Larger Left Atrial Volume Research Articles

Evolution of post–pulmonary vein isolation atrial fibrillation inducibility at redo ablation: Electrophysiological evidence of extra–pulmonary vein substrate progression

The electrophysiological substrate underlying atrial fibrillation (AF) progression remains difficult to identify. The goals of this study were to study the evolution of post-pulmonary vein isolation (PVI) AF inducibility (AFI) after AF ablation and to compare patients with organized atrial tachycardia recurrence (OATr) versus those with paroxysmal or persistent AF recurrence. We studied 99 patients who underwent de novo AF ablation (p1) and redo ablation (p2) for AF recurrence (AFr) or OATr. Stepwise AF ablation was performed at p1 and p2: (1) PVI, (2) coronary sinus defragmentation, and (3) left atrial (LA) defragmentation. Burst pacing followed each step, with AFI defined as sustained AF >5 minutes, triggering the next step. Patients with OATr underwent OAT ablation and inducibility testing post-redo PVI. Inducibility progression (IP) was defined as AFI at further steps of p2 compared to p1. Among patients with AFr, 34 of 72 patients (47%) exhibited post-PVI IP vs 2 of 27 (7.4%) patients with OATr (P = .0002). Stratification for persistent AF/paroxysmal AF/OATr showed a consistent association between recurrence phenotype and IP. Pulmonary vein (PV) reconnection incidence was 90%, without association with recurrence type or IP. LA volume was larger in patients with IP than in those without IP (86.7 ± 25.3 mL vs 72.0 ± 28.9 mL; P=.001). Right atrial dimensions increased between p1 and p2 in patients with IP vs no IP and in patients with AFr vs OATr. Patients with AFr after first ablation exhibit IP more frequently at redo ablation than do patients with OATr. IP correlates with more advanced AFr type, larger LA volumes, and progressive right atrial enlargement. PV reconnection is not associated with AFr. Changes in post-PVI AFI may accurately indicate progression of extra-PV AF-maintaining substrate.

Incremental Benefit of Left Ventricular Global Longitudinal Strain over Clinical and Left Atrial Parameters for Predicting New-Onset Atrial Fibrillation

Background: Although LV dysfunction is associated with atrial fibrillation (AF), AF often occurs in the absence of reduced LVEF. The effect of subclinical LV dysfunction on AF has not been fully studied. We sought the association between subclinical LV dysfunction (measured with global longitudinal strain, GLS) and new-onset AF. Methods: We evaluated 531 consecutive pts without a history of AF who underwent strain echo after cryptogenic stroke. Standard echo parameters were measured, and speckle-tracking was used to measure LA and LV strain. Baseline clinical and echo parameters of the pts who developed AF and those who did not were compared. Results: Over 2.5 years of follow-up, 61 pts (11%) had AF. Pts who developed AF were older, larger LA volume, worse LA strain, and worse GLS than those who did not. Area under the receiver-operating curve for GLS (0.84) was comparable to LA pump strain (0.83) and LA reservoir strain (0.85). In the nested Cox models, GLS demonstrated an independent and incremental predictive value over the clinical and LA parameters. Moreover, adding GLS to the combined clinical and LA parameters model resulted in a significantly improved reclassification (net reclassification improvement, 0.32; p = 0.016). Importantly, the predictive value of GLS was confirmed in pts with abnormal LA volumes (LA volume index ≥34 ml/m2) but not in pts with normal LA volumes. Conclusion: GLS is associated with new-onset AF, especially in pts with abnormal LA volumes. This effect is independent of and incremental to the clinical and LA parameters.

P6474Clustering hypertension and overweight are synergistically associated with much larger left atrial volume. data from 3762 healthy individuals

P6474Clustering hypertension and overweight are synergistically associated with much larger left atrial volume. data from 3762 healthy individuals

Diagnostic value of electrocardiographic P-wave characteristics in atrial fibrillation recurrence and tachycardia-induced cardiomyopathy after catheter ablation.

