Measurements Of Left Atrial Function Research Articles

Left Atrial Strain Insights in Atrial Fibrillation and the Interplay with Metabolic Syndrome.

Understanding the interplay between metabolic syndrome and left atrial (LA) function is crucial, especially in patients newly diagnosed with atrial fibrillation (AF). We evaluated the association between subclinical atrial function and metabolic syndrome in patients diagnosed with new-onset AF. A retrospective analysis was conducted on 220 patients, aged between 20 and 100years, who were newly diagnosed with AF. These patients were divided into two groups based on the presence or absence of metabolic syndrome. LA reservoir strain, a measure of LA function, was assessed using transthoracic echocardiography. Statistical methods, including receiver operating characteristic (ROC) curve and logistic regression analyses, were employed to evaluate the association between LA strain and metabolic syndrome. Among the 220 patients, 108had metabolic syndrome and displayed more adverse clinical characteristics. The LA reservoir strain was significantly lower in this group (9.7% ± 5.2% vs. 12.0% ± 5.8%, p = 0.003). ROC curve analysis identified 9.3% as the optimal cutoff value for predicting metabolic syndrome, with a sensitivity of 50.9% and specificity of 70.5%. Further, multivariate analysis confirmed that an LA reservoir strain below 9.3% was independently linked to metabolic syndrome (odds ratio 4.261, 95% confidence interval 1.134-16.009, p = 0.032). The findings reveal a significant association between lower LA reservoir strain values and the presence of metabolic syndrome in patients newly diagnosed with AF. An LA strain value below 9.3% serves as a critical diagnostic and prognostic indicator, highlighting its clinical importance in managing patients with AF.

Abstract 18784: Impaired Left Atrial Strain is a Risk Factor for New-Onset Atrial Fibrillation

Introduction: Atrial fibrillation (AF) is the most common cardiac arrhythmia, affecting millions of individuals. Left atrial (LA) strain, a measure of LA function and remodeling, holds potential as a prognostic indicator for AF development. We aimed to examine whether LA strain is associated with new onset AF. Methods: We performed a nested case-control study within an electronic health record-based longitudinal cohort of primary care patients from a multi-institutional healthcare system spanning 2001 to 2018. Cases included patients who developed new-onset AF during a follow-up period of 7.3 years and had undergone transthoracic echocardiography (TTE) within three years of the follow-up start. Several LA strain parameters were compared between the case and control groups, including Peak Atrial Longitudinal Strain (PALS), Left Atrial Conduit Strain (LACS), and Peak Atrial Contraction Strain (PACS). Results: The study included 216 patients who developed AF during follow-up each matched with a corresponding age- and sex-matched control without AF. The AF group had significantly lower PALS (25.9 ± 8.9 vs. 34.3 ± 10.4, p<0.001) and LACS (13.6 ± 5.2 vs. 19.9 ± 7.6, p<0.001) compared to the non-AF group. Subgroup analyses of AF patients, stratified by the time to AF development, revealed more substantial differences between the AF and non-AF groups when the initial TTE was conducted closer to the onset of AF. Specifically, when the TTE was performed within 2 years prior to AF onset, the disparities in LA strain parameters were more pronounced compared to TTEs conducted between 2-5 years prior or beyond 5 years prior to AF onset. Conclusions: Impaired left atrial strain is strongly associated with new-onset AF, particularly when measured 2 years prior to AF onset, indicating a higher risk of developing AF in the near future. Incorporating LA strain assessment into clinical decision-making can enhance the evaluation of individuals at risk for AF.

Abstract 13142: Prediction of Embolic Stroke in People Without Atrial Fibrillation and Prior Stroke Using Measures of Atrial Myopathy: The Atherosclerosis Risk in Communities (ARIC) Study

