Left ventricular rotation and right-left ventricular interaction in congenital heart disease: the acute effects of interventional closure of patent arterial ducts and atrial septal defects

Urgent neonatal balloon atrial septostomy in simple transposition of the great arteries: predictive value of fetal cardiac parameters

OBJECTIVES

To investigate the impact of abnormal perinatal loading conditions on cardiac geometry and function in term fetuses and neonates with transposition of the great arteries with intact interventricular septum (simple TGA), and to explore the predictive value of fetal cardiac parameters for an urgent balloon atrial septostomy (BAS) after birth.

METHODS

This was a prospective longitudinal follow-up study of women delivering at term, including both uncomplicated pregnancies with normal outcome and pregnancies affected by fetal simple TGA. Conventional, spectral-tissue Doppler and speckle-tracking echocardiographic parameters were obtained within 1 week before delivery and within the first few hours after delivery. Neonates with simple TGA that required urgent BAS were assessed after the procedure and before corrective arterial switch surgery. Cardiac parameters were normalized by cardiac cycle length, ventricular end-diastolic length or end-diastolic dimension, as appropriate. Fetal and neonatal cardiac parameters were compared between simple-TGA cases and controls, and perinatal changes in the simple-TGA group were assessed. Receiver-operating-characteristics (ROC)-curve analysis was used to assess the predictive value of fetal cardiac parameters for urgent BAS after birth in the simple-TGA group.

RESULTS

A total of 67 pregnant women delivering at term were included in the study (54 normal pregnancies and 13 with a diagnosis of fetal simple TGA). Compared with normal term fetuses, term fetuses with simple TGA exhibited more globular hypertrophied ventricles, increased biventricular systolic function and diastolic dysfunction (right ventricular (RV) sphericity index (SI), 0.58 vs 0.54; left ventricular (LV)-SI, 0.55 vs 0.49; combined cardiac output (CCO), 483 vs 406 mL/min/kg; LV torsion, 4.3 vs 3.0 deg/cm; RV isovolumetric relaxation time (IVRT'), 127 vs 102 ms; P < 0.01 for all). Compared with normal neonates, neonates with simple TGA demonstrated biventricular hypertrophy, a more spherical right ventricle and altered systolic and diastolic functional parameters (RV-SI, 0.61 vs 0.43; RV myocardial performance index, 0.47 vs 0.34; CCO, 697 vs 486 mL/min/kg; LV-IVRT', 100 vs 79 ms; RV-IVRT', 106 vs 71 ms; P < 0.001 for all). Paired comparison of neonatal and fetal cardiac indices in the simple-TGA group showed persistence of the fetal phenotype, increased biventricular systolic myocardial contractility and CCO, and diastolic dysfunction (RV systolic myocardial velocity (S'), 0.31 vs 0.24 cm/s; LV-S', 0.23 vs 0.18 cm/s; CCO, 697 vs 483 mL/min/kg; LV torsion, 1.1 vs 4.3 deg/cm; P < 0.001 for all). Several fetal cardiac parameters in term fetuses with simple TGA demonstrated high predictive value for an urgent BAS procedure after birth. Our proposed novel fetal cardiac index, LV rotation-to-shortening ratio, as a potential marker of subendocardial dysfunction, for a cut-off value of ≥ 0.23, had an area under the ROC curve (AUC) of 0.94, sensitivity of 100% and specificity of 83%. For RV/LV end-diastolic area ratio ≥ 1.33, pulmonary-valve-to-aortic-valve-dimension ratio ≤ 0.89, RV/LV cardiac output ratio ≥ 1.38 and foramen-ovale-dimension-to-total-interatrial-septal-length ratio ≤ 0.27, AUC was 0.93-0.98, sensitivity was 86% and specificity was 83-100% for all.

