Left Atrial End-diastolic Volume Research Articles

Exercise physiology of the left atrium: quantity and timing of contribution to cardiac output.

Although the phases of left atrial (LA) function at rest have been studied, the physiological response of the LA to exercise is undefined. This study defines the exercise behavior of the normal left atrium by quantitating its volumetric response to graded effort. Healthy subjects (n = 131) were enrolled from the Health eHeart cohort. Echocardiograms were obtained at baseline and during ramped supine bicycle exercise. Left ventricular volume index, stroke volume index (LVSVI), left atrial end-systolic volume index (LAESVI), left atrial end-diastolic volume index (LAEDVI), and left atrial emptying fraction (LAEF), reservoir fraction, and conduit fraction were analyzed. The LVSVI increased with low exercise but did not increase further with peak exercise; cardiac output increased through the agency of heart rate. The LAESVI and LAEDVI decreased and the LAEF increased with exercise. As a result, the LA reservoir volume index was static throughout exercise. The reservoir fraction decreased from 46% at rest to 40% with low exercise (P < 0.001) in association with increased LVSVI and remained similar at peak exercise. The conduit volume index increased from 20 mL/m2 at rest to 24 mL/m2 at low exercise and stayed the same at peak exercise. Similarly, the conduit fraction increased from 54% at rest to 60% at low exercise (P < 0.001) and did not change further with peak exercise. Although atrial function increased with exercise, the major contribution to the augmentation of LV stroke volume is LA conduit fraction, a marker of active ventricular relaxation. Furthermore, the major determinant of raising cardiac output during high-level exercise is heart rate.NEW & NOTEWORTHY Diseases of the left atrium (LA) are major sources of disability (e.g., strokes and fatigue), but its exercise physiology has been unstudied. Such knowledge may allow early recognition of disease and suggest therapies. We show that in normal subjects, low-level exercise decreases LA volume and increases its ejection fraction. However, these changes offset each other volumetrically, and the contribution to LV filling from a full to an empty LA (reservoir function) is static. Higher levels of exercise do not change LA reservoir contribution. Blood flowing directly from the pulmonary vein to LV (conduit flow) impelled by augmented LV active relaxation (suction) is the major source of a modest increase in LV stroke volume. The major source of increased cardiac output with exercise is heart rate. During all stages of exercise, the LA works hard but only to keep up. We believe that our findings provide an additional set of benchmarks through which to quantitate LA pathology and gauge its progression.

Abstract 12541: Left Atrial Cardiomyopathy and Associations With Left Atrial Structure and Function

Introduction: Abnormally negative P-wave terminal force in lead V1 (aPTFV1 &lt;-5000μV*ms) is an electrocardiographic marker of left atrial (LA) myopathy and is associated with an increased risk of stroke, independent of atrial fibrillation. Whether the LA myopathy associated with aPTFV1 is associated with LA structural/mechanical dysfunction is unknown. Hypothesis: aPTFV1 is positively correlated with markers of LA mechanical dysfunction including LA end diastolic volume (LAEDV), systolic volume (LAESV), and ejection fraction (LA EF). Methods: Dallas Heart Study participants free of atrial fibrillation with concomitant cardiac MRI (CMR) and ECG were included. Participants were categorized as aPTFV1, defined as &lt;-5000μV*ms, or normal PTFV1 (nPTFV1). Demographics, established cardiovascular risk factors, and CMR markers of LA and LV structure/function were compared. Multivariable forward step-wise logistic regression models tested the association of aPTFV1 with the univariate variables (p&lt;0.1 for entry/exit). Results: Among 1,880 participants, 214 had an aPTFV1. Participants with aPTFV1 were more likely to be older, black, and have traditional atherosclerotic risk factors including hypertension, diabetes, smoking, and prior stroke (Table 1). aPTFV1 was associated with larger LAEDV and LAESV, and lower LA EF. Multivariable regression models demonstrated increased LV mass, but no markers of LA structural or mechanical dysfunction were associated with an aPTFV1. Modeling explained little of the variability in PTFV1 (cumulative R 2 = 0.03). Conclusions: In a large, multi-ethnic cohort, important differences in traditional cardiovascular risk exist between aPTFV1 and nPTFV1; however, cardiac MRI-derived LA structure/function explain very little of the variability in PTFV1. These data suggest the LA cardiomyopathy associated with aPTFV1 may be a manifestation of electrical rather than structural/mechanical dysfunction.