Introduction: There is no effective way to predict embolic stroke (ES) in people without atrial fibrillation (AF). Atrial myopathy—characterized by left atrial (LA) remodeling—is associated with ES independent of AF. Hypothesis: An ES prediction model for people without AF or stroke can be developed with measures of atrial myopathy. Methods: ARIC study participants without AF, stroke, or anticoagulation at visit 5 (2011-13) were followed for 5 years. Covariates included CHA 2 DS 2 VASc variables, P-wave indices, echocardiographic measures of LA function and size, and N-terminal B-type Natriuretic Peptide (NTproBNP). The primary outcome was ischemic stroke. A secondary outcome of possible embolic stroke (PES) was defined as non-lacunar strokes and strokes with new AF within 1 year of stroke. Cox proportional hazards models were created for 5-year ischemic stroke (model A) and PES (model B) risk. Stepwise backwards selection (inclusion threshold P<0.20) generated parsimonious models. Model discrimination and calibration were evaluated by the c-statistic and Hosmer-Lemeshow χ 2 statistic, respectively. Results: 91 ischemic strokes (53 PES) were identified in 4154 participants (59.9% female, mean age 75.1(5.0) years). Age, sex, peripheral arterial disease, hypertension, abnormal P-wave axis, and left atrial reservoir strain were included in model A. Model B added NTproBNP. The C-statistics for models A and B were 0.653 (0.596-0.709) and 0.744 (0.680-0.808), respectively. Both models were well calibrated. Conclusions: Prediction of ES may be achieved using measures of atrial myopathy in people without AF and prior stroke. Validation of our model is needed.

Relationship between the strain measures of left atrial function and heart failure worsening.

Two-dimensional speckle tracking evaluation (2D-STE) is a useful tool to evaluate the complexity of atrial function by the analysis of the different phases of atrial deformation and by the combination with Doppler measurements of diastolic function. To evaluate the role of the left atrial (LA) strain parameters to predict worsening chronic heart failure (CHF). We enrolled outpatients affected by CHF referred to our heart failure unit. Each patient underwent a medical visit, an electrocardiogram (ECG), and an echocardiographic examination. LA function was assessed by 2D-STE. The three phases of LA strain, that is, the reservoir (LAr), the conduit (LAcd), and the contraction (LAct)-were evaluated. Moreover, the ratio between E and LAr (E/LAr) and those between LAr and septal (LAr/Ees), lateral (LAr/Eel), and septal-lateral (LAr/Eem) E/e' were measured. During follow-up, the events related to worsening of heart failure were evaluated. Two hundred eleven patients were enrolled. During a mean follow-up of 14±7months, 37 patients showed at least one event related to heart failure worsening. At univariate Cox regression analysis, LAr, LAcd, LAct, E/LAr, LAr/Ees, LAr/Eel, and LAr/Eem were all associated with events related to heart failure worsening, but at multivariate regression analyses, only LAr (Hazard Ratio, HR: .95; 95% Confidence Interval, CI: .92-.99; p: .031), LAct (HR: 1.06; 95% CI: 1.01-1.12; p: .027), E/LAr (HR: 1.10; 95%CI: 1.0-1.16; p<.001), LAr/Ees (HR: .57; 95% CI: .37-.87; p: .010), and LAr/Eem (HR: .71; 95% CI: .53-.96; p: .026) remained significantly associated with the events. Finally, in a predictive model including the other relevant echocardiographic parameters LAr<18%, LAct>-10.0%, LAr/Ees<1.28, and E/LAr>3.70 were associated with a statistically significant overall net reclassification improvement. In CHF patients, the measure of the LA reservoir and contraction by 2D-STE is independently associated with heart failure worsening, but the accuracy in predicting the events is even greater when the reservoir is combined with the Doppler measures of diastolic function.

The effect of urgent blood pressure reduction on left atrial strain in patients with hypertensive attack : Blood pressure lowering affects LA strain.

Left atrial (LA) strain is a robust measure of LA function and is a useful parameter to assess left ventricular filling pressure. While initially considered as a "load-independent" parameter of LA function, later studies have found that acute changes in LA preload may affect LA reservoir and contractile strains. Acute alterations in blood pressure (BP) induces a change in left ventricular (LV) filling pressure without imposing a volume load, thus providing an opportunity to assess the effects of the change in LA afterload on LA mechanics. This study aims to understand the effect of acute BP changes on LA strain. A total of 40 patients admitted to the emergency department with hypertensive urgency were included. All patients underwent a comprehensive echocardiographic examination including measurement of LA reservoir, conduit and contractile strains. A repeat set of measurements were obtained after BP lowering. Average drop in mean BP following intervention was 18.1 ± 5.4%. LV end-systolic and end-diastolic volumes, as well as maximum and minimum LA volumes were decreased significantly after BP reduction. The absolute increases in reservoir and contractile strains were 2.3 ± 4.7% (7.9% ± 13.8% relative to baseline) and 2.5 ± 3.3% (13.5 ± 19.0% relative to baseline), respectively, with both changes being statistically significant (p = 0.003 for reservoir and p < 0.001 for contractile strains). There were no significant changes in conduit strain after BP intervention (p = 0.79). The change in both LA reservoir and contractile strains were more evident in those with a previous diagnosis of hypertension and those with a smaller degree of change in mean BP after intervention. In patients with an acute hypertension, lowering BP leads to an acute improvement in LA reservoir and contractile strains. Thus, acute changes in systemic BP should be considered when LA mechanics are evaluated.

