Impairment of left atrial function in pediatric patients with repaired tetralogy of Fallot: a cardiovascular magnetic resonance imaging study

Longitudinal Evaluation of Atrial Function in Patients with Tetralogy of Fallot

Atrial function provides insight into ventricular diastolic function. Invasive assessment of left ventricular (LV) diastolic function correlates with development of sustained ventricular tachyarrhythmias in patients with repaired tetralogy of Fallot (rTOF). Non-invasive assessment of atrial function may prove key towards assessment of diastolic function. We longitudinally evaluated the progression of biatrial function in patients with rTOF, regardless of pulmonary valve replacement (PVR). Patients with rTOF who had multiple CMR were identified. CMR examinations were retrospectively reviewed. Left (LA) and right (RA) atrial size and function were measured in the two and four-chamber views and assessed over time and after PVR. Left and right atrial reservoir, conduit, pump strain and strain rates were determined using tissue tracking. Thirty-six patients with rTOF were identified (64% male), ten (28%) had PVR during the study. Median age of PVR was 16.5 years. No improvement in RA or LA function was observed after PVR. A decline in RA reservoir strain rate (p < 0.05) and RA pump strain (p < 0.05) were observed despite improvements in right ventricular systolic function (p < 0.05). In patients who had multiple CMR without PVR, RA reservoir strain rate (p < 0.05) and pump strain rate (p < 0.05) worsened over time. LA pump strain decreased over time in all patients. There is progressive decline of several RA functional parameters over time. No significant improvement in LA or RA function after PVR was observed. Additional studies are needed to understand how these changes may relate to poor outcomes and potentially better guide timing of PVR.

Atrioventricular Area Difference Aids Diastolic Filling in Patients with Repaired Tetralogy of Fallot

A hydraulic force aids diastolic filling of the left ventricle (LV) and is proportional to the difference in short-axis area between the left ventricle and atrium; the atrioventricular area difference (AVAD). Patients with repaired Tetralogy of Fallot (rToF) and pulmonary regurgitation (PR) have reduced LV filling which could lead to a negative AVAD and a hydraulic force impeding diastolic filling. The aim was to assess AVAD and to determine whether the hydraulic force aids or impedes diastolic filling in patients with rToF and PR, compared to controls. Twelve children with rToF (11.5 [9-13] years), 12 pediatric controls (10.5 [9-13] years), 12 adults with rToF (21.5 [19-27] years) and 12 adult controls (24 [21-29] years) were retrospectively included. Cine short-axis images were acquired using cardiac magnetic resonance imaging. Atrioventricular area difference was calculated as the largest left ventricular short-axis area minus the largest left atrial short-axis area at beginning of diastole and end diastole and indexed to height (AVADi). Children and adults with rToF and PR had higher AVADi (0.3 cm2/m [- 1.3 to 0.8] and - 0.6 [- 1.5 to - 0.2]) at beginning of diastole compared to controls (- 2.7 cm2/m [- 4.9 to - 1.7], p = 0.015) and - 3.3 cm2/m [- 3.8 to - 2.8], p = 0.017). At end diastole AVADi did not differ between patients and controls. Children and adults with rToF and pulmonary regurgitation have an atrioventricular area difference that do not differ from controls and thus a net hydraulic force that contributes to left ventricular diastolic filling, despite a small underfilled left ventricle due to pulmonary regurgitation.

Application of left atrial strain derived from cardiac magnetic resonance feature tracking to predict cardiovascular disease: A comprehensive review

The structural and functional changes of the left atrium (LA)are important for maintaining the filling of the left ventricle (LV), whether the hemodynamics is stable or not, and are valuable for evaluating LV diastolic dysfunction and grading the severity. Studies over the past decade have shown that LA structural alterations are linked to several cardiovascular disorders, and LA enlargement has been identified as a strong predictor of several cardiovascular diseases. However, LA structural or volumetric abnormalities are commonly seen in the advanced stages of disease and do not adequately represent functional changes throughout the cardiac cycle. In recent years, LA strain obtained using cardiac magnetic resonance feature tracking (CMR-FT)technology has been shown to provide early monitoring of LA tension damage while also comprehensively reflecting LA functional changes in three phases, providing deeper insights into cardiovascular disease risk, prognosis of cardiovascular disease, and evaluation of therapeutic efficacy. When compared to the ultrasound speckle tracking approach, the CMR-FT technique provides improved spatial resolution, repeatability, and reproducibility. We report a comprehensive review of the most recent studies on CMR-LA strain in the past five years, including normal reference values, early detection of disease, incremental diagnosis, improvement of risk stratification, assessment of the value of atrial-ventricular hemodynamics and coupled injury, major adverse cardiovascular events and prognostic value, as well as future research perspectives and current limitations, aiming at providing an objective reference for the further exploration of the value of the application of CMR-LA strain in various cardiac disorders.