CONCLUSIONS

Simple-TGA fetuses exhibited cardiac remodeling at term with more profound alterations in these cardiac parameters after birth, suggestive of adaptation to abnormal loading conditions and possible adaptive responses to hypoxemia. Perinatal adaptation in simple TGA might reflect persistence of the abnormal parallel arrangement of cardiovascular circulation and the presence of widely patent fetal shunts imposing volume load on the neonatal heart. The fetal cardiac parameters that showed high predictive value for urgent BAS after birth might reflect the impact of late-gestation pathophysiology and progressive hypoxemia on fetal cardiac geometry and function in simple TGA. If these findings are validated in larger prospective studies, detailed cardiac assessment of fetuses with simple TGA near term could facilitate improvements in perinatal management and refinement of the timing of postnatal intervention strategies to prevent adverse pregnancy outcomes. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Left ventricular rotation and torsion in neonates and infants younger than three months with symptomatic ventricular septal defect: Acute effects from open heart surgery

PURPOSE

We evaluated ventricular rotation, torsion, and strain changes in infants using preoperative and postoperative M-mode echocardiography after early surgery for symptomatic ventricular septal defects (VSD).

METHODS

Thirty-five patients with VSD underwent vector velocity imaging echocardiography before and after open heart surgery. Their rotational variables were compared with 18 controls.

RESULTS

All the patients (19 boys and 16 girls; median age: 44.4 days; range: 13-84 days) showed normal septal motion preoperatively; however, septal motion changed into flat septum or paradoxical septal motion after surgery. Left ventricular end-diastolic internal dimension and fractional shortening significantly decreased after surgery (P = .001 and P = .000). Patients showed significant postoperative reduction of peak systolic apical rotation and maximal torsion (P = .010 and P = .000). Peak systolic basal rotation decreased after surgery but it was not significantly (P = .106). No significant differences were found in longitudinal and circumferential systolic strains between patients and controls.

CONCLUSION

Abnormal motion of the ventricular septum was confirmed by postoperative M-mode echocardiography. Decreased rotation/torsion variables may reflect postoperative changes of ventricular loading conditions. Because systolic strain was preserved, postoperative echocardiographic results should not be interpreted as abnormal or decreased ventricular function.

Normative Data for Left and Right Ventricular Systolic Strain in Healthy Caucasian Italian Children by Two-Dimensional Speckle-Tracking Echocardiography

BACKGROUND

There is an increasing interest in echocardiographic strain (ε) measurements for the assessment of ventricular myocardial function in children; however, pediatric nomograms remain limited. Our aim was to establish pediatric nomograms for the left ventricular (LV) and the right ventricular (RV) ε measured by two-dimensional speckle-tracking echocardiography (2D-STE) in a large cohort of healthy children prospectively enrolled.

METHODS

Echocardiographic measurements included STE LV longitudinal and circumferential and RV longitudinal global end-systolic ε. Age, weight, height, heart rate (HR), and body surface area (BSA) were used as independent variables in different analyses to predict the mean values of each measurement. Echocardiograms were performed by Philips-iE33 systems (Philips, Bothell, WA) and offline measurements on Philips-Q-Lab-9.

RESULTS

In all, 721 subjects (age 31 days to 17 years; 48% female) were studied. Low coefficients of determination (R²) were noted among all of the ε parameters evaluated and adjusted for age, weight, height, BSA, and HR (i.e., R² all ≤ 0.10; range, 0.01-0.088). This hampered the possibility of performing z-scores with a sufficient reliability. Thus, we are limited to presenting data as mean values (±SD) stratified for age groups and divided by gender. LV longitudinal ε values decreased with age (P < .001), while no significant age-related variations were noted for RV longitudinal ε. A significant base-to-apex (lowest to highest) gradient in circumferential LV ε values was noted at all ages (P < .001).

CONCLUSIONS

We report pediatric echocardiographic normative data for 2D-STE for the LV and RV ε by using vendor-specific software. Our results confirm previous observations, showing only little variations of strain parameters with age and gender.

