrence on long term. The most used method to assess LA size is echocardiography-measured diameter, but the most accurate remains computed tomography (CT).The aim of our study was to determine whether there is an association between left atrial diameters measured in echocardiography and the left atrial volume determined by CT in patients who underwent AF ablation.The study included 93 patients, of whom 60 (64.5%) were men and 64 (68.8%) had paroxysmal AF, who underwent AF catheter ablation between January 2018 and June 2019. Left atrial diameters in echocardiography were measured from the long axis parasternal view and the LA volume in CT was measured on reconstructed three-dimensional images.The LA in echocardiography had an antero-posterior (AP) diameter of 45.0 ± 6 mm (median 45; Inter Quartile Range [IQR] 41–49, range 25–73 mm), longitudinal diameter of 67.5 ± 9.4 (median 66; IQR 56–88, range 52–100 mm), and transversal diameter of 42 ± 8.9 mm (IQR 30–59, range 23–64.5 mm). The volume in CT was 123 ± 29.4 mL (median 118; IQR 103–160; range 86–194 mL). We found a significant correlation (r = 0.702; P < .05) between the AP diameter and the LA volume. The formula according to which the AP diameter of the LA can predict the volume was: LA volume = AP diam³ + 45 mL.There is a clear association between the left atrial AP diameter measured on echocardiography and the volume measured on CT. The AP diameter might be sufficient to determine the increase in the volume of the atrium and predict cardiovascular outcomes.     

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

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

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

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

已达到消融终点的长程持续性心房颤动复发危险因素分析

目的：探讨已达到消融终点的长程持续性心房颤动（房颤）患者复发的危险因素。方法：纳入达到消融终点的长程持续性房颤患者256例,消融终点定义为双侧肺静脉电隔离,二尖瓣峡部和左心房顶部线性消融双向阻断且碎裂电位消失。根据随访结果将患者分为房颤复发组（n＝43）和无复发组（n＝213）。通过多因素 COX 回归分析探讨房颤复发的独立危险因素。结果：经过（19．5±3．6）个月随访,与无复发组相比,房颤复发组患者右心房内径较大,为（53．31±6．55）mm 对（48．74±5．87）mm;房颤持续时间较长,为（81．83±45．75）个月对（53．16±40．23）个月;左心房内径较大,为（49．85±6．82）mm 对（46．77±5．83）mm,P 均＜0．01。多因素 COX 回归分析发现,左心房内径增大（OR＝1．01,95％CI：1．01～1．28,P ＜0．05）,右心房内径增大（OR＝2．85,95％CI：1．15～7．03,P ＜0．05）、房颤持续时间延长（OR＝1．01,95％CI：1．01～1．02,P ＜0．05）是房颤复发的独立危险因素。结论：除左心房内径和房颤持续时间外,右心房内径增大也是已达到消融终点的长程持续性房颤复发的独立危险因素。     

Predicting new onset atrial fibrillation post acute myocardial infarction: Echocardiographic assessment of left atrial size

Background

Atrial fibrillation (AF) commonly occurs following acute myocardial infarction (AMI). Left atrial (LA) size has been reported to predict new onset AF in this cohort, however, the optimal metric of left atrial size for risk stratification following AMI is unknown.

Methods

Patients presenting to a tertiary hospital with incident AMI (NSTEMI or STEMI) and no history of AF were recruited. All patients underwent guideline-based workup and management for AMI, including transthoracic echocardiographic assessment. Three alternative metrics of left atrial size were determined: LA area, maximal and minimal LA volume indexed to body surface area (LAVImax and LAVImin). The primary endpoint was new onset AF diagnoses.

Results

Four hundred thirty three patients were included in the analysis, of which 7.1% had a new diagnosis of AF within a median follow-up of 3.8 years. Univariate predictors of incident AF included age, hypertension, revascularization with CABG, NSTEMI presentation, right atrial area, and all three metrics of LA size. Among three multivariable models created for the prediction of new onset AF utilizing alternate metrics of LA size, LAVImin was the only LA size metric found to be an independent predictor.

Conclusions

LAVImin is an independent predictor of new onset AF post AMI. LAVImin outperforms echocardiographic assessment of diastolic dysfunction and alternative metrics of LA size (including LA area and LAVImax) for risk stratification. Further studies are needed to validate our findings in post AMI patients, and evaluate whether LAVImin holds similar advantages over LAVImax in other cohorts.     