Abnormal P-wave characteristics were reportedly associated with left ventricular interstitial fibrosis as defined by cardiac magnetic resonance images. The objective of this study is to investigate the utility of P-wave characteristics to predict atrial fibrillation (AF) recurrence and the recovery of left ventricular systolic dysfunction (LVSD) after catheter ablation (CA) for AF. Two hundred and five AF patients (109 paroxysmal and 96 persistent) who underwent CA were enrolled. We measured maximum P-wave duration (max PWD) and P-wave terminal force in lead V1 (PTFV1) calculated as a product of P-wave terminal amplitude (PTaV1) and duration (PTdV1) in lead V1 during sinus rhythm. AF recurrence was noted in 50 patients at 12months after CA. Patients with AF recurrence had a higher prevalence of persistent AF, a larger left atrial volume, and a longer max PWD than those without. We divided the patients into 2 groups: 156 patients with left ventricular ejection fraction (LVEF) > 45% and 49 patients with LVEF ≤ 45% (Low-EF group). In Low-EF group, tachycardia-induced cardiomyopathy (TIC) was defined as improvement in LVEF ≥ 15% or LVEF ≥ 50% at 5months after CA. TIC and non-TIC groups consisted of 37 and 12 patients, respectively. Max PWD, PTFV1, PTdV1, and PTaV1 were significantly greater in non-TIC-group than in TIC-group. PTFV1 had the highest diagnostic accuracy to discriminate between TIC and no-TIC-groups; cut-off value for PTFV1 was determined as 56.7mVms (area under the ROC curve = 0.80; 75% sensitivity; and 76% specificity). Max PWD was a useful predictor of AF recurrence and the complete recovery of LVSD after CA. PTFV1 had the highest diagnostic accuracy to discriminate between TIC and no-TIC-groups.

Prognostic Value of Frailty and Diastolic Dysfunction in Elderly Patients.

High prevalence of frailty and of diastolic dysfunction (DD) in heart failure and high mortality in frail adults have been noted. We characterized frailty by quantifying differences on echocardiography, and assessed the added prognostic utility of frailty and DD grade in an elderly population. One hundred and ninety-one patients ≥65 years who had at least 1 cardiovascular risk factor were prospectively recruited for clinically indicated echocardiography at the present institute. Weight loss, exhaustion, and deficits in physical activity, gait speed, and handgrip strength were used to categorize patients as frail (≥3 features), intermediately frail (1 or 2 features), or non-frail (0 features). DD grade ≥2 was defined as severe. Frailty was associated with larger left atrial volume, smaller stroke volume, and worse DD grade after adjustment for age. In a period of 14 months, 29 patients (15%) had cardiovascular events. The addition of frailty score and severe DD significantly improved the prognostic power of a model containing male gender (model 1, male gender, χ2=6.4; model 2, model 1 plus frailty score, χ2=16.7, P=0.004; model 3, model 2 plus severe DD, χ2=25.5, P=0.015). Both frailty and DD grade were significantly associated with future cardiovascular events in an elderly population with preserved ejection fraction and ≥1 risk factor of cardiovascular disease.

Left atrial pressure pattern without a-wave in sinus rhythm after cardioversion affects the outcomes after catheter ablation for atrial fibrillation.

The a-wave in left atrial pressure (LAP) is often not observed after cardioversion (CV). We hypothesized that repeated atrial fibrillation (AF) occurs in patients who do not show a-wave pattern after CV. We investigated the impact of "LAP pattern without a-wave" on the outcome after catheter ablation (CA) for AF. We studied 100 patients (64 males, age 66 ± 8years, 42 with non-paroxysmal AF) who underwent CA for AF. Sustained- or induced-AF were terminated with internal CV, and LAP was measured during sinus rhythm (SR) after CV. LAP pattern without a-wave was defined as absence of a-wave (the "a-wave" was defined as a protruding part by 0.2mmHg or more from the baseline) in LAP wave form. AF was terminated with CV in all patients. Recurrent AF was detected in 35/100 (35%) during the follow-up period (13.1 ± 7.8month). Univariate analysis revealed higher prevalence of LAP pattern without a-wave (71 vs. 17%, P < 0.0001), larger left atrial volume, elevated E wave, and decreased deceleration time as significant variables. On multivariate analysis, LAP pattern without a-wave was only independently associated with recurrent AF (P = 0.0014, OR 9.865, 95% CI 2.327-54.861). Moreover, patients with LAP pattern without a-wave had a higher risk of recurrent AF than patients with a-wave (25/36 patients, 69 vs. 10/64 patients, 16%, log-rank P < 0.0001). Left atrial pressure pattern without a-wave in sinus rhythm after cardioversion could predict recurrence after catheter ablation for AF.

