Left Atrial Mechanical Function Research Articles

The role of atrial pacing site in reducing filling pressures by accelerated pacing in virtual HFpEF patients

Abstract Background Patients with heart failure with preserved ejection fraction (HFpEF) and pacemakers have been shown to benefit from moderately accelerated pacing rates compared to the standard 60bpm. HFpEF patients often present with prolonged P-wave duration (PWD) and atrial fibrillation. Right atrial appendage pacing (RAAP) lengthens PWD, RA septal (RASP) has a neutral effect, while Bachmann’s bundle pacing (BBP) normalizes or shortens PWD compared to sinus rhythm. The mechanical and hemodynamic effects of atrial pacing site selection remain unknown. Aim To investigate the impact of RAAP, RASP and BBP on cardiac mechanics and hemodynamics in an established cohort of virtual HFpEF patients undergoing accelerated pacing. Method HFpEF with prolonged PWD was simulated using the validated CircAdapt computational model of the human cardiovascular system. First, left ventricular (LV) diastolic dysfunction was simulated by decreasing LV myocardial relaxation rate and compliance, such that mean left atrial (LA) pressure (mLAP) was 15mmHg. Second, PWD was prolonged by prescribing a gradual electrical activation delay from RA to LA of 140ms. We then simulated atrial pacing with three different lead positions (Fig.1, left) and gradually increased pacing rate with a constant 120-ms paced atrioventricular (AV) delay. The CircAdapt model computed regional LA strain and mLAP with RAAP, RASP, and BBP. Cardiac output (5L/min) and mean arterial pressure (92mmHg) were kept constant in all simulations. Results Simulated BBP demonstrated the most synchronous LA mechanical activation and function, characterized by uniform segmental LA strain patterns and highest LA reservoir strain (LASR) (Fig.1, middle, with colored arrows highlighting the mechanical dyssynchrony). Hemodynamically (Fig.1, right), BBP acutely decreased mLAP (-1.0mmHg) at the initial heart rate of 60bpm, while RAAP increased it (+0.3mmHg). As pacing rate accelerated, BBP reduces filling pressure (mLAP: -2.8mmHg), more than RASP (-1.8mmHg) or RAAP (-1.2mmHg) at 80bpm. At high pacing rates, RASP and RAAP adversely increase mLAP, due to the prolonged atrial contraction duration and shorter LV filling time. Conclusion Our simulations of different atrial pacing sites in virtual HFpEF patients suggest that BBP yields the most synchronous LA activation pattern and a more substantial reduction in filling pressures with accelerated atrial pacing compared to RASP. Reduction in mLAP with accelerated pacing was attenuated with RAAP. While our study concentrated on a specific paced AV interval, the favorable outcomes observed with BBP could be further improved by including different, rate-adaptive, AV protocols.Fig 1.

Investigation of left atrial mechanical function and left ventricular systolic and diastolic parameters in athletes performing resistance exercise and combined exercise

Some individuals who go to fitness centers for various purposes perform resistance exercise (RE) alone, while others engage in combined exercise (CE) by including cardio exercises along with RE. Studying the effects of these two different training methods on left ventricular (LV) systolic and diastolic parameters and left atrial mechanical function is an important step toward understanding the effects of different types of exercise on cardiac function. This knowledge has significant implications for public health, as it can inform the development of targeted and effective exercise programs that prioritize cardiovascular health and reduce the risk of adverse outcomes. Therefore, the primary aim of this study is to comprehensively investigate the LV systolic and diastolic parameters of athletes who engage in RE and CE using ECHO, to contribute to the growing body of literature on the cardiovascular effects of different types of exercise. Forty-two amateur athletes aged between 17 and 52 were included in our study. The participants consisted of the RE (n = 26) group who did only resistance exercise during the weekly exercise period, and the CE group (n = 16) who also did cardio exercise with resistance exercises. After determining sports age (year), weekly exercise frequency (day), and training volume (min) in addition to demographic information of RE and CE groups, left ventricular systolic and diastolic parameters and left atrial functions were determined by ECHO. Findings from our study revealed that parameters including the left ventricular end-diastolic diameter (LVEDD) (p = .008), left ventricular end-diastolic volume (LVEDV) (p = .020), stroke volume index (SV-I) (p = .048), conduit volume (CV-I) (p = .001), and aortic strain (AS) (p = .017) were notably higher in the RE group compared to the CE group. Also left atrial active emptying volüme (LAAEV) of CE was higher than the RE group (p = .031). In conclusion, the cardiac parameters of the RE group showed more athlete’s heart characteristics than the CE group. These results may help to optimize the cardiovascular benefits of exercise routines while minimizing the potential risks associated with improper training.

Ablation-induced left atrial mechanical dysfunction recovers in weeks after ablation.