Left atrial remodeling after Mitraclip implantation

Abstract Objective Changes in left atrial (LA) size and function are associated with major adverse cardiovascular outcomes such as atrial fibrillation, heart failure, stroke, and death. Reverse LA remodelling occurs after successful surgical mitral valve repair for severe MR. Changes in LA volumes after MV repair have reported in several studies. However, LA data are limited in the setting of transcatheter repair. Materials an methods From November 2016 to July 2018, clinical and echocardiographic data of 42 patients with mitral regurgitation who underwent Mitraclip implantation in our division were evaluated for LA function: LA global longitudinal strain (LA GLS); LAESV (Left atrial end-systolic volume), LAEDV (Left atrial end-diastolic volume); LA emptying Fraction at baseline, at 1 month, at 6 months and 1 year of follow up were assessed. The variation of continuous variables was evaluated using a student T test for paired data or the Wilcoxon matched-pair signed rank test when appropriate. The categorical variables between two groups were evaluated using the chi-square test (χ2). P values &amp;lt;0.05 were considered significant. Results The etiology of the mitral regurgitation was primary in 33,3% and secondary in 66,7% of the included patients. The MR degree was 3+ in 21,4% of patients and 4+ in 78,6%. When compared to baseline at 6 months and 1 year a statistically significant reduction was observed for both LAESV (p&amp;lt;0.001) and LAEDV (p&amp;lt;0.001). At 6 months, compared to baseline, the LA GLS reached statistic relevance (p 0.05) with a significant improvement at 1 year (p 0.001). Finally, we did not find significant differences in LA emptying fraction at different time point analyzed. Conclusions A successful MitraClip procedure can reverse the process of LA remodeling within 12 months, and this can be detected by Two-dimensional speckle tracking echocardiography (2D STE) through an improvement in the LA reservoir function. These data generate the hypothesis that the GLS, compared to conventional echocardiographic parameters, represents an advanced method that quantify atrial function in Mitraclip implanted patients. Funding Acknowledgement Type of funding source: Public hospital(s)

Relationship between cardiac structure and function and atrial fibrillation related hospitalizations following catheter ablation

Abstract Background Even though catheter ablation (CA) is an effective treatment for atrial fibrillation (AF), AF-related hospitalizations and cardioversions are common following this procedure. Purpose To investigate whether echocardiographic measures of left atrial (LA) function could predict AF-related hospitalizations and cardioversions. Methods This was a substudy of a trial that randomized patients to amiodarone vs place to reduce AF recurrence following CA. Transthoracic echocardiography was performed prior to CA and included assessment of: end-systolic and end-diastolic LA volumes, emptying fraction (LAEF), atrial strain, and global longitudinal strain (GLS). Poisson regression was used to assess predictive value for AF-related hospitalizations and cardioversions. Multivariable adjustments were made for: age, gender, ejection fraction, AF burden, AF subtype, dyspnea, and class 1c antiarrhythmics. Results Of the 212 patients, 80 were hospitalized for AF (206 times), and 77 were cardioverted (192 times) within the 6 months follow-up period. Mean age was 60 years, 83% were men, and mean LVEF was 50%. In univariable analyses, LA volumes, LAEF and GLS were predictors of the outcomes but did not remain significant predictors after multivariable adjustments. During echocardiography 162 patients were in sinus rhythm and 50 had AF rhythm. Rhythm during the echocardiogram modified the association between GLS and outcomes (p for interaction &amp;lt;0.05 for both endpoints), such that GLS predicted both AF-related hospitalizations and cardioversions in patients with sinus rhythm but not AF during the echocardiogram (figure). Conclusion Global longitudinal strain predicts AF-related hospitalizations and cardioversions after CA, but only in patients presenting in sinus rhythm during the echocardiogram. Patients presenting with impaired global longitudinal strain should be considered high-risk patients following CA who may benefit from close follow-up. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): The Danish Heart Foundation

Evaluation of left atrial remodeling in kidney transplant patients using cardiac magnetic resonance imaging.

Increased left atrial (LA) size predicts cardiovascular events in patients with end-stage kidney disease. There is a paucity of data on LA changes after kidney transplantation (KT). Accordingly, we used cardiac magnetic resonance imaging (CMR) to evaluate LA remodeling after KT, and examined its relationship with left ventricular (LV) measurements, blood pressure and cardiac biomarkers. In this prospective multi-center cohort study, 39 pre-transplant dialysis patients underwent KT and 42 eligible transplant recipients remained on dialysis. CMR, blood pressure and serum measurements for N-terminal pro b-type natriuretic peptide (NT-proBNP), high sensitivity C-reactive protein (hsCRP), and growth differentiation factor-15 (GDF-15) were performed at baseline and 12months. After 12months, there were no significant changes in LA end-systolic volume index, LA end-diastolic volume index, or LA ejection fraction (LAEF) within the KT or dialysis group; changes over time did not differ between the 2 groups (all p > 0.25). At baseline and over 12months, LA volumes and LAEF positively correlated with LV volumes and mass while LAEF positively correlated with LV function. Changes in LA volumes also positively correlated with NT-proBNP and systolic blood pressure (sBP) while LAEF negatively correlated with NT-proBNP. GDF-15 correlated with LA measurements at baseline but not in 12-month changes. hsCRP did not correlate with any LA measurements. LA volumes and function as measured by CMR did not change significantly over 12months post-KT. There were significant associations between LA and LV remodeling, NT-proBNP and sBP, suggesting common underlying pathophysiological mechanisms.