Echocardiographic Measures of Left Atrial Structure and Function and the Association with Atrial Fibrillation following Acute Coronary Syndrome

Introduction: Acute coronary syndrome (ACS) is associated with an increased risk of developing atrial fibrillation (AF). This arrhythmia is associated with adverse outcomes, making it important to identify high-risk patients. The aim was to evaluate the prognostic value of measures of left atrial (LA) structure and function in AF prediction following ACS. Methods: Three hundred and eighty-one patients who had a percutaneous coronary intervention for ACS were included in the study. Our endpoint was new-onset AF. Results: With a median follow-up time of 5.4 [3.9–6.8] years, 56 patients (14.7%) developed AF. Patients developing AF had significantly (p ≤ 0.05) increased maximal and minimal LA volumes (LAV_max and LAV_min, respectively). LAV_max and LAV_min remained significantly increased in AF patients when indexing to either body surface area (LAV_max/BSA and LAV_min/BSA, respectively), left ventricle length in end diastole (LAV_max/LVLd and LAV_min/LVLd, respectively), or late mitral annular diastolic velocity (LAV_max/a’ and LAV_min/a’, respectively), while LA expansion index (LAEi), LA emptying fraction (LAEF), and peak LA longitudinal strain (PALS) were decreased. In univariable Cox regressions, all LA measures were found to be predictors of AF. After multivariable adjustment for clinical and echocardiographic parameters, all measures reflecting atrial function (LAV_min, LAV_min/BSA, LAV_min/LVLd, LAV_min/a’, LAV_max/a’, LAEF, LAEi, and PALS) (p ≤ 0.05) but no structural measures (LAV_max, LAV_max/BSA, and LAV_max/LVLd) remained significant independent predictors of AF. Conclusion: Echocardiographic measures of LA function are independent predictors of AF following ACS. Evaluation of LA function might improve the prognostic workup, aid in risk stratification for AF, and improve selection for further examinations.

Annals for Educators - January 2023.

Annals for Educators - January 2023.

Cardiorespiratory fitness, obesity and left atrial function in patients with atrial fibrillation

BackgroundLow cardiorespiratory fitness (CRF) and obesity are related to the development and maintenance of atrial fibrillation (AF). The aim of this study was to determine the association between CRF, obesity and left atrial (LA) mechanical parameters in patients with AF.MethodsA cohort of 154 consecutive paroxysmal and persistent AF patients (Age: 62 ± 10, 26% female) referred for exercise stress testing and transthoracic echocardiography were included. We included patients in sinus rhythm with preserved left ventricular ejection fraction who were able to complete a maximal exercise test. Left atrial strain in the reservoir (LASr), booster (LASb) and conduit (LASc) phases were assessed using dedicated software. LA stiffness, emptying fraction (LAEF) and LA to LV ratio were calculated using previously described formulas.ResultsCRF was positively associated with LAEF (β = 1.3, 95% CI 0.1–2.3, p = 0.02), reservoir (β = 1.5, 95% CI 0.9–2.1, p < 0.001), booster (β = 0.8, 95% CI 0.4–1.2, p < 0.001) and conduit strain (β = 0.7, 95% CI 0.3–1.1, p = 0.001). We observed an inverse association between CRF and both LA stiffness index (β = −0.02, 95% CI (−0.03)–(−0.01), p < 0.001) and LA to LV ratio (β = −0.03, 95% CI (−0.04)–(−0.01), p < 0.001). Obese patients had significantly higher indexed LA volumes compared to overweight and normal BMI patients. The association between obesity and measures of LA function and stiffness did not reach statistical significance.ConclusionAmong AF patients, higher CRF was independently associated with greater LA function and compliance. Obesity was associated with higher LA volumes yet preserved mechanical function.

