Bidirectional Association Among the Type of Atrial Fibrillation, Sleep-Disordered Breathing Severity, Heart Failure Progression, and Left Atrial Enlargement, in Patients with Atrial Fibrillation.

This study aimed to clarify (1) the association among the atrial fibrillation (AF) type, sleep-disordered breathing (SDB), heart failure (HF), and left atrial (LA) enlargement, (2) the independent predictors of LA enlargement, and (3) the effects of ablation on those conditions in patients with AF. The study's endpoint was LA enlargement (LA volume index [LAVI] ≥ 78 mL/m2).Of 423 patients with nonvalvular AF, 236 were enrolled. We evaluated the role of the clinical parameters such as the AF type, SDB severity, and HF in LA enlargement. Among them, 141 patients exhibiting a 3% oxygen desaturation index (ODI) of ≥ 10 events/hour underwent polysomnography to evaluate the SDB severity measured by the apnea-hypopnea index (AHI). The LA enlargement and HF were characterized by the LA diameter/LAVI, an increase in the B-type natriuretic peptide level, and a lower left ventricular ejection fraction.This study showed that non-paroxysmal AF (NPAF) rather than paroxysmal AF (PAF), the SDB severity, LA enlargement, and HF progression had bidirectional associations and exacerbated each other, which generated a vicious cycle that contributed to the LA enlargement. NPAF (OR = 4.55, P < 0.001), an AHI of ≥ 25.10 events/hour (OR = 1.55, P = 0.003), and a 3% ODI of ≥ 15.43 events/hour (OR = 1.52, P = 0.003) were independent predictors of an acceleration of the LA enlargement. AF ablation improved the HF and LA enlargement.To break this vicious cycle, AF ablation may be the basis for suppressing the LA enlargement and HF progression subsequently eliminating the substrates for AF and SDB in patients with AF.

Left atrial function in middle-aged men and women with and without paroxysmal atrial fibrillation: Data from the Akershus Cardiac Examination (ACE) 1950 study.

PURPOSE: To assess left atrial (LA) function in individuals with known paroxysmal atrial fibrillation (AF) compared with healthy and nonhealthy individuals without atrial fibrillation. METHODS: The Akershus Cardiac Examination 1950 Study included 3,706 individuals all born in 1950. LA strain assessment of reservoir (LASr), conduit (LAScd) and contractile (LASct) functions were performed in all participants by investigators blinded to clinical data. Participants with cardiovascular disease, obesity, diabetes, pulmonary or renal disease were defined as nonhealthy, and those without as healthy. Patients with paroxysmal AF were identified through medical history and ECG documentation. RESULTS: LA strain assessment was feasible in 3,229 (87%) of the participants (50% women). The healthy group (n = 758) had significantly higher LASr and LAScd than the nonhealthy (n = 2,376), but LASct was similar between the groups. Participants with paroxysmal AF had significantly lower values of all strain parameters than the other groups. Multivariable logistic regression showed a significantly reduced probability of having AF per standard deviation increase in LASr and LASct. A nonlinear restricted cubic spline model fitted better with the association of LASr with paroxysmal AF than the linear model, and LA strain values below the population mean associated with an increased probability of having AF, but for values above the population mean no such association was present. CONCLUSION: Compared to participants without AF, those with known paroxysmal AF had significantly lower values of all LA strain parameters during sinus rhythm. Lower values of LA strain were associated with a significantly increased probability of having AF.

The Impact of Sodium-Glucose Cotransporter-2 Inhibitors on Atrial Electromechanical Conduction Time.