Left atrial structure and function among different subtypes of atrial fibrillation: an echocardiographic substudy of the AMIO-CAT trial.

Little is known about cardiac structure and function among atrial fibrillation (AF) subtypes; paroxysmal AF vs. persistent AF (PxAF), and across AF burden. We sought to assess differences in left atrial (LA) measures by AF subtype and burden. This was a cross-sectional echocardiographic substudy of a randomized trial of AF patients scheduled for catheter ablation. Patients had an echocardiogram performed 0-90 days prior to study inclusion. We performed conventional echocardiographic measures, left ventricular (LV) and LA speckle tracking. Measures were compared between AF subtype and burden (0%, 0-99%, and 99-100%) determined by 72-h Holter monitoring. Of 212 patients, 107 had paroxysmal AF and 105 had PxAF. Those with PxAF had significantly reduced systolic function (LV ejection fraction: 48% vs. 53%; P < 0.001), larger end-systolic and end-diastolic LA volumes (LAVi and LAEDVi), reduced LA emptying fraction (LAEF: 29% vs. 36%, P < 0.001), and reduced LA strain (LAs) (LAs: 20% vs. 26%, P < 0.001). LA measures remained significantly lower in PxAF after multivariable adjustments. All LA measures and measures of systolic function were significantly impaired in patients with 99-100% AF burden, whereas all measures were similar between the other groups (LAVi: 40mL/m2 vs. 33mL/m2 vs. 34mL/m2; LAEDVi: 31mL/m2 vs. 21mL/m2 vs. 22mL/m2, LA emptying fraction: 23% vs. 35% vs. 36%, LAs: 16% vs. 25% vs. 25%, for 99-100%, 0-99%, and 0% AF, respectively, P < 0.001 for all). These differences were consistent after multivariable adjustments. LA mechanics differ between AF subtype and burden and these characteristics influence the clinical interpretation of these measures.

Extent of Late Gadolinium Enhancement Predicts Thromboembolic Events in Patients With Hypertrophic Cardiomyopathy.

Thromboembolic complications such as ischemic stroke or peripheral arterial thromboembolism are known complications in hypertrophic cardiomyopathy (HCM). We sought to assess the clinical and cardiovascular magnetic resonance (CMR) characteristics of patients with HCM suffering from thromboembolic events and analyzed the predictors of these unfavorable outcomes.Methods and Results:The 115 HCM patients underwent late gadolinium enhanced (LGE) CMR and were included in the study. Follow-up was 5.6±3.6 years. The primary endpoint was the occurrence of thromboembolic events (ischemic stroke or peripheral arterial thromboembolism). It occurred in 17 (14.8%) patients (event group, EG), of whom 64.7% (11) were men. During follow-up, 10 (8.7%) patients died. Patients in the EG showed more comorbidities, such as heart failure (EG 41.2% vs. NEG (non-event group) 14.3%, P<0.01) and atrial fibrillation (AF: EG 70.6% vs. NEG 36.7%, P<0.01). Left atrial end-diastolic volume was significantly higher in the EG (EG 73±24 vs. NEG 50±33 mL/m2, P<0.01). Both the presence and extent of LGE were enhanced in the EG (extent% EG 23±15% vs. NEG 8±9%, P<0.0001). No patient without LGE experienced a thromboembolic event. Multivariate analysis revealed AF and LGE extent as independent predictors. LGE extent (>14.4%) is an independent predictor for thromboembolic complications in patients with HCM and might therefore be considered as an important risk marker. The risk for thromboembolic events is significantly elevated if accompanied by AF.

Left Atrial End-Diastolic Volume Index as a Predictor of Cardiovascular Outcomes: The Heart and Soul Study.

The left atrial end-systolic volume index (LAESVI) is a predictor of cardiovascular outcomes and is the recommended measurement of left atrial size. The left atrial end-diastolic volume index (LAEDVI), representing the minimum or residual left atrial volume, has not been fully evaluated as a predictor of cardiovascular events. This study evaluated the predictive power of LAEDVI compared with LAESVI for heart failure (HF) hospitalizations, a composite of HF hospitalizations, myocardial infarction, stroke, and heart disease death, and all-cause mortality. We measured LAESVI and LAEDVI in subjects without atrial fibrillation or flutter or significant mitral valve disease. Using Cox proportional-hazard models, the association of LAESVI and LAEDVI with the stated outcomes was examined. After a mean of 7.3±2.6 years of follow-up, there were 147 HF hospitalizations, 118 myocardial infarctions, 45 strokes, 96 heart disease deaths, and 351 deaths from all causes in 938 subjects. When comparing the highest and the lowest quartiles of LAEDVI, there was a near 6-fold increase in the hazard ratio (HR) for HF hospitalization (HR, 5.96; P<0.001). This was higher than what was seen with LAESVI (HR, 4.85; P<0.001). Similar associations were noted for the composite cardiovascular outcome (HR for LAEDVI, 2.97; P<0.001) and for all-cause mortality (HR for LAEDVI, 2.08; P<0.001). In adjusted models, LAEDVI demonstrated equal or better predictive power than LAESVI for HF hospitalization and the composite cardiovascular outcome. LAEDVI is a strong predictor of cardiovascular events in ambulatory patients with stable coronary heart disease and may merit routine use.