Left ventricular synchrony, torsion, and recoil mechanics in Ebstein's anomaly: insights from cardiovascular magnetic resonance

BACKGROUND

Disease progression and heart failure development in Ebstein's Anomaly (EA) of the tricuspid valve is characterized by both right and left ventricular (LV) deterioration. The mechanisms underlying LV dysfunction and their role in heart failure development are incompletely understood. We hypothesized that LV dyssynchrony and impaired torsion and recoil mechanics induced by paradoxical movement of the basal septum may play a role in heart failure development.

METHODS

31 EA patients and 31 matched controls underwent prospective cardiovascular magnetic resonance (CMR). CMR feature tracking (CMR-FT) was performed on apical, midventricular and basal short-axis and 4D-volume analysis was performed using three long-axis views and a short axis cine stack employing dedicated software. Circumferential uniformity ratio estimates (CURE) time-to-peak-based circumferential systolic dyssynchrony index (C-SDI), 4D volume analysis derived SDI (4D-SDI), torsion (Tor) and systolic (sysTR) and diastolic torsion rate (diasTR) were calculated for the LV. QRS duration, brain natriuretic peptide, NYHA and Total R/L-Volume Index (R/L Index) were obtained.

RESULTS

EA patients (31.5 years; controls 31.4 years) had significantly longer QRS duration (123.35 ms ± 26.36 vs. 97.33 ms ± 11.89 p < 0.01) and showed more LV dyssynchrony (4D-SDI 7.60% ± 4.58 vs. 2.54% ± 0.62, p < 0.001; CURE 0.77 ± 0.05 vs. 0.86 ± 0.03, p < 0.001; C-SDI 7.70 ± 3.38 vs. 3.80 ± 0.91, p = 0.001). There were significant associations of LV dyssynchrony with heart failure parameters and QRS duration. Although torsion and recoil mechanics did not differ significantly (p > 0.05) there was an association of torsion and recoil mechanics with dyssynchrony parameters CURE (sysTR r = -0.426; p = 0.017, diasTR r = 0.419; p = 0.019), 4D-SDI (sysTR r = 0.383; p = 0.044) and C-SDI (diasTR r = -0.364; p = 0.044).

CONCLUSIONS

EA is characterized by LV intra-ventricular dyssynchrony, which is associated with heart failure and disease severity parameters. Markers of dyssynchrony can easily be quantified from CMR-FT, and may have a role in the assessment of altered cardiac function, carrying potential management implications for EA patients.

Reference Ranges of Left Ventricular Strain Measures by Two-Dimensional Speckle-Tracking Echocardiography in Children: A Systematic Review and Meta-Analysis

BACKGROUND

Establishment of the range of reference values and associated variations of two-dimensional speckle-tracking echocardiography (2DSTE)-derived left ventricular (LV) strain is a prerequisite for its routine clinical adoption in pediatrics. The aims of this study were to perform a meta-analysis of normal ranges of LV global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) measurements derived by 2DSTE in children and to identify confounding factors that may contribute to variance in reported measures.

METHODS

A systematic review was launched in MEDLINE, Embase, Scopus, the Cumulative Index to Nursing and Allied Health Literature, and the Cochrane Library. Search hedges were created to cover the concepts of pediatrics, STE, and left-heart ventricle. Two investigators independently identified and included studies if they reported 2DSTE-derived LV GLS, GCS, or GRS. The weighted mean was estimated by using random effects models with 95% CIs, heterogeneity was assessed using the Cochran Q statistic and the inconsistency index (I(2)), and publication bias was evaluated using the Egger test. Effects of demographic (age), clinical, and vendor variables were assessed in a metaregression.