OBJECTIVE: This study aims to explore the impact of sodium-glucose cotransporter-2 (SGLT-2) inhibitors, a newer class of oral antidiabetic drugs, on atrial electromechanical delay (EMD) in patients with type 2 diabetes mellitus (DM). This is particularly relevant given the significantly higher incidence of atrial fibrillation (AF) in diabetic patients compared to the general population. Atrial electromechanical delay is recognized as an important factor influencing the development of atrial fibrillation. METHODS: This study included 30 type 2 DM patients (53.3% female, mean age 60.07 ± 10.03 years), initiating treatment with SGLT-2 inhibitors. The patients were assessed using echocardiography at baseline and again at 6 months, focusing on basic echocardiographic parameters and atrial electromechanical delay times (EMD) measured via tissue Doppler imaging. RESULTS: No significant changes were observed in intra-atrial EMD times. However, significant reductions were noted in interatrial EMD times, decreasing from 15.13 ± 5.87 ms to 13.20 ± 6.12 ms (P = 0.029). Statistically significant shortening occurred in lateral pulmonary acceleration (PA) times (from 58.73 ± 6.41 ms to 54.37 ± 6.97 ms, P < 0.001), septal PA times (from 50.90 ± 6.02 ms to 48.23 ± 5), and tricuspid PA times (from 43.60 ± 6.28 ms to 41.30 ± 5.60 ms, P = 0.003). Additionally, there was a significant reduction in the E/e' ratio from 8.13 ± 4.0 to 6.50 ± 2.37 (P = 0.003). CONCLUSION: SGLT-2 inhibitors might positively influence atrial electromechanical conduction, reducing DM-related functional impairments and the risk of arrhythmias, particularly AF.

Assessing the correlation between the degree of tricuspid regurgitation and pulmonary hypertension: A comprehensive study.

OBJECTIVES: To evaluate the relationship between severity of tricuspid regurgitation (TR) and pulmonary hypertension. METHODS: Cross-sectional study of 118 patients with pulmonary hypertension was carried out at a single center in Jeddah, Saudi Arabia, between 2018-2021. Patients who had pulmonary or tricuspid valves organic diseases, previously undergone tricuspid or pulmonary valve surgeries, had permanent pacemakers or critically ill were excluded. RESULTS: A high proportion of patients were women (n=100, 85%) and obese (n=57, 48%). Patients with more than mild TR had higher systolic pulmonary artery pressure (sPAP) than those with trivial or mild regurgitation (p<0.001). There was a significant association between severity of TR (p<0.001) and right chambers size (p=0.001). Furthermore, pulmonary artery pressure (PAP) was significantly higher in patients with mild right ventricular impairment (p=0.001). CONCLUSION: Increase in degree of TR and right atrial size were predictors of elevated sPAP. Our findings highlight the interplay among TR, right heart size, ventricular function, and PAP. Understanding these associations can aid in risk stratification, monitoring disease progression, and potentially guiding treatment in those patients.

Speckle-Tracking: Incremental Role in Diastolic Assessment of Pediatric Patients with Chronic Kidney Disease. / Strain do Átrio Esquerdo pela Técnica de Speckle-Tracking: Contribuição para a Avaliação da Função Diastólica em Pacientes Pediátricos com Doença Renal Crônica.

BACKGROUND: Cardiovascular complications are the leading cause of mortality in pediatric patients with chronic kidney disease (CKD). Echocardiographic assessment of diastolic function in CKD has been limited to spectral and tissue Doppler imaging, known to be less reliable techniques in pediatrics. Two-dimensional Speckle tracking echocardiography (2DST) derived left atrial (LA) strain has recently been confirmed as a robust measure of diastolic function. OBJECTIVES: To investigate LA strain role in diastolic assessment of children at different stages of CKD. METHODS: From February 2019 to July 2022, 55 CKD patients without cardiovascular symptoms and 55 controls were evaluated by standard and 2DST echocardiograms. The level of significance was set at 5% (p<0.05). RESULTS: Patients and controls had similar age [9.78 (0.89 - 17.54) vs. 10.72 (1.03 -18,44) years; p = 0.41] and gender (36M:19F vs. 34M:21F; p=0.84). There were 25 non-dialysis patients and 30 dialysis patients. Left ventricular ejection fraction was ≥ 55% in all of them. Comparing CKD and controls, LA reservoir strain was lower (48.22±10.62% vs. 58.52±10.70%) and LA stiffness index was higher [0.14 (0.08-0.48)%-1 vs. 0.11 (0.06-0.23) %-1]; p<0.0001. LV hypertrophy was associated with lower LA reservoir strain (42.05±8.74% vs. 52.99±9.52%), higher LA stiffness [0.23(0.11 - 0.48)%-1 vs. 0.13 (0.08-0.23) %-1 and filling indexes (2.39±0.63 cm/s x %-1 vs. 1.74±0.47 cm/s x %-1; p<0.0001. Uncontrolled hypertension was associated with lower LA reservoir strain (41.9±10.6% vs. 50.6±9.7; p=0.005). CONCLUSIONS: LA strain proved to be a feasible tool in the assessment of pediatric CKD patients and was associated with known cardiovascular risk factors.

FUNDAMENTO: As complicações cardiovasculares são a principal causa de morte em pacientes pediátricos com doença renal crônica (DRC). A avaliação ecocardiográfica da função diastólica na DRC tem se limitado à avaliação espectral por Doppler espectral e por Doppler tecidual, técnicas sabidamente menos confiáveis na pediatria. O strain do átrio esquerdo (AE) pela técnica do speckle tracking bidimensional (2DST) foi recentemente confirmada como uma medida robusta da função diastólica. OBJETIVOS: Investigar o papel do strain do AE na avaliação da função diastólica de crianças em diferentes estágios da DRC. MÉTODOS: De fevereiro de 2019 a julho de 2022, 55 pacientes com DRC sem sintomas cardiovasculares e 55 controles foram avaliados por ecocardiografia convencional e por ecocardiografia com 2DST. O nível de significância adotado foi de 5% (p < 0,05). RESULTADOS: Pacientes e controles tinham idade similares [9,78 (0,89 ­ 17,54) vs. 10,72 (1,03 ­18,44) anos; p = 0,41] e sexo (36M:19F vs. 34M:21F; p = 0,84) similares. Havia 25 pacientes não dialíticos e 30 pacientes dialíticos. A fração de ejeção do ventrículo esquerdo foi ≥ 55% em todos. Em comparação aos controles, os pacientes com DRC apresentaram strain de reservatório mais baixo (48,22±10,62% vs. 58,52±10,70%) e índice de rigidez do AE mais alto [0,14 (0,08­0,48)%-1 vs. 0,11 (0,06­0,23) %-1]; p<0,0001. A hipertrofia ventricular esquerda associou-se com um strain de reservatório mais baixo (42,05±8,74% vs. 52,99±9,52%), e valores mais altos de índice de rigidez [0,23 (0,11 ­ 0,48)%-1 vs. 0,13 (0,08­0,23) %-1 e de índice de enchimento do AE (2,39±0,63 cm/s x %-1 vs. 1,74±0,47 cm/s x %-1; p<0,0001). Hipertensão não controlada associou-se com strain de reservatório do AE mais baixo (41,9±10,6% vs. 50,6±9,7; p=0,005). CONCLUSÃO: O strain do AE mostrou-se uma ferramenta útil na avaliação de pacientes pediátricos com DRC e associado com fatores de risco cardiovasculares conhecidos.

Value of 2D speckle tracking technique combined with real-time 3-dimensional echocardiography in the evaluation of the right atrial function in patients with 3-branch coronary artery disease without myocardial infarction.

To evaluate the right atrial function in patients with 3-branch coronary artery disease (TBCAD) without myocardial infarction by 2D speckle tracking echocardiography (2D-STE) combined with real-time 3-dimensional echocardiography (RT-3DE). Fifty-six patients admitted to our hospital without myocardial infarction with TBCAD were selected. We divided them into 2 groups according to the coronary angiography results: 28 patients in group B (the rate of stenosis is 50% ~< 75%); 28 patients in group C (the rate of stenosis is ≥75%); in addition, 30 healthy volunteers were screened as group A. All subjects underwent RT-3DE to obtain the right atrial volume (RAVmax, RAVmin, and RAVp), and then we calculated the right atrial passive and active ejection fraction (RAPEF, RAAEF), and maximum volume index (RAVImax). In addition, to measure the strain rates (RASRs, RASRe, RASRa) of the right atrium during systole, early diastole, and late diastole, 2D-STE was applied. Correlations between the 2D-STE parameters and the results of N-terminal pro-brain natriuretic peptide (NT-proBNP) and Gensini scores were analyzed by Pearson linear analysis. Compared with group A, RAPEF and RASRe were reduced, while RAAEF and RASRa were elevated in group B (P < .05). RAPEF, RASRs, RASRe, and RASRa were decreased compared with groups A and B, while RAVmax, RAVmin, RAVp, RAVImax, and RAAEF were increased in group C (P < .05). There was a significant correlation between 2D-STE parameters and the results of NT-proBNP and Gensini scores (P < .05). The storage, conduit, and pump functions of the right atrium are reduced in patients with 3-branch coronary artery disease without myocardial infarction; 2D-STE combined with RT-3DE is valuable in the evaluation of the right atrium in patients with coronary artery disease.

Coronary microvascular dysfunction and atrial reservoir function.

BACKGROUND: Coronary microvascular dysfunction (CMD) refers to structural and functional abnormalities of the coronary microcirculation, which may be diagnosed using invasive coronary physiology. CMD is responsible for impaired diastolic cardiac function. It has recently been suggested that left atrial strain (LASr) represents a highly sensitive tool for detecting cardiac diastolic function abnormalities. Accordingly, the aim of this study was to investigate the relationship between CMD and LASr. METHODS: Consecutively enrolled patients with non-obstructed coronary arteries (NOCA) underwent CMD and LASr evaluation by invasive thermodilution and noninvasive echocardiography, respectively. RESULTS: Forty-two (42) patients were included, out of which 26 presented with CMD. There were no significant differences between CMD-positive and negative patients in terms of clinical and echocardiographic characteristics. LASr was significantly reduced in patients with CMD (24.6% ± 6.1 vs. 30.3 ± 7.8%, p = 0.01). A moderate correlation was observed between coronary flow reserve and LAsr (r = 0.47, p = 0.002). A multivariate logistic regression analysis demonstrated that CMD was independently associated with LASr (OR = 0.88, 95%CI 0.78-0.99.135, p = 0.04). A LASr cut-off of 25.5% enabled an optimal classification of patients with or without CMD. CONCLUSION: Patients with NOCA and CMD had a significantly reduced LASr compared with patients without CMD, suggesting the early impairment of diastolic function in these patients.

Prognostic value of left atrial strain in aortic stenosis: A systematic review.

PURPOSE: Aortic stenosis (AS) is a common valvular heart disease with high morbidity and mortality. Recently, the association between peak atrial longitudinal strain (PALS) and AS clinical outcomes has been identified. This systematic review evaluates the prognostic value of PALS for adverse events in AS. METHODS: We performed a systematic literature review to identify clinical studies that evaluated Speckle-Tracking Echocardiography (STE)-derived PALS to predict adverse outcomes in patients with AS. We excluded studies that compared echocardiography to computed tomography and studies that focused on diseases other than AS. RESULTS: We included 18 studies reporting on 2660 patients. Patients with symptomatic AS had decreased PALS when compared to patients with asymptomatic AS. Patients with AS who had adverse events had decreased PALS when compared to patients with AS with no events. Each unit increase of PALS was independently associated with decreased risk for the primary endpoint. PALS cut-off values were associated with increased risk for the primary endpoint. CONCLUSION: This systematic review suggests PALS as an independent predictor for cardiovascular events in patients with AS and highlights the importance of evaluating LA mechanics for AS prognosis.

Role of Early Left Atrial Functional Decline in Predicting Cardiotoxicity in HER2 Positive Breast Cancer Patients Treated With Trastuzumab.