Predicting Left Atrial Appendage Thrombus from Left Atrial Volume and Confirmation by Computed Tomography with Delayed Enhancement.

Assessing thromboembolic risk is crucial for proper management of patients with atrial fibrillation. Left atrial volume is a promising predictor of cardiac thrombosis. To determine whether left atrial volume can predict left atrial appendage thrombus in patients with atrial fibrillation, we conducted a prospective study of 73 patients. Left atrial and ventricular volumes were evaluated by cardiac computed tomography with retrospective electrocardiographic gating and then indexed to body surface area. Left atrial appendage thrombus was confirmed or excluded by cardiac computed tomography with delayed enhancement. Seven patients (9.6%) had left atrial appendage thrombus; 66 (90.4%) did not. Those with thrombus had a significantly higher mean left atrial end-systolic volume index (139 ± 55 vs 101 ± 35 mL/m2; P=0.0097) and mean left atrial end-diastolic volume index (122 ± 45 vs 84 ± 34 mL/m2; P=0.0077). On multivariate logistic regression analysis, left atrial end-systolic volume index (per 10 mL/m2 increase) was significantly associated with left atrial appendage thrombus (odds ratio [OR]=1.24; 95% CI, 1.03-1.50; P=0.02); so too was the left atrial end-diastolic volume index (per 10 mL/m2 increase) (OR=1.29; 95% CI, 1.05-1.60; P=0.02). These findings suggest that increased left atrial volume increases the risk of left atrial appendage thrombus. Therefore, patients with atrial fibrillation and an enlarged left atrium should be considered for cardiac computed tomography with delayed enhancement to confirm whether thrombus is present.

Left Ventricular Extracellular Volume Expansion Is Not Associated with Atrial Fibrillation or Atrial Fibrillation-mediated Left Ventricular Systolic Dysfunction.

To determine whether left ventricular (LV) extracellular volume (ECV) expansion is associated with atrial fibrillation (AF) or AF-mediated LV systolic dysfunction (LVSD) while minimizing the influence of biologic and imaging methodologic confounders. This study examined the prevalence of LV ECV expansion in 137 patients with AF (mean age, 62 years ± 11 [standard deviation]; 92 male patients and 45 female patients; 83 paroxysmal and 54 persistent) who underwent preablation cardiovascular MRI. Biologic confounders were minimized by measuring the ECV fraction and excluding patients with severe LV hypertrophy, defined as wall thickness greater than 1.5 cm. Imaging confounders were minimized by using an arrhythmia-insensitive-rapid (AIR) cardiac T1 mapping pulse sequence. Other cardiac functional parameters, including LV ejection fraction (LVEF) and left atrial end-diastolic volume indexed to body surface area, were assessed using cine cardiovascular MRI. A substudy was conducted in 32 patients with no AF (mean age, 54 years ± 16) in sinus rhythm to establish control values and convert these values between the AIR sequence and literature-based modified Look-Locker inversion recovery (MOLLI) values. The mean ECV was not significantly different (P > .05) between patients with AF with a normal LVEF (24.5% ± 2.8; n = 107), patients with AF with LVSD (24.5% ± 2.5; n = 30), and patients with no AF (24.4% ± 3.8; n = 32), but there was a significant interaction between ECV and CHA2DS2-VASc score (P = .045). Compared with the literature data obtained from healthy control patients scanned using MOLLI, 99.3% of patients with AF had ECV below the fibrosis cutoff point (32.8% when converted from MOLLI T1 mapping to AIR T1 mapping), including a subset of patients with AF (n = 28) with low CHA2DS2-VASc score (0/1 for men/women). Study results suggest that an LV ECV expansion is not associated with AF or AF-mediated LVSD. Supplemental material is available for this article. © RSNA, 2020See also the commentary by Stillman in this issue.

Left atrial mechanical remodelling assessed as the velocity of left atrium appendage wall motion during atrial fibrillation is associated with maintenance of sinus rhythm after electrical cardioversion in patients with persistent atrial fibrillation.