Prevalence and Risk Factors for Paroxysmal Atrial Fibrillation and Flutter Detection after Cryptogenic Ischemic Stroke

Long-term cardiac monitoring with implantable loop recorders (ILRs) has revealed occult paroxysmal atrial fibrillation and flutter (PAF) in a substantial minority of cryptogenic ischemic stroke (CIS) patients. Herein, we aim to define the prevalence, clinical relevance, and risk factors for PAF detection following early poststroke ILR implantation. A retrospective study of CIS patients (n = 100, mean age 65.8 years; 52.5% female) who underwent ILR insertion during, or soon after, index stroke admission. Patients were prospectively followed by the study cardiac electrophysiologist who confirmed the PAF diagnosis. Univariate and multivariate analyses compared clinical, laboratory, cardiac, and imaging variables between PAF patients and non-PAF patients. PAF was detected in 31 of 100 (31%) CIS patients, and anticoagulation was initiated in almost all (30 of 31, 96.8%). Factors associated with PAF detection include older age (mean [year] 72.9 versus 62.9; P = .003), white race (odds ratio [OR], 4.5; confidence interval [CI], 1.8-10.8; P = .001), prolonged PR interval (PR > 175 ms; OR, 3.3; CI, 1.2-9.4; P = .022), larger left atrial (LA) diameter (mean [cm] 3.7 versus 3.5; P = .044) and LA volume index (mean [cc/m2]; 30.6 versus 24.2; P = .014), and lower hemoglobin (Hb)A1c (mean [%] 6.0 versus 6.4; P = .036). Controlling for age, obesity (body mass index > 30 kg/m2; OR, 1.2; CI, 1.1-1.4; P = .033) was independently associated with PAF detection. PAF was detected with high prevalence following early postcryptogenic stroke ILR implantation and resulted in significant management changes. Older age, increased PR interval, LA enlargement, and lower HbA1c are significantly associated with PAF detection. Controlling for age, obesity is an independent risk factor. A larger prospective study is warranted to confirm these findings.

Atrial functional mitral regurgitation. Three-dimensional echocardiographic study

Atrial fibrillation can lead to left atrium remodelling and induce functional mitral regurgitation. The aim of this study is to establish those features of the mitral annulus that are related to atrial functional mitral regurgitation. A total of 29 patients with persistent atrial fibrillation and 36 controls in sinus rhythm were retrospectively enrolled. The characteristics of the mitral annulus were analysed by three-dimensional transoesophageal echocardiography in both groups. The 2D and 3D echocardiographic parameters were correlated with the effective regurgitant orifice. Patients with atrial fibrillation had a larger left atrium volume, anteroposterior diameter at end-diastole, and lower percentage of change in this diameter (P=.015, P=.019 and P<.001, respectively). In the multiple regression analysis, the ellipticity index (β: -0.756, P=.004) and height-anterolateral-posteromedial diameter ratio (β: -0704, P=.003) were independent parameters that correlated with the effective regurgitant orifice (R2: 0.699, P=.019) in patients with atrial fibrillation. Atrial fibrillation leads to atrial dilation and alterations in the size and dynamics of the anteroposterior diameter, producing a circular mitral annulus. The independent determining factors of atrial functional mitral regurgitation in the atrial fibrillation group were the ellipticity index and the height-anterolateral-posteromedial diameter ratio.

Left atrial dysfunction as a determinant of pulmonary hypertension in patients with severe aortic stenosis and preserved left ventricular ejection fraction.