The immediate impact of catheter ablation on left atrial mechanical function and the timeline for its recovery in patients undergoing ablation for atrial fibrillation (AF) remain uncertain. The mechanical function response to catheter ablation in patients with different AF types is poorly understood. A total of 113 AF patients were included in this retrospective study. Each patient had three magnetic resonance imaging (MRI) studies in sinus rhythm: one pre-ablation, one immediate post-ablation (within 2days after ablation), and one post-ablation follow-up MRI (≤ 3months). We used feature tracking in the MRI cine images to determine peak longitudinal atrial strain (PLAS). We evaluated the change in strain from pre-ablation, immediately after ablation to post-ablation follow-up in a short-term study (< 50days) and a 3-month study (3months after ablation). The PLAS exhibited a notable reduction immediately after ablation, compared to both pre-ablation levels and those observed in follow-up studies conducted at short-term (11.1 ± 9.0days) and 3-month (69.6 ± 39.6days) intervals. However, there was no difference between follow-up and pre-ablation PLAS. The PLAS returned to 95% pre-ablation level within 10days. Paroxysmal AF patients had significantly higher pre-ablation PLAS than persistent AF patients in pre-ablation MRIs. Both type AF patients had significantly lower immediate post-ablation PLAS compared with pre-ablation and post-ablation PLAS. The present study suggested a significant drop in PLAS immediately after ablation. Left atrial mechanical function recovered within 10days after ablation. The drop in PLAS did not show a substantial difference between paroxysmal and persistent AF patients.

Contribution of TNF-R1 to reduced exercise capacity in hypertensive heart disease. Mediating role of left atrial mechanical function reserve

Abstract Background Tumor necrosis factor alpha (TNF-alpha) plays a relevant pathophysiological role in cardiovascular disorders, including hypertensive heart disease (HHD) – a clinical condition frequently contributing to the development of heart failure with preserved ejection fraction (HFpEF). TNF receptor 1 (TNF-R1) has been found to mediate proinflammatory and proapoptotic effects of TNF-alpha, and its soluble circulating form proved to be effective in predicting incident HF. Existing evidence indicates the association between TNF pathways activation and cardiac dysfunction, but exact mechanisms mediating this link are unclear. Objectives We sought to investigate the association of TNF-R1 with exercise capacity, and left ventricular (LV) and left atrial (LA) function reserve in asymptomatic patients with HHD. Methods We enrolled 80 (55±12 yo) patients with HHD and normal exercise tolerance (stage A and B HF). Echocardiography (including LA and LV strain assessment) was performed at rest and immediately post exercise test. Blood samples for TNF-R1 were drawn in fasting conditions. Exercise reserve of cardiac function parameters was calculated by subtracting resting value from exercise value. Results The study population was categorized into 2 subsets using a median value of exercise capacity (9.2 METs). Patients with higher exercise capacity were characterized by lower TNF-R1 concentrations and higher LA reservoir and LA contractile strain reserves (Table). No significant intergroup differences were found for exercise reserves in LV ejection fraction (LVEF), LV global longitudinal strain and diastolic parameters (e’ and E/e’). TNF-R1 significantly correlated with peak atrial longitudinal strain (PALS) and peak atrial contraction strain (PACS) reserves (r=-0.27; p&amp;lt;0.02 and r=-0.24; p&amp;lt;0.04, respectively), but not with LVEF, global longitudinal strain (GLS), e’ and E/e’ reserves. Regression-based mediation analysis revealed that the relationships between TNF-R1 and exercise capacity were mediated by PALS and PACS reserve, as evidenced by the reduction in variance of exercise capacity (METs) explained by TNF-R1 after the inclusion of PALS and PACS reserve to the models (decrease in beta coefficient from -0.24 to -0.19 for PALS, and to -0.20 for PACS, Figure). Conclusions In patients with HHD, higher TNF-R1 is associated with lower exercise capacity, and this relationship may be mediated by lower LA strain reserve. This finding may contribute to elucidating the mechanisms behind the involvement of the left atrium in HF progression.Mediation analysis

Left Atrial Mechanical Function And Stiffness In Patients With Premature Ventricular Contraction: A Speckle Tracking Study.

Ventricular extrasystole (PVC) is characterized by premature ventricular depolarization and is associated with increased risk of arrhythmias and structural heart disease. This study aimed to investigate the association between the PVC burden and left atrial (LA) function in individuals without known cardiac disease. A cross-sectional study was conducted on 102 patients with PVCs who were admitted to a cardiology clinic. Transthoracic echocardiography was used to assess left ventricle (LV) parameters, including LV mass, LV ejection fraction (LVEF), LV global longitudinal strain (LVGLS), and LA function was evaluated using strain imaging. The PVC burden was categorized into three groups: &lt;10 %, 10-20 %, and &gt;20 %. Changes in LV dimensions and LV mass index were associated with the groups with the PVC burden with 10-20 %, and &gt;20 %. but differences in LVEF and LVGSL were not significant. Mean E / e' increased as the PVC burden increased (p&lt;0.001). The mean global LA peak strain decreased as the PVC burden increased (p&lt;0.001), while other mean LA measurements increased as the PVC burden increased (p&lt;0.001) A higher PVC burden was associated with impaired LA function, as indicated by decreased global LA peak strain (PVC burden &lt;10 %=38.1±3.2 vs. PVC burden 10-20 %=32.4±3.2 vs. PVC burden &gt;20 %=27.7±2.6, in all groups p&lt;0.001) and with increased LA stiffness (PVC burden &lt;10 %=18.6±3.2 vs. PVC burden 10-20 %=27.5±5.5 vs. PVC burden &gt;20 %=39.0±7.9, in all groups p&lt;0.001). A strong negative correlation was found between global LA peak strain and LA stiffness (r=-0.779, p&lt;0.001). In individuals without known cardiac disease, a higher PVC burden was associated with impaired LA function, indicated by increased E / e', decreased LA strain, and increased LA stiffness. These findings suggest that PVC burden may contribute to LA dysfunction, potentially increasing the risk of cardiovascular events.

The insufficiency of recreational exercises in improving cardiovascular fitness: an investigation of ventricular systolic and diastolic parameters and left atrial mechanical functions

AimThis study aimed to compare the left ventricular (LV) systolic and diastolic parameters and left atrial (LA) mechanical functions of individuals engaging in recreational sports and resistance exercises on a weekly basis.MethodsA total of 43 male amateur athletes were included in this study, of which 24 performed resistance exercises (REs) (29.70 ± 8.74 year, weight: 81.70 ± 12.64 kg, height: 176.05 ± 7.73 cm, BMI: 27.64 ± 4.97 kg/m2), and 19 participated in recreational football training and were included in the recreational sports group (31.73 ± 6.82 year, weight: 86.00 ± 18.52 kg, height: 178.62 ± 4.95 cm, BMI: 25.55 ± 3.42 kg/m2). The exercises were standardized according to the weekly exercise frequency and volume. After recording the participants’ demographic information, the LV systolic and diastolic parameters and LA mechanical functions were measured using echocardiography (ECHO) and Tissue Doppler Imaging.ResultsSignificant differences were observed in various cardiac parameters between the recreational sports group (REG) and resistance exercise Group (RSG). Specifically, the left ventricular (LV) diastolic diameter, LV end diastolic volume index (LVEDVi), and stroke volume index were notably higher in the REG compared to the RSG (t = 2.804, p = .010, effect size (ES) = 2.10; t = 3.174, p = .003, ES = 0.98; t = 3.36, p = .002, ES = 1.02, respectively). Notably, the RSG exhibited higher values for LV mass index (LVMi) and isovolumic relaxation time (IVRT) than the REG (t = 2.843, p = .007, ES = 0.87; t = 2.517, p = .016, ES = 0.76) in terms of LV systolic and diastolic parameters. Regarding left atrial (LA) mechanics, the REG demonstrated increased LA total emptying volume index, LA maximum volume index, LA volume before systole measured at the onset of the p-wave index, and conduit volume index compared to RSG (t = 2.419, p = .020, ES = 0.75; t = 2.669, p = .011, ES = 0.81; t = 2.111, p = .041, ES = 0.64; t = 2.757, p = .009, ES = 0.84, respectively).ConclusionOur study revealed significant variations in LV and LA functions between REG and RSG. Our data suggest that REs led to substantial cardiac remodeling, altering myocardial structure and function. In contrast, the effect of recreational exercise on cardiac adaptation was less pronounced than that of resistance exercise. Consequently, we propose that individuals engaging in recreational exercise should consider modalities that impose higher cardiovascular demand for more effective cardiac conditioning.

Left atrial strain superior to structural remodeling in identifying occult atrial fibrillation.

Occult atrial fibrillation (AF) is a significant risk factor for occult stroke but is difficult to detect. Myocardial strain, based on speckle tracking echocardiography (STE), can detect subclinical changes in left atrial (LA) function. This study aimed to investigate the diagnostic value of LA strain in identifying asymptomatic AF patients with normal electrocardiograms and healthy volunteers. A total of 354 subjects were retrospectively enrolled. Patients were divided into two groups based on whether they had AF during echocardiography. Patients with sinus rhythm during echocardiography were further divided into healthy control group and occult AF group. Patients with AF during echocardiography were further divided into paroxysmal AF group and persistent AF group. LA mechanical function measured by STE was compared between patients with asymptomatic AF and volunteers. Conventional echocardiographic indicators were measured. The diagnostic value of LA strain for identifying asymptomatic AF was assessed by univariate and multivariate regression analysis and receiver operating characteristic (ROC) curves. Occult AF patients had higher NT-proBNP levels, larger RA area, larger LAVmax and decreased LAEF than control group. However, occult AF patients had lower NT-proBNP levels, RA area and LAVmax and higher LAEF than paroxysmal and persistent AF. The measured LA reservoir strain (LASr), LA conduit strain (LAScd), LA contraction strain (LASct) of occult AF group was significantly lower than that of control group. However, occult AF patients had preserved LAScd and LASct than paroxysmal and persistent AF. RA area, LAEF and LASr were remarkable correlation with occult AF after adjustment for NT-proBNP, LAVmax, and LAScd. The area under curve of ROC for LASr was the greatest among RA area, LAEF and LASr, with a cut-off value of 34.1% (sensitivity: 75.4%, specificity: 87.6%). LASr can identify occult AF in the asymptomatic population. Patients with LASr values ≤34.1% have a higher incidence of occult cardiac dysfunction. These findings help identify patients with occult AF and further risk stratification for the AF population.

