Conduit Function Research Articles

Left atrial strain parameters derived by echocardiography are impaired in patients with acute myocarditis and preserved systolic left ventricular function

Purpose: Data derived by cardiac magnetic resonance (CMR) feature tracking suggest that not only left ventricular but also left atrial function is impaired in patients with acute myocarditis. Therefore, we investigated the diagnostic value of speckle tracking echocardiography of the left ventricle and left atrium in patients with acute myocarditis and normal left ventricular ejection fraction (LVEF). Methods and results: 30 patients with acute myocarditis confirmed by CMR according to the Lake Louise criteria and 20 healthy controls were analyzed including global longitudinal strain (GLS) and left atrial (LA) strain parameters. Although preserved LVEF was present in both groups, GLS was significantly lower in patients with acute myocarditis (GLS − 19.1 ± 1.8% vs. GLS − 22.1 ± 1.7%, p < 0.001). Further diastolic dysfunction measured by E/e’ mean was significantly deteriorated in the myocarditis group compared to the control group (E/e’ mean 6.4 ± 1.6 vs. 5.5 ± 1.0, p = 0.038). LA reservoir function (47.6 ± 10.4% vs. 55.5 ± 10.8%, p = 0.013) and LA conduit function (-33.0 ± 9.6% vs. -39.4 ± 9.5%, p = 0.024) were significantly reduced in patients with acute myocarditis compared to healthy controls. Also left atrial stiffness index (0.15 ± 0.05 vs. 0.10 ± 0.03, p = 0.003) as well as left atrial filling index (1.67 ± 0.47 vs. 1.29 ± 0.34, p = 0.004) were deteriorated in patients with myocarditis compared to the control group. Conclusion: In patients with acute myocarditis and preserved LVEF not only GLS but also LA reservoir function, LA conduit function and left atrial stiffness index as well as left atrial filling index were impaired compared to healthy controls indicating ventricular diastolic dysfunction and elevated LV filling pressures.

Relationships of Whole-Heart Myocardial Mechanics and Cardiac Morphometrics by Transthoracic Echocardiography with Main Prognostic Factors of Heart Failure in Non-Ischemic Dilated Cardiomyopathy.

there are many prognostic factors of heart failure (HF) based on their evaluation from imaging, to laboratory tests. In clinical practice, it is crucial to use widely available, cheap, and easy-to-use prognostic factors, such as left ventricular ejection fraction (LVEF), New York Heart Association (NYHA) functional class, 6 min walk test (6MWT), B-type natriuretic peptide (BNP), etc. We sought to evaluate the relationships between whole-heart myocardial mechanics and cardiac morphometrics with the main commonly used prognostic factors of HF in patients with non-ischemic dilated cardiomyopathy (NIDCM). two-dimensional (2D) echocardiography for myocardial mechanics (global longitudinal, radial, and circumferential strains of the left ventricle; right ventricular longitudinal strain; strain values of reservoir, conduit, and contraction function of both atria) and cardiac morphometric (diameters and volumes of both atria and ventricles) parameters were performed, and the HF main traditional prognostic factors were identified. We assessed 109 patients (68.8% male; 49.7 ± 10.5 years) with newly diagnosed NIDCM. Myocardial mechanics and morphometrics were weakly correlated with the patient's age, gender, and smoking (R = 0.2, p < 0.05). Stronger relationships were observed with NYHA class, 6MWT, and BNP (the strongest correlations were with LVEF: R = -0.499, R 0.462, R = -0.461, p < 0.001, respectively). There were moderately strong correlations with LVEF and other whole-heart myocardial mechanics or morphometrics. Moreover, LVEF with global regurgitation volume (GRV) and right ventricle free wall longitudinal strain (RVFWLS) were the most usually detected parameters in multivariate analysis to be associated with changes in HF prognostic factors. in NIDCM patients, the main prognostic factors of HF are correlated with whole-heart myocardial mechanics and morphometrics. However, LVEF, GRV, and RVFWLS are the most usually found 2D echocardiographic factors associated with changes in HF prognostic factors.

Right Ventricular Function During Exercise After Pulmonary Endarterectomy for Chronic Thromboembolic Pulmonary Hypertension.