Reduced Peak Atrial Systolic Mitral Annular Velocity Predicts the Development of Nonvalvular Atrial Fibrillation

We investigated whether the echocardiographic parameters of the left atrium (LA) can predict the development of nonvalvular atrial fibrillation (AF). Among 14,062 patients ( > 20 years old) who underwent an echocardiographic examination were evaluated, 2,606 patients who underwent follow-up ECG with an interval of > 6 months were investigated. Newly developed AF was noted in 42 (1.6%) patients with follow-up duration of 31.8 ± 8.9 months. Cox regression analysis revealed that a higher left atrial volume index (hazard ratio [HR ]= 1.06; 95% confidence interval [CI] 1.03–1.09, P < 0.001), relative wall thickness (RWT) of ≥ 0.407 (HR = 2.74, 95% CI 1.39–5.41, P = 0.004), a reduced peak atrial systolic mitral annular velocity (HR = 0.845, 95% CI 0.72–0.99, P = 0.037), and an advanced age (HR = 1.04, 95% CI 1.01–1.07, P = 0.009) were independently related to the development of nonvalvular AF. Therefore, reduced A ' , which is parameter of LA contractile function, might be an important predictor for the development of nonvalvular AF.     

The Impact of Age on the Electroanatomical Characteristics and Outcome of Catheter Ablation in Patients with Atrial Fibrillation

Age and Atrial Fibrillation. Background: Previous studies have indicated that atrial fibrillation (AF) in patients over the age of 60 at diagnosis is a risk factor for a substantial increase in cardiovascular events. However, information about the impact of age on the atrial substrate and clinical outcome after catheter ablation of AF is limited. Methods: This study included 350 patients (53 ± 12 years, 254 males) who underwent circumferential pulmonary vein isolation (CPVI) of AF, guided by a NavX mapping system. The subjects were divided into three groups according to their age, as follows: Group I: age ≤50 (n = 141), Group II: age = 51–64 (n = 149) and Group III: age ≥65 years old (n = 60). The mean voltage and total activation time of the individual atria were obtained by using a NavX mapping system before ablation. Several parameters, including the gender, AF duration, and left atrial (LA) diameter were analyzed. Results: The younger age group had a significantly smaller LA diameter (Group I vs Group II vs Group III, 36.89 ± 7.11 vs 39.16 ± 5.65 vs 40.77 ± 4.95 mm, P = 0.002) and higher LA bipolar voltage (2.09 ± 0.83 vs 1.73 ± 0.73 vs 1.86 ± 0.67 mV, respectively, P = 0.024), compared with the older AF patients. The LA bipolar voltage exhibited a significant reduction when the patients became older, however, that did not occur in the right atrium. The incidence of an AF recurrence was higher in the older age group than in the younger age groups. A subgroup of patients with lone AF was analyzed and age was found to be an independent predictor of the AF recurrence after receiving the first CPVI in the multivariable model (P < 0.05). Conclusions: Age has a significant impact on the LA substrate properties and outcome of the catheter ablation of AF. (J Cardiovasc Electrophysiol, Vol. 21, pp. 966‐972, September 2010)     

左心房/肺静脉重构在孤立性心房颤动进展中的作用

目的 探讨孤立性心房颤动（房颤）进展过程中左心房/肺静脉重构的作用.方法 连续47例孤立性房颤患者在房颤心律下接受左心房/肺静脉CT检查,其中25例为阵发性房颤,22例为新发持续性房颤.通过对两组间有差异的CT指标进行Logistic回归分析,确定孤立性房颤进展的预测指标.结果 新发持续性房颤组的平均房颤持续时间为1～12（6.4±4.3）周.与阵发性房颤组比较,新发持续性房颤组呈现如下的左心房/肺静脉重构特征：（1）左心房非对称扩张;（2）左心房容积显著增大;（3）肺静脉开口扩张.经Logistic回归分析,左心房容积（P=0.003,OR=1.139,95%可信区间：1.046～1.240）是预测孤立性房颤进展最强的独立指标.左心房容积≥108 ml预测孤立性房颤由阵发性进展为持续性的敏感性为68.2%,特异性为88%.结论 孤立性房颤在由阵发性进展为持续性的过程中伴随有显著的左心房和肺静脉重构;左心房容积显著增加是该过程的独立预测指标.     