Trastuzumab is widely used in HER2 breast cancer. However, it may cause left ventricular (LV) dysfunction. A decrease in LV global longitudinal strain (GLS) has been previously demonstrated to be a good predictor of subsequent cancer therapy related dysfunction (CTRCD). Left atrial morphological remodeling during Trastuzumab therapy has also been shown. The aim of this study is exploring the relationship between early changes in left atrial function and the development of Trastuzumab-induced cardiotoxicity. Consecutive patients with diagnosis of HER2+non-metastatic breast cancer treated with Trastuzumab were prospectively enrolled. A clinical, conventional, and advanced echocardiographic assessment was performed at baseline and every three months, until a one-year follow-up was reached. One-hundred-sixteen patients completed the 12 months follow-up, 10 (9%) cases of CTRCD were observed, all after the sixth month. GLS and LVEF significantly decreased in the CTRCD group at 6 months of follow-up, with an earlier (3 months) significant worsening in left atrial morpho-functional parameters. Systolic blood pressure, early peak atrial longitudinal strain (PALS), peak atrial contraction (PACS) and left atrial volume (LAVI) changes resulted independent predictors of CTRCD at multivariable logistic regression analysis. Moreover, early changes in PALS and PACS resulted good predictors of CTRCD development (AUC 0.85; p = 0.008, p < 0.001 and 0.77; p = 0.008, respectively). This prospective study emphasizes that the decline in PALS and PACS among trastuzumab-treated patients could possibly increase the accuracy in identifying future CTRCD in non-metastatic HER2 breast cancer cases, adding predictive value to conventional echocardiographic assessment.

Conduit Flow Compensates for Impaired Left Atrial Passive and Booster Functions in Advanced Diastolic Dysfunction.

BACKGROUND: Quantification of left atrial (LA) conduit function and its contribution to left ventricular (LV) filling is challenging because it requires simultaneous measurements of both LA and LV volumes. The functional relationship between LA conduit function and the severity of diastolic dysfunction remains controversial. We studied the role of LA conduit function in maintaining LV filling in advanced diastolic dysfunction. METHODS: We performed volumetric and flow analyses of LA function across the spectrum of LV diastolic dysfunction, derived from a set of consecutive patients undergoing multiphasic cardiac computed tomography scanning (n=489). From LA and LV time-volume curves, we calculated 3 volumetric components: (1) early passive emptying volume; (2) late active (booster) volume; and (3) conduit volume. Results were prospectively validated on a group of patients with severe aortic stenosis (n=110). RESULTS: The early passive filling progressively decreased with worsening diastolic function (P<0.001). The atrial booster contribution to stroke volume modestly increases with impaired relaxation (P=0.021) and declines with more advanced diastolic function (P<0.001), thus failing to compensate for the reduction in early filling. The conduit volume increased progressively (P<0.001), accounting for 75% of stroke volume (interquartile range, 63-81%) with a restrictive filling pattern, compensating for the reduction in both early and booster functions. Similar results were obtained in patients with severe aortic stenosis. The pulmonary artery systolic pressure increased in a near-linear fashion when the conduit contribution to stroke volume increased above 60%. Maximal conduit flow rate strongly correlated with mitral E-wave velocity (r=0.71; P<0.0001), indicating that the increase in mitral E wave in diastolic dysfunction represents the increased conduit flow. CONCLUSIONS: An increase in conduit volume contribution to stroke volume represents a compensatory mechanism to maintain LV filling in advanced diastolic dysfunction. The increase in conduit volume despite increasing LV diastolic pressures is accomplished by an increase in pulmonary venous pressure.

Cardioneuroablation for vasovagal syncope: insights on patients' selection, centre settings, procedural workflow and endpoints-results from an European Heart Rhythm Association survey.

