Mechanical concordance between left atrium and left atrial appendage in nonvalvular atrial fibrillation: can it be exploited to avoid transesophageal echocardiography prior to electrical cardioversion during Covid-19 pandemic?

Modified Haller Index is inversely associated with asymptomatic status in atrial fibrillation patients undergoing electrical cardioversion: a preliminary observation

BACKGROUND

No previous study evaluated the possible influence of chest wall conformation on symptoms perception in atrial fibrillation (AF) patients candidates for electrical cardioversion (ECV). We aimed at evaluating the anthropometric and clinical characteristics of patients with persistent AF undergoing ECV, categorized according to the presence or absence of symptoms.

METHODS

This study retrospectively analyzed a series of persistent AF patients scheduled for early ECV who underwent pre-procedural clinical evaluation, MHI (the ratio of chest transverse diameter over the distance between sternum and spine) assessment, transthoracic and transesophageal echocardiography implemented with strain analysis of both left atrium and left atrial appendage. Thromboembolic risk and burden of comorbidities were assessed by CHA2DS2-VASc Score and Charlson Comorbidity Index (CCI), respectively. The independent predictors of "asymptomatic AF" were assessed.

RESULTS

A total of 25 asymptomatic and 90 symptomatic AF patients were retrospectively examined. Compared to symptomatic AF patients, those asymptomatic were significantly older (78.4±3.8 vs. 71.0±7.7 years, P<0.001), predominantly males (84 vs. 44.4%, P<0.001), with significantly lower MHI (2.0±0.1 vs. 2.4±0.1, P<0.001), higher CHA2DS2-VASc Score (5.8±1.1 vs. 3.6±1.1, P<0.001) and CCI (6.8±1.4 vs. 2.3±0.9, P<0.001), and greater impairment in biventricular systolic function and atrio-auricolar myocardial strain indices. On multivariate logistic regression analysis, CHA2DS2-VASc Score (OR=2.65, 95% CI: 1.53-4.60) and CCI (OR=2.36, 95% CI: 1.16-4.66) were linearly associated with the endpoint "asymptomatic AF," whereas MHI (OR 0.76, 95% CI 0.59-0.97) was inversely associated with the asymptomatic status. A MHI <2.2 was the best cut-off for detecting asymptomatic AF patients.

CONCLUSIONS

MHI is inversely associated with asymptomatic status in persistent AF patients undergoing ECV. MHI assessment might represent an innovative practical approach to AF patients.

Advances in TEE-Centric Intraprocedural Multimodal Image Guidance for Congenital and Structural Heart Disease

Percutaneous interventions are gaining rapid acceptance in cardiology and revolutionizing the treatment of structural heart disease (SHD). As new percutaneous procedures of SHD are being developed, their associated complexity and anatomical variability demand a high-resolution special understanding for intraprocedural image guidance. During the last decade, three-dimensional (3D) transesophageal echocardiography (TEE) has become one of the most accessed imaging methods for structural interventions. Although 3D-TEE can assess cardiac structures and functions in real-time, its limitations (e.g., limited field of view, image quality at a large depth, etc.) must be addressed for its universal adaptation, as well as to improve the quality of its imaging and interventions. This review aims to present the role of TEE in the intraprocedural guidance of percutaneous structural interventions. We also focus on the current and future developments required in a multimodal image integration process when using TEE to enhance the management of congenital and SHD treatments.

The value of left atrial longitudinal strain in evaluating left atrial appendage spontaneous echo contrast in non-valvular atrial fibrillation

Background

Spontaneous echo contrast (SEC) observed in transesophageal echocardiography (TEE) is a reliable predictor of the risk of future ischemic stroke in patients with non-valvular atrial fibrillation (NVAF). Left atrial strain globally reflects atrial function, remodeling and distensibility. The left atrial appendage (LAA) is a myogenic remnant of the left atrium, which can actively relax and contract. The left atrial appendage (LAA) is an important part of releasing the pressure of the left atrium. The key role of the left atrium is to regulate the left ventricular filling pressure, act as a reservoir for pulmonary venous return during ventricular contraction, and act as a conduit, transferring blood to the Left ventricle during early ventricular diastole. The purpose of this study was to explore the relationship between left atrial function and left atrial appendage spontaneous echo contrast (LAASEC).

Methods

A retrospective study of 338 patients with non-valvular AF was conducted. Two-dimensional speckle-tracking echocardiography provided the following metrics of LA strain: LA strain during the reservoir phase (LASr), LA strain during the conduit phase (LAScd). LA or LAA has the dense SEC of more than grade 3, which is defined as mud like change or pre thrombosis.