Background Pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension improves resting hemodynamics and right ventricular (RV) function. Because exercise tolerance frequently remains impaired, RV function may not have completely normalized after PEA. Therefore, we performed a detailed invasive hemodynamic study to investigate the effect of PEA on RV function during exercise. Methods and Results In this prospective study, all consenting patients with chronic thromboembolic pulmonary hypertension eligible for surgery and able to perform cycle ergometry underwent cardiac magnetic resonance imaging, a maximal cardiopulmonary exercise test, and a submaximal invasive cardiopulmonary exercise test before and 6 months after PEA. Hemodynamic assessment and analysis of RV pressure curves using the single-beat method was used to determine load-independent RV contractility (end systolic elastance), RV afterload (arterial elastance), RV-arterial coupling (end systolic elastance-arterial elastance), and stroke volume both at rest and during exercise. RV rest-to-exercise responses were compared before and after PEA using 2-way repeated-measures analysis of variance with Bonferroni post hoc correction. A total of 19 patients with chronic thromboembolic pulmonary hypertension completed the entire study protocol. Resting hemodynamics improved significantly after PEA. The RV exertional stroke volume response improved 6 months after PEA (79±32 at rest versus 102±28 mL during exercise; P<0.01). Although RV afterload (arterial elastance) increased during exercise, RV contractility (end systolic elastance) did not change during exercise either before (0.43 [0.32-0.58] mm Hg/mL versus 0.45 [0.22-0.65] mm Hg/mL; P=0.6) or after PEA (0.32 [0.23-0.40] mm Hg/mL versus 0.28 [0.19-0.44] mm Hg/mL; P=0.7). In addition, mean pulmonary artery pressure-cardiac output and end systolic elastance-arterial elastance slopes remained unchanged after PEA. Conclusions The exertional RV stroke volume response improves significantly after PEA for chronic thromboembolic pulmonary hypertension despite a persistently abnormal afterload and absence of an RV contractile reserve. This may suggest that at mildly elevated pulmonary pressures, stroke volume is less dependent on RV contractility and afterload and is primarily determined by venous return and conduit function.

Incremental Effect of Mitral Regurgitation on Left Atrial Dysfunction and Atrioventricular Interaction in Hypertensive Patients by MRI.

Mitral regurgitation may occur when hypertension causes left ventricular (LV) and left atrial (LA) remodeling. However, its role in LA function in hypertensive patients remains unclear. To explore how mitral regurgitation affects LA function in hypertension and to investigate atrioventricular interaction in hypertensive patients with mitral regurgitation. Retrospective. A total of 193 hypertensive cases and 64 controls. A 3.0 T/balanced steady-state free precession. LA volume (LAV), LA strain (reservoir, conduit, and active), LA ejection fraction, and LV strain (global peak longitudinal [GLS], circumferential [GCS], and radial strain [GRS]) were evaluated and compared among groups. Regurgitant fraction (RF) was evaluated in regurgitation patients and used to subdivide patients into mild (RF: 0%-30%), moderate (RF: 30%-50%), and severe (RF: >50%) regurgitation categories. One-way analysis of variance, Spearman and Pearson's correlation coefficients (r), and multivariable linear regression analysis. A P value <0.05 was considered statistically significant. Hypertensive patients without mitral regurgitation showed significantly impaired LA reservoir and conduit functions and significantly decreased LV GLS but preserved pump function and LAV compared to controls (P=0.193-1.0). Hypertensive cases with mild regurgitation (N=22) had significantly enlarged LAV and further reduced LA reservoir function, while the group with moderate regurgitation (N=20) showed significantly reduced LA pump function, further impaired conduit function, and significantly reduced LV strain. The severe regurgitation (N=13) group demonstrated significantly more severely impaired LA and LV functions and LAV enlargement. Multivariable linear regression showed that regurgitation degree, GRS, GCS, and GLS were independently correlated with the LA reservoir, conduit, and active strain in hypertensive patients with mitral regurgitation. Mitral regurgitation may exacerbate LA and LV impairment in hypertension. Regurgitation degree, LV GRS, GCS, and GLS were independent determinants of the LA strain in hypertensive patients with mitral regurgitation, which demonstrated atrioventricular interaction. 4. Stage 3.

Reverse remodeling of left atrium assessed by cardiovascular magnetic resonance feature tracking in hypertrophic obstructive cardiomyopathy after septal myectomy

BackgroundAssessing the structure and function of left atrium (LA) is crucial in hypertrophic obstructive cardiomyopathy (HOCM) because LA remodeling correlates with atrial fibrillation. However, few studies have investigated the potential effect of myomectomy on LA phasic remodeling in HOCM after myectomy using cardiovascular magnetic resonance (CMR) feature tracking (FT). This study aims to evaluate the LA structural and functional remodeling with HOCM after myectomy by CMR-FT and to further investigate the determinants of LA reverse remodeling. MethodsIn this single-center study, we retrospectively studied 88 patients with HOCM who received CMR before and after myectomy between January 2011 and June 2021. Preoperative and postoperative LA parameters derived from CMR-FT were compared, including LA reservoir function (total ejection fraction [EF], total strain [εs], peak positive strain rate [SRs]), conduit function (passive EF, passive strain [εe], peak early negative strain rate [SRe]) and booster function (booster EF, active strain [εa], late peak negative strain rate [SRa]). Eighty-six healthy participants were collected for comparison. Univariate and multivariate linear regression identified variables associated with the rate of change of εa. ResultsCompared with preoperative parameters, LA reservoir function (total EF, εs, SRs), booster function (booster EF, εa, SRa), and SRe were significantly improved after myectomy (all P < 0.05), while no significant differences were observed in passive EF and εe. Postoperative patients with HOCM still had larger LA and worse LA function than healthy controls (all P < 0.05). After analyzing the rates of change in LA parameters, LA boost function, especially εa, showed the most dramatic improvement beyond the improvements in reservoir function, conduit function, and volume. In multivariable regression analysis, minimum LA volume index (adjusted β = − 0.39, P < 0.001) and Δleft ventricular outflow tract (LVOT) pressure gradient (adjusted β = − 0.29, P = 0.003) were significantly related to the rate of change of εa. ConclusionsPatients with HOCM after septal myectomy showed LA reverse remodeling with a reduction in LA size and restoration in LA reservoir and booster function but unchanged LA conduit function. Among volumetric and functional changes, booster function had the greatest improvement postoperatively. Besides, preoperative LAVmin index and ΔLVOT might be potential factors associated with the degree of improvement in εa.

Cardiovascular magnetic resonance myocardial feature tracking for the determination of left atrial strain in hypertensive left ventricular hypertrophy and hypertrophic cardiomyopathy

To measure the left atrial (LA) function in patients with hypertrophic cardiomyopathy (HCM; with [OHCM] and without obstruction [NOHCM]) and hypertension-related left ventricular hypertrophy (H-LVH) using cardiovascular magnetic resonance imaging feature tracking (CMR-FT). Patients who met the criteria for HCM (n=68), H-LVH (n=46), and 30 healthy controls participated. Left atrial strain was analysed using CMR-FT in cine images with two and four chambers. The strain rate and LA strain measurements showed that patients with HCM, and H-LVH had impaired conduit and reservoir functions (versus controls). These capacities were more severely impaired in OHCM than those seen in NOHCM and H-LVH. The LA volume parameters (LAVIpac, LAVImin and LAVImax) from the OHCM group were higher than both the NOHCM and H-LVH groups (all p<0.05). There were differences between the OHCM and H-LVH groups in terms of the parameters for LA reservoir function (εs), booster pump function (SRa), and conduit function (SRe, LA passive EF, εe; p<0.05). The strongest correlations included the associations between LA total EF and εs, εe and LA passive EF, and SRe and LA passive EF. CMR-FT can reliably identify LA dysfunction and deformation in the early stages of HCM and H-LVH.

The loss of left atrial contractile function predicts a worse outcome in HFrEF patients.

In chronic heart failure, high intracardiac pressures induce a progressive remodeling of small pulmonary arteries up to pulmonary hypertension. At the end of left atrial conduit function, pulmonary and left heart end-systolic pressures equalization might affect left atrial systole. In this single-center prospective study, we aimed to investigate whether peak atrial contraction strain (PACS), measured by speckle tracking echocardiography, was independently associated with prognosis in heart failure with reduced ejection fraction (HFrEF). Outpatients with HFrEF and sinus rhythm referred to our echo-labs were enrolled. After clinical and echocardiographic evaluation, off-line speckle tracking echocardiography analysis was performed. Primary and secondary endpoint were cardiovascular death and heart failure hospitalization, respectively. Spline knotted survival model identified the optimal prognostic cut-off for PACS. The 152 patients were stratified based on PACS <8% (n = 76) or PACS ≥8% (n = 76). Patients with PACS <8% had lower left ventricle and left atrial reservoir strain and higher New York Heart Association (NYHA) class and left atrial volume index (LAVI). Over a mean follow-up of 3.4 ± 2 years, 117 events (51 cardiovascular death, 66 heart failure hospitalizations) were collected. By univariate and multivariate Cox analysis, PACS emerged as a strong and independent predictor of cardiovascular death and heart failure hospitalization, after adjusting for age, sex, left ventricle strain, and E/e', LAVI (HR 0.6 per 5 unit-decrease in PACS). Kaplan-Meier curves showed a sustained divergence in event-free survival rates for the two groups. The reduction of PACS significantly and independently affects cardiovascular outcome in HFrEF. Therefore, its assessment, although limited to patients with sinus rhythm, could offer additive prognostic information for HFrEF patients.

