Left Atrial Strain Correlates with Elevated Filling Pressures in Pediatric Heart Transplantation Recipients.

BACKGROUND: Noninvasive assessment of diastolic function in pediatric heart transplantation (PHTx) patients is important for monitoring of rejection, cardiac allograft vasculopathy, and nonspecific graft failure. We hypothesized that left atrial strain (LAS) would correlate with pulmonary capillary wedge pressure (PCWP) and that cutoff values to identify elevated left ventricular (LV) filling pressure could be derived for clinical practice and future testing. METHODS: This was a secondary analysis of a prospectively collected cohort of PHTx patients undergoing same-day cardiac catheterization with biopsy and transthoracic echo. There were 70 patients with 85 clinical encounters. Traditional mitral inflow Doppler, LAS, LV diastolic strain and strain rate, and ratios for mitral E to LV diastolic strain and strain rate were assessed. Correlation with PCWP was performed, and receiver operator characteristic curves were generated for an elevated mean PCWP, acute rejection, and cardiac allograft vasculopathy. RESULTS: Decreased LAS during the atrial reservoir phase (Ɛres) correlated with higher invasively measured PCWP (r = -0.40, P < .001). An Ɛres cutoff of 14.5% had good discriminatory ability for an elevated PCWP (sensitivity 75%, specificity 82%), and Ɛres > 22.0% had 100% negative predictive value; Ɛres was superior to other measures of diastolic function. Subanalyses for recent acute rejection (n = 9) showed good discriminatory ability for Ɛres of 14.5% (sensitivity 89%, specificity 74%). CONCLUSIONS: LAS correlates with invasively measured PCWP and can identify elevated pressures better than traditional and other advanced diastolic function parameters. Use of LAS in PHTx patients may aid in noninvasive monitoring for rejection and nonspecific graft dysfunction.

Comprehensive left ventricular myocardial deformation assessment in children with Kawasaki disease.

OBJECTIVE: Children with Kawasaki disease (KD) with persistent coronary artery aneurysms (CAAs) can develop chronic vasculopathy and subsequent myocardial ischemia. Early detection of this process is challenging. Myocardial deformation analysis can detect early alterations in myocardial performance. We aim to determine whether there are differences in myocardial deformation between KD patients with and without CAAs. DESIGN: This is a cross-sectional study of 123 echocardiograms performed on 103 children with KD. Myocardial deformation was measured with two-dimensional speckle tracking (2DSTE). The echocardiograms were divided into groups according to the KD phase in which they were performed: acute, subacute, and convalescent/chronic. The convalescent/chronic phase group was then divided based on the presence or absence of CAAs. Left ventricular (LV) global longitudinal strain (GLS), global longitudinal strain rate (GLSSR), global circumferential strain (GCS), global circumferential systolic strain rate (GCSSR), peak torsion, and torsion rate were measured. RESULTS: The numbers of echocardiograms analyzed in each of the KD phase groups were: 31 acute, 25 subacute, and 67 convalescent/chronic. Myocardial deformation was within normal limits in all groups. However, GLSSR, GCSSR, peak torsion, and torsion rate were lower in the convalescent/chronic phase group than in the acute phase group (mean, -1.37 ± 0.24 vs -1.55 ± 0.21 1/s; -1.63 ± 0.27 vs -1.84 ± 0.35 1/s; 2.49 ± 1.13 vs 3.41 ± 2.60 °/cm, and 21.97 ± 8.36 vs 26.69 ± 10.86 °/cm/s; P < .05 for all). The convalescent/chronic phase subgroup with CAAs had lower GLSSR and GCSSR than the subgroup without CAAs (mean, -1.23 ± 0.22 vs -1.42 ± 0.22 1/s; -1.46 ± 0.25 vs -1.68 ± 0.26 1/s, P < .05 for both). CONCLUSIONS: Children in the convalescent/chronic phase of KD have a subtle decrease in strain rate when compared to the acute phase, although within the normal range. This decrease is more pronounced in children with CAAs than those without CAAs. Longitudinal studies are needed to discern whether low-normal strain rate predicts decreased myocardial function in the long term.

Serial Strain Analysis Identifies Hypoplastic Left Heart Syndrome Infants at Risk for Cardiac Morbidity and Mortality: A Pilot Study.

BACKGROUND: Validated, objective measures of right ventricular (RV) function assessment in hypoplastic left heart syndrome (HLHS) are needed. In other populations, speckle-tracking echocardiography-derived strain is a sensitive measure that outperforms conventional parameters of RV function. We hypothesized that speckle-tracking echocardiography-derived measures of RV function would be worse in patients with HLHS who have a poor cardiac outcome. METHODS: Prospective serial echocardiography was performed in 35 infants with HLHS during the first 6 months of life. Patients not undergoing staged palliation or with other variants of single RV were excluded. Traditional RV measurements and strain analysis were performed from standard apical and basal views. The primary outcome of cardiac death, heart transplantation, or persistent ≥ moderate RV dysfunction was examined using Cox regression analysis, and receiver operating characteristic curve analyses were performed to derive cutoff values. RESULTS: At median follow-up of 10.9 months (interquartile range 5.6, 15.2), eight patients reached the outcome and demonstrated worse RV strain measures compared with those without the outcome. A post-Norwood global longitudinal strain (GLS) of > -16% (area under the curve [AUC] = 0.76; P = .04) and pre-Glenn GLS > -13% (AUC, 0.98; P ≤ .01) were highly sensitive and specific for poor outcome. Other thresholds included post-Norwood GLS rate (GLSr) > -1.15 %/s (AUC, 0.78; P = .03), pre-Glenn GLSr = -0.85%/sec (AUC, 0.89; P < .01), post-Glenn circumferential strain rate > -0.85%/sec (AUC, 0.92; P < .01), and GLSr > -0.85%/sec (AUC, 0.84; P = .02). CONCLUSIONS: Strain analysis may help identify at-risk HLHS infants. In this pilot study, interstage strain indices were worse in infants with HLHS who had a poor cardiac outcome.

Left ventricular rotational mechanics in early infancy: Normal reference ranges and reproducibility of peak values and time to peak values.

INTRODUCTION: Left ventricular cardiac twist and torsion values have been described in premature and term neonates, but not in early infancy. Early and late peak untwist rates and time to peak (TTP) values have not been described in infants. METHODS: 53 term infants were enrolled prospectively. The following parameters were obtained by two blinded observers at 1-2months postnatal age: peak twist and torsion (twist indexed to LV length), peak twist rate and torsion rate, TTP twist, early peak untwist rate, TTP early untwist rate, late peak untwist rate, TTP late untwist rate. Reproducibility was assessed using intraclass correlation and Bland Altman analysis. RESULTS: Intraclass correlation was ≥0.87 for all peak rotational mechanics values. Measures of TTP values had intraclass correlation (ICC) values ≤0.77, with TTP twist rate demonstrating the lowest ICC (0.69). The only measure which demonstrated significant bias was TTP twist rate. Peak twist demonstrated modest correlation (R=0.52, p<0.001) with global circumferential strain, and no correlation with ejection fraction, global longitudinal strain, or left ventricular myocardial performance index. CONCLUSIONS: Measurements of rotational mechanics and timing to peak values have acceptable reproducibility. Peak twist, twist rate, and early untwist rate values in early infancy are similar to those reported in premature neonates, and higher than those reported in older children. Twist indexed to LV length (torsion) is lower in early infancy than in premature neonates, but higher than in term neonates.