Science, Medicine, and the Anesthesiologist

Science, Medicine, and the Anesthesiologist

From Left Atrial Dimension to Curved M-Mode Speckle-Tracking Images: Role of Echocardiography in Evaluating Patients with Atrial Fibrillation

Left atrial (LA) enlargement and dysfunction increase the risk of atrial fibrillation (AF). Traditional echocardiographic evaluation of the left atrium has been limited to dimensional and semi-quantification measurement of the atrial component of ventricular filling, with routine measurement of LA function not yet implemented. However, functional parameters, such as LA emptying fraction (LAEF), may be more sensitive markers for detecting AF-related changes than LA enlargement. Speckle-tracking echocardiography has proven to be a feasible and reproducible technology for the direct evaluation of LA function. The clinical application, advantages, and limitations of LA strain and strain rate need to be fully understood. Furthermore, the prognostic value and utility of this technique in making therapeutic decisions for patients with AF need further elucidation. Deep learning neural networks have been successfully adapted to specific tasks in echocardiographic image analysis, and fully automated measurements based on artificial intelligence could facilitate the clinical diagnostic use of LA speckle-tracking images for classification of AF ablation outcome. This review describes the fundamental concepts and a brief overview of the prognostic utility of LA size, LAEF, LA strain and strain rate analyses, and the clinical implications of the use of these measures.

Association of Echocardiographic Measures of Left Atrial Function and Size With Incident Dementia

Atrial myopathy-characterized by alterations in left atrial (LA) function and size-is associated with ischemic stroke, independent of atrial fibrillation (AF). Electrocardiographic markers of atrial myopathy are associated with dementia, but it is unclear whether 2-dimensional echocardiographic (2DE)-defined LA function and size are associated with dementia. To examine the association of LA function and size with incident dementia. The Atherosclerosis Risk in Communities (ARIC) study is a community-based prospective cohort. An exploratory, retrospective analysis was conducted. ARIC centers are located in Forsyth County, North Carolina; Jackson, Mississippi; Washington County, Maryland; and suburban Minneapolis, Minnesota. For this analysis, visit 5 (2011-2013) served as the baseline. Participants without prevalent AF and stroke and who had 2DEs in 2011-2013 were included and surveilled through December 31, 2019. LA function (reservoir strain, conduit strain, contractile strain, emptying fraction, passive emptying fraction, and active emptying fraction), and LA size (maximal and minimal volume index) as evaluated by 2DE. Dementia cases were identified using in-person and phone cognitive assessments, hospitalization codes, and death certificates. Cox proportional hazards models were used. Among 4096 participants (mean [SD] age, 75 [5] years; 60% women; 22% Black individuals), 531 dementia cases were ascertained over a median follow-up of 6 years. Dementia incidence for the lowest LA quintile was 4.80 for reservoir strain, 3.94 for conduit strain, 3.29 for contractile strain, 4.20 for emptying fraction, 3.67 for passive emptying fraction, and 3.27 for active emptying fraction per 100 person-years. After full-model adjustments, there were statistically significant associations between measures of LA function and dementia; the hazard ratios (HRs) from the lowest vs highest quintile for reservoir strain were 1.98 (95% CI, 1.42-2.75); for conduit strain, 1.50 (95% CI, 1.09-2.06); for contractile strain, 1.57 (95% CI, 1.16-2.14); for emptying fraction, 1.87 (95% CI, 1.31-2.65); and for active emptying fraction, 1.43 (95% CI, 1.04-1.96). LA passive emptying fraction was not significantly associated with dementia (HR, 1.26 [95% CI, 0.93-1.71]). Dementia incidence for the highest LA maximal volume index quintile was 3.18 per 100 person-years (HR for highest vs lowest quintile, 0.77 [95% CI, 0.58-1.02]) and for the highest minimal volume index quintile was 3.50 per 100 person-years (HR for the highest vs lowest quintile, 0.95 [95% CI, 0.71-1.28]). Both measures were not significantly associated with dementia. These findings were robust to sensitivity analyses that excluded participants with incident AF or stroke. In this exploratory analysis of a US community-based cohort, several echocardiographic measures of lower LA function were significantly associated with an increased risk of subsequent dementia. Measures of LA size were not significantly associated with dementia risk. These findings suggest that impaired LA function may be a risk factor associated with dementia.

