Predictors of bronchopulmonary dysplasia or death in premature infants with a patent ductus arteriosus.

BACKGROUND: Preterm infants with a patent ductus arteriosus (PDA) are at risk for death or development of bronchopulmonary dysplasia (BPD). However, PDA treatment remains controversial. We investigated if PDA treatment and other clinical or echocardiographic (ECHO) factors were associated with the development of death or BPD. METHODS: We retrospectively studied clinical and ECHO characteristics of preterm infants with birth weight <1,500 g and ECHO diagnosis of a PDA. Logistic regression and classification and regression tree analyses were performed to assess variables associated with the combined outcome of death or BPD. RESULTS: Of 187 preterm infants with a PDA, 75% were treated with indomethacin or surgical ligation and 25% were managed conservatively. Death or BPD occurred in 80 (43%) infants. The results of logistic regression analyses showed that lower gestational age (odds ratio (OR): 0.5), earlier year of birth during the study period (OR: 0.9), and larger ductal diameter (OR: 4.3) were associated with the decision to treat the PDA, whereas gestational age was the only variable associated with death or BPD (OR: 0.6; 95% confidence interval: 0.5-0.8). CONCLUSION: Only lower gestational age and not PDA treatment or ECHO score was associated with the adverse outcome of death or BPD. Further investigation of PDA management strategies and effects on adverse outcomes of prematurity is needed.

Echocardiographic predictors of early postsurgical myocardial dysfunction in pediatric patients with aortic valve insufficiency.

In chronic aortic insufficiency (AI), left-ventricular (LV) dysfunction must be detected early to allow timely surgery. Strain and strain rate have been used for this purpose in adults, but the value of this method in pediatric AI has not been established. Forty patients with moderate to severe AI were included in this retrospective study. LV function was assessed by strain analysis and conventional echocardiography both before and after surgery. Of the 32 patients with preserved preoperative ejection fraction (EF; >50 %), 8 had postoperative dysfunction (<50 %). Mean conventional indices of global LV systolic performance for the entire cohort of patients with AI were predominantly in the normal range before surgery. Preoperative values for LV global longitudinal strain (GLS) and strain rate (GLSr) were normal. After surgery, there was a significant decrease in shortening and EF. There was a significant decrease from preoperative to postoperative values for both GLS (-16.07 ± 3.82 vs. -11.06 ± 3.88; p < 0.0001) and GLSr (-0.89 ± 0.24 vs. -0.72 ± 0.27; p = 0.0021). A preoperative GLS of -15.3 (AUC = 0.83, CI = 0.69-0.98, p < 0.0001) and a GLSr of -0.79/s (AUC = 0.86, CI = 0.73-0.98, p < 0.0001) were determined to be predictors of early postoperative dysfunction after surgical repair of moderate to severe AI. A preoperative GLS value of ≤-15.3 and GLSr value of -0.79/s or less are predictors of postoperative ventricular dysfunction, which is defined by EF <50 %. GLS and GLSr value determination may be useful as part of the echocardiographic assessment AI and may help determine the optimal timing of surgery in pediatric patient with at least moderate AI.

Tissue Doppler-derived measurement of isovolumic myocardial contraction in the pediatric population.

Multiple echocardiographic techniques have been utