Left atrial deformation imaging and atrial fibrillation in patients with rheumatic mitral stenosis

Incremental diagnostic and prognostic utility of left atrial deformation in heart failure using speckle tracking echocardiography

Left atrium (LA) is a very important component of cardiovascular performance. The assessment of LA function has gathered the interest with expanding research supporting the utility as a biomarker for outcomes in heart failure (HF). Echocardiography is the main imaging modality which helps in a qualitative and quantitative assessment of the LA size and function. Recent advances in probe technology and software analysis have provided a better understanding of LA anatomy, physiology, pathology, and function. A variety of parameters have been defined as markers of LA function but there is no single parameter that best defines LA function. Speckle tracking echocardiography-derived analysis of LA deformation provides a window on all phases of LA function (reservoir, conduit, and booster pump). There is accumulative published data that supported the diagnostic and prognostic values of LA deformation integration during echo assessment of LA in HF. This review article summarized the clinical utility of LA deformation that may help in prediction, diagnosis, categorization, risk stratification, and guiding the proper selection of therapy in HF patients in daily practice.

Potential Diagnostic and Prognostic Values of Left Atrial Strain in Valvular Heart Disease

There has been increasing evidence supporting the importance of left atrial (LA) functional analysis and measurement in various physiologic and pathologic cardiovascular conditions due to its high diagnostic and prognostic values. Assessment of LA strain (LAS) has emerged as an early marker of subclinical LA dysfunction. Using speckle-tracking echocardiography, LAS can be measured in all phases of LA function (reservoir, conduit, and booster pump). In valvular heart disease (VHD), surgical and nonsurgical interventions should be performed before irreversible left ventricular (LV) and/or LA myocardial dysfunction. The current guidelines recommended using LV strain as a parameter for early detection and timely intervention. Currently, many published data have shown the diagnostic and prognostic values of LAS in VHD, which is encouraging to integrate LAS during echo assessment. In this review, we aim to collect the current data about the clinical utility of LAS changes in risk stratification, predicting outcome, and guiding the time of intervention in VHD. The review summarized these data according to the type of valve pathologies.

Myocardial strain of the left ventricle by speckle tracking echocardiography: From physics to clinical practice

Speckle tracking echocardiography (STE) is a reliable imaging technique of recognized clinical value in several settings. This method uses the motion of ultrasound backscatter speckles within echocardiographic images to derive myocardial velocities and deformation parameters, providing crucial insights on several cardiac pathological and physiological processes. Its feasibility, reproducibility, and accuracy have been widely demonstrated, being myocardial strain of the various chambers inserted in diagnostic algorithms and guidelines for various pathologies. The most important parameters are Global longitudinal strain (GLS), Left atrium (LA) reservoir strain, and Global Work Index (GWI): based on large studies the average of the lower limit of normality are -16%, 23%, and 1442 mmHg%, respectively. For GWI, it should be pointed out that myocardial work relies primarily on non-invasive measurements of blood pressure and segmental strain, both of which exhibit high variability, and thus, this variability constitutes a significant limitation of this parameter. In this review, we describe the principal aspects of the theory behind the use of myocardial strain, from cardiac mechanics to image acquisition techniques, outlining its limitation, and its principal clinical applications: in particular, GLS have a role in determine subclinical myocardial dysfunction (in cardiomyopathies, cardiotoxicity, target organ damage in ambulatory patients with arterial hypertension) and LA strain in determine the risk of AF, specifically in ambulatory patients with arterial hypertension.

Left atrial phasic function: physiology, clinical assessment and prognostic value

Left atrial (LA) phasic function provides significant insights into the pathophysiology of cardiovascular disease. LA function is described in three phases: reservoir (atrial filling, during systole), conduit (passive emptying, during early diastole) and contractile (active emptying, during late diastole). LA phasic function can be evaluated by different imaging modalities, and a variety of techniques including volumetric analysis, deformation (strain) and Doppler methods. LA phasic function (particularly LA reservoir strain) is more sensitive and provides earlier detection of LA dysfunction than alterations in LA volume. LA function parameters have also demonstrated significant diagnostic and prognostic value, particularly in heart failure, atrial fibrillation and stroke. However, there remain barriers to implementation of phasic function parameters in clinical practice and guidelines. This review outlines the physiology of LA phasic function, methods of assessment, and its diagnostic and prognostic utility in varying pathologies.

Atrial Cardiomyopathy in Valvular Heart Disease: From Molecular Biology to Clinical Perspectives

This review discusses the evolving topic of atrial cardiomyopathy concerning valvular heart disease. The pathogenesis of atrial cardiomyopathy involves multiple factors, such as valvular disease leading to atrial structural and functional remodeling due to pressure and volume overload. Atrial enlargement and dysfunction can trigger atrial tachyarrhythmia. The complex interaction between valvular disease and atrial cardiomyopathy creates a vicious cycle of aggravating atrial enlargement, dysfunction, and valvular disease severity. Furthermore, atrial remodeling and arrhythmia can predispose to atrial thrombus formation and stroke. The underlying pathomechanism of atrial myopathy involves molecular, cellular, and subcellular alterations resulting in chronic inflammation, atrial fibrosis, and electrophysiological changes. Atrial dysfunction has emerged as an essential determinant of outcomes in valvular disease and heart failure. Despite its predictive value, the detection of atrial fibrosis and dysfunction is challenging and is not included in the clinical routine. Transthoracic echocardiography and cardiac magnetic resonance imaging are the main diagnostic tools for atrial cardiomyopathy. Recently published data have revealed that both left atrial volumes and functional parameters are independent predictors of cardiovascular events in valvular disease. The integration of atrial function assessment in clinical practice might help in early cardiovascular risk estimation, promoting early therapeutic intervention in valvular disease.