AIMS: Cardioneuroablation (CNA) is a catheter-based intervention for recurrent vasovagal syncope (VVS) that consists in the modulation of the parasympathetic cardiac autonomic nervous system. This survey aims to provide a comprehensive overview of current CNA utilization in Europe. METHODS AND RESULTS: A total of 202 participants from 40 different countries replied to the survey. Half of the respondents have performed a CNA during the last 12 months, reflecting that it is considered a treatment option of a subset of patients. Seventy-one per cent of respondents adopt an approach targeting ganglionated plexuses (GPs) systematically in both the right atrium (RA) and left atrium (LA). The second most common strategy (16%) involves LA GP ablation only after no response following RA ablation. The procedural endpoint is frequently an increase in heart rate. Ganglionated plexus localization predominantly relies on an anatomical approach (90%) and electrogram analysis (59%). Less utilized methods include pre-procedural imaging (20%), high-frequency stimulation (17%), and spectral analysis (10%). Post-CNA, anticoagulation or antiplatelet therapy is prescribed, with only 11% of the respondents discharging patients without such medication. Cardioneuroablation is perceived as effective (80% of respondents) and safe (71% estimated <1% rate of procedure-related complications). Half view CNA emerging as a first-line therapy in the near future. CONCLUSION: This survey offers a snapshot of the current implementation of CNA in Europe. The results show high expectations for the future of CNA, but important heterogeneity exists regarding indications, procedural workflow, and endpoints of CNA. Ongoing efforts are essential to standardize procedural protocols and peri-procedural patient management.

Role of Sleep-Disordered Breathing and Epicardial Connections in the Recurrence of Atrial Fibrillation.

The presence of epicardial connections (ECs) between the pulmonary veins (PVs) and atrium may contribute to atrial fibrillation (AF) recurrence. This study aimed to determine the impact of sleep-disordered breathing (SDB) on the presence of ECs and the interplay between SDB and ECs on AF recurrence.We retrospectively reviewed 400 consecutive non-valvular AF patients. Among them, 235 patients exhibiting a 3% oxygen desaturation index (ODI) of ≥ 10 events/hour underwent polysomnography to evaluate the SDB severity, measured by the apnea-hypopnea index (AHI). To facilitate the ablation of AF and ECs, a high-density mapping catheter (HDMC) was employed. AF recurrence was evaluated over a 12-month period post-AF ablation.The key findings included: 1) 63% of AF patients with ECs had SDB with an AHI ≥ 20 events/hour. 2) Despite achieving complete PV isolations and precise EC ablation using an HDMC, SDB presence was associated with an increased AF recurrence. 3) Continuous positive airway pressure therapy for SDB improved AF recurrence among the AF patients with both ECs and SDB (57% versus 73%; P = 0.016). 4) AHI (odds ratio [OR] = 1.91, ≥ 28.4 events/hour) and left atrial volume (LAV) (OR = 1.42, ≥ 128.3 mL) were independent predictors of the presence of ECs, and AHI (OR = 1.44, ≥ 27.8 events/hour) was an independent predictor of the presence of AF recurrence.It is essential for physicians to recognise the potential complexity of ECs and SDB in AF patients. Thus, screening and treating SDB in AF patients presenting with ECs might play a pivotal role in suppressing AF recurrence.

Incidence, Risk Factors, and Outcomes of Left Atrial Enlargement in Patients Requiring Right Ventricular Pacing: A Retrospective Study of 461 Cases from 2012 to 2020.

BACKGROUND Long-term right ventricular (RV) pacing has been linked to left atrial enlargement (LAE). The incidence and risk factors associated with significant LAE after RV pacing remain unknown. This retrospective study included 461 patients requiring RV pacing at 2 centers between 2012 and 2020 and aimed to evaluate the incidence, risk factors, outcomes, and complications of LAE. MATERIAL AND METHODS A total of 461 patients with normal-sized pre-implant left atrial dimension and dual-chamber pacing pacemaker implantation for complete atrioventricular block were enrolled. Patients were grouped based on a ≥20% increase from their baseline left atrial dimension by echocardiography, indicating significant LAE, and initial characteristics, echocardiographic data, and outcomes were compared. RESULTS During a mean 7.0±4.9 years follow-up period, 96 patients (20.8%) developed significant LAE, whereas 365 patients did not. In multivariate logistic regression analysis, smaller pre-implant left atrial dimension (OR, 0.776; 95% CI, 0.728-0.828; P<0.001), lower post-implant left ventricular ejection fraction (OR, 0.976; 95% CI, 0.957-0.995; P=0.014), post-implant development of moderate to severe mitral regurgitation (OR, 2.357; 95% CI, 1.172-4.740; P=0.016), and RV pacing duration ≥3.3 years (OR, 1.576; 95% CI, 1.039-2.646; P=0.045) were independent predictors of significant LAE after RV-dependent pacing. There was a significant difference in the incident stroke events between patients without and with significant LAE (9.9% vs 17.7%; log-rank P=0.047). CONCLUSIONS Long-term RV pacing was linked to significant LAE in 20.8% of patients with complete atrioventricular block, with those affected experiencing a higher stroke rate during follow-up.