Role of reduced left atrial mechanical function reserve in exercise intolerance progression in hypertensive heart disease

Abstract Funding Acknowledgements Type of funding sources: None. Background The identification of mechanisms in hypertensive heart disease (HHD) that favor the development of symptomatic heart failure (HF) is essential. Little is known about the role of left atrial (LA) mechanical response to exertion in this context. Objectives We sought to investigate the association of LA strain parameters response to exercise with functional capacity and symptomatic HF in a representative group with HHD. Methods Echocardiography (including LA strain and strain-derived LA stiffness index assessment) was performed at rest and immediately post exercise test in 61 patients with stage A, 67 patients with stage B and 73 patients with stage C HF. Results There was a progressive worsening of exercise capacity from stage A through stage B to stage C, which was accompanied by a gradual impairment of changes from rest to exercise in LA reservoir and contractile strain, whereas LA stiffness reserve remained unchanged until the HF stage C (Table). In multivariable analysis including LA and left ventricular reserve and clinical variables, changes from rest to exercise in LA reservoir strain and mitral annular e’ (both beta 0.16, SE 0.07, p = 0.02) were the only cardiac function parameters independently correlating with exercise capacity. However, LA stiffness reserve and E/e’ were the strongest associations of symptomatic HF stage C (Akaike information criterion 111.6 and 101.1, respectively). Conclusions LA reservoir strain and LA stiffness exercise reserves are among the mediators of reduced functional capacity in HHD, however the trajectories of changes of these parameters are not parallel. While LA strain reserve progressively deteriorates across HF stages, a marked impairment in LA stiffness reserve can only be seen in patients with HF symptoms. This suggests a potential role for these parameters in stratifying the risk of progression to overt HF in HHD.

Comparison of various tools for diagnosis of an atrial cardiomyopathy for outcome prediction after pulmonary vein isolation in patients with persistent atrial fibrillation - What is the Holy Grail?

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Medtronic Background Atrial cardiomyopathy (ACM) is associated with an increased risk for new-onset atrial fibrillation (AF), progression from paroxysmal to persistent AF-forms and higher arrhythmia recurrence rates after PVI. Therefore, the current ESC guidelines on AF recommend to characterize the underlying ACM to better inform and treat AF patients. Over the past decade, various diagnostic tools were established to diagnose an ACM by analyzing left atrial (LA) structure, and LA electrical and mechanical function. Aim To compare head-to-head electroanatomical mapping (EAM) to assess LA low-voltage substrate (LVS), late gadolinium enhancement (LGE)-MRI to analyse LGE-extent, body surface electrocardiograpghic imaging (ECGI) to measure total atrial conduction time (TACT), digital ECG to analyse amplified p-wave duration (aPWD), and TTE to quantify LA emptying fraction (LA-EF) and LA strain (LAS) regarding ACM diagnosis and outcome prediction after PVI in a homogenous study population. Methods Thirty-six ablation-naive patients (65±9years, 86% male) with persistent AF undergoing PVI were electrically cardioverted prior to PVI and all analyses were performed in sinus rhythm. LGE-MRI, ECGI using a 252-electrode-array, digital ECG and TTE were conducted one day prior to PVI. Subsequently, a high-density LA voltage map (2124±490 sites) was acquired followed by circumferential PVI. MRI-post-processing-analyses were performed by two independent expert laboratories (Marrek for Utah and Adas3D medical for the image-intensity-ratio(IIR)-method). Analysis of aPWD and LAS during reservoir (LASr), conduit (LAScd) and contraction phase (LASct) were performed automatically. Arrhythmia recurrence was recorded within 12 months. Relevant ACM was defined as presence of a LA-LVS≥2cm2 at 0.5mV, a LGE-extent≥20% using the Utah method, a LA-EF&amp;lt;34%, a LASr&amp;lt;23.5%, a LAScd&amp;lt;13.4%, and a LASct&amp;lt;5.4% as described previously. For the IIR-, ECGI-, and automatically measured aPWD-methods, ROC analyses were performed to find the optimal threshold for diagnosis of a relevant ACM as defined in EAM (LA-LVS≥2cm2 at 0.5mV) due to a lack of a predefined threshold. Results A LGE-extent of ≥12% using an IIR cut-off of 1.20, a TACT≥148ms and an automatically measured aPWD≥140ms predicted a relevant ACM as defined in EAM with a sensitivity of 76% and a specificity of 60% for LGE IIR 1.20, a sensitivity of 95% and a specificity of 93% for TACT, and a sensitivity of 86% and a specificity of 80% for aPWD, respectively. Arrhythmia recurrence was significantly higher in patients with a LA-LVS≥2cm2 at 0.5mV, a LGE-extent≥12% at 1.20IIR, a TACT≥148ms, an aPWD≥140ms, a LA-EF&amp;lt;34% and a LASct&amp;lt;5.4%. Conclusion ACM can be diagnosed using EAM, LGE-MRI, ECGI, ECG and TTE and is associated with an increased arrhythmia recurrence rate after PVI. However, only measurement of aPWD in digital ECG, and LA-EF and LAS in TTE are easy, cost-effective, non-invasive methods without any risk for complications.

Hypertensive Heart Disease-The Imaging Perspective.

Hypertensive heart disease (HHD) develops in response to the chronic exposure of the left ventricle and left atrium to elevated systemic blood pressure. Left ventricular structural changes include hypertrophy and interstitial fibrosis that in turn lead to functional changes including diastolic dysfunction and impaired left atrial and LV mechanical function. Ultimately, these changes can lead to heart failure with a preserved (HFpEF) or reduced (HFrEF) ejection fraction. This review will outline the clinical evaluation of a patient with hypertension and/or suspected HHD, with a particular emphasis on the role and recent advances of multimodality imaging in both diagnosis and differential diagnosis.

