Analysis of The Left Atrial Function Using Two-Dimensional Strain in Patients with Recent Diagnosis of Hereditary Hemochromatosis

Echocardiographic evaluation of left atrial strain for predicting iron overload in pediatric patients with β-thalassemia with preserved ejection fraction

Pediatric patients with β-thalassemia (β-TM) with preserved ejection fraction may experience early myocardial damage. This prospective study aimed to investigate left atrial (LA) function restructure in pediatric patients with β-TM by two-dimensional speckle tracking echocardiography (2D-STE) and evaluate the value of LA strain for predicting myocardial iron overload (MIO). We recruited 50 β-TM pediatric patients and 30 healthy children aged 3-14 years. The patients were assigned to a normal left ventricular (LV) lesion group (n = 20) and an enlarged LV lesion group (n = 30). Subjects all underwent echocardiography to measure conventional cardiac function parameters and LA strain parameters. The results displayed that LA reservoir strain (LASr), conduit strain (LAScd), contractile strain (LASct) and strain rate were significantly reduced in pediatric patients with β-TM with preserved ejection fraction. LASr, LAScd, and LASct were negatively correlated with the E/e' ratio, of which LASr had the most significant correlation (r = - 0.69, P < 0.001). LASr and LASct correlated positively with T2* (r = 0.70 and 0.62, respectively, all P < 0.001). In the multiple regression, LASr and LASct were independent predictors for T2*. The areas under the curve for LASr and LASct were 0.87 (P < 0.001) and 0.78 (P = 0.004), respectively. Our results demonstrated that LA strains were dramatically impaired in pediatric patients with β-TM, and LASr is an efficient indicator for detecting LV early diastolic dysfunction in β-TM pediatric patients and reflects early myocardial damage. LASr and LASct were independently predictive of MIO, but LASr was a more sensitive predictor.

Assessment of Left Atrial Structure and Function by Echocardiography in Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia with significant morbidity and mortality. Exacerbated by the aging population, the prevalence of AF is gradually increasing. Accurate evaluation of structure and function of left atrium (LA) has important prognostic significance in patients with AF. Echocardiography is the imaging technique of first choice to assess LA structure and function due to its better availability, accessibility and safety over cardiac computed tomography and cardiac magnetic resonance. Therefore, the aim of this review is to summarize the recent research progress of evaluating LA size by three-dimensional echocardiography and LA function by speckle tracking echocardiography (STE) in predicting the occurrence and recurrence of AF and determining the risk of stroke in AF. In addition, we summarized the role of traditional echocardiography in detecting AF patients that are at high risk of heart failure or cardiovascular death.

Regional Diversities in Fibrogenesis Weighed as a Key Determinant for Atrial Arrhythmogenesis

Atrial fibrosis plays a key role in atrial myopathy, resulting in the genesis of atrial fibrillation (AF). The abnormal distribution of fibrotic tissue, electrical coupling, paracrine interactions, and biomechanical–electrical interactions have all been suggested as causes of fibrosis-related arrhythmogenesis. Moreover, the regional difference in fibrogenesis, specifically the left atrium (LA) exhibiting a higher arrhythmogenesis and level of fibrosis than the right atrium (RA) in AF, is a key contributor to atrial arrhythmogenesis. LA fibroblasts have greater profibrotic cellular activities than RA fibroblasts, but knowledge about the regional diversity of atrial regional fibrogenesis remains limited. This article provides a comprehensive review of research findings on the association between fibrogenesis and arrhythmogenesis from laboratory to clinical evidence and updates the current understanding of the potential mechanism underlying the difference in fibrogenesis between the LA and RA.