The velocity of left atrium appendage (LAA) wall motion during atrial fibrillation (AF) is a potential marker of mechanical remodelling. In this study, we investigated whether the velocity of LAA wall motion during AF predicted the success of electrical cardioversion and long-term sinus rhythm maintenance. Standard echocardiographic data were obtained by transthoracic echocardiography, and LAA wall motion velocities were measured by transoesophageal echocardiography. With logistic regression and receiver operating characteristic curve analyses, we related echocardiographic and clinical data to cardioversion outcomes and sinus rhythm maintenance at 12 months. Of 121 patients prospectively included in the study, electrical cardioversion restored sinus rhythm in 97 (81.2%), and 51 (42%) patients maintained sinus rhythm at 12 months. Patients in whom cardioversion restored sinus rhythm had higher LAA wall motion velocities than did the patients with failed cardioversions (p <0.001). Compared to patients with AF at 12 months, patients who maintained sinus rhythm had lower maximum and end-diastolic left atrial volumes (p ≤ 0.01), lower E/e’ ratios (p = 0.005), higher s’ values (p = 0.013), and higher LAA motion velocities (p < 0.001). On multivariate logistic regression, only LAA wall motion velocity and E/e’ ratios remained significant predictors of sinus rhythm maintenance at 12 months (p ≤ 0.04). LAA wall motion velocity was also a significant predictor of sinus rhythm maintenance when corrected for clinical variables (p = 0.039). Conclusion: LAA wall motion velocity, as a marker of mechanical remodelling, can predict short-term and long-term sinus rhythm maintenance after electrical cardioversion in AF.

LA Mechanics in Decompensated Heart Failure: Insights From Strain Echocardiography With Invasive Hemodynamics

ObjectivesThe aim of this study was to assess the effect of congestion and decongestive therapy on left atrial (LA) mechanics and to determine the relationship between LA improvement after decongestive therapy and clinical outcome in immediate or chronic heart failure with reduced ejection fraction (HFrEF). BackgroundLA mechanics are affected by volume/pressure overload in decompensated HFrEF. MethodsA total of 31 patients with HFrEF and immediate heart failure (age 64 ± 15 years, 74% male, left ventricular ejection fraction 20 ± 12%) underwent serial echocardiography during decongestive therapy with simultaneous hemodynamic monitoring. LA function was assessed by strain (rate) imaging. Patients were re-evaluated 6 weeks after discharge and prospectively followed up for the composite endpoint of heart failure readmission and all-cause mortality. ResultsLA reservoir function was markedly reduced at baseline and improved with decongestion (peak atrial longitudinal strain from 6.4 ± 2.2% to 8.8 ± 3.0% and strain rate from 0.29 ± 0.11 s–1 to 0.38 ± 0.13 s–1), independent of changes in left ventricular global longitudinal strain, LA end-diastolic volume, and mitral regurgitation severity (p < 0.001). Both measures continued to rise at 6 weeks (up to 13.4 ± 6.1% and 0.50 ± 0.19 s–1, respectively; p < 0.001). LA pump strain rate only increased 6 weeks after discharge (–0.25 ± 0.12 s–1 to –0.55 ± 0.29 s–1; p < 0.010). Changes in LA mechanics correlated with changes in wedge pressure (r = –0.61; p < 0.001). Lower peak atrial longitudinal strain values after decongestion were associated with increased risk for the composite endpoint of heart failure and mortality (p < 0.019). ConclusionsLA reservoir and booster function, while severely impaired during immediate decompensation, significantly improve during and after decongestive therapy. Poor LA reservoir function after decongestion is associated with worse outcome.

P1270 Systolic blood pressure at age 40 is associated with left atrial volumes at age 64

Abstract Funding Acknowledgements Vestre Viken Hospital Trust Background Left atrial (LA) enlargement is associated with elevated blood pressure (BP) and with cardiovascular morbidity and mortality. In the assessment of LA size, echocardiographic guidelines recommend the use of LA end-systolic volume (LAVmax). LA end-diastolic volume (LAVmin) and LA emptying fraction (LAEF) may add valuable information in risk assessment. The knowledge of early adulthood BP and its association to LA volumes and LAEF later in life is limited. Purpose To explore the association between systolic BP at age 40 and LA volumes and LAEF at age 64. Methods We linked data from subjects who had participated in both a nationwide cardiovascular screening survey (1990-1991) at the age of 40, and the Akershus Cardiac Examination (ACE) 1950 Study (2012-2015) at the age of 64 (n = 2,597). In the ACE 1950 Study, LAVmax and LAVmin were measured with echocardiography according to the summation of discs method. LAEF was calculated as (LAVmax-LAVmin/LAVmax)x100%. The association between systolic BP at age 40 and LA volumes and LAEF at age 64 was assessed in univariate and multivariate linear regression analyses. Results Systolic BP at age 40 was associated with LAVmax and LAVmin but not with LAEF at age 64. In our multivariate model, a 10 mm Hg higher systolic BP at age 40 was associated with a 0.9 ml greater LA end-systolic volume and a 0.5 ml greater LA end-diastolic volume at age 64. Conclusion Early adulthood systolic BP is associated with LA volumes 24 years later in life. Table. Association of systolic blood pressure at age 40 to left atrial (LA) volumes and LAEF at age 64 Univariate Multivariate* Dependent variable B (95% CI) p-value B (95% CI) p-value LAVmax (ml) 2.4 (2.0, 2.9) &amp;lt;0.001 0.9 (0.4, 1.4) 0.001 LAVmin (ml) 1.5 (1.1, 1.8) &amp;lt;0.001 0.5 (0.1, 0.9) 0.015 LAEF (%) -0.01 (-0.3, 0.3) 0.938 0.2 (-0.2, 0.5) 0.294 *Adjusted for gender, body mass index, smoking, resting heart rate and antihypertensive treatment, all assessed at age 40. B (95% CI), regression coefficient for systolic blood pressure (per 10 mm Hg) with 95% confidence interval; LAVmax, LA end-systolic volume; LAVmin LA end-diastolic volume; LAEF, LA emptying fraction