S-29-5: EARLY CHANGES IN LEFT ATRIAL STRAIN AND GLOBAL VENTRICULAR FUNCTION IN HYPERTENSIVE PATIENTS WITH HEART FAILURE WITH PRESERVED EF

Background: Hypertension is one of leading causes in heart failure with preserved ejection fraction (HFpEF).Left atrial (LA) maximal volume and index (LAVI) had a prognostic value in patients with heart failure and incidence of atrial fibrilation (AF). Recently, LA mechanical function and LA strain have been introduced as alternative methods to assess LA performance more accuratly. Aim: To evaluate the relation between early changes in LA function and strain (PALS) and correlate the association with global left ventricular (LV) function and longitudinal strain (GLS) in patients with HFpEF.and arterial hypertension. Methods: We evaluated 152 subjects in sinus rhythm: 22 normals (31y ± 5), and 70 pts with HFpEF (65y ± 12), 60 pts HFrEF (64 y ± 10). Echocardiography was performed in all patients and follow up after 12 monts and analyzed offline in order to extract the global and segmental strain values of the LV and LA and LA volume and LAVI. Results: The two groups of patients were comparable for most of clinical variables. LV volumes, ejection fraction, stroke volume, and mitral valve effective regurgitant orifice were similar between the two groups. The LA diameter and maximal volume were higher in HFrEF group. The GLS is significantly reduced in HFrEF group. LV GLS is the main parameter for myocardial dysfunction, which changed significantly in the HFrEF (p &lt; 0,001) at 12mFU. Reduced PALS in HFrEF was associated with impairment of all measures of LV systolic and diastolic function and events of atrial fibrilation / 33 % in HFrEF and 12 % in HFpEF/ and the correlation between global longitudinal strain and PALS was highly significant (p &lt; 0.001; r = 0.71). At 12mFU, PALS was significantly associated with lower global longitudinal strain in group with HFrEF (p &lt; 0.001, r = 0.61), LAVI &gt; 28 ml/m2 (p &lt; 0.01,r = 0.57) and slightly decreased in HFpEF /p &lt; 0.5, r = 0.34/. ROC analysis shows the cut of value of 29 % for PALS which correlated with AF events. Conclusions: PALS and GLS are significantly reduced in HFpEF patients and decreased in HFpEF. PALS provides additional,prognostic value beyond LA volume and LAVI. Severe LV myocardial dysfunction and reduced GLS and decreased PALS, even still normal LAVI is a prognostic index for AF.

Mechanical function of the left atrium within 28 days after restoration of sinus rhythm in patients with paroxysmal atrial fibrillation

Objective: Atrial fibrillation is a strong independent risk factor for cardioembolic stroke, with a significant impact on morbidity, mortality and healthcare costs. The aim of our study is to investigate left atrial mechanical function in healthy subjects and patients with atrial fibrillation paroxysms less than 48 hours with low risk of thromboembolic complications at 1 and 28 days after restoration of sinus rhythm. Methods: Thirty-six healthy controls and patients with paroxysms of non-valvular atrial fibrillation less than 48 hours (n=25) with low-risk CHA2DS2VASc score were included in the study. The mechanical function of the left atrium (LA) was investigated by the 2D speckle tracking program. Transthoracic echocardiography was performed on the 1st and 28th days after restoration of sinus rhythm by pharmacological cardioversion. Results: Despite the absence of differences in left ventricular systolic function and LA size between the groups, there was a significant decrease in LA deformation and strain rate on day 1 immediately after sinus rhythm recovery in the patients. In the pump phase, the decrease was about 3%, reservoir phase – 10%, and conduit phase – 7% compared to the control group. The strain rate also decreased in the patient group: -1.5 s-1 versus control: -2.14 s-1 (p&amp;lt;0.0001). On the 28th day after restoration of sinus rhythm, there were significant changes in reservoir and conduit functions in patients group in comparison with control group. Global longitudinal LA strain (reservoir phase) decreased to 7%, conduit phase decreased to 11% compared with the control group. In patients group we can see the dynamics during 28 days: pump phase and strain rate were significantly improved, however reservoir and conduit did not significantly change and were lower than in healthy. Conclusion: Mechanical function of the LA in patients with non-valvular atrial fibrillation and low risk of thromboembolic complications, studied with speckle tracking on the first day was significantly impaired compared with the control group (reservoir phase and strain rate). By day 28, mechanical function improved compared to day 1, but reservoir phase remained significantly lower than normal.

Left atrial strain quantified after myocardial infarction is associated with early left ventricular remodeling.