Left atrial volumetric/mechanical coupling index in the general population: distribution and prediction of incident atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): The Copenhagen City Heart Study was funded by the Danish Heart Foundation, and the echocardiographic substudy was further funded by the Lundbeck Foundation. Background Atrial fibrillation (AF) represent a global health burden. Identifying people at risk based on echocardiography has always been challenging. Hence, we aimed to assess the distribution of left atrial volumetric/mechanical coupling index (LACI) in the general population and test its potential to predict incident AF. Methods In a large community-based population study, LACI was calculated by dividing the left atrial (LA) maximal volume by the a’ peak velocity obtained by color Tissue-Doppler Imaging. Clinical endpoint was incident AF. The exclusion criteria were history of AF or previous heart failure. Results A total of 1021 patients formed the study cohort (mean age 52.8 ± 13.3, 45% (n = 459) were male); Median LACI was 2.84 [IQR: 2.14-3.82], rarely exceeding the value of 6. During a follow-up period of 16.1 years (IQR15.6-16.3), 8.9 % (n = 91) of patients developed AF. LACI independently predicted AF (HR 1.11 [1.04-1.17], p = 0.001 unadjusted and HR 1.20 (1.06-1.35), p = 0.003 after a comprehensive multivariable adjustment (including clinical, biochemical, and echocardiographic variables). The Figure illustrates the strong relationship between LACI and the incidence of AF, almost linear, with no plateau effect. In a sensitivity analysis, the association between LACI and incident AF persisted in both hypertensive (HR 1.12 (1.05-1.19) p = 0.001) and non-hypertensive participants (HR 1.18 (1.03-1.35) p = 0.02). Conclusion LACI is a measure of LA function which is routinely available and presents a skewed distribution towards low values in the general population. LACI independently predicts incident AF, irrespective the presence of systemic arterial hypertension. Abstract Figure

Measures of left atrial function predict incident heart failure in a low-risk general population: the Copenhagen City Heart Study.

This study investigated left atrial (LA) parameters as measured on transthoracic echocardiography as predictors of incident heart failure (HF) in a community cohort. In a large general population study (n=2221), participants underwent a health examination with echocardiography. The maximum and minimum LA volumes indexed to body surface area (LAVImax and LAVImin) were measured and the LA emptying fraction (LAEF) and LA expansion index (LAEI) were calculated. Among 1951 participants without atrial fibrillation or significant valve disease, the mean age was 59 ± 16 years and 58% were women. At baseline, 1% (n=16) had a left ventricular ejection fraction of <50%, 44% had hypertension, and 10% had diabetes. During follow-up (median 15.8 years, interquartile range: 11.3-16.2 years), 187 (10%) participants were diagnosed with incident HF. Participants who were diagnosed with HF during follow-up had a larger LAVImax and LAVImin and a lower LAEF and LAEI compared to participants without HF. In unadjusted analysis, LAVImax, LAVImin, LAEF and LAEI were predictors of incident HF. After multivariable adjustment for clinical and echocardiographic parameters, only LAVImin remained an independent predictor of incident HF (hazard ratio per 1 standard deviation increase: 1.22 [95% confidence interval 1.01-1.47], p=0.038). In the general population, LAVImin is an independent predictor of incident HF. LAVImax, currently the only LA measure in a routine echocardiographic examination, was not an independent predictor of incident HF.

Left Atrial Systolic Force in Hypertensive Patients with Left Ventricular Hypertrophy-: A Predictor of Incident Atrial Fibrillation. The LIFE Study