Comparison of left atrial phasic function in hypertrophic cardiomyopathy versus systemic hypertension using strain rate imaging

The aim of this study was to determine if left atrial (LA) phasic function evaluated by Doppler tissue imaging-derived strain and strain rate would be differentially decreased in patients with hypertrophic cardiomyopathy (HC) compared to patients with hypertension and to normal controls. Thirty-seven patients with HC were compared to 44 patients with systemic hypertension (SH) and 65 normal controls using transthoracic echocardiography. Maximal and minimal LA volume and LA volume just before active atrial contraction (pre-P LA volume) were measured, and phasic LA volumes were calculated. Global and segmental systolic strain rate, early diastolic strain rate, and late diastolic strain rate (A-Sr) and strain were measured from Doppler tissue imaging. Left ventricular mass was increased in the HC and SH groups compared to normal controls, but diastolic dysfunction was greater in the HC group. LA volumes were increased in patients with HC compared to those with SH and to normal controls, with corresponding reductions in A-Sr and atrial strain in the HC group. In contrast, only early diastolic strain rate was decreased in the SH group compared to controls. A-Sr remained reduced in patients with HC compared to the SH group, even after adjusting for left ventricular mass. When left ventricular mass, parameters of diastolic function (peak E and E' velocity), and the effect of patient group (SH vs HC) were examined in a stepwise regression model, patient group (SH vs HC) was the only independent determinant of A-Sr. In conclusion, HC results in LA enlargement with reduced LA phasic function that is reflected in reductions in A-Sr and atrial strain. Atrial enlargement is a likely consequence of the greater diastolic dysfunction in the HC group.     

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

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

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

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

Predictive value of total atrial conduction time measured with tissue Doppler imaging for postoperative atrial fibrillation after coronary artery bypass surgery

Objective

Postoperative atrial fibrillation (POAF) complicating coronary artery bypass grafting surgery (CABG) increases morbidity and stroke risk. Total atrial conduction time (PA-TDI duration) has been identified as an independent predictor of new-onset atrial fibrillation (AF). We aimed to assess whether PA-TDI duration is a predictor of AF after CABG.

Methods

In 128 patients who had undergone CABG, preoperative clinical and echocardiographic data were compared between patients with and without POAF. The PA-TDI duration was assessed by measuring the time interval between the beginning of the P wave on the surface ECG and point of the peak A wave on TDI from left atrium (LA) lateral wall just over the mitral annulus.

Results

Patients with POAF (38/128, 29.6 %) were older (68.1?±?11.1 vs. 59.3?±?10.2 years; p?<?0.001), had higher LA maximum volume, had prolonged PA-TDI duration, and had lower ejection fraction compared with patients without POAF. PA-TDI duration was found to be significantly increased in POAF group (134.3?±?19.7 vs. 112.5?±?17.7 ms; p?=?0.01). On multivariate analysis, age (95 % CI?=?1.03–1.09; p?=?0.003), LA maximum volume (95 % CI?=?1.01–1.06; p?=?0.03), and prolonged PA-TDI duration (95 % CI, 1.02–1.05; p?=?0.001) were found to be the independent risk factors of POAF.

Conclusions

In this study, LA maximum volume and PA-TDI duration were found to be the independent predictors of the development of POAF after CABG. Echocardiographic predictors of left atrial electromechanical dysfunction may be useful in risk stratifying of patients in terms of POAF development after CABG.     

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.     

New-onset atrial fibrillation during acute coronary syndromes: Predictors and prognosis