S-11-5: CLINICAL IMPLICATION OF FMD

A healthy endothelium maintains vascular tone and structure by regulating the balance between vasodilation and vasoconstriction, growth inhibition and growth promotion, antithrombosis and prothrombosis, anti-inflammation and proinflammation, and also antioxidation and pro-oxidation. The vascular endothelium is involved in the release of various vasodilators, including nitric oxide (NO), prostaglandins, and endothelium-derived hyperpolarizing factor as well as vasoconstrictors. NO plays an important role in the regulation of vascular tone, the inhibition of platelet aggregation, and the suppression of smooth muscle cell proliferation. Cardiovascular diseases are associated with endothelial dysfunction. In addition, endothelial dysfunction is an early feature of atherosclerosis and vascular diseases in humans. Therefore, it is clinically important to estimate the degree of endothelial dysfunction. Several methods have been used to assess endothelial function in humans. Measurement of flow-mediated vasodilation (FMD) using an ultrasound is noninvasive and is an accurate indicator of NO production. Measurement of FMD is widely performed as an index of conduit artery endothelial function. Several investigators have shown that FMD is an independent predictor for cardiovascular outcomes. It is thought that FMD is useful for surrogate endpoint of cardiovascular outcomes and index of atherosclerotic treatment. However, the evaluation technique by the FMD measurement system still requires skills in measurement of the vessel diameter by an ultrasound system, and is difficult to handle. In addition, there is a problem in that the technique requires a large-scale apparatus and lacks in simplicity. In this session, we would like to explain in detail concerning the methods of assessing and clinical importance of endothelial function, especially FMD.

The association of left atrial mechanics with left ventricular morphology in patients with hypertrophic cardiomyopathy: a cardiac magnetic resonance study.

Hypertrophic cardiomyopathy (HCM) is related with structural and pathologic changes in the left atrium (LA) and left ventricle (LV). The aim of this study was to explore the association between LA mechanics and LV characteristics in patients with HCM using cardiac magnetic resonance feature tracking (CMR-FT). A total of 76 patients with HCM and 26 healthy controls were included in the study. The parameters including the extent of LV late gadolinium enhancement (LGE-%) and the LV early diastolic longitudinal strain rate (edLSR) were assessed for LV. LA conduit, booster, and reservoir functions were assessed by LA fractional volumes and strain analyses using CMR-FT. HCM patients were classified as HCM patients without LGE, with mild LGE-% (0% < LGE-% ł 10%), and prominent LGE-% (10% < LGE-%). HCM patients had worse LA functions compared with the controls (p < 0.05). The majority of LA functional indices were more impaired in HCM patients with regard to LGE. LA volumes were higher in HCM patients with prominent LGE-% compared with HCM patients with mild LGE-% (p < 0.05). However, only a minority of LA functional parameters differed between the 2 groups. LA strain parameters showed weak to modest correlations with LV LGE-% and LV edLSR. LV characteristics, to some extent, influence LA mechanics, but they might not be the only factor inducing LA dysfunction in patients with HCM.

PS-C35-4: ASSOCIATION OF SODIUM INTAKE WITH ADVERSE LEFT ATRIAL FUNCTION AND LEFT ATRIOVENTRICULAR COUPLING

Objective: In this study, we investigated the relationship between 24-hour urinary sodium (a surrogate for estimating dietary sodium intake), ambulatory blood pressure parameters, cardiac MRI-assessed left atrial function and left atrioventricular coupling, as well as the influence of nighttime blood pressure and body mass index(BMI) on 24-hour urinary sodium and subclinical cardiac function. Design and method: Participants in our study included 398 individuals, all of whom were subjected to 24-hour urine collection, 24-hour ambulatory blood pressure measurement, and cardiac magnetic resonance imaging to determine left atrial function (myocardial strain) as well as left atrioventricular coupling index. LACI is defined as the ratio of left atrial end-diastolic volume divided by left ventricular end-diastolic volume. Our study evaluated the relationship between 24-hour urinary sodium and ambulatory blood pressure parameters, left atrial function, and left atrioventricular coupling index, and used mediation analysis to explain the indirect effects of nighttime blood pressure and BMI between 24-hour urinary sodium and left atrial function and left atrioventricular coupling index. Results: It was found that the average age of the participants was 55.70 ± 11.30 years old, with 58% of the participants being male and 47.5% experiencing hypertension. The mean urinary sodium value was 172.01 ± 80.24mmol/24 hours, and the average body mass index was 25.46 ± 3.78 kg/m2. After adjusting for age, gender, history of diabetes, smoking status, alcohol consumption, and use of diuretics, 24-hour urinary sodium was correlated with multiple ambulatory blood pressure parameters, especially with nighttime diastolic blood pressure. Left atrial structure and function (left atrial reservoir function and left atrial conduit function) and left atrioventricular coupling index were correlated (P &lt; 0.05). Mediation analysis showed that BMI explained 16% of the indirect effect of 24-hour urinary sodium and left atrial function (left atrial reservoir function and left atrial conduit function), and 30% of the indirect effect of LACI. Independent of the mediator, 24-hour urinary sodium had a significant direct effect on left atrial reservoir function, left atrial conduit function, and left atrioventricular coupling. Conclusions: Higher 24-hour urinary sodium was associated with a greater BMI as well as poor left atrial function and left atrioventricular coupling, and the BMI mediated the relationship between 24-hour urinary sodium and subclinical left cardiac function, and, more importantly, 24-hour urinary sodium may directly affect the left atrial function and left atrioventricular coupling independent of intermediary factors.

Soluble urokinase plasminogen activator receptor (suPAR) promotes atherosclerosis

Patients with chronic kidney disease (CKD) frequently suffer from cardiovascular disease (CVD). The rate of CVD events rises steadily with the progression of CKD and is markedly increased as compared to people without CKD (1). The underlying arterial disease consists of at least two types, namely arteriosclerosis (without atheroma formation) and atherosclerosis (2). Arteriosclerosis is characterized by stiffness, media calcification, and reduced cushioning function of the arteries. Atherosclerosis initially is characterized by intima–media thickening, and subsequently by plaque formation, intima calcification, and altered conduit function.

631 THE IMPACT OF BMI ON MYOCARDIAL WORK AND LEFT ATRIAL STRAIN IN YOUNG OVERWEIGHT PATIENTS WITH PRESERVED LEFT VENTRICULAR EJECTION FRACTION

Abstract Introduction Overweight and obesity are a health problem of growing significance all over the world with increasing prevalence in both developed and developing countries. Numerous studies have demonstrated a relationship between obesity and cardiovascular diseases, underscoring the need to early treat this pathological condition. Overweight and obesity cause structural and functional changes on left ventricular (LV) and left atrial (LA) performance, which lead to heart failure. In this context we aimed to evaluate the impact of BMI on myocardial work parameters and left atrial strain to early detect LV and LA performance changes in overweight patients. Methods 80 young individuals were prospectively enrolled, distinguishing between overweight patients with BMI greater than or equal to 25 to 29.9 kg/m^2 (n= 36; 45±11 years) and normal weight patients with BMI greater than or equal to 18.5 to 24.9 kg/m^2 (n=44; 43±9 years). All patients underwent transthoracic echocardiogram to calculate global longitudinal strain (GLS), global work index (GWI), global work efficiency (GWE), global wasted work (GWW), global constructive work (GCW) and left atrial strain. Results Overweight patients have higher BSA (1,9±0,16 vs 1,6±0,17 mq; p&amp;lt;0,0001), Diastolic Blood pressure (81±12 vs 74±10 mmHg; p= 0,01) mean arterial pressure (98±15 vs 91±11 mmHg; p = 0,01), Heart Rate (71±13 vs 70±12 bpm; p= 0,02) and Global Longitudinal Strain (-19,3% ±1,7 vs -20,3% ±1,8; p = 0,02). With respect to myocardial work parameters, in overweight patients GWE (93% vs 95%; p=0,01) is significantly reduced, whereas GWW (132 vs 102 mmHg%; p=0,03) is significantly increased. Left atrial reservoir (LAres) (36% vs 40%; p=0,04) and conduit (-19% vs -24%; p=0,005) function are significantly reduced in overweight patients. BMI inversely correlates with GWE (r=-0,36; p=0,005) and LAres (r=-0,33; p=0,007), whereas it directly correlates with GWW (r=0,31; p = 0,006). Conclusions Overweight induces early LV and LA performance changes that can be precociously detected by myocardial work and left atrial strain, in order to better characterize individual cardiovascular risk profile.

Left atrial structure and function: association with blood pressure variability in pregnant women.

The aim of this study was to investigate the relationship between left atrial (LA) abnormalities and ambulatory blood pressure variability (BPV) in pregnant women and their relationship with hypertension-related clinical outcomes in pregnancy. This single-center, prospective study included 119 pregnant women. All participants underwent 24-h ambulatory blood pressure (BP) monitoring and echocardiographic examination before 20 weeks of gestation. BPV was evaluated using 24-h ambulatory BP monitoring. SD of the mean of SBP (SBP-SD) and DBP variability was calculated as 24-h, daytime and nighttime SBP and DBP. The patients were classified into two groups based on median 24-h SBP-SD (11.3 mmHg). LA features of the patients were compared according to the high and low BPV groups. One hundred and nineteen pregnant women (mean age, 28.6 ± 5.2 years) were included in the study. The mean office SBP and DBP were 108.7 ± 15.4 mmHg and 68.2 ± 10.2 mmHg, respectively. In pregnant women with high BPV, even though BP is normal, reservoir and conduit LA functions have decreased and LA stiffness has increased. Gestational hypertension and composite outcomes were more common in pregnant women with high BPV. Among the LA parameters, the most associated with composite outcome was conduit LA function. In pregnancy, higher BPV is associated with worse LA function. The LA conduit strain offers potential value in predicting hypertension-related clinical outcomes in pregnancy.

Effect of Infarct Location and Size on Left Atrial Function: A Cardiovascular Magnetic Resonance Feature Tracking Study.

Background: LA function has been recognized as a significant prognostic marker in many cardiovascular diseases. Cardiovascular magnetic resonance feature tracking (CMR-FT) represents a promising technique for left atrial function evaluation. The size and location of myocardial infarction are important factors in the cause of adverse left ventricular remodeling, but the effect on the left atriam is unclear. Purpose: to investigate the effect of location and size of previous myocardial infarction (MI) on LA function using CMR-FT. Study type: retrospective. Population: patients formerly diagnosed with anterior MI (n = 42) or non-anterior MI (n = 40) and healthy controls (n = 47). Field Strength/Sequence: a 3.0T MR, Steady state free precession (SSFP), Phase-sensitive inversion recovery (PSIR). Assessment: infarct location and size were assigned and quantified by late-gadolinium enhancement (LGE) imaging. LA performance was analyzed using CMR-FT in 2- and 4-chamber cine images, including LA reservoir, conduit and booster pump function. Statistics: descriptive statistics, ANOVA with post Bonferroni correction, Kruskal−Wallis H, Spearman’s correlation, intraclass correlation coefficient. Results: Anterior MI patients had impaired LA reservoir function (LATEF, εs, SRs), conduit function (LAPEF, εe, SRs) and booster pump function (LAAEF, εa) compared with controls (p < 0.05). Non-anterior MI patients had impaired LA strain (εs, εe, εa; p < 0.05) but preserved LAEFs (p > 0.05). After adjusting the area of MI, there was no significant difference in the LA morphology and function between the anterior and non-anterior wall groups. Stratification analysis by MI size revealed that LA volumes and LAEFs were unchanged in patients with MI size ≤ 15% compared with controls (p > 0.05); only εs and εe were decreased (p < 0.05). Increased LAVIpre-a, LAVImin and decreased LATEF, and LAAEF were found in patients with MI size > 15% compared with the MI size ≤ 15% group (p < 0.05). LVSVI, εs and MI size were significant correlated with LAVI pre-a in multiple stepwise regression analysis. Data conclusions: The location of myocardial infarction is not a major factor affecting the morphology and function of the left atrium. Patients with MI size > 15% experience more pronounced post-infarction LA remodeling and dysfunction than MI size ≤ 15% patients.

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.