The Clinical Applications of Left Atrial Strain: A Comprehensive Review.

Left atrial (LA) strain imaging, which measures the deformation of the LA using speckle-tracing echocardiography (STE), has emerged recently as an exciting tool to help provide diagnostic and prognostic information for patients with a broad range of cardiovascular (CV) pathologies. Perhaps due to the LA's relatively thin-walled architecture compared with the more muscular structure of the left ventricle (LV), functional changes in the left atrium often precede changes in the LV, making LA strain (LAS) an earlier marker for underlying pathology than many conventional echocardiographic parameters. LAS imaging is typically divided into three phases according to the stage of the cardiac cycle: reservoir strain, which is characterized by LA filling during systole; conduit strain, which describes LA deformation during passive LV filling; and booster strain, which provides information on the LA atrium during LA systole in late ventricular diastole. While additional large-population studies are still needed to further solidify the role of LAS in routine clinical practice, this review will discuss the current evidence of its use in different pathologies and explore the possibilities of its applications in the future.

Application value of real-time 3D speckle tracking imaging in left atrial function evaluation of patients with paroxysmal atrial fibrillation.

OBJECTIVE: To evaluate left atrial volume and function in patients with paroxysmal atrial fibrillation (AF) combined with left atrial appendage thrombosis and patients with paroxysmal AF without left atrial appendage thrombosis by 3-dimensional speckle tracking imaging (3D-STI), and to explore the application value of this set of parameters in the evaluation of left atrial function in patients with paroxysmal AF. MATERIALS AND METHODS: A total of 40 patients with paroxysmal AF admitted from December 2018 to December 2020 were selected as the observation group. All patients with paroxysmal AF in the observation group underwent transesophageal echocardiography. According to the presence of left atrial appendage thrombosis, the patients were divided into the AF without thrombosis group (24 cases) and the AF with thrombosis group (16 cases). Thirty normal people were selected as control group who were chosen as having no heart-related disease. The left atrial volume parameters (Left atrial maximum volume LAVmax, Left atrial minimum volume LAVmin, Left atrial volume before atrial contraction LAVpre-A, Left atrial stroke volume LAEV), left atrial ejection fraction (LAEF) and left atrial strain parameters (Left atrial reservoir longitudinal strain LASr, Left atrial conduit longitudinal strain LAScd, Left atrial contraction longitudinal strain LASct, Left atrial reservoir circumferential strain LASr-c, Left atrial conduit circumferential strain LAScd-c, Left atrial contraction circumferential strain LASct-c) of the 3 groups were measured by 3D-STI. RESULTS: With the progression of paroxysmal AF, the left atrial volume increased, and the reservoir, conduit and contractile function were damaged. The left atrial volume continued to increase, and the reservoir, conduit and contractile function further decreased significantly in patients with AF combined with left atrial appendage thrombosis. LAEF was positively correlated with LASr and LASr_c. CONCLUSION: Real-time 3-dimensional spot tracking imaging (3D-STI) can evaluate the changes in left atrial volume and function in patients with paroxysmal AF, and has a certain reference value for clinical judgment of disease progression and prognosis.

Automatic 3D left atrial strain extraction framework on cardiac computed tomography.