RESULTS

The search identified 2,325 children from 43 data sets. The reported normal mean values of GLS among the studies varied from -16.7% to -23.6% (mean, -20.2%; 95% CI, -19.5% to -20.8%), GCS varied from -12.9% to -31.4% (mean, -22.3%; 95% CI, -19.9% to -24.6%), and GRS varied from 33.9% to 54.5% (mean, 45.2%; 95% CI, 38.3% to 51.7%). Twenty-six studies reported longitudinal strain only from the apical four-chamber view, with a mean of -20.4% (95% CI, -19.8% to -21.7%). Twenty-three studies reported circumferential strain (mean, -20.3%; 95% CI, -19.4% to -21.2%) and radial strain (mean, 46.7%; 95% CI, 42.3% to 51.1%) from the short-axis view at the midventricular level. A significant apex-to-base segmental longitudinal strain gradient (P < .01) was observed in the LV free wall. There was significant between-study heterogeneity and inconsistency (I(2) > 94% and P < .001 for each strain measure), which was not explained by age, gender, body surface area, blood pressure, heart rate, frame rate, frame rate/heart rate ratio, tissue-tracking methodology, location of reported strain value along the strain curve, ultrasound equipment, or software. The metaregression showed that these effects were not significant determinants of variations among normal ranges of strain values. There was no evidence of publication bias (P = .40).

CONCLUSIONS

This study defines reference values of 2DSTE-derived LV strain in children on the basis of a meta-analysis. In healthy children, mean LV GLS was -20.2% (95% CI, -19.5% to -20.8%), mean GCS was -22.3% (95% CI, -19.9% to -24.6%), and mean GRS was 45.2% (95% CI, 38.3% to 51.7%). LV segmental longitudinal strain has a stable apex-to-base gradient that is preserved throughout maturation. Although variations among different reference ranges in this meta-analysis were not dependent on differences in demographic, clinical, or vendor parameters, age- and vendor-specific referenced ranges were established as well.

Left Ventricular Rotational Mechanics in Preterm Infants Less Than 29 Weeks' Gestation over the First Week after Birth

BACKGROUND

There is a paucity of data on left ventricular (LV) rotational physiology, twist, and torsional mechanics in preterm infants. The principal aims of the present study were to assess the feasibility and reproducibility of measuring LV rotation, twist, and torsion in preterm infants (<29 weeks' gestation) using two-dimensional speckle-tracking echocardiography and to examine the changes in those parameters over the first week after birth.

METHODS

This was a prospective observational study involving preterm infants <29 weeks' gestation. Echocardiographic evaluations were performed on days 1, 2, and 5 to 7 after delivery. LV basal and apical rotation, LV twist, LV twist rate (LVTR), and LV untwist rate (LVUTR) were measured from the basal and apical short-axis parasternal views and calculated using two-dimensional speckle-tracking echocardiography. Torsion was also calculated by normalizing LV twist to LV end-diastolic length. One-way repeated-measures analysis of variance was used to compare values across the three time points. Intra- and interobserver reproducibility were assessed using Bland-Altman analysis and the intraclass correlation coefficient.

RESULTS

Fifty-one infants with a mean ± SD gestational age of 26.8 ± 1.5 weeks and a mean birth weight of 945 ± 233 g were included. There was high intra- and interobserver reproducibility for basal and apical rotation, LV twist, and LV torsion, with intraclass correlation coefficients ranging from 0.78 to 0.96 (P < .001 for all). Intra- and interobserver intraclass correlation coefficients for LVTR and LVUTR ranged from 0.70 to 0.88 (P < .001 for all). Apical rotation remained constant over the first week of age in a positive counterclockwise fashion (11.8 ± 5.0° vs 12.1 ± 6.1° vs 11.7 ± 8.3°, P = .92). Basal rotation changed from counterclockwise on day 1 to clockwise on day 7 (median, 5.5° [interquartile range, -0.3° to 8.3°] vs 4.0 [interquartile range, -4.7° to 7.2°] vs -4.5° [interquartile range, -5.8° to -2.3°], P < .001), with resultant net increases in twist and torsion (P < .05). There was no change in LVTR (P = .60), but LVUTR increased across the same time period (P = .01).

CONCLUSIONS

Assessment of twist, LVTR, and LVUTR is feasible in preterm infants, with acceptable reproducibility. There are increases in LV twist and torsion in addition to LVUTR, suggesting changes in LV mechanics during the first week of age.