In patients with severe aortic stenosis (AS), the presence of pulmonary hypertension (PH) has been linked to a poor prognosis. We aimed to assess the main determinants of PH in patients with severe AS and preserved left ventricular ejection fraction (LVEF). We prospectively enrolled 108 consecutive patients with isolated severe AS (indexed aortic valve area <0.6cm2/m2) and LVEF >50%, in sinus rhythm. Left atrial (LA) function was assessed using longitudinal deformation parameters (by speckle tracking echocardiography). PH (defined as systolic pulmonary artery pressure >40mmHg) was present in 20 patients. Patients with severe AS and PH were older (p = 0.05), had higher BNP values (p = 0.05) and a greater degree of LV diastolic dysfunction: higher E/e' and E/A ratios and lower EDT values (p < 0.03 for all) compared to patients without PH. There were no differences between groups regarding AS severity and LV systolic function parameters. Patients with PH had a more impaired LA function: lower septal and lateral late diastolic peak velocity a' (p < 0.001 and p = 0.04 respectively) and lower LA peak longitudinal strain and strain rate parameters (p ≤ 0.005 for all). In multivariable analysis, LA late diastolic longitudinal strain rate was the only independent correlate of PH in our patients (p = 0.04). Patients with isolated severe AS, preserved LVEF and PH had larger LA volumes, a more impaired LA function, and higher LV filling pressures compared to those without PH. LA booster pump function, reflected by late diastolic longitudinal strain rate, emerged as an independent correlate of PH in these patients.

Factors influencing postoperative atrial fibrillation in patients undergoing on-pump coronary artery bypass grafting, single center experience

BackgroundThe reported incidence of AF after CABG surgery varies from 20 to 40%, with the arrhythmia usually occurring between second and fourth postoperative days. Postoperative AF after CABG was associated with greater in-hospital mortality and worse survival at long-term follow-up. Therefore, intensive attention has focused on the prevention of AF in high-risk patients. Many perioperative factors have been suggested to increase the incidence of postoperative AF after conventional CABG. In this study we are trying to examine some of these risk factors as predictors for Post-operative AF in our patients. In this study, our aim was to identify the perioperative predictors of AF in our patients who underwent Coronary Artery Bypass Grafting.MethodsOur Patients were divided into two groups; Group A included patients who did not develop PO AF (168 patients) and Group B patients who developed PO AF (84 patients). Perioperative Data, including gender, age, demographic variables and postoperative morbidity and mortality were extracted from the medical records.ResultsThis retrospective cohort study was conducted on 252 consecutive adult patients underwent CABG, in King Faisal Specialist Hospital and Research Center in Jeddah, Saudi Arabia. The mean age for patients with PO AF was 65 years (P = .0001). Eight-three patients (49.4%) were diabetics in group A and 56 patients (66.7%) in group B (P = .0001). Patients who developed POAF had a lower ejection fraction (44.8 ± 5.7%) (P = .0001), diastolic dysfunction (P = .0001), Larger Left atrial volume (P = .0001). Bleeding requiring re-opening for exploration and Postoperative shock were identified as significant predictors for POAF. Multivariate logistic regression (odds ratio, ±95% CI, P value) was performed to identify the effect of age, preoperative heart rate, ejection fraction, postoperative bleeding, Shock, ventilator time, Sensitivity was 89.5%, specificity was 94.6%, positive predictive value was 89.5%, and negative predictive value was 94.6%.ConclusionIn our study, advanced age, enlarged LA volume, low ejection fraction, combined surgeries and prolonged ventilation time were found to be predictors of atrial fibrillations after coronary artery bypass grafting.