103 Normal values and gender differences of left atrial volumes

Abstract Funding Acknowledgements Vestre Viken Hospital Trust Background Left atrial (LA) enlargement is associated with cardiovascular morbidity and mortality. Echocardiographic guidelines recommend body surface area (BSA) indexed LA end-systolic volume (LAVimax) in the assessment of LA size with an upper normal limit of 34 ml/m² for both genders and all age groups. LA end-diastolic volume (LAVimin) and LA emptying fraction (LAEF) may add valuable information in risk assessment, but there are limited data on normal values. Purpose To add knowledge and explore gender differences of LA volumetric measures. Methods In The Akershus Cardiac Examination 1950 Study, all inhabitants of Akershus County, Norway, born in 1950 were invited. In 3,489 individuals LAVmax and LAVmin were measured with echocardiography according to the summation of discs method and indexed to BSA. LAEF was calculated. A healthy group was defined by excluding those with heart failure, atrial fibrillation, coronary artery disease, stroke, hypertension, diabetes, chronic obstructive pulmonary disease, body mass index &amp;gt; 30kg/m², eGFR &amp;lt; 60 ml/min/1.73 m², left ventricular ejection fraction &amp;lt; 50%, E/e’&amp;gt;14 and E/A &amp;gt; 2.0. Data are presented as mean ± standard deviation (SD) and a normal range of mean ± 2SD. T-tests were used for comparisons. Results In 840 healthy individuals, aged 63.8 ± 0.6 years, mean LAVimax was 25.6 ± 6.3 ml/m² and the normal range was 13.0-38.2 ml/m². Men had significantly larger volumes than women. Conclusion We present LA volumes and LAEF in a large cohort from the general population at age 64. The upper normal limit of LAVimax in 840 healthy individuals was 38 ml/m². Men had larger LA volumes than women, contrary to most previous studies. Thus, 13% of the healthy men in our cohort would be defined with an enlarged atrium with the current cut-off value at 34 ml/m². Table. Left atrial (LA) volumes and LAEF Total (mean ± SD) Total (2SD range) Male (mean ± SD) Female (mean ± SD) P-value (male vs. female) All participants (n = 3489) LAVimax (ml/m&amp;sup2;) 26.8 ± 7.6 11.6-42.0 27.9 ± 8.1 25.6 ± 6.8 &amp;lt;0.001 LAVimin (ml/m&amp;sup2;) 14.7 ± 5.8 3.1-26.3 15.5 ± 6.5 13.9 ± 4.9 &amp;lt;0.001 LAEF (%) 45.6 ± 9.7 26.2-65.0 45.3 ± 10.2 45.9 ± 9.2 0.07 Healthy group (n = 840) LAVimax (ml/m&amp;sup2;) 25.6 ± 6.3 13.0-38.2 26.6 ± 6.7 24.9 ± 5.8 &amp;lt;0.001 LAVimin (ml/m&amp;sup2;) 13.7 ± 4.3 5.1-22.3 14.1 ± 4.6 13.3 ± 3.9 0.008 LAEF (%) 46.8 ± 8.8 29.2-64.4 47.0 ± 9.1 46.5 ± 8.4 0.37 LAVimax, LA end-systolic volume, body surface area (BSA)-indexed; LAVimin, LA end-diastolic volume, BSA-indexed; LAEF, LA emptying fraction; SD, standard deviation

1039 Time course of left atrial performance in patients with paroxysmal atrial fibrillation undergoing radio-frequency catheter isolation of pulmonary veins