BACKGROUND AND OBJECTIVE: Strain analysis provides insights into myocardial function and cardiac condition evaluation. However, the anatomical characteristics of left atrium (LA) inherently limit LA strain analysis when using echocardiography. Cardiac computed tomography (CT) with its superior spatial resolution, has become critical for in-depth evaluation of LA function. Recent studies have explored the feasibility of CT-derived strain; however, they relied on manually selected regions of interest (ROIs) and mainly focused on left ventricle (LV). This study aimed to propose a first-of-its-kind fully automatic deep learning (DL)-based framework for three-dimensional (3D) LA strain extraction on cardiac CT. METHODS: A total of 111 patients undergoing ECG-gated contrast-enhanced CT for evaluating subclinical atrial fibrillation (AF) were enrolled in this study. We developed a 3D strain extraction framework on cardiac CT images, containing a 2.5D GN-U-Net network for LA segmentation, axis-oriented 3D view extraction, and LA strain measure. The segmentation accuracy was evaluated using Dice similarity coefficient (DSC). The model-extracted LA volumes and emptying fraction (EF) were compared with ground-truth measurements using intraclass correlation coefficient (ICC), correlation coefficient (r), and Bland-Altman plot (B-A). The automatically extracted LA strains were evaluated against the LA strains measured from 2D echocardiograms. We utilized this framework to gauge the effect of AF burden on LA strain, employing the atrial high rate episode (AHRE) burden as the measurement parameter. RESULTS: The GN-U-Net LA segmentation network achieved a DSC score of 0.9603 on the test set. The framework-extracted LA estimates demonstrated excellent ICCs of 0.949 (95 % CI: 0.93-0.97) for minimal LA volume, 0.904 (95 % CI: 0.86-0.93) for maximal LA volume, and 0.902 (95 % CI: 0.86-0.93) for EF, compared with expert measurements. The framework-extracted LA strains demonstrated moderate agreement with the LA strains based on 2D echocardiography (ICCs >0.703). Patients with AHRE > 6 min had significantly lower global strain and LAEF, as extracted by the framework than those with AHRE ≤ 6 min. CONCLUSION: The promising results highlighted the feasibility and clinical usefulness of automatically extracting 3D LA strain from CT images using a DL-based framework. This tool could provide a 3D-based alternative to echocardiography for assessing LA function.

Diastolic Filling in Patients After Heart Transplantation Is Impaired Due to an Altered Geometrical Relationship Between the Left Atrium and Ventricle.

BACKGROUND: The geometrical relationship between atrial and ventricular short-axis cross-sectional area determines the hydraulic forces acting on intracardiac blood. This is important for diastolic filling. In patients undergoing heart transplantation (HTx), the left atrium is often enlarged as a result of the standard surgical technique. We hypothesized that diastolic filling in HTx patients is affected by the surgery altering the geometrical relationship between atrium and ventricle. METHODS AND RESULTS: This retrospective, cross-sectional study included 25 HTx patients (median age, 52 [range, 25-70] years), 15 patients with heart failure with reduced ejection fraction (median age, 63 [range, 52-75] years), 15 patients with heart failure with preserved ejection fraction (median age, 74 [range, 56-82] years), and 15 healthy controls (median age, 64 [range, 58-67] years) who underwent cardiac magnetic resonance imaging. Left ventricular, atrial, and total heart volumes (THV) were obtained. Atrioventricular area difference at end diastole and end systole was calculated as the largest ventricular short-axis area minus the largest atrial short-axis area. Left atrial minimum volume normalized for THV (LAmin/THV) was larger in HTx patients (median, 0.13 [range, 0.07-0.19]) compared with controls (median, 0.05 [range, 0.03-0.08], P <0.001), whereas left ventricular volume normalized for THV (left ventricular end-diastolic volume/THV) was similar between HTx and controls (median, 0.19 [range, 0.12-0.24] and median, 0.22 [range, 0.20-0.25], respectively). At end diastole, when atrioventricular area difference reached its largest positive value in controls, 11 HTx patients (44%) had a negative atrioventricular area difference, indicating impaired diastolic filling. CONCLUSIONS: Diastolic filling is impaired in HTx patients due to an altered geometrical relationship between the left atrium and ventricle. When performing cardiac transplantation, a surgical technique that creates a smaller left atrium may improve diastolic filling by aiding hydraulic forces.