Left ventricular remodeling (LVR) is common and associated with adverse outcome after ST-elevation myocardial infarction (STEMI). We aimed to investigate the association between left atrial (LA) mechanical function using speckle tracking imaging and early LVR at follow-up in STEMI patients. Baseline 3D thoracic echocardiograms were performed within 48h following admission and at a median follow-up of 7 months after STEMI. A>20% increase in the left ventricular (LV) end-diastolic volume compared to baseline at follow-up was defined as LVR. LA global longitudinal strain was evaluated for the reservoir, conduit, and contraction (LASct) phases. A total of 121 patients without clinical heart failure (HF) were prospectively included, between June 2015 and October 2018 (age 58.3±12.5 years, male 98 (81%)). Baseline and follow-up LV ejection fraction (LVEF) were 46.8% [41.0, 52.9] and 52.1% [45.8, 57.0] respectively (p<.001). Compared to other patients, those with LVR had significantly lower values of LASct at baseline(-7.4% [-10.1, -6.5] vs. -9.9% [-12.8, -8.1], p<.01), both on univariate and baseline LV volumes-adjusted analyses. Baseline LA strain for reservoir and conduit phases were not associated with significant LVR at follow-up. Intra- and interobserver analysis showed good reproducibility of LA strain. Baseline LASct may help identifying patients without HF after STEMI who are at higher risk of further early LVR and subsequent HF and who may benefit from more intensive management.

Abstract 12901: Cardiac Reverse Remodeling and Functional Changes Assessed by Speckle Tracking Echocardiography After Septal Myectomy in Patients With Symptomatic Hypertrophic Obstructive Cardiomyopathy

Introduction &amp; Hypothesis: Surgical septal myectomy is an effective treatment in patients with symptomatic hypertrophic obstructive cardiomyopathy (HOCM). Reducing the hemodynamic burden through septal myectomy in HOCM patients is expected to result in cardiac reverse remodeling, but it is unknown whether it improves myocardium functional parameters, which are proven prognosticators for clinical outcome. Therefore, this study aimed to investigate the left atrial (LA) and left ventricular (LV) size and function using conventional and speckle tracking echocardiography (STE) before and after septal myectomy in patients with HOCM. Methods: A total of 65 patients with symptomatic HOCM who underwent surgical septal myectomy from 2006 to 2021 were retrospectively analyzed. Patients were excluded if they underwent a valve repair or replacement at the same time. Finally, clinical, echocardiographic, and electrocardiographic variables before and after the surgery were comprehensively analyzed. Results: After septal myectomy, there were significant decreases in LA volume index (72±22 vs. 57±18 ml/m 2 , p &lt;0.001) suggestive of improvement of diastolic function. In the analysis of STE, there was no significant difference in LA strain (19.3±8.5 vs. 19.1±8.2%, p=0.883) and LV global longitudinal strain (LS) (-10.3±3.6 vs. -9.6±3.4%, p=0.150) before and after septal myectomy. When we analyzed LV regional LS by dividing into septum and non-septum, septal LS showed a little aggravation (-8.7±4.5 vs. -7.6±3.7 %, p=0.077) with marginal statistical significance. In addition, non-septal LS was not significantly different after septal myectomy (-10.9±4.5 vs. -10.5 ±4.2 %, p= 0.458). The change of LA volume index was significantly correlated with change of QRS duration. Interestingly, the septal LS was deteriorated and non-septal LS tended to be improved as widening of QRS duration. Conclusions: After septal myectomy, as hemodynamic load due to LVOT obstruction relieves, there is a significant reduction in LA volume. However, there is no improvement in the global LA and LV mechanical function. Widening of QRS duration, a marker of effective septal myectomy, is associated with LA volume reduction and improvement of longitudinal strain in non-septal LV.

Abstract 14845: Evaluation of Heart Failure With Preserved Ejection Fraction in Patients With Symptomatic Atrial Fibrillation by Invasive Assessment of Left Atrial Compliance

Background: Atrial fibrillation (AF) and HFpEF are both associated with left atrial (LA) cardiomyopathy. We hypothesise that HFpEF is common in patients with symptomatic AF due to the presence of LA cardiomyopathy involving reduced LA compliance (LAC). Methods: Consecutive patients with AF and preserved left ventricular (LV) function were prospectively recruited. Gold-standard diagnosis of HFpEF was undertaken by invasive assessment of LA pressure; participants had ‘AF-HFpEF’ if baseline mean LA pressure (mLAP) was &gt;15mmHg and ‘early AF-HFpEF’ if mLAP exceeded 15mmHg only after 500mls fluid challenge. LAC was assessed by monitoring atrial pressures and LA size during infusion of 15mL/kg normal saline over 8 minutes. Transmural LAC was calculated as ΔLA diameter/Δ(LA pressure - RA pressure). All participants were also studied with resting and exercise echocardiography, electrophysiology (EP) study, cardiopulmonary exercise testing and AF Symptom Severity questionnaires. Results: Of 105 participants, 49 (46.7%) had AF-HFpEF, 26 (24.8%) had early AF-HFpEF and 30 (28.6%) had no HFpEF. AF-HFpEF was associated with increased BMI (p=0.03) and higher prevalence of hypertension (p&lt;0.01). AF-HFpEF was associated with lower transmural LAC compared to those with no HFpEF (1.36±0.45 vs 3.32±0.46, p=0.01). As shown in the table, participants with AF-HFpEF also displayed reduced LA mechanical function at rest and during exercise, LA electrical remodelling, reduced cardiorespiratory fitness and increased AF symptom burden. Conclusions: HFpEF is common in patients with symptomatic AF and is associated with increased BMI and hypertension. AF-HFpEF is characterized by a global LA cardiomyopathy involving reduced LAC, reduced LA mechanical function and LA electrical remodelling. Diagnosis of HFpEF in patients with AF may identify those with increased symptom burden, reduced exercise capacity and increased risk of stroke. (Trial registration: ACTRN12620000639921)

Impact of empagliflozin on left atrial mechanical and conduction functions in patients with type 2 diabetes mellitus.

