Left atrial mechanics in children: insights from new applications of strain imaging

Left Atrial Strain in Multisystem Inflammatory Syndrome in Children and Associations with Systemic Inflammation and Cardiac Injury

Multisystem inflammatory syndrome in children (MIS-C) commonly involves cardiac injury with both systolic and diastolic dysfunction. Left atrial strain (LAS) detects subclinical diastolic dysfunction in adults but is infrequently used in children. We evaluated LAS in MIS-C and the associations with systemic inflammation and cardiac injury. In this retrospective cohort study, LAS parameters [reservoir (LAS-r), conduit (LAS-cd), and contractile (LAS-ct)] obtained from admission echocardiograms of MIS-C patients were compared to healthy controls and between MIS-C patients with and without cardiac injury (BNP > 500 pg/ml or troponin-I > 0.04 ng/ml). Correlation and logistic regression analyses were performed to assess LAS associations with admission inflammatory and cardiac biomarkers. Reliability testing was performed. We identified 118 patients with MIS-C and 20 healthy controls. Median LAS parameters were reduced in MIS-C patients compared to controls (LAS-r: 31.8 vs. 43.1%, p < 0.001; LAS-cd: - 28.8 vs. - 34.5%, p = 0.006; LAS-ct: - 5.2 vs. - 9.3%, p < 0.001) and reduced in MIS-C patients with cardiac injury (n = 59) compared to no injury (n = 59) (LAS-r: 29.6 vs. 35.8%, p = 0.001; LAS-cd: - 26.5 vs. - 30.4%, p = 0.036; LAS-ct: - 4.6 vs. - 9.3%, p = 0.008). A discrete LAS-ct peak was absent in 65 (55%) MIS-C patients but present in all controls (p < 0.001). Procalcitonin correlated strongly with averaged E/e' (r = 0.55, p = 0.001). Moderate correlations were found for ESR and LAS-ct (r = - 0.41, p = 0.007) as well as BNP and LAS-r (r = - 0.39, p < 0.001) and LAS-ct (r = 0.31, p = 0.023). Troponin-I had only weak correlations. Intra-rater reliability was good for all LAS parameters, and inter-rater reliability was good to excellent for LAS-r, and fair for LAS-cd and LAS-ct. LAS analysis, particularly the absence of a LAS-ct peak, was reproducible and may be superior to conventional echocardiographic parameters for detecting diastolic dysfunction in MIS-C. No strain parameters on admission were independently associated with cardiac injury.

Left atrial stiffness and strain are novel indices of left ventricular diastolic function in children: validation followed by application in multisystem inflammatory syndrome in children due to COVID-19

AIMS

We hypothesized left atrial (LA) stiffness may serve as a surrogate marker in children to differentiate elevated pulmonary capillary wedge pressure (PCWP) from normal and help detect diastolic dysfunction in myocardial injury due to multisystem inflammatory syndrome in children (MIS-C).

METHODS AND RESULTS

We validated LA stiffness in 76 patients (median age 10.5 years), 33 had normal PCWP (<12 mmHg) and 43 had elevated PCWP (≥12 mmHg). LA stiffness was applied to 42 MIS-C patients [28 with myocardial injury (+) and 14 without myocardial injury (-)], defined by serum biomarkers. The validation group consisted of a group with and without cardiomyopathies, whose PCWP values ranged from normal to severely elevated. Peak LA strain was measured by speckle-tracking and E/e' from apical four chamber views. Noninvasive LA stiffness was calculated as: LAStiffness=E/e'LAPeakStrain (%-1). Patients with elevated PCWP showed significantly elevated LA stiffness [median 0.71%-1 vs. 0.17%-1, P < 0.001]. Elevated PCWP group showed significantly decreased LA strain (median: 15.0% vs. 38.2%, P < 0.001). Receiver operator characteristic (ROC) curve for LA stiffness yielded an area under the curve (AUC) of 0.88 and cutoff value of 0.27%-1. In MIS-C group, ROC curve yielded an AUC of 0.79 and cutoff value of 0.29%-1 for identifying myocardial injury.

CONCLUSION

In children with elevated PCWP, LA stiffness was significantly increased. When applied to children with MIS-C, LA stiffness classified myocardial injury accurately. LA stiffness and strain may serve as noninvasive markers of diastolic function in the pediatric population.

Left atrial strain in multisystem inflammatory syndrome in children (MIS-C) and associations with systemic inflammation and cardiac injury

Background

Multisystem inflammatory syndrome in children (MIS-C) commonly involves cardiac injury with both systolic and diastolic dysfunction. Left atrial strain (LAS) detects subclinical diastolic dysfunction in adults but is infrequently used in children. We evaluated LAS in MIS-C and the associations with systemic inflammation and cardiac injury.