Decreased left atrial myocardial strain in patients with suboptimal blood pressure control

ABSTRACTBackground: Suboptimal blood pressure (BP) control is commonly observed in patients receiving antihypertensive agents, but the relationship between uncontrolled BP and left atrial (LA) impairment remains unknown. Methods: This study enrolled 279 hypertensive patients who had been medicated, as well as 85 matched normal controls. The BP of systolic <140 mmHg and diastolic<90 mmHg was defined as optimal (HT1 group, n=146), otherwise as suboptimal BP control (HT2 group, n = 133). LA myocardial function was assessed by the systolic (SSa), early diastolic (SEa), and late diastolic (SAa) LA strains. Results: Both the HT1 group and HT2 group had higher BP reading, thicker interventricular septum, larger LA volume index, and enhanced active atrial emptying fraction than the control group (all <0.05). When compared with normal subjects, hypertensive patients displayed obvious reduction in the SSa (50.0 ± 10.9 vs. 35.9 ± 8.0%), SEa (30.1 ± 7.7 vs. 18.5 ± 7.1%) and SAa (19.9 ± 6.4 vs. 17.8 ± 4.2%) (all p < 0.001). In addition to a further impaired SEa found in the HT2 group than in the HT1 group (17.2 ± 5.3 vs. 19.8 ± 8.3%, p = 0.002), the treated BP of >140/90 mmHg appeared an independent risk factor associated with the abnormal SEa (odds ratio, 2.957; interval of confidence, 1.614-5.415; p = 0.001). Conclusions: Suboptimal BP control status in hypertensive patients is related to a further reduction of LA myocardial function assessed by the novel 2DSTI free strain, and suboptimal BP might be regarded as a composite risk factor and therefore a simplified treatment target. However, the prognostic value of LA free strain in patients with inability to achieve the BP target needs to be evaluated in future prospective studies.

Effect of Aging on Left Atrial Compliance and Electromechanical Properties in Subjects Without Structural Heart Disease

Aging is associated with changes in left atrial (LA) structure and function. The present study aimed at describing the effect of aging on LA properties in a large cohort of subjects without structural heart disease. We divided 386 subjects (mean age 58 years [range 16 to 91]; 188 men [49%]) clinically referred for echocardiography according to age groups. The P-wave dispersion (PWD), reflecting total atrial conduction time, was measured on a 12-lead surface electrocardiogram as the difference between maximum and minimum P-wave duration. The PA-TDI duration reflecting the total atrial conduction time was measured on tissue Doppler imaging (TDI) as the time between onset of P wave on surface electrocardiogram to peak A'-wave velocity. Two-dimensional speckle-tracking echocardiography was used to assess LA reservoir function, reflecting LA compliance. In the overall population, mean PWD, PA-TDI, and LA reservoir strain were 43 ± 12ms, 129 ± 27ms, and 36 ± 13%, respectively. Increasing age was independently associated with prolonged PWD (β= 0.161; p <0.001), PA-TDI (β= 0.476; p <0.001), and reduced LA reservoir strain (β=-0.259; <0.001), suggesting age-related fibrotic changes of the LA myocardium. The association between age and LA reservoir strain was modulated by body mass index (β=-0.582; p <0.001) and LA volume index (β=-0.117; p= 0.014). In conclusion, aging is associated with longer PWD and PA-TDI duration along with a decrease in LA reservoir function. Obesity and larger LA volumes are independently associated with reduced LA compliance.

Gothic aortic arch and cardiac mechanics in young patients after arterial switch operation for d-transposition of the great arteries

BackgroundIn patients who have undergone arterial switch operation (ASO) for d-transposition of the great arteries a gothic aortic arch (GA) morphology has been found and it has been associated with abnormal aortic bio-elastic properties. HypothesisGA is frequent in ASO patients and may have an impact on cardiac mechanics. Our study aims were to assess 1- the occurrence of GA in a large sample of patients after ASO; 2- the association between GA and aortic bio-elastic properties; and 3- the impact of GA on left ventricular (LV) function using speckle tracking echocardiography (STE). MethodsWe studied one hundred and five asymptomatic patients, who have undergone first stage ASO for d-TGA, with normal left ventricular ejection fraction (LVEF ≥53%). ResultsForty-six (44%) patients showed a GA (mean age 11.5±7.2years, 26 males) while fifty-nine (56%) patients (mean age 9.6±6.7years, 37 males) did not present GA. The two groups were comparable for age, sex, BSA, and office blood pressure values. In group GA aortic root was significantly dilated (27.4±7.5mm vs. 21.2±6.9mm, p<0.0001), aortic stiffness index (Group GA=1.8±1.2 vs. 1.4±0.7, p=0.025) was significantly increased, left atrial volume was larger (p=0.0145), global longitudinal strain (Group GA=−18.4±2.5% vs. −20.1±3.3%, p=0.012) and basal LV longitudinal strains (Group GA=−16.9±4.8% vs. −20.4±7.0%, p=0.013) were significantly reduced. ConclusionsAfter ASO the presence of a GA is associated with a significantly dilated aortic root, stiffer aortic wall, larger left atrial volume, and worse LV longitudinal systolic deformations, well known predictors of cardiovascular morbidity and mortality.

Conduction recovery following catheter ablation in patients with recurrent atrial fibrillation and heart failure

BackgroundAtrial fibrillation (AF) catheter ablation is increasingly proposed for patients suffering from AF and concomitant heart failure (HF). However, the optimal ablation strategy remains controversial. We performed this study to assess the prevalence of pulmonary vein (PV) or linear lesion reconnection in HF patients undergoing repeated procedures. Methods and resultsAt seven high-volume centres, 165 patients with HF underwent a repeat procedure after a first AF ablation including PV isolation alone (47 patients, group A) or PV isolation plus left atrial lines (118 patients, group B). Group A patients presented more often paroxysmal AF (p<0.001), less enlarged left atrium (p<0.001) and less left ventricular systolic dysfunction (p=0.031) compared to Group B, that more commonly had atypical atrial flutter (p<0.001). Forty-one (87%) patients in Group A and 69 (58%) in Group B presented at least one reconnected PV (p<0.001). Sixty-one (52%) patients in Group B presented at least one reconnected atrial line (left isthmus or roof). Patients without any reconnected PV (n=54, 33%) more frequently experienced persistent AF (p<0.001), had longer AF duration (p=0.047) and larger left atrial volume (p<0.001). Twenty-five patients (15%) with no PV and/or line reconnection did not significantly differ, concerning baseline characteristics, compared to those with at least one reconnected ablation site. ConclusionAs in the general AF population undergoing catheter ablation, PV reconnection is frequent in patients with HF and symptomatic recurrence. However, one third of patients presented arrhythmic recurrences even in the absence of PV reconnection, highlighting the importance of the underlying atrial substrate.

Early changes of left atrial function in chronic asymptomatic alcoholics by two-dimensional speckle-tracking echocardiography

Background Chronic excessive alcohol intake has been reported as a possible cause of dilated cardiomyopathy. Two-dimensional speckle-tracking echocardiography (2D-STE) is a novel method for the angle-independent and objective quantification of myocardial deformation. This study sought to assess left atrial function changes among alcoholics related to the duration of heavy drinking by 2D-STE.Methods We classified 92 asymptomatic alcoholics into mild, moderate and severe groups. Thirty age-matched controls were also recruited. We measured left atrial (LA) phasic volumes (max, min and pre-atrial contraction volume) using Simpson’s method in apical four-chamber view. Passive emptying (LAPEF) and active emptying (LAAEF) indices were calculated. Global longitudinal strain rate (SRs) during left ventricular (LV) ejection, early diastolic strain rate (SRe) during LV early diastole and peak negative strain rate (SRa) after the P-wave were also obtained by averaging all atrial segments.Results The alcoholics had larger LA volumes (max, min and pre-atrial contraction volume) since moderate stage (P < 0.01). LAPEF, SRs SRe, and E/A ratio showed progressive decrease according to the grades of alcoholism. The differences between the groups were significant, beginning from the moderate group (P < 0.01). During LAAEF, SRa values increased with the disease severity up to moderate alcoholics and then deteriorated significantly in severe alcoholics (P < 0.01).Conclusions These data suggest that 2D-STE may be considered a promising tool for the early detection of impairment of LA function in alcoholics.