It remains unknown whether left atrial systolic force (LASF), a measure of left atrial function, can be used as a predictor of new-onset atrial fibrillation (NOAF). Furthermore, the effect of the treatment with atenolol and losartan on LASF is unclear. A total of 758 patients without atrial fibrillation at baseline were enrolled from the Losartan Intervention For Endpoint (LIFE) reduction in hypertension echocardiography sub-study. Participants of the LIFE study were randomized to either atenolol-or losartan-based treatment. The mean follow-up was 59 months. LASF was calculated using the average mitral orifice area and mitral peak. The velocity was obtained by Doppler echocardiography. At baseline, 25% of patients had a LASF ≤ 10.3 kdyn. Compared to other quartiles, this quartile had a higher proportion of men, lower heart rate, body mass index, and age. After controlling for these variables, patients in the first quartile had a lower stroke volume compared to other quartiles. New-onset AF occurred in 29 (8.1/1,000 patient-years of follow-up) patients. In multivariable Cox regression analyses with backward elimination, increasing LASF was associated with a lower risk of NOAF (hazard ratio [HR] = 0.90 [95% confidence interval 0.85-0.96], p = 0.001). Integrated discrimination improvement was 0.054 (p = 0.004) and there was a borderline significant net reclassification improvement of 19.2% (p = 0.075). Over time LASF decreased more in the atenolol-based than the losartan-based treatment group ( &lt; 0.001). Low LASF was associated with a higher risk of new-onset AF. Losartan-based treatment was associated with better preservation of LASF compared to atenolol-based treatment.

Left atrial strain predicts cardiovascular response to exercise in young adults with suboptimal blood pressure.

To investigate the left ventricular response to exercise in young adults with hypertension, and identify whether this response can be predicted from changes in left atrial function at rest. A total of 127 adults aged 18-40years who completed clinical blood pressure assessment and echocardiography phenotyping at rest and during cardiopulmonary exercise testing, were included. Measurements were compared between participants with suboptimal blood pressure ≥120/80mm Hg (n=68) and optimal blood pressure <120/80mm Hg (n=59). Left ventricular systolic function during exercise was obtained from an apical four chamber view, while resting left atrial function was assessed from apical four and two chamber views. Participants with suboptimal blood pressure had higher left ventricular mass (p = 0.031) and reduced mitral E velocity (p = 0.02) at rest but no other cardiac differences. During exercise, their rise in left ventricular ejection fraction was reduced (p = 0.001) and they had higher left ventricular end diastolic and systolic volumes (p = 0.001 and p = 0.001, respectively). Resting cardiac size predicted left ventricular volumes during exercise but only left atrial booster pump function predicted the left ventricular ejection fraction response ( = .29, p = 0.011). This association persisted after adjustment for age, sex, body mass index, and mean arterial pressure. Young adults with suboptimal blood pressure have a reduced left ventricular systolic response to exercise, which can be predicted by their left atrial booster pump function at rest. Echocardiographic measures of left atrial function may provide an early marker of functionally relevant, subclinical, cardiac remodelling in young adults with hypertension.

Usefulness of Left Atrial Strain to Predict End Stage Renal Failure in Patients With Chronic Kidney Disease

Left atrial (LA) enlargement predicts adverse cardiovascular events in patients with chronic kidney disease (CKD). The aim of our study was to evaluate the value of LA reservoir strain, a novel measure of LA function, as a prognostic marker for adverse renal outcomes. A total of 280 patients (65.8 ± 12.2years, 63% male) with stable Stage 3 and 4 CKD without prior cardiac history were evaluated with transthoracic echocardiography and prospectively followed for up to 5 years. The primary end point was progressive renal failure, which was the composite of death from renal cause, end-stage renal failure and/or doubling of serum creatinine. Over a mean follow up of 3.9 ± 2.7years, 56 patients reached the composite endpoint. By log rank test, older age, lower baseline eGFR, anemia, diabetes mellitus, higher urinary albumin/creatinine ratio, number of antihypertensive medications, higher indexed left ventricular mass, larger LA volumes, and impaired LA reservoir strain were significant predictors of the composite outcome (p <0.01 for all). Multi-variable Cox regression analysis found LA reservoir strain, eGFR, number of antihypertensive medications and urinary albumin/creatinine ratio were independent predictors for progressive renal failure (p <0.01 for all). Impaired LA reservoir strain was associated with a 2.5-fold higher risk of the composite outcome (HR 2.51, 95% CI 1.19 to 5.30, p = 0.02) and was the only echocardiographic parameter that predicted progressive renal failure independent of established clinical risk factors for end-stage renal failure. Its utility requires validation in high risk CKD patients with cardiac disease.

Associations of Left Atrial Function and Structure With Supraventricular Ectopy: The Multi-Ethnic Study of Atherosclerosis.