Machine learning approach in diagnosing Takotsubo cardiomyopathy: The role of the combined evaluation of atrial and ventricular strain, and parametric mapping

BackgroundCardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) is a key diagnostic tool in the differential diagnosis between non-ischemic cause of cardiac chest pain. Some patients are not eligible for a gadolinium contrast-enhanced CMR; in this scenario, the diagnosis remains challenging without invasive examination. Our purpose was to derive a machine learning model integrating some non-contrast CMR parameters and demographic factors to identify Takotsubo cardiomyopathy (TTC) in subjects with cardiac chest pain. Material and methodsThree groups of patients were retrospectively studied: TTC, acute myocarditis, and healthy controls. Global and regional left ventricular longitudinal, circumferential, and radial strain (RS) analysis included were assessed. Reservoir, conduit, and booster bi-atrial functions were evaluated by tissue-tracking. Parametric mapping values were also assessed in all the patients. Five different tree-based ensemble learning algorithms were tested concerning their ability in recognizing TTC in a fully cross-validated framework. ResultsThe CMR-based machine learning (ML) ensemble model, by using the Extremely Randomized Trees algorithm with Elastic Net feature selection, showed a sensitivity of 92% (95% CI 78–100), specificity of 86% (95% CI 80–92) and area under the ROC of 0.94 (95% CI 0.90–0.99) in diagnosing TTC. Among non-contrast CMR parameters, the Shapley additive explanations analysis revealed that left atrial (LA) strain and strain rate were the top imaging markers in identifying TTC patients. ConclusionsOur study demonstrated that using a tree-based ensemble learning algorithm on non-contrast CMR parameters and demographic factors enables the identification of subjects with TTC with good diagnostic accuracy. Translational outlookOur results suggest that non-contrast CMR features can be implemented in a ML model to accurately identify TTC subjects. This model could be a valuable tool for aiding in the diagnosis of subjects with a contraindication to the contrast media. Furthermore, the left atrial conduit strain and strain rate were imaging markers that had a strong impact on TTC identification. Further prospective and longitudinal studies are needed to validate these findings and assess predictive performance in different cohorts, such as those with different ethnicities, and social backgrounds and undergoing different treatments.

Analysis of Left Atrial Function after Percutaneous Intramyocardial Septal Radiofrequency Ablation in Hypertrophic Cardiomyopathy

Introduction: The main goal of our research was to explore the effect of percutaneous intramyocardial septal radiofrequency ablation (PIMSRA) on left atrial (LA) phasic function in hypertrophic cardiomyopathy (HCM). Methods: The study included 13 patients who underwent PIMSRA at our hospital. The function of LA including reservoir, conduit, and booster pump was analyzed and compared before and 6 months after PIMSRA in HCM patients. LA reservoir function parameters contain maximal LA volume, minimal LA volume (LAV min), LA ejection fraction (LAEF), LA expansion index (LAEI), and reservoir strain; LA conduit function includes LA volume before atrial systole, LA passive volume, LA passive ejection fraction, and conduit strain; LA booster function involves LA booster volume, LA active ejection fraction, and LA contraction strain. Additionally, 20 healthy controls were selected to compare the LA function of HCM patients. Results: The preoperative LA reservoir and conduit function in HCM patients were significantly impaired compared with the control group, while the change in booster pump function was not obvious. HCM patients at 6 months after PIMSRA had remarkably enhanced reservoir and conduit functions which were manifested by lower LAV min, higher LAEF, LAEI, reservoir, and conduit strain than before the operation, and the differences among these parameters between patients after PIMSRA and the healthy control group were not significant. However, with regard to LA contraction function, there was no significant improvement at 6 months after PIMSRA compared with before operation. Conclusion: PIMSRA is effective in the amelioration of LA reservoir and conduit function in patients with HCM but not in a marked improvement of LA contraction function in these individuals in short term.

Abstract 10439: Assessment of Left Atrial Deformation in Patients With Total Anomalous Pulmonary Venous Connection by Two-Dimensional Speckle-Tracking Echocardiography - A Single-Center Retrospective Cohort Study

