Right Atrial Strain in Preterm Infants With a History of Bronchopulmonary Dysplasia.

BACKGROUND: Few studies have utilized right atrial (RA) strain to evaluate right ventricular (RV) diastolic dysfunction in preterm infants with bronchopulmonary dysplasia (BPD). We aimed to evaluate the associations of RA strain with BPD severity and respiratory outcomes in preterm infants with BPD. METHODS: We retrospectively studied 153 infants with BPD born before 32 weeks of gestational age at CHA Bundang Medical Center. Peak longitudinal right atrial strain (PLRAS) was obtained using velocity vector imaging and compared among infants across BPD severity. Conventional echocardiographic parameters and clinical characteristics were also evaluated. RESULTS: In infants with severe BPD, mean gestational age (27.4 ± 2.1 weeks) and mean birth weight (971.3 ± 305.8 g) were significantly smaller than in those with mild BPD (30.0 ± 0.9 weeks, 1,237.3 ± 132.2 g) and moderate BPD (29.6 ± 1.3 weeks, 1,203.2 ± 214.4 g). PLRAS was significantly lower in infants with severe BPD (26.3 ± 10.1%) than in those in the moderate BPD group (32.4 ± 10.9%) or mild BPD group (31.9 ± 8.3%). Tricuspid E/e' and maximum RA volume index were similar across BPD severity. A decrease in PLRAS was significantly correlated with increased duration of mechanical ventilation duration; however, tricuspid E/e' and maximum RA volume index were not. CONCLUSIONS: Evaluating PLRAS with other parameters in infants with BPD might detect RV diastolic dysfunction. Longer follow-up and larger study populations may elucidate the association between PLRAS and respiratory outcomes in infants with BPD.

Sequential Changes in Left Ventricular Systolic Myocardial Deformation Mechanics in Children with Recurrent Kawasaki Disease.

BACKGROUND: Sequential changes in left ventricular (LV) systolic function over time in patients with recurrent episodes of Kawasaki disease (KD) remain unclear. METHODS: Twenty-five children with recurrent KD were retrospectively studied. Using conventional echocardiographic parameters and myocardial deformation analysis, systolic LV function in children in initial and recurrent KD episodes were compared with separate control groups, comprising 15 controls each. Recurrent KD was defined as occurring at an interval of ≥2 months between the initial and recurrent episodes. RESULTS: The interval range between initial and recurrent episodes of KD was 3-103 months. In children with KD, 8 (32%) were <1 year of age at the initial episode, 10 (40%) had a recurrence within 1 year of the initial episode, and 4 (16%) and 5 (20%) were intravenous immune globulin nonresponders in initial and recurrent episodes, respectively. In both the initial and recurrent episodes of KD, the mean LV longitudinal peak systolic ε was all within normal range. However, when compared to controls, mean LV longitudinal peak systolic ε was decreased in patients with KD in the acute phases of both the initial and recurrent episodes. When compared to controls, mean LV longitudinal peak systolic ε was decreased in patients with KD in the convalescent phase of the recurrent episodes. CONCLUSIONS: Subclinical decreases in myocardial systolic deformation, as evidenced by decreased LV longitudinal peak systolic ε, may persist in children in the convalescent phase of recurrent KD; further studies involving larger numbers of patients may be needed for verification.

Long Term Outcomes of Left Atrial Reservoir Function in Children with a History of Kawasaki Disease.

BACKGROUND: Decreased left atrial (LA) reservoir function is reported to be associated with elevated left ventricular (LV) end diastolic pressure and LV diastolic dysfunction. Echocardiographic parameters that reflect LA reservoir function include LA total emptying fraction [(maximum LA volume - minimum LA volume) / maximum LA volume], peak LA longitudinal strain (PLALS) at systole, and LA stiffness index (E/E´/PLALS). We aimed to investigate the long-term outcomes of LV diastolic function in children with a history of Kawasaki disease (KD) (KDHx group) by assessing LA reservoir function. METHODS: Retrospectively, echocardiograms performed at a mean follow-up period of 5 years after the acute phase of KD in 24 children in the KDHx group were compared to those from 20 normal control subjects. LA total emptying fraction, PLALS, LA stiffness index, LV peak longitudinal systolic strain (ε), and strain rate (SR) were evaluated with conventional echocardiographic parameters. RESULTS: The mean age at long term follow-up echocardiography in children in the KDHx group was 6.8 years. Five children (20.8%) had coronary artery lesions (CALs) in the acute stage of KD. No children showed CALs at a mean follow-up period of 5 years after the acute phase of KD. There were no significant differences in the conventional echocardiographic parameters and in LA total emptying fraction, PLALS, LA stiffness index, LV peak longitudinal systolic ε, and SR, between the children in the KDHx and control group. CONCLUSION: LV diastolic function assessed by LA reservoir function parameters at long-term follow-up in children in the KDHx group appears to be favorable.