Results

Patients with level 3 SEC (n = 81) has lower LASr than those with lower grades of SEC (n = 257) (7.20 ± 3.70 vs. 17.48 ± 8.67, P < 0.001). Multivariate logistic regression model showed that the type of atrial fibrillation (persistent∼), increased heart rate, decreased LASr were independently associated with the dense LAASEC (OR (CI 95%), 5.558 (1.618-19.09), 1.016 (1.006-1.026) 0.002, 1.224 (1.085-1.381), both P < 0.01). Venn Diagram showed that lower CHADVASC2 score groups had dense SEC cases. Receiver operating characteristic (ROC) curve was used for analyzing results and selecting cut off values. The cut off point for LASr < 8.85% and CHADVASC2 score was >2 scores with sensitivity and specificity were 79% and 85%.

Conclusion

Lower LASr is independently associated with the dense LAASEC in NVAF and has incremental values superior to clinical scores. The decrease of LASr may be a potential non-invasive parameter for evaluating the higher risk of LAA thrombosis.

Association of Left Atrial Deformation Analysis by Speckle Tracking Echocardiography With Left Atrial Appendage Thrombus in Patients With Primary Valvular Heart Disease

BACKGROUND

This study aimed to investigate the correlation between the functional parameters of the left atrium (LA) derived from deformation imaging, two-dimensional (2D) speckle tracking echocardiography (STE), and tissue Doppler imaging (TDI) strain and strain rate (SR) and the function of the left atrial appendage (LAA) as measured by transesophageal echocardiography (TEE) in patients with primary valvular heart disease.

METHODS

This cross-sectional research included 200 primary valvular heart disease cases, categorized into Group I (n = 74) with thrombus and Group II (n = 126) without thrombus. All patients were subjected to standard 12 lead electrocardiography, transthoracic echocardiography (TTE), strain and SR imaging of the LA by TDI and 2D speckle tracking, and TEE.

RESULTS

At a cut-off value of <10.50%, peak atrial longitudinal strain (PALS) is a predictor of thrombus with an area under the curve (AUC) of 0.975 (95% CI: 0.957-0.993), sensitivity of 94.6%, specificity of 93.7%, positive predictive value (PPV) of 89.7%, negative predictive value (NPV) of 96.7%, and accuracy of 94%. At a cut-off value of <0.295 m/s, LAA emptying velocity is a predictor of thrombus with an AUC of 0.967 (95% CI: 0.944-0.989), sensitivity of 94.6%, specificity of 90.5%, PPV of 85.4%, NPV of 96.6%, and accuracy of 92%. The PALS (<10.50%) and LAA velocity (<0.295 m/s) are significant predictors of thrombus (P = 0.001, β = 2.745, SE = 0.804, OR = 15.56, and 95% CI: 3.219-75.245; and P = 0.002, β = 2.499, SE = 0.799, OR = 12.17, and 95% CI: 2.543-58.201, respectively). Peak systolic strain < 12.55% and SR < 1.065/s are insignificant predictors of thrombus (β = 1.167, SE = 0.996, OR = 3.21, and 95% CI: 0.456-22.631; and β = 1.443, SE = 0.929, OR = 4.23, and 95% CI: 0.685-26.141, respectively).

CONCLUSIONS

Among LA deformation parameters derived from TTE, PALS is the best predictor of reduced LAA emptying velocity and LAA thrombus in primary valvular heart disease, regardless of the rhythm.

Molecular Approaches and Echocardiographic Deformation Imaging in Detecting Myocardial Fibrosis

The pathological remodeling of myocardial tissue is the main cause of heart diseases. Several processes are involved in the onset of heart failure, and the comprehension of the mechanisms underlying the pathological phenotype deserves special attention to find novel procedures to identify the site of injury and develop novel strategies, as well as molecular druggable pathways, to counteract the high degree of morbidity associated with it. Myocardial fibrosis (MF) is recognized as a critical trigger for disruption of heart functionality due to the excessive accumulation of extracellular matrix proteins, in response to an injury. Its diagnosis remains focalized on invasive techniques, such as endomyocardial biopsy (EMB), or may be noninvasively detected by cardiac magnetic resonance imaging (CMRI). The detection of MF by non-canonical markers remains a challenge in clinical practice. During the last two decades, two-dimensional (2D) speckle tracking echocardiography (STE) has emerged as a new non-invasive imaging modality, able to detect myocardial tissue abnormalities without specifying the causes of the underlying histopathological changes. In this review, we highlighted the clinical utility of 2D-STE deformation imaging for tissue characterization, and its main technical limitations and criticisms. Moreover, we focalized on the importance of coupling 2D-STE examination with the molecular approaches in the clinical decision-making processes, in particular when the 2D-STE does not reflect myocardial dysfunction directly. We also attempted to examine the roles of epigenetic markers of MF and hypothesized microRNA-based mechanisms aiming to understand how they match with the clinical utility of echocardiographic deformation imaging for tissue characterization and MF assessment.