Left atrial volume and function in dogs with naturally occurring myxomatous mitral valve disease

ObjectiveMyxomatous mitral valve disease (MMVD) induces progressive left atrial (LA) enlargement. The LA modulates left ventricular filling and performance through its reservoir, conduit, and contractile function. Assessment of LA size and function may provide valuable information on the level of cardiac compensation. Left atrial function in dogs with naturally occurring MMVD remains largely unexplored. The objective of this study was to evaluate LA volume and function in dogs with naturally occurring MMVD. AnimalsThis prospective study included 205 client-owned dogs of different breeds, 114 healthy dogs, and 91 dogs with MMVD of different disease severities. MethodsUsing two-dimensional echocardiography, the biplane area-length method was applied to assess LA volume and calculate volumetric indices of LA reservoir, conduit, and contractile function. ResultsLeft atrial volume and LA stroke volume increased, whereas LA reservoir and contractile function decreased with increasing disease severity. A maximal LA volume <2.25mL/kg was the optimal cut off identified for excluding congestive heart failure in dogs with chronic MMVD with a sensitivity of 96% and a specificity of 100%. An active LA emptying fraction <24% and/or a LA expansion index <126% were suggestive of congestive heart failure in dogs with chronic MMVD with a sensitivity of 77% and a specificity of 89% and a sensitivity of 82% and a specificity of 82%, respectively. ConclusionDogs with MMVD appear to have larger LA volumes with poorer LA function. Deteriorating LA function, characterized by a decreasing reservoir and active contractile function, was evident in dogs with MMVD with increasing disease severity.

Effect of Sex Differences on the Association Between Stroke Risk and Left Atrial Anatomy or Mechanics in Patients With Atrial Fibrillation

Embolic stroke in atrial fibrillation is more prevalent in women than in men, yet the basis for this difference remains unclear. This study seeks to elucidate whether there are any sex differences in the relationships between stroke risk (CHADS2 score, CHA2DS2-VASc score without a sex category, and estimated stroke rate) and left atrial (LA) anatomy or mechanics in patients with atrial fibrillation. LA emptying fraction and global peak atrial longitudinal strain were assessed in 414 subjects with paroxysmal or persistent atrial fibrillation (156 women and 258 men). Linear regression models with an interaction term were performed to test the effect of sex difference on associations between the embolic risk and LA function or anatomy. Sensitivity analyses were performed in 228 age, heart rate, and rhythm-matched subjects (114 women and men). Women were older and had larger LA volumes and lower LA mechanics than men. Significant negative association between the CHADS2 score and LA emptying fraction was only demonstrated in women with a significant interaction between sexes. Similar significant interactions were found in global peak atrial longitudinal strain but not in LA volume. These findings were corroborated in the comparisons against CHA2DS2-VASc score without a sex category and the estimated stroke rate. Sensitivity analyses in the matched subgroup also confirmed the robustness of these sex differences in LA emptying fraction, but less so in global peak atrial longitudinal strain. Significant sex interactions on the association between global LA function and risk stratification schemes exist, which may be a reason for the higher prevalence of embolic stroke in women.

Cardiac Magnetic Resonance-Measured Left Atrial Volume and Function and Incident Atrial Fibrillation: Results From MESA (Multi-Ethnic Study of Atherosclerosis).

Early detection of structural changes in left atrium (LA) before atrial fibrillation (AF) development could be helpful in identification of those at higher risk for AF. Using cardiac magnetic resonance imaging, we examined the association of LA volume and function, and incident AF in a multiethnic population free of clinical cardiovascular diseases. In a case-cohort study embedded in MESA (Multi-Ethnic Study of Atherosclerosis), baseline LA size and function assessed by cardiac magnetic resonance feature-tracking were compared between 197 participants with incident AF and 322 participants randomly selected from the whole MESA cohort. Participants were followed up for 8 years. Incident AF cases had a larger LA volume and decreased passive, active, and total LA emptying fractions and peak global LA longitudinal strain (peak LA strain) at baseline. In multivariable analysis, elevated LA maximum volume index (hazard ratio, 1.38 per SD; 95% confidence interval, 1.01-1.89) and decreased peak LA strain (hazard ratio, 0.68 per SD; 95% confidence interval, 0.48-0.96), and passive and total LA emptying fractions (hazard ratio for passive LA emptying fractions, 0.55 per SD; 95% confidence interval, 0.40-0.75 and hazard ratio for active LA emptying fractions, 0.70 per SD; 95% confidence interval, 0.52-0.95), but not active LA emptying fraction, were associated with incident AF. Elevated LA volumes and decreased passive and total LA emptying fractions were independently associated with incident AF in an asymptomatic multiethnic population. Including LA functional variables along with other risk factors of AF may help to better risk stratify individuals at risk of AF development.