Clinical Utility of Left Atrial Strain in Children in the Acute Phase of Kawasaki Disease.

BACKGROUND: We aimed to evaluate the diagnostic utility of peak left atrial longitudinal strain (PALS) during left ventricular (LV) systole to differentiate children in the acute phase of Kawasaki disease (aKD) from controls. We also aimed to compare the diagnostic utility of PALS with those of conventional echocardiographic indices of diastolic function. METHODS: Retrospectively measured PALS, LV longitudinal peak systolic strain, and strain rate obtained via velocity vector imaging were compared in a derivation cohort comprising 95 aKD and 67 controls. The utility of PALS in differentiating aKD from controls was compared with those of E/E', E/A, and maximum left atrial volume index (LAVImax). Derived cutoffs from receiver operating characteristic curves were validated in a separate validation cohort comprising 37 aKD and 19 controls. RESULTS: In the derivation cohort, PALS was significantly decreased in aKD as compared with in controls. For differentiating aKD from controls, PALS outperformed E/E', E/A, and LAVImax. However, cutoffs of PALS (≤40% and ≤39%, before and after adjusting for the presence of significant mitral regurgitation and LV systolic dysfunction, respectively), like those of E/E', E/A, and LAVImax, showed low sensitivity and poor discriminative ability for differentiating aKD from controls. In the validation cohort, for differentiating aKD from controls, both cutoffs of PALS showed low sensitivity, like those of E/E', E/A, and LAVImax. CONCLUSION: In aKD, impaired left atrial reservoir function could be detected as decreased PALS. For differentiating aKD from controls, PALS outperforms E/E', E/A, and LAVImax. However, like E/E', E/A, and LAVImax, PALS as a single parameter is limited in its clinical utility to differentiate aKD from controls because of its low sensitivity and poor discriminative ability.

Progression of Right Ventricular Systolic Dysfunction Detected by Myocardial Deformation Imaging in Asymptomatic Preterm Children.

BACKGROUND: To detect progression of right ventricular (RV) systolic dysfunction (RVSD) in asymptomatic preterm children from infancy to 24-month corrected age, using velocity vector imaging (VVI). METHODS: Retrospective study comparing sequential RV longitudinal peak systolic strain (LPSS) from 24 children born at < 33 weeks of gestational age and 10 term infants recruited as controls, obtained at a mean of 4-month (first exam) and 24-month corrected age (second exam). RESULTS: In 7/24 (29.2%) of preterm children, RV LPSS of < 16%, defined as RVSD, was detected at the second exam; 5/7 of these children had RV LPSS > 16% at the first exam, and only 2/7 of these children had a history of moderate or severe bronchopulmonary dysplasia. CONCLUSION: In asymptomatic preterm children, routine echocardiographic screening using VVI could detect RVSD which could progress from 4-24 month corrected age.

Outcomes of Left Ventricular Function According to Treatment Response for a Patent Ductus Arteriosus in Preterm Infants.

BACKGROUND: To evaluate the outcomes of left ventricular (LV) function according to treatment response for a hemodynamically significant patent ductus arteriosus (hsPDA) in preterm infants. METHODS: Echocardiograms of 21 preterm infants born at gestational age < 31 weeks obtained at term-equivalent age were retrospectively studied. Among preterm infants with a hsPDA, 9 underwent ligation after failure of pharmacological closure (ligation group) and 6 experienced successful pharmacological closure (medication group). Six preterm infants without hsPDA (no-hsPDA group) were studied as controls. LV peak longitudinal systolic strain (ε) of each infant was retrospectively obtained from echocardiograms using velocity vector imaging, along with neonatal outcomes. RESULTS: Pharmacological closures were attempted at postnatal day 2-3. In the ligation group, the median postnatal age at ligation was 20 days. In the ligation group, LV peak longitudinal systolic ε was significantly decreased at term-equivalent age compared to the other groups. Between the medication and no-hsPDA groups, LV peak longitudinal systolic ε did not differ significantly. Among the neonatal outcomes, infants who experienced necrotizing enterocolitis (NEC) showed significantly decreased LV peak longitudinal systolic ε compared to the infants who did not experience NEC . CONCLUSION: We speculate that in preterm infants with an hsPDA, in cases of medical treatment failure, early PDA ligation at less than 20 days of postnatal age would be beneficial for preserving LV systolic function.