Postoperative evaluation of left atrial stiffness in patients with congenital heart diseases

Left atrial (LA) stiffness is one of the most important factors involved in LA remodeling. LA stiffness has rarely been studied postoperatively in patients with congenital heart diseases (CHDs). This study aimed to evaluate LA stiffness in CHD patients postoperatively. Seventy-five patients (CHDs, 67; controls, 8; age range, 10-41 years) who underwent cardiac catheterization at our institution were included in this study. From the pulmonary artery wedge pressure waveform obtained during cardiac catheterization, the pressure range between the v wave and x trough was determined, and this value was divided by the LA reservoir strain obtained by echocardiography to calculate LA stiffness, as previously reported. LA stiffness was significantly higher in postoperative CHD patients than in controls (0.28 ± 0.17 vs. 0.13 ± 0.03, p = 0.001). Nineteen of 52 (37%) patients in their teens, 8 of 11 (73%) patients in their 20 s, and 1 of 4 (25%) patients aged > 30 years had elevated LA stiffness values. In particular, all patients with an LA reservoir strain < 20% had elevated LA stiffness. In postoperative CHD patients, LA stiffness was frequently elevated from a young age. CHD patients with elevated LA stiffness should be cautious of possible LA dysfunction in the future.

Left atrial strain analysis in the realm of pediatric cardiology: Advantages and implications

BACKGROUND

Left atrial (LA) strain analysis has emerged as a noninvasive technique for assessing LA function and early detection of myocardial deformation. Recently, its application has also shown promise in the pediatric population, spanning diverse cardiac conditions that demand accurate and sensitive diagnostic measures.

OBJECTIVE

This research article endeavors to explore the role of LA strain parameters and contribute to the growing body of knowledge in pediatric cardiology, paving the way for more effective and tailored approaches to patient care.

METHODS

A comprehensive literature review was conducted to gather evidence from studies using echocardiographic strain imaging techniques across pediatric populations.

RESULTS

LA strain parameters exhibited greater sensitivity than conventional atrial function indicators, with early detection of diastolic dysfunction and LA remodeling in pediatric cardiomyopathy, children with multisystem inflammatory syndrome, rheumatic heart disease, as well as childhood renal insufficiency and obesity offering prognostic relevance as potential markers in these pediatric subpopulations. However, there remains a paucity of evidence concerning pediatric mitral valve pathology, justifying further exploration.

CONCLUSION

LA strain analysis carries crucial clinical and prognostic implications in pediatric cardiac conditions, with reliable accuracy and sensitivity to early functional changes.

Left Atrial Dysfunction in Children with Repaired Pulmonary Artery Atresia with Ventricular Septal Defect: A Cardiovascular Magnetic Resonance Imaging Study

(1) Background: The left atrium (LA) is much more than a reservoir for left ventricular filling. The aim of this study was to assess the LA volume and function in patients with repaired pulmonary artery atresia with ventricular septal defect (rPA/VSD) using CMR. (2) Methods: 31 pediatric patients with rPA/VSD and 30 healthy controls were prospectively recruited. Left atrial ejection fraction (EF), strain and strain rate of three phases (reservoir, conduit, and pump) and left atrial volume were measured with cardiac function analysis software. (3) Results: Patients with rPA/VSD had decreased maximal volume index (p = 0.008). Compared to controls, LA reservoir strain and strain rate, conduit strain and strain rate, booster pump strain rate, total EF and passive EF were significantly lower (p = 0.001, p < 0.001, p = 0.001, p = 0.02, p = 0.03, p < 0.001, p < 0.001); the patients with preserved but lower RVEF(<50%) had lower reservoir strain, reservoir strain rate and pump strain rate (p = 0.01, p = 0.02, p = 0.04, respectively) than the patients with higher RVEF (≥50%). (4) Conclusions: In patients with rPA/VSD, LA function was altered when biventricular EF was preserved, which may provide an early indication of left ventricular diastolic dysfunction. CMR can detect LA dysfunction at an early stage, even before LA enlargement.