Abstract Background Radio-frequency catheter isolation of pulmonary veins (RF-PVI) is associated with changes of left atrial (LA) structure and function. However, there is limited knowledge regarding the long-term impact of successful RF-PVI on the LA mechanics. The aim of the current study was to assess the time course of LA performance in patients with paroxysmal atrial fibrillation (pAF) undergoing RF-PVI. Methods The study population included 24 consecutive patients (age:62 ± 21 years; 66% male) with symptomatic pAF and preserved left ventricular ejection fraction (≥50%) undergoing the first RF-PVI and 23 healthy controls. A comprehensive echocardiographic examination was performed one day before and 1 day, 3- and 12- months after RF-PVI. The reservoir, conduit and contractile LA strain (LAS), strain rate (LASR) and mechanical dispersion (LAMD) were assessed using two-dimensional speckle tracking echocardiography in apical views. Results At baseline, patients with pAF showed a significant reduction of all three components of LAS and LASR compared with controls (all p &amp;lt; 0.01). At 1 day after RF-PVI, LAS and LASR showed significant decrease compared with baseline (all p &amp;lt; 0.05) (figure). At 3-month follow up, LAS and LASR recovered to baseline values while LAMD showed a significant improvement (77ms vs 58ms, p = 0.003). At 12-month follow up, both reservoir and contractile LAS showed further improvement compared to 3-month values (31% vs 27%, and 15% vs 13%, both p &amp;lt; 0.05). Yet, even after 12 months, LAS values remained significantly lower compared with healthy controls (p &amp;lt; 0.05). LA emptying fraction was restored and LA end-systolic (max) and end-diastolic (min) volume index showed a significant decrease compared to baseline and 3-month values (all p &amp;lt; 0.05). Conclusion Successful RF-PVI is associated with acute decrease in LAS, followed by recovery to baseline values within 3 months and further improvement during one year. Reservoir and contractile LAS appears to be the most clinically useful indices to monitor LA performance in patients with pAF undergoing RF-PVI. Figure Time course of LA reservoir and contractile strain, LA max and min volume index, and LA mechanical dispersion (Baseline, 1-day FUP, 3- and 12-month FUP). Abstract 1039 Figure.

The Effect of Strict Volume Control Assessed by Repeated Bioimpedance Spectroscopy on Cardiac Function in Peritoneal Dialysis Patients

Adequate fluid management plays an important role in decreasing cardiovascular risk in peritoneal dialysis (PD) patients. We evaluated whether strict volume control monitored by bioimpedance spectroscopy (BIS) affects cardiac function in PD patients. This study is a secondary analysis of a multicentre, prospective, randomized, controlled trial. Fluid overload was assessed by the average overhydration/extracellular water (OH/ECW) at baseline, 6 months and 12 months. Patients were categorized as time-averaged overhydrated (TA-OH/ECW ≥15%) or normohydrated (TA-OH/ECW <15%), and echocardiographic parameters were compared between groups. Among a total of 151 patients, 120 patients exhibited time-averaged normohydration. Time-averaged overhydrated patients had a significantly higher left atrial (LA) diameter and E/e′ ratio and a lower left ventricular (LV) ejection fraction at 12 months than time-averaged normohydrated patients. LA diameter, end-systolic volume and end-diastolic volume were decreased at 12 months compared to baseline in time-averaged normohydrated patients only. TA-OH/ECW was independently associated with ejection fraction at 12 months (β = −0.190; p = 0.010). TA-OH/ECW, but not OH/ECW at 12 months, was an independent risk factor for LV dysfunction (odds ratio 4.020 [95% confidence interval 1.285–12.573]). Overhydration status based on repeated BIS measurements is an independent predictor of LV systolic function in PD patients.

Intensity and Distribution of Patchy Late Gadolinium Enhancement in Left Atrium in Patients With Atrial Fibrillation.

Late gadolinium enhancement (LGE) cardiac magnetic resonance imaging (MRI) studies were performed on healthy individuals to establish signal intensity thresholds for reproducible left atrial (LA) patchy LGE detection. Using established criteria, differences in LA patchy LGE between healthy volunteers (HV) and patients with atrial fibrillation (AF) or hypertension were analyzed. Fifty-three patents with AF (mean age 56 years, 60% men), 25 patients with hypertension and no history of AF (mean age 54 years, 40% men), and 28 HV (mean age 50 years, 52% men) were enrolled in an observational, non-interventional, case-control prospective study. LA patchy LGE quantification was performed using LGE MRI (1.5 T scanner, voxel size 1.25x1.25x2.5 mm) and the custom-built software based on estimation of LA voxel image intensity ratio and comparison with threshold value obtained from HV data. Based on analysis of healthy individuals' data, the optimal threshold value for the left atrial patchy LGE quantification was determined at 1.38. Patients with AF had a higher extent of LA patchy LGE (9.1 [1.72; 18.58] %) than patients with hypertension (3.81 [0.57; 9.51] %) and HV (0.78 [0.05; 3.5] %). The predominant location of LA patchy LGE in AF was in the pulmonary vein ostia region, in hypertension - LA posterior wall, and in HV - lower part of LA posterior wall. In AF patients, the extent of LA patchy LGE correlated with LA end-diastolic volume (r=0.37) and LA ejection fraction (r=-0.4), in HV - with age (r=0.66) and LA end-diastolic volume (r=0.4). AF and hypertension are associated with higher extent and different location of LA patchy LGE compared to changes caused by natural aging. The extent of LA patchy enhancement correlates with LA dilatation.