Stacked machine learning models to classify atrial disorders based on clinical ECG features: a method to predict early atrial fibrillation

OBJECTIVES

Atrial Tachycardia (AT) and Left Atrial Enlargement (LAE) are atrial diseases that are significant precursors to Atrial Fibrillation (AF). There are ML models for ECG classification; clinical features-based classification is required. The suggested work aims to create stacked ML models that categorize Sinus Rhythm (SR), Sinus Tachycardia (ST), AT, and LAE signals based on clinical parameters for AF prognosis.

METHODS

The classification was based on thirteen clinical parameters, such as amplitude, time domain ECG aspects, and P-Wave Indices (PWI), such as the ratio of P-wave length and amplitude ((P (ms)/P (µV)), P-wave area (µV*ms), and P-wave terminal force (PTFV1(µV*ms). Apart from classifying the ECG signals, the stacked ML models prioritized the clinical features using a pie formula-based technique.

RESULTS

The Stack 1 model achieves 99% accuracy, sensitivity, precision, and F1 score, while the Stack 2 model achieves 91%, 91%, 94%, and 92% for identifying SR, ST, LAE, and AT, respectively. Both stack models obtained a computational time of 0.06 seconds. PTFV1 (µV*ms), P (ms)/P (µV)), and P-wave area (µV*ms) were ranked as crucial clinical features.

CONCLUSION

Clinical feature-based stacking ML models may help doctors obtain insight into important clinical ECG aspects for early AF prediction.

Surgical Reconstruction of Mitral Restenosis Complicated by a Critically Small Left Ventricular Cavity and Giant Left and Right Atriomegaly (Clinical Case)

Background. Comprehensive reconstruction of the left and right parts of the heart in giant left atriomegaly, adequate tactics of mitral valve replacement in case of concomitant tricuspid insufficiency and dilation of the right atrium lead to an improvement in the functional state of the myocardium as early as at the hospital stage. Case description. Patient B., a 67-year-old woman, was examined and treated from July 12 to August 2, 2016 at the Department of Surgical Treatment of Acquired Heart Diseases of the National Amosov Institute of Cardiovascular Surgery of the National Academy of Medical Sciences of Ukraine with a diagnosis: stage IV mitral restenosis, condition after closed mitral commissurotomy in 2001, critically small cavity of the left ventricle, giant left atriomegaly, IV degree tricuspid insufficiency, right atriomegaly, high pulmonary hypertension, permanent form of atrial fibrillation for 15 years since 2001, NYHA class IV heart failure, IIB. The patient underwent surgical intervention: mitral valve replacement + W-shaped plastic surgery of the left atrium in combination with dosed resection of left atrium + tricuspid valve plasty with the imposition of a support ring + resection of the right atrium. Conclusion. Given the initial serious condition of the patient with advanced mitral restenosis, critically small left ventricular cavity, giant left atriomegaly of 169.4 × 115.8 mm (according to computed tomography) and high pulmonary hypertension (65 mm Hg), concomitant pathology of the right parts of the heart (tricuspid insufficiency and right atriomegaly), adequate tactics in mitral valve replacement and radical correction of the left atriomegaly lead to an improvement in the functional state of the heart as early as at the hospital stage.

Left Atrial Remodeling after Mitral Valve Repair for Primary Mitral Regurgitation: Evolution over Time and Prognostic Significance

Left atrial (LA) dilatation is associated with worse outcomes in primary mitral regurgitation (MR). However, the effects of mitral valve repair on LA size and its prognostic implications are not well known. In the current study, LA volume index (LAVi) and LA reservoir strain (LASr) were evaluated immediately before and after surgery, and during long-term follow-up in 226 patients undergoing mitral valve repair for primary MR (age 62 ± 13 years, 66% male). Mean LAVi was reduced significantly after surgery and at long-term follow-up (from 56 ± 28 to 38 ± 21 to 32 ± 17 mL/m2; p < 0.001). LASr reduced significantly after surgery but increased again during the long-term (from 23.6 ± 9.4 to 11.5 ± 5.0 to 17.3 ± 7.5%; p < 0.001). Age, pre-operative LAVi, MR severity, and postoperative transmitral pressure gradient were associated with LA reverse remodeling by the long-term check-up. During a median follow-up of 72 (40−114) months, 43 (19%) patients died. Patients with LAVi ≥ 42 mL/m2 at long-term follow-up showed significant higher mortality rates compared to patients with LAVI < 42 mL/m2 (p < 0.001), even after adjusting for clinical covariates. In conclusion, significant LA reverse remodeling was observed both immediately and at long-term follow-up after mitral valve repair. LA dilatation at long term follow-up after surgery was still associated with all-cause mortality.