BackgroundHigh levels of supraventricular ectopy are associated with greater risk of atrial fibrillation, stroke, and death. Little information is available about differences by race/ethnicity in the extent of supraventricular ectopy, or about whether high levels of supraventricular ectopy are associated with impaired left atrial (LA) function and LA enlargement.Methods and ResultsIn the MESA (Multi‐Ethnic Study of Atherosclerosis), 1148 participants (47% men; mean age, 67 years) had cardiovascular magnetic resonance imaging in 2010 to 2012, followed by 14‐day ambulatory electrocardiographic monitoring in 2016 to 2018. We analyzed participant characteristics and cardiovascular magnetic resonance measures of LA function and structure in relation to average count of premature atrial contractions (PACs) per hour and average number of runs per day of supraventricular tachycardia. In adjusted regression analyses, older age, male sex, White race, elevated NT‐proBNP (N‐terminal pro‐B‐type natriuretic peptide), and a history of clinically detected atrial fibrillation were associated with more PACs/hour. Chinese and Hispanic participants had on average fewer PACs/hour than White participants (Chinese participants, 31% less [95% CI, 8%–49%]; Hispanic participants, 38% less [95% CI, 19%–52%]). Greater LA total emptying fraction was associated with fewer PACs/hour (per SD, 16% fewer PACs/hour [95% CI, 7%–25% fewer PACs/hour]). Larger LA minimum volume was associated with more PACs/hour (per SD, 7% more PACs/hour [95% CI, 2%–13% more PACs/hour]). Associations of LA volumes with runs of supraventricular tachycardia/day were similar in direction but were weaker.ConclusionsImpaired LA function and LA enlargement were associated with more PACs/hour on extended ambulatory electrocardiographic monitoring. Measurement of supraventricular ectopy may provide information about the extent of atrial myopathy.

Measurement of Left Atrial Function by Speckle Tracking Echocardiography in Atrial Fibrillation Patients after Percutaneous Coronary Intervention in Zagazig University Hospital.

Background: Echocardiography can provide comprehensive information concerning thromboembolic risk in patients with atrial fibrillation (AF). Global LA strain associated with a higher prevalence of left atrial stasis and is superior to conventional parameters of LA analysis as thromboembolic risk stratification of AF. The aim of this work is to demonstrate the importance of global LA Strain as predictor of stroke risk in patients with AF after PCI.Patients and methods: This work included 63 consecutive coronary artery disease patients who were admitted for elective PCI (42 with permanent AF as case group & 21 with sinus rhythm as control group). All patients were evaluated by history, examination, 2D and Doppler echocardiography and 2D-speckle tracking echocardiography (2D-STE). Patients with permanent AF only were evaluated by CHA2DS2-VASc Risk Score calculation, INR & TEE to detect echocardiographic features of high stroke risk.Results: The results showed that the global LA strain was highly statistically significantly lower in patients in case group than patients in control group (16.01±7.43 vs. 33.25±11.21, P< 0.001). 9 patients had abnormalities on TEE. The global LA strain was highly statistically significantly lower in patients with high risk features of stroke than patients without these features (6.8 ± 1.1 vs. 18.2 ± 6.5, P

Association between natriuretic peptides and left atrial structural and functional properties in atrial fibrillation following catheter ablation