Abstract P153: Early Changes in Left-Atrial and Left-Ventricular Geometry and Function in Women After Preeclampsia as Detected by Cardiac Magnetic Resonance Imaging

Objectives: Preeclampsia (PE), the leading cause of maternal and neonatal morbidity and mortality, is associated with an increased long-term risk for cardiovascular disease (CVD). We aimed to characterize myocardium and investigate potential functional and structural cardiac alterations in asymptomatic women after PE using cardiovascular magnetic resonance (CMR) imaging. Methods and Results: We performed a post-pregnancy case-control study (clinicaltrials.gov ID: NCT03313063). In total, 22 cases and 23 controls were recruited. Participants were matched by age, BMI and parity. Hemodynamic and morphologic characteristics of the myocardium were assessed using established and innovative CMR technics as parametric mapping, late gadolinium enhancement (LGE) imaging and tissue-tracking. Increased left-atrial end-diastolic volume (LA-EDV normalized to BSA: 37.69±6.83 vs. 32.85±6.28, p=0.02) and stroke volume (LA-SV normalized to BSA: 22.57±5.83 vs 18.96±5.10, p=0.02) with a slight tendency to left-ventricular hypertrophy (LV-SV normalized to BSA: 47.28±7.03 vs. 51.58±6.32, p=0.04, LV remodeling index: 0.59±0.11 vs. 0.53±0.08, p=0.045) were found in the post-PE group. Associations between history of PE and changes in LA dimensions remained even after adjustment for BMI, age, parity, DBP, smoking status and years postpartum (adj. β-coefficient for LA-EDV [95% CI]: 9.14 [1.47; 16.81], adj. β-coefficient for LA-SV [95% CI]: 6.74 [0.77; 12.70]). Global circumferential (GCS) and radial (GRS) stains were significantly reduced in post-PE women (-18.28±2.53 vs. -19.82±2.12 and 30.72±6.99 vs. 35.09±6.73, respectively). We could not detect significant differences in T1 or T2 mapping between the groups or fibrosis in LGE imaging. Conclusion: Our findings confirm PE as a risk factor for CVD later in life. Changes in LV and LA dimensions were found as early as 2 years after PE pregnancy. These changes might point toward a manifest end-organ damage following PE in the future. We propose that post-PE women will notably benefit from early cardiovascular screenings.

Embolic Stroke of Undetermined Source: A Population with Left Atrial Dysfunction

Background: Cryptogenic stroke, now defined as embolic stroke of undetermined source (ESUS), represents about a quarter of all ischemic strokes and the reoccurrence is high. Understanding this stroke subtype better would likely guide treatment recommendations. In this study, we tested the hypothesis that left atrial (LA) shape and function at rest, as well as with exercise, are abnormal compared to matched normal controls. Methods: The study design was prospective enrollment of ESUS subjects who underwent measurement of LA function at rest and exercise by 2D and 3D echocardiograms. The exercise portion of the study was conducted using a ramped supine bicycle protocol during which LA function was measured. Stroke subjects were matched with normal subjects by age, gender, and body surface area. Results: Over a 1-year enrollment period, 18 ESUS patients met inclusionary criteria and were studied. Their average age was 58 years old and 44% were female. ESUS subjects have larger LA end-diastolic volume at rest (14 versus 11 mL/m2, P = .04) and with exercise (11 versus 6 mL/m2, P = .001) compared to normal controls. In ESUS, there was a lack of response to maximal exercise of LA function as measured by the LA ejection fraction (61% versus 73% P = .001) and the LA function index (.68 versus .82, P = .02). The 3D analysis showed spherical remodeling of the LA in ESUS. This remodeling was documented by the sphericity index, which was increased in both diastole (.40 versus .32, P = .02) and systole (.63 versus .71 P = .03). Conclusions: In support of our hypothesis, we found that ESUS subjects have LA dysfunction and remodeling at rest and exercise in comparison to healthy, matched controls. Evaluation of the left atrium in this high-risk stroke subtype has potential to inform stroke prevention strategies and to suggest pathways for research.

Ventricular global longitudinal strain is altered in children with sickle cell disease.

Cardiac disease is the primary cause of death in sickle cell disease (SCD). Right and left ventricular global longitudinal strain (RVGLS, LVGLS) are early markers of systolic dysfunction but are not well investigated among children with SCD. One hundred and forty-three patients with HbSS or HbSβ0 -thalassaemia (median age 11years, range 5-19years) and 71 controls matched for age and sex were compared. RVGLS and LVGLS were measured and compared with conventional measures of echocardiography and markers of haemolysis and inflammation. RVGLS was higher in children with SCD than in controls (-25·72%±3·45% vs. -24·54%±2·41%, P=0·005); LVGLS was not different. RVGLS decreased with older age in children with SCD (ρ=0·338, P<0·001) but not among controls. Decreased RVGLS was associated with increased left atrial end diastolic volume (ρ=0·181, P=0·04); RVGLS increased with cardiac output (r=-0·279, P=0·01). RVGLS and LVGLS were not associated with disease-modifying therapies, degree of anaemia or haemolysis markers. Elevated RVGLS may indicate an early RV compensatory mechanism in response to upstream myocardial insults and elevated cardiac output. Global longitudinal strain may serve as an early marker of altered myocardial function in children with SCD.