Empagliflozin, an oral anti-diabetic drug that inhibits the sodium-dependent glucose co-transporter 2 (SGLT2), has pleiotropic effects on the myocardium. The aim of the study is to investigate the effect of empagliflozin on atrial electromechanical delay (AEMD) and the left atrial (LA) mechanical functions in patients with type 2 diabetes mellitus (DM). In total 62 patients (40.3% female, mean age 50.5 ± 8.6 years old) with type 2 DM were enrolled to the study. Participants were used a SGLT2 inhibitor (empagliflozin 10-25 mg/daily) for 6months. Patients were examined initially and after 6 months with echocardiography. LA volume was recorded, atrial conduction times were measured using tissue Doppler imaging (TDI). No significant change was observed in LA volumes (maximal, minimal, and presystolic), total emptying and passive emptying volume at the end of 6months; however, there was a significant decrease in active emptying volume (8.3 ± 2.9ml/m2 vs. 7.9 ± 2.9ml/m2 , p=0.04). The posteroanterior lateral, septal, and tricuspid conduction times significantly decreased after the empagliflozin treatment. The decrease in right inter-AEMD was statistically significant (13.25 ± 10.21 ms vs. 10.85 ± 9.14 ms, p=0.011). The changes in inter-AEMD were found to be correlated with the changes in LA active emptying volume (r=0.408). Empagliflozin may enhance the structure and electrical conductions of the atrium and may prevent DM patients from DM-2-related functional disorder and arrhythmia.

Left atrial strain and clinical outcome in patients with significant mitral regurgitation after surgical mitral valve repair.

BackgroundThis study aimed to investigate the prognostic value of left atrial (LA) strain in patients with significant mitral regurgitation (MR) after surgical mitral valve (MV) repair.MethodsA total of 169 patients (age 55 ± 15 years, 88 men) with moderate or severe MR on echocardiogram at least 6 months after surgical MV repair for primary MR were studied. Two-dimensional, Doppler, and speckle tracking echocardiography including MR quantitative measures, chamber size, and LA strain were comprehensively analyzed. The primary outcome was a composite of cardiovascular death, heart failure hospitalization, and MV reoperation.ResultsDuring a median of 44.4 months [interquartile range (IQR): 18.7–70.3 months] of follow-up, 44 patients (26%) experienced clinical events; these patients had greater MR volume, elevated mean diastolic pressure gradient and pulmonary artery systolic pressure, and enlarged chamber size compared with patients who did not experience events. Patients with events showed significantly lower LA strain [13.3% (IQR: 9.3–23.8%) vs. 24.0% (IQR: 13.1–31.4%), p = 0.003] and higher MR volume/LA strain [3.09 ml/% (IQR: 2.06–5.80 ml/%) vs. 1.57 ml/% (IQR: 1.04–2.72 ml/%), p < 0.001] than those without events. MR volume/LA strain was a good predictor of clinical outcomes (cut-off 1.57 ml/%, area under the curve 0.754, p < 0.001). On multivariable Cox proportional analysis, MR volume/LA strain was independently associated with clinical outcomes (hazard ratio: 1.269, 95% confidence interval: 1.109–1.452, p < 0.001) along with pulmonary artery systolic pressure.ConclusionA measure of LA mechanical function relative to MR volume is associated with clinical outcomes in patients with significant MR after surgical MV repair.

Clinical Utility of Left Atrial Asynchrony and Mechanical Function in Patients with Hypertrophic Cardiomyopathy.

The aim of this study was to examine whether left atrial dispersion and left atrial strain as measured by speckle tracking echocardiography and clinical parameters are predictors of the development of atrial fibrillation in patients with hypertrophic cardiomyopathy. A total of 151 patients (69% male, mean age 48.9 ± 14.2 years) with hypertrophic cardiomyopathy were included in the study. The patients' demographic, clinical, electrocardiographic, 2-dimensional classic and speckle tracking echocardiographic data were collected. Atrial fibrillation was identified by 12-lead electrocardiograms or 24-72 hours of Holter recordings during the follow-up period. Atrial dispersion was defined as the standard deviation of time to peak strain in 12 left atrial segments. During the follow-up period, 40 patients (26%) developed atrial fibrillation. Peak atrial longitudinal strain (16.8 ± 6 vs. 22.1 ± 6.6, p ≤ 0.001) was significantly lower in the patients who developed atrial fibrillation than in those who did not. However, atrial dispersion was significantly higher in the group which developed atrial fibrillation (61 [46.7,78.6] vs. 41.3 [30.6-51], p ≤ 0.001). In multivariate Cox regression analysis, atrial dispersion (msn) (hazard ratio: 1.019, 95% confidence interval: 1.004-1.033, p = 0.01), peak atrial longitudinal strain, and age were found to be independent predictors of atrial fibrillation. In patients with hypertrophic cardiomyopathy, atrial dispersion, peak atrial longitudinal strain and age are predictive of the development of atrial fibrillation. Atrial dispersion measured by a speckle tracking-based method may provide further information on left atrial function in patients with hypertrophic cardiomyopathy or other disease states.