Echocardiographic measures of atrial function may predict atrial fibrillation in stroke patients

Objective: In patients with a prior stroke or transient ischemic attack (TIA) and atrial fibrillation anticoagulant treatment is indicated. This study’s purpose was to investigate if echocardiography can predict unknown AF in patients after stroke.Design: Prospectively, 174 stroke/TIA patients without diagnosed AF underwent echocardiographic evaluation including tissue Doppler imaging (TDI) focusing on functional parameters of the left atrium and left ventricular diastolic function. AF screening was performed during 30 d.Results: Fifteen patients (8.6%) were diagnosed with AF. Echocardiography in the AF group compared to those without AF, showed larger left atrial volume index (LAVI), (37.2 ± 6.7 vs. 31.6 ± 8.6 ml/m2, p = 0.018), lower A’ velocities in ventricular (5.9 ± 2.2 vs. 7.2 ± 1.6, p = 0.010) and atrial (4.8 ± 1.4 vs. 5.9 ± 1.4, p = 0.013) septa, higher LAVI/A’ in ventricular septum (6.7 (5.0–8.7) vs. 4.2 (3.2–5.5), p = 0.001) and atrial septum (8.5 (5.9–11.0) vs. 5.1 (4.1–6.8), p = 0.003). Receiver operating characteristic analyses to detect AF was performed, area under the curve for LAVI was 0.71 (0.61–0.83), p = 0.008, and for LAVI/A’ in ventricular septum 0.76 (0.59–0.93), p = 0.006 and atrial septum 0.78 (0.63–0.93), p = 0.002, respectively.Conclusions: LAVI and measures of atrial contraction as measured by TDI predict unknown AF in patients after an stroke/TIA and may be used to detect silent AF.

Excessive interatrial adiposity is associated with left atrial remodeling, augmented contractile performance in asymptomatic population.

PurposePericardial adipose tissue had been shown to exert local effects on adjacent cardiac structures. Data regarding the mechanistic link between such measures and left atrial (LA) structural/functional remodeling, a clinical hallmark of early stage heart failure (HF) and atrial fibrillation (AF) incidence, in asymptomatic population remain largely unexplored.MethodsThis retrospective analysis includes 356 subjects free from significant valvular disorders, atrial fibrillation, or clinical HF. Regional adipose tissue including pericardial and periaortic fat volumes, interatrial septal (IAS), and left atrioventricular groove (AVG) fat thickness were all measured by multidetector computed tomography (MDCT) (Aquarius 3D Workstation, TeraRecon, San Mateo, CA, USA). We measured LA volumes, booster performance, reservoir capacity as well as conduit function, and analyzed their association with adiposity measures.ResultsAll four adiposity measures were positively associated with greater LA volumes (all P < 0.05), while IAS and AVG fat were also related to larger LA kinetic energy and worse reservoir capacity (both P < 0.01). In multivariate models, IAS fat thickness remained independently associated with larger LA volumes, increased LA kinetic energy and ejection force (β-coef: 0.17 & 0.15, both P < 0.05), and impaired LA reservoir and conduit function (β-coef: −0.20 & −0.12, both P < 0.05) after adjusting for clinical variables.ConclusionAccumulated visceral adiposity, especially interatrial fat depots, was associated with certain LA structural/functional remodeling characterized by impaired LA reservoir and conduit function though augmented kinetic energy and ejection performance. Our data suggested that interatrial fat burden may be associated with certain detrimental LA functions with compensatory LA adaptation in an asymptomatic population.