Methods

In this retrospective cohort study, conventional parameters and LAS (reservoir [LAS-r], conduit [LAS-cd], and contractile [LAS-ct]) obtained from admission echocardiograms of MIS-C patients were compared to healthy controls and between MIS-C patients with and without cardiac injury (BNP >500 pg/ml or troponin-I >0.04 ng/ml). Correlation and logistic regression analyses were performed to assess LAS associations with admission inflammatory and cardiac biomarkers. Reliability testing was performed.

Results

Median LAS components were reduced in MIS-C patients (n=118) compared to controls (n=20) (LAS-r: 31.8 vs. 43.1%, p<0.001; LAS-cd: -28.8 vs. -34.5%, p=0.006; LAS-ct: -5.2 vs. -9.3%, p<0.001) and reduced in MIS-C patients with cardiac injury (n=59) compared to no injury (n=59) (LAS-r: 29.6 vs. 35.8%, p=0.001; LAS-cd: -26.5 vs. -30.4%, p=0.036; LAS-ct: -4.6 vs. -9.3%, p=0.008). An LAS-ct peak was absent in 65 (55%) MIS-C patients but present in all controls (p<0.001). Procalcitonin had strong correlation with averaged E/e' (r=0.55, p=0.001); ESR had moderate correlation with LAS-ct (r=-0.41, p=0.007); BNP had moderate correlation with LAS-r (r=-0.39, p<0.001) and LAS-ct (r=0.31, p=0.023), and troponin-I had only weak correlations. No strain indices were independently associated with cardiac injury on regression analysis. Intra-rater reliability was good for all LAS components; and inter-rater reliability was good to excellent for LAS-r, and fair for LAS-cd and LAS-ct.

Conclusions

LAS analysis, particularly the absence of a LAS-ct peak, was reproducible and may be superior to conventional echocardiographic parameters for detecting diastolic dysfunction in MIS-C. No strain parameters on admission were independently associated with cardiac injury.

Cardiac Imaging in Childhood Cancer Survivors: A State-of-the-Art Review

Childhood cancer survival has improved significantly in the past few decades, reaching rates of 80% or more at 5 years. However, with improved survival, early- and late-occurring complications of chemotherapy and radiotherapy exposure are becoming progressively more evident. Cardiovascular diseases represent the leading cause of non-oncological morbidity and mortality in this highly vulnerable population. Therefore, the necessity of reliable, noninvasive screening tools able to early identify cardiac complications early is now pre-eminent in order to implement prevention strategies and mitigate disease progression. Echocardiography, may allow identification of myocardial dysfunction, pericardial complications, and valvular heart diseases. However, additional imaging modalities may be necessary in selected cases. This manuscript provides an in-depth review of noninvasive imaging parameters studied in childhood cancer survivors. Furthermore, we will illustrate brief surveillance recommendations according to available evidence and future perspectives in this expanding field.

Advanced Echocardiographic Analysis in Medium-Term Follow-Up of Children with Previous Multisystem Inflammatory Syndrome

Multisystem inflammatory syndrome in children (MIS-C) is a severe hyperinflammatory disease related to SARS-CoV2 infection, with frequent cardiovascular involvement in the acute setting. The aim of the study was to evaluate the cardiac function at 6 months. Thirty-two patients diagnosed with MIS-C were enrolled and underwent advanced echocardiogram at discharge and at 6 months. According to the left ventricular ejection fraction (LVEF) at admission, the patients were divided into group A (LVEF < 45%) and group B (LVEF ≥ 45%) and the follow-up results were compared. At discharge, all patients had normal LV and RV systolic function (LVEF 61 ± 4.4%, LV global longitudinal strain −22.1%, TAPSE 20.1mm, s’ wave 0.13m/s, RV free wall longitudinal strain −27.8%) with normal LV diastolic function (E/A 1.5, E/e’ 5.7, and left atrial strain 46.5%) and no significant differences at 6 months. Compared to group B, the group A patients showed a reduced, even if normal, LV global longitudinal strain at discharge (−21.1% vs. −22.6%, p-value 0.02), but the difference was no longer significant at the follow-up. Patients with MIS-C can present with depressed cardiac function, but if treated, the cardiac function recovered without late onset of cardiac disease. This favorable result was independent of the severity of acute LV dysfunction.