Background: Total anomalous pulmonary venous connection (TAPVC) is a rare congenital heart disease of newborns characterized by insufficient left ventricle growth and diastolic dysfunctions. We hypothesized that reduced blood flow into the left heart in the uterus could also affect left atrium (LA) growth, leading to anomalies after birth. We compared the age-related changes in LA parameters detected using two-dimensional speckle-tracking echocardiography (2DSTE) in patients with TAPVC. Method: The LA datasets of 28 neonates with isolated TAPVC were analyzed before surgery and during follow-ups and compared with those of age-matched healthy controls (January 2009–2022). The LA strain (ε), indicating LA function, was analyzed using QLAB represented by reservoir (εR), conduit (εCD), and contractile (εCT) functions. LA pressure was determined by performing catheterization. Results: Compared to the control group, the TAPVC group had significantly smaller LA maximum size preoperatively and normal and larger time-dependent increase in the LA maximum and minimum size, respectively. All 2DSTE-determined LA functions showed significant reductions at all time points in the TAPVC group compared to those in the control group (median εR, εCD, and εCT; before surgery: 17.0 vs. 26.0, 12.9 vs. 15.9, and 6.3 vs. 10.4; follow up at 1-2 years: 30.0 vs. 45.7, 23.2 vs. 29.6, and 6.1 vs. 16.3; follow up at 5-7 years: 31.2 vs. 43.1, 25.0 vs. 31.2, and 5.2 vs. 10.8, respectively; p &lt; .01). However, compared to before surgery, εR and εCD did represent a significantly increased trend at follow-ups (median εR and εCD: 16.8→27.5 and 1.1→23%, respectively). Patients with pulmonary venous obstruction (PVO) at birth showed significantly decreased εR and εCD and higher LA pressure compared to those without PVO. Conclusion: This study showed that LA impairments existed even after repair in patients with TAPVC, suggesting that LA function loss mediated by less blood flow persist in childhood.

Evaluation of Atrial Electromechanical Delay and Left Atrial Phasic Function in Individuals with Electrocardiographic Early Repolarization Pattern.

Atrial electromechanical delay (EMD) and left atrial (LA) phasic function have been demonstrated to be predictors for the development of atrial fibrillation (AF). In the present study, we aimed to evaluate atrial EMD and LA phasic function in individuals with electrocardiographic early repolarization pattern (ERP). Eighty consecutive individuals with ERP and 40 age- and gender-matched control subjects without ERP were compared in this cross-sectional study. Atrial electromechanical coupling (Pa') was measured from lateral mitral annulus (Pa'lateral), septal mitral annulus (Pa'septal), and lateral tricuspid annulus (Pa'tricuspid) using tissue Doppler echocardiography to calculate intra- and inter-atrial EMD. LA maximal volume, LA minimal volume, and LA volume before atrial contraction were calculated using the biplane area-length method to assess LA phasic function. LA diameter, LA volume index, Pa'lateral, Pa'septal, Pa'tricuspid electrical activity and intra-left atrial EMD were significantly increased in the ERP patients. Mitral lateral, septal, tricuspid lateral annular tissue Doppler s' and e' waves were significantly decreased in the ERP patients. There were no significant difference between the groups in terms of interatrial EMD, intra-right atrial EMD, LA total emptying volume and LA total emptying fraction indicating LA reservoir function, LA passive emptying volume and LA passive emptying fraction indicating LA conduit function, LA active emptying volume and LA active emptying fraction indicating LA pump function. Left atrial EMD parameters are affected in individuals with ERP, but LA phasic functions are not affected. Further prospective studies are needed to clarify whether individuals with ERP have an increased susceptibility to AF.

Early Outcome of Simplified Standardized Trileaflet Polytetrafluoroethylene Valved Conduit Placement.

Use of the expanded polytetrafluoroethylene (ePTFE) valved conduit in the pulmonary position during the correction of congenital heart defects has significantly increased in popularity over the last decade due to its promising conduit longevity. We describe the standardized process to create and implant a trileaflet ePTFE pulmonary conduit along with the early outcomes of such procedures at our institute. Records of 100 consecutive patients who underwent ePTFE valved conduit placement using our technique from April 2018 through February 2022 were retrospectively analyzed. The function of the conduit was evaluated by transthoracic echocardiography. The mean age of the patients was 28 ± 13.2 years old at the time of the operation. The conduit diameters ranged from 16 to 24 mm (mean 23.0 ± 1.9 mm). Conduit placement was utilized for pulmonary valve replacement in 68 patients, conduit change in 25 patients, and as a part of total repair in 7 patients. There were 2 in-hospital conduit-unrelated deaths from multi-organ dysfunction and pulmonary hypertensive crisis. From the postoperative echocardiography, the average peak pressure gradient across the conduit was 18.6 ± 9.0 mm Hg, and the conduit regurgitation was graded as none or trace in 81 patients, mild in 17 patients, and moderate in 2 patients. At 589 days of median follow-up, there was no conduit reoperation. Follow-up imaging of 60 available patients at a median time of 511 days did not show a significant change in conduit function. Our standardized ePTFE valved conduit creation and placement demonstrated satisfactory clinical and echocardiographic outcomes.