Atrial longitudinal strain in cardiac aTTR amyloidosis and occurrence of atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. BACKGROUND In systemic amyloidosis cardiac infiltration by amyloid fibrils leads to increased stiffness of the myocardium and of the atrial walls. There is a reduction in left atrial mechanical function and a high risk of thrombi formation. Atrial deformation by speckle tracking echocardiography peak atrial longitudinal strain (PALS) can predict the incidence of atrial fibrillation (AF) and ischaemic stroke in the general population and in patients (pts) with cryptogenic stroke. The predictive value of PALS seems to differ in different pts populations according to the prevalence of ventricular versus atrial myopathy (1). PURPOSE to compare parameters of atrial function in cardiac amyloidosis pts in sinus rhythm (SR) and AF and to observe if they are associated with the occurrence of new onset AF at follow-up (FUP). METHODS between 2016-2021 all pts with diagnosis of cardiac aTTR amyloidosis referred to the Clinic underwent an echocardiographic study including 2D-speckle tracking evaluation of left ventricular and left and right atrial strain. All pts received a regular FUP (clinical, echo, ECG and 24 hours Holter monitoring). Atrial function was evaluated by PALS in all pts and by PALS and PACS (peak atrial longitudinal strain during atrial contraction phase) in pts in SR. RESULTS 47 pts with aTTR cardiac amyloid (39/47 wild-tipe) were studied. Mean age = 82 ± 5 years, LV mass = 190 ± 46 g/m2; LV EF= 53%±9, GLS= -10%±4, EF/GLS ratio=-5,5 ± 2, left atrial (LA) volume = 49 ± 9 ml/m2, LA PALS 9,7%±6,6, right atrial (RA) PALS 15,9 ± 9,6. At the time of diagnosis 29 pts were in SR and 18 pts were in AF. Pts in AF had lower PALS (5,1%±3,7 in AF pts vs 11,9%±6,9 in SR pts, p = 0,001) and lower (less negative) GLS (-9,1%±3,1 in AF pts vs -11,8%± 4,2 in SR pts, p = 0,02). LA volume was not significantly different in AF pts compare to SR pts (51,4 ml/m2 ± 7,65 vs 47,6 ml/m2 ± 10,9; p = 0,19). During a median FUP of 21 months 8 pts had a new onset AF. There was no significant difference in atrial size and atrial deformation parameters between pts who had new onset AF at FUP compared to pts who did not (Tab 1). The only parameter associated with new onset AF at FUP was GLS (-8.21%± 2,8 vs -13.01%±4,02, CI -10.8—5.6 vs -14.8—11.18, respectively, in pts who developed new onset AF compared to pts who did not, p = 0.007). 5 pts had a cardioembolic stroke at FUP: at the time of the admission for stroke they were all in AF. CONCLUSIONS Our data show that in this group of pts with aTTR cardiac amyloidosis all echo parameters of LA size and function were overall impaired. In this setting of advanced disease LA volume was not significantly different in pts in AF compared to pts in SR and was not associated with new-onset AF at FUP. Deformation parameters were significantly more impaired in pts in AF compared to pts in SR, however PALS was not associated with the occurrence of new onset AF at follow-up. The only parameter associated with the occurrence of new onset AF at follow-up was GLS. Abstract Table 1

Severe Rheumatic Mitral Stenosis, Worse Left Atrial Mechanics is Closely Associated with Echo Criteria for Intervention.

Background:Rheumatic mitral valve (MV) stenosis is associated with progressive left atrial (LA) fibrosis and functional impairment, Pulmonary artery systolic pressure (PASP) and right ventricular (RV) dysfunction. The aims of the study were to determine in those patients with severe MV stenosis if LA mechanical function as assessed by speckle tracking echocardiography could identify those with increased PASP, atrial fibrillation (AFib), and RV dysfunction.Subjects and Methods:Patients with severe MV stenosis were identified from the institutional echo database. Echocardiograms were read off line and measurements included atrial and ventricular strain. Patients were divided into tertiles of LA reservoir strain (LASr) values and data compared between the groups.Results:Ninety-seven patients, 67 females, mean age 47.4 ± 11.9 years, had MV mean gradient of 8.3 ± 5.1 mmHg, MV area by pressure half time of 1.3 ± 0.3 cm2 and LASr of 11.18% ± 6.4%. Those patients in the lowest LASr tertile had more AFib (72%, P = 0.0001), PASP >50 mm Hg (39%, P = 0.005), and worst RV impairment. In multivariable logistic regression analysis, LASr, age, and mean MV gradient were the independent predictors of AFib and PASP >50 mm Hg. Cutoffs, determined by receiver operating characteristic curve analysis had high specificity for the composite outcome of Afib and PASP >50 mmHg (85% for LASr <7.7%).Conclusion:In severe MV stenosis LASr, age and mean MV gradient, are independent predictors of Afib and PASP >50 mmHg. LASr <7.7% has high sensitivity and specificity in identifying those who meet ESC guideline 2017 criteria for valve intervention, suggesting its potentially helpful addendum to the surveillance of patients with MV stenosis.