Real time three-dimensional echocardiographic quantification of left atrial volume in orthotopic heart transplant recipients: Comparisons with cardiac magnetic resonance imaging

Assessment of left atrial function in patients with metabolic syndrome by four-dimensional automatic left atrial quantification

OBJECTIVE

This study aimed at assessing the changes of left atrial (LA) volume and strain function in metabolic syndrome (MS) patients using four-dimensional automatic left atrial quantification (4D-LAQ) and exploring independent correlative factors for LA function.

METHODS

A total of 110 MS patients and 70 normal controls were selected and assigned into the MS group and the control group, respectively. Echocardiogram parameters were routinely examined and the thickness of epicardial adipose tissue (EAT) were measured with a parasternal long axis of left ventricle(LV). The LA volume and strain parameters were determined using 4D-LAQ. The independent correlation factors for LA strain parameters in MS patients were investigated through linear regression analysis.

RESULTS

Compared with the control group, LA volume parameters were increased in the MS group, LA strain parameters and LA emptying fraction (LAEF) were decreased (all P < 0.05). EAT thickness is associated with LA reservoir longitudinal strain (LASr), conduit longitudinal strain (LAScd), reservoir circumferential strain (LASr-c), and conduit circumferential strain (LAScd-c) (all P < 0.05). LA contraction longitudinal (LASct) and circumferential strain (LASct-c) were not statistically significant. Regression analysis results show that systolic blood pressure (SBP) and triglyceride (TG) are independent correlative factors. Intra-observer and inter-observer repeatability test showed that the LA parameters examined by 4D-LAQ had good agreement.

CONCLUSIONS

4D-LAQ is capable of effectively assessing the LA function in MS patients and providing a useful reference for clinical diagnosis. SBP and TG serve as the independent correlative factors for LA function.

Multi-modality assessment and role of left atrial function as an imaging biomarker in cardiovascular disease

The left atrium (LA) plays a vital role in maintaining normal cardiac function. LA volume and function have been utilised as important imaging biomarkers, with their prognostic value demonstrated in multiple cardiac conditions. More recently, there has been a sharp increase in the number of publications utilising LA strain by echocardiography and cardiac magnetic resonance (CMR) imaging. However, little is known about its prognostic value or reproducibility as a technique. In this review, we aim to highlight the conventional and novel imaging techniques available for LA assessment, using echocardiography and CMR, their role as an imaging biomarker in cardiovascular disease, the reproducibility of the techniques and the current limitations to their clinical application. We identify a need for further standardisation of techniques, with establishment of ‘normal’ cut-offs before routine clinical application can be made.

Impaired left atrial function in clinically well heart transplant patients

Left atrial (LA) enlargement is present in the majority of adult heart transplant (HT) recipients. We used speckle-tracking echocardiography to investigate whether LA phasic function in HT patients is altered and explored its relationship to HT-related clinical variables. This study evaluated LA function in 112 clinically well HT patients and 40 healthy controls. Clinical data included recipient age at HT, donor age, ischemia time, left ventricular function, and biochemical indicators. Atrial deformation and volume indices were measured with two-dimensional and three-dimensional speckle-tracking echocardiography, respectively. Components of phasic atrial function were calculated and correlations to clinical variables were explored. Compared with controls, HT patients had worse LA reservoir, conduit, and pump function. LA reservoir function of the bicaval group was better than the biatrial group, but differences did not persist after adjustment for potential confounders. Among patients with HT, those with lower LAS-peak had an older recipient age, larger LA volume, as well as worse left ventricular systolic function than those patients with higher LAS-peak. However, E/e', biochemical indicators and donor-related information were similar across the quartiles of LA function. In HT cohort, we observed impairment in all phases of LA function, and LA reservoir function was decreased independent of surgical technique. LAS-peak was associated with worse left ventricular systolic function, which suggested that LA function may play an important role in HT patients.

Assessment of biatrial function in clinically well pediatric bicaval heart transplantation patients by three-dimensional echocardiography

Atrial size and function are closely correlated with atrial contributions to cardiovascular performance. Therefore, in this study, we aimed to assess atrial size and function in pediatric heart transplantation (HTx) patients using three-dimensional echocardiography (3DE). We enrolled 33 clinically well pediatric HTx patients and 33 healthy controls with a similar distribution of sex and age to the HTx patients. All patients underwent two-dimensional echocardiography (2DE) and 3DE. 2DE- and 3DE-derived biatrial maximal volume (Vmax), minimal volume (Vmin), ejection volume (EV), ejection fraction (EF), volume before atrial contraciton (VpreA), passive EV, passive EF, active EV and active EF were obtained in all patients. The 3D left atrail (LA) Vmax, Vmin and VpreA increased significantly in HTx patients after being indexed by BSA, while 3D LAEV and passive EV decreased significantly (P < 0.05). Moreover, the 3D LAEF, LA passive EF, and LA active EF all decreased significantly in HTx patients (P < 0.05). The 3D right atrial (RA) Vmax, Vmin, and VpreA increased significantly in HTx patients (P < 0.05), while the 3D RAEF and RA passive EF decreased significantly in HTx patients (P < 0.05). 3DE-derived LAVmax, LAVpreA, LA passive EV, LAEF, and LA passive EF were all lower than the corresponding 2D parameters. 3DE-derived RAVpreA, RA passive EV and RAEF were all lower than the corresponding 2D parameters. Atrial sizes and function assessed by 3DE- and 2DE-derived parameters, yield significantly discordant results in pediatric HTx patients. 3DE confirms significantly enlarged atrial sizes and decreased atrial functions in pediatric HTx patients.