Abstract Background Atrial natriuretic peptides (ANP) and brain natriuretic peptides (BNP) are acutely released from the atrial myocytes upon increased mechanical distension of the atria. The relationship between imaging measures of left atrial (LA) structure and function and natriuretic peptides following catheter ablation (CA) have not been clearly delineated. Purpose To characterize the relationship between LA structure and function and natriuretic peptides. Methods We performed an echocardiographic substudy of a randomized trial of AF patients scheduled for CA. Echocardiographic measurements included: LA volume at end-systole (LAVi), at end-diastole (LAEDVi), emptying fraction (LAEF), LA reservoir strain (LAs), and global longitudinal strain (GLS). Patients were stratified by tertiles of mid-regional proANP (MR-proANP) concentrations in circulation (&amp;lt;92 pmol/l, 92–146 pmol/l, &amp;gt;146 pmol/l), and NT-proBNP (&amp;lt;10pmol/l, 10–38 pmol/l, &amp;gt;38 pmol/l). Linear regressions were performed to compare baseline echocardiographic measures to natriuretic peptide concentrations at baseline, 1 month, 3 months and 6 months of follow-up. MR-proANP and NT-proBNP were logarithm transformed in these analyses. Multivariable adjustments were made for: age, gender, AF subtype, AF burden, rhythm during echocardiogram, rhythm at study visit for blood sampling, time known with AF, beta-blocker use, and CHA-2DS2-VASc score. Results We included 101 patients with AF. The mean age was 58 years, 82% were men, 46% had persistent AF. Increasing tertiles of MR-proANP at baseline were associated with abnormal LA size and function (3rd vs 1st tertile: LAVi: 42mL/m2 vs 32mL/m2; LAEDVi: 31mL/m2 vs 20mL/m2; LAEF: 38% vs 26%; LAs: 27% vs 19%; GLS: −18% vs −14%) whereas both LA and left ventricular measures were associated with increasing NT-proBNP concentrations at baseline. After multivariable adjustments, only LA volumes and LAEF remained significantly associated with MR-proANP, whereas only LA volumes and GLS remained significantly associated with NT-proBNP. At follow-up, impaired LA function associated with persistently elevated concentrations, which was not the case for LAVi (figure). Conclusion MR-proANP reflects LA dysfunction better than NT-proBNP. Measures of LA function rather than LAVi associates with persistently elevated natriuretic peptide concentrationsw, which may indicate that functional measures are more closely associated with evidence of LA myocardial stretch than LAVi. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): The Danish Heart Foundation

Left atrial emptying fraction: a powerful predictor of events in severe aortic stenosis

Abstract Background Increasing evidence suggests that left atrial (LA) structural and functional changes have an important role in risk stratification and prediction of clinical outcomes. We know from multiple data that left atrial maximum volume (LAVI), measured at end-systole, is a powerful prognostic marker in multiple patient groups. However, recent studies have suggested that this marker may not be the best representative of diastolic function as it does not image the full spectrum of atrial mechanics. Another measure of LA function is the left atrial emptying fraction (LAEF), which has proved to be a significant prognostic marker in many patient groups. Less known is its role in event prediction in severe aortic stenosis patients, a disease with a very important burden in modern societies. Purpose The authors hypothesised that LAEF is a powerful predictor of clinical outcomes at 1 year in patients with severe aortic stenosis. Methods We retrospectively evaluated 151 patients referred to our echocardiography laboratory with the diagnosis of severe aortic stenosis. All patients underwent transthoracic echocardiography. LA maximum volume was indexed to body surface area. LAEF was calculated as LAVI-LA minimum volume divided by LAVI. Patients were followed for 1 year regarding clinical outcomes. Clinical outcome was defined as a composite of hospital admission for a cardiovascular (CV) cause, emergency department recurrence for a CV cause or CV death. Logistic binary regression was used to evaluate associations of LAEF with the outcome. Results A total of 51.7% of patients (n=78) were males. Mean patient age was 76.6±8.0 years. A total of 38.4% of patients were diabetics (n=56), 96% had dyslipidaemia (n=145) and 25% (n=37) had atrial fibrillation. Mean left ventricular ejection fraction (LVEF) was 60.6±7.3, and mean LAVI was 41.4±12.1. In a multivariable regression model including clinical and echocardiographic markers, higher LAVI and pulmonary artery systolic pressure (PASP) were associated with lower LAEF. Receiver operating characteristic curve analysis showed that the predictive value of LAEF for outcomes at 1 year was 0.693 (AUC=0.693, CI 95% 0.578–0.809, p=0.002), performing better than other echocardiographic markers such as LAVI (AUC=0.567, CI 95% 0.440–0.694, p=0.286), PASP (AUC=0.582, CI 95% 0.451–0.714, p=0.191) and LVEF (AUC=0.590, CI 95% 0.464–0.716, p=0.153). After adjustment of baseline characteristics, a LAEF less than 41.3% remained a good predictor of clinical outcomes at 1 year (OR 2.615, CI 95% 1.085–6.305, p=0.32). Conclusions In this cohort of severe aortic stenosis patients, a reduced LAEF was associated with greater incidence of cardiovascular events, being a stronger predictor than LAVI, PASP or LVEF. This study suggests that LA dysfunction over LA volumes correlates better with clinical outcomes. Funding Acknowledgement Type of funding source: None