Subclinical Changes in Left Heart Structure and Function at Preschool Age in Very Low Birth Weight Preterm Infants

Background

Survivors of preterm birth are at risk of long-term cardiovascular consequences. The objective of this prospective observational study was to assess left heart function at preschool age in preterm children with very low birth weight (VLBW).

Methods

We recruited children aged 5–6 years from preterm infants and full-term children. All subjects underwent conventional echocardiography and speckle-tracking echocardiography. The results were compared between the preterm and term groups.

Results

Eighty-seven VLBW preterm children and 29 term controls were included in the study. After adjusting for body surface area, the preterm group compared to the full-term group had significantly smaller left ventricular (LV) end-diastolic and end-systolic internal dimensions (31.2 vs. 33.5 mm, p = 0.048; and 20.0 vs. 21.6 mm, respectively; p = 0.024), lower LV end-diastolic and end-systolic volumes (38.8 vs. 46.3 mL, p = 0.024; and 12.8 vs. 15.6 mL, respectively; p = 0.008). Left atrial (LA) maximal and minimal volume were also significantly smaller in the preterm group (15.4 vs. 18.9 mL, p = 0.017; and 6.2 vs 7.5 mL, respectively; p = 0.018). LV global longitudinal strain (−21.4 vs. −23.2%, p < 0.0001) and systolic strain rate (−1.30 vs. −1.37 /s, p = 0.001) were significantly lower in the preterm group than in the term control group. LA longitudinal strain was decreased (43.9 vs. 52.8%, p < 0.0001) and left atrial stiffness index (0.17 vs. 0.14, p < 0.0001) was increased in preterm infants. However, all the measurements in both groups were within normal range.

Conclusions

Subclinical changes of left heart structure and function were found in VLBW infants at preschool age. Additional long-term follow-ups of the cardiovascular outcomes are needed in this vulnerable population.

Longitudinal Assessment of Cardiac Outcomes of Multisystem Inflammatory Syndrome in Children Associated With COVID-19 Infections

Background

In multisystem inflammatory syndrome in children, there is paucity of longitudinal data on cardiac outcomes. We analyzed cardiac outcomes 3 to 4 months after initial presentation using echocardiography and cardiac magnetic resonance imaging.

Methods and Results

We included 60 controls and 60 cases of multisystem inflammatory syndrome in children. Conventional echocardiograms and deformation parameters were analyzed at 4 time points: (1) acute phase (n=60), (2) subacute phase (n=50; median, 3 days after initial echocardiography), (3) 1‐month follow‐up (n=39; median, 22 days), and (4) 3‐ to 4‐month follow‐up (n=25; median, 91 days). Fourteen consecutive cardiac magnetic resonance imaging studies were reviewed for myocardial edema or fibrosis during subacute (n=5) and follow‐up (n=9) stages. In acute phase, myocardial injury was defined as troponin‐I level ≥0.09 ng/mL (>3 times normal) or brain‐type natriuretic peptide >800 pg/mL. All deformation parameters, including left ventricular global longitudinal strain, peak left atrial strain, longitudinal early diastolic strain rate, and right ventricular free wall strain, recovered quickly within the first week, followed by continued improvement and complete normalization by 3 months. Median time to normalization of both global longitudinal strain and left atrial strain was 6 days (95% CI, 3–9 days). Myocardial injury at presentation (70% of multisystem inflammatory syndrome in children cases) did not affect short‐term outcomes. Four patients (7%) had small coronary aneurysms at presentation, all of which resolved. Only 1 of 9 patients had residual edema but no fibrosis by cardiac magnetic resonance imaging.

Conclusions

Our short‐term study suggests that functional recovery and coronary outcomes are good in multisystem inflammatory syndrome in children. Use of sensitive deformation parameters provides further reassurance that there is no persistent subclinical dysfunction after 3 months.

Peak left atrial longitudinal strain: A potential diagnostic entity in children with multi-inflammatory syndrome in children

The multi-inflammatory syndrome in children is a poorly understood febrile illness potentially linked to an immune response to COVID-19 infection. The disease is characterized by fever and elevated acute-phase reactants. A number of children with clinical and laboratory evidence of cardiovascular involvement have normal echocardiograms by conventional assessment. The peak left atrial longitudinal strain obtained by atrial deformation analysis could potentially be diagnostic of this condition in children who do not have abnormalities identified on conventional assessment.

Echocardiographic Findings in Pediatric Multisystem Inflammatory Syndrome Associated With COVID-19 in the United States

BACKGROUND

Centers from Europe and United States have reported an exceedingly high number of children with a severe inflammatory syndrome in the setting of coronavirus disease 2019, which has been termed multisystem inflammatory syndrome in children (MIS-C).

OBJECTIVES

This study aimed to analyze echocardiographic manifestations in MIS-C.

METHODS

A total of 28 MIS-C, 20 healthy control subjects and 20 classic Kawasaki disease (KD) patients were retrospectively reviewed. The study reviewed echocardiographic parameters in the acute phase of the MIS-C and KD groups, and during the subacute period in the MIS-C group (interval 5.2 ± 3 days).

RESULTS

Only 1 case in the MIS-C group (4%) manifested coronary artery dilatation (z score = 3.15) in the acute phase, showing resolution during early follow-up. Left ventricular (LV) systolic and diastolic function measured by deformation parameters were worse in patients with MIS-C compared with KD. Moreover, MIS-C patients with myocardial injury were more affected than those without myocardial injury with respect to all functional parameters. The strongest parameters to predict myocardial injury in MIS-C were global longitudinal strain, global circumferential strain, peak left atrial strain, and peak longitudinal strain of right ventricular free wall (odds ratios: 1.45 [95% confidence interval (CI): 1.08 to 1.95], 1.39 [95% CI: 1.04 to 1.88], 0.84 [95% CI: 0.73 to 0.96], and 1.59 [95% CI: 1.09 to 2.34], respectively). The preserved LV ejection fraction (EF) group in MIS-C showed diastolic dysfunction. During the subacute period, LVEF returned to normal (median from 54% to 64%; p < 0.001) but diastolic dysfunction persisted.

CONCLUSIONS

Unlike classic KD, coronary arteries may be spared in early MIS-C; however, myocardial injury is common. Even preserved EF patients showed subtle changes in myocardial deformation, suggesting subclinical myocardial injury. During an abbreviated follow-up, there was good recovery of systolic function but persistence of diastolic dysfunction and no coronary aneurysms.

Left atrial myocardial dysfunction in patients with primary aldosteronism as assessed by speckle-tracking echocardiography

BACKGROUND

We investigated the left atrial myocardial deformation in patients with primary aldosteronism using the speckle-tracking echocardiographic (STE) strain imaging technique.

METHODS

Our study included 107 primary aldosteronism patients [52 aldosterone-producing adenoma (APA) and 55 idiopathic hyperaldosteronism (IHA)] and 50 primary hypertensive patients. We performed conventional echocardiography to measure left atrial volume and ejection fraction, and STE to estimate left atrial myocardial deformation including peak velocity, strain and strain rate and calculate the ratio of E/e' to left atrial strain during left ventricular systole as the left atrial stiffness index.

RESULTS

Patients with APA, compared with those with IHA and primary hypertension had a significantly (P < 0.001) lower serum potassium concentration and higher 24-h urinary aldosterone excretion and plasma aldosterone-to-renin ratio. Patients with APA had a significantly (P < 0.01) larger maximal, precontraction, and minimal left atrial volumes and lower total, active and passive left atrial emptying fractions than those with IHA and primary hypertension. Among the three groups, patients with APA showed lowest left atrial velocity, strain, and strain rate during ventricular systole, early diastole and late diastole (P < 0.05) and highest left atrial stiffness index (P < 0.001). In unadjusted analysis, the left atrial strain, strain rate and stiffness index were significantly (P < 0.05) associated with plasma aldosterone concentration and urinary aldosterone excretion. After adjustment for various confounding factors, these associations remained statistically significant for urinary aldosterone excretion (P < 0.05) but not plasma aldosterone concentration (P ≥ 0.05).

CONCLUSION

Patients with primary aldosteronism, especially APA, had impaired left atrial deformation mechanics and increased left atrial stiffness, providing a promising insight into early detection of subclinical left atrial dysfunction by strain echocardiography.

Predictors and Consequences of Pediatric Hypertension: Have Advanced Echocardiography and Vascular Testing Arrived?

PURPOSE OF REVIEW

Pediatric hypertension is relatively common and associated with future adult hypertension. Elevated blood pressure in youth predicts future adult cardiovascular disease and blood pressure control can prevent progression of pediatric kidney disease. However, pediatric blood pressure is highly variable within a given child and among children in a population.

RECENT FINDINGS

Therefore, modalities to index aggregate and cumulative blood pressure status are of potential benefit in identifying youth in danger of progression from a risk factor of subclinical phenotypic alteration to clinically apparent event. In this review, we advocate for the health risk stratification roles of echocardiographically assessed cardiac remodeling, arterial stiffness assessment, and assessment by ultrasound of arterial thickening in children and adolescents with hypertension.