IntroductionNew-onset atrial fibrillation (AF) frequently complicates myocardial infarction, with an incidence of 6–21%.ObjectiveTo assess the predictors and prognosis of new-onset AF during acute coronary syndromes (ACS).MethodsWe performed a retrospective observational cohort study including 902 consecutive patients (mean age 64 years, 77.5% male) admitted to a single center over a two-year period, with a six-month follow-up.ResultsAF rhythm was identified in 13.8% patients, of whom 73.3% presented new-onset AF and 26.8% pre-existing AF. New-onset AF was more frequent in older (p<0.001) and hypertensive patients (p=0.001) and in those with previous valvular heart disease (p<0.001) and coronary artery bypass grafting (p=0.049). During hospitalization, patients with new-onset AF more often had respiratory infection (p=0.002) and heart failure (p<0.001), and higher values of NT-proBNP (p=0.007) and peak creatinine (p=0.001). On echocardiography they had greater left atrial (LA) diameter (p<0.001) and more frequent significant mitral regurgitation (p<0.001) and left ventricular ejection fraction (LVEF) ≤40% (p<0.001) and were less likely to have significant coronary lesions (p=0.009) or to have undergone coronary revascularization (p<0.001). In multivariate analysis, age (OR 1.06, p=0.021), LVEF ≤40% (OR 4.91, p=0.002) and LA diameter (OR 1.14, p=0.008) remained independent predictors of new-onset AF. Together with age, diabetes and maximum Killip class, this arrhythmia was an independent predictor of overall mortality (OR 3.11, p=0.032).ConclusionsAge, LVEF ≤40% and LA diameter are independent predictors of new-onset AF during ACS. This arrhythmia is associated with higher overall mortality (in-hospital and in follow-up).     

Left atrial deformation analysis by speckle tracking echocardiography for prediction of cardiovascular outcomes

The incremental value of left atrial (LA) deformation analysis by speckle tracking echocardiography compared with LA volume or LA ejection fraction as a cardiovascular risk marker has not been evaluated prospectively. We sought to compare LA function by speckle tracking echocardiography to other conventional LA parameters for prediction of adverse cardiovascular outcomes. This prospective study included 312 adults (mean age 71 ± 6 years, 56% men) in sinus rhythm who were followed for development of first atrial fibrillation, congestive heart failure, stroke, transient ischemic attack, myocardial infarction, coronary revascularization, and cardiovascular death. Global peak atrial longitudinal strain (PALS) by speckle tracking echocardiography was measured in all subjects by averaging all atrial segments. Left atrium was assessed with biplane LA volume, LA ejection fraction, 4-chamber LA area, and M-mode dimension. Of 312 subjects at baseline, 43 had 61 new events during a mean follow-up of 3.1 ± 1.4 years. All LA parameters, traditional parameters, and parameters derived by speckle tracking echocardiography were independently predictive of combined outcomes (p <0.0001 for all comparisons). Overall performance for prediction of cardiovascular events was greatest for global PALS (area under receiver operator characteristic curve: global PALS 0.83, indexed LA volume 0.71, LA ejection fraction 0.69, LA area 0.64, LA diameter 0.59). A graded association between degree of LA enlargement and risk of cardiovascular events was evident only for global PALS and indexed LA volume. In conclusion, global PALS is a strong and independent predictor of cardiovascular events and appears to be superior to conventional parameters of LA analysis.     

Risks for atrial fibrillation and congestive heart failure in patients >/=65 years of age with abnormal left ventricular diastolic relaxation

We sought to determine the risk for the first episodes of atrial fibrillation (AF) and congestive heart failure (CHF) in a cohort of patients aged >/=65 years who had abnormal left ventricular (LV) diastolic relaxation. Records were reviewed for all residents of Olmsted County, Minnesota, who had >/=1 transthoracic echocardiogram performed at the Mayo Clinic between 1990 and 1998, and who were in sinus rhythm and did not have a history of AF, CHF, valvular or congenital heart disease, permanent pacemaker, or stroke. Of 994 patients who qualified and had LV diastolic function assessment, abnormal LV relaxation was identified in 569 (57%), 105 of whom (18%) developed a first episode of AF or CHF over a mean follow-up of 4.0 +/- 2.7 years. Age (p <0.0001), history of myocardial infarction (p <0.0001), history of diabetes mellitus (p = 0.041), electrocardiographic LV hypertrophy (p = 0.0223), and indexed left atrial (LA) volume (p = 0.0003) were independent predictors. A stepwise increase in age-adjusted risk was evident when stratified by tertiles of indexed LA volume (<27 ml/m(2); 27 to 37 ml/m(2); >37 ml/m(2)). Compared with patients with normal LV diastolic function (n = 148, 15%), the risks for first episodes of AF or CHF were not different in those with abnormal diastolic relaxation if LA volume was <27 ml/m(2) (p = 0.303). In conclusion, these data suggest the presence of a wide spectrum of risks for AF or CHF in the elderly who have abnormal LV diastolic relaxation, with the highest risks evident in those with the largest left atria. When LA volume was <27 ml/m(2), however, the risks for these events were not different from those with normal LV diastolic function.