Clinical Investigation
Echocardiography in Children
Left Atrial Strain and Function in Pediatric Hypertrophic Cardiomyopathy

https://doi.org/10.1016/j.echo.2021.04.014Get rights and content

Highlights

  • LA conduit and reservoir function are impaired in children with phenotypic HCM.

  • Children with phenotypic HCM have lower left atrial strain values.

  • Lower LA conduit function is associated with worsened aerobic capacity in pediatric HCM.

Background

Left atrial (LA) strain and dysfunction are early markers of diastolic dysfunction, associated with poor exercise capacity in adults with hypertrophic cardiomyopathy (HCM). Literature on assessment of LA mechanics in pediatric HCM is lacking. The aim of this study was to assess LA strain and LA function in pediatric patients who have HCM with (phenotype positive [P+]) and without (genotype positive, phenotype negative [G+P−]) ventricular hypertrophy and evaluate their correlation with exercise stress test parameters.

Methods

Seventy-eight children (3–25 years of age) with HCM (P+, n = 46; G+P−, n = 32) and 20 healthy control subjects were retrospectively studied. LA conduit function, reservoir function, and pump function were computed using phasic LA volumetric analysis. LA reservoir strain (LASr) and LA contractile strain were measured using speckle-tracking echocardiography. Exercise test findings within 12 months of echocardiography were recorded.

Results

LA conduit function (36% vs 48%, P < .001) and LA reservoir function (137% vs 180%, P < .001) were lower in P+ than in G+P− patients. LA contractile function did not differ between the groups (31% vs 32%, P = .87). Compared with patients with G+P− HCM, those with P+HCM had lower four-chamber LASr (29% vs 41%, P < .001), two-chamber LASr (30% vs 41%, P < .001), average LASr (29% vs 42%, P < .001), and LA contractile strain (9% vs 12%, P = .016). In the cohort of patients with HCM who underwent stress testing (n = 35), LA conduit function weakly correlated with aerobic capacity (r = 0.42, P = .019).

Conclusions

Children with P+HCM have reduced LA function, measurable by both volumetric and strain analysis. Altered LA mechanics are associated with poor exercise capacity. This study lays the foundation for the evaluation of novel LA parameters in pediatric HCM and warrants larger longitudinal studies to assess its clinical significance.

Section snippets

Study Population

A retrospective chart review was performed on all pediatric patients with HCM followed at Cleveland Clinic Children's Hospital between May 2010 and December 2018. Seventy-eight patients between 1 and 25 years of age who were diagnosed with HCM according to the American Heart Association/American College of Cardiology guidelines were included. This included ventricular hypertrophy (maximal wall thickness 1.5 cm or ≥2 SDs above the mean [Z score ≥ 2] for age, sex, or body size) in the absence of

Study Population

The HCM cohort consisted of 78 subjects with a median age of 16 years (range, 3–25 years), of whom 60 (64%) were male (Table 1). Phenotypic criteria for HCM were present in 59% patients (P+ group, n = 46) whereas the remaining carried the genotype but lacked phenotypic characteristics (G+P− group, n = 32). The most common reason for diagnosis was screening because of family history (n = 49 [63%]), with murmur being the second most common presentation (n = 17 [22%]). Among the 58 patients with

Discussion

This is the largest study describing conventional and novel parameters of DD in the pediatric HCM population. This study has several important findings emphasizing the importance of LA assessment in pediatric HCM. LAS and volumetric function parameters were significantly lower in patients with phenotypic (P+) HCM compared with those with a positive genotype but without significant hypertrophy (G+P−). LAS had good interobserver and intraobserver reproducibility in this population. Compared with

Conclusion

Our study sheds light on the role of LA function in children with HCM. This is the largest study on assessment of LA mechanics in the pediatric HCM cohort. We demonstrate that altered atrial mechanics, as measured by volumetric and strain analysis, are present even in the pediatric population with phenotypic HCM. The weak but significant correlation of LA conduit function with aerobic capacity may have prognostic implications, although longitudinal data are warranted to determine its value.

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    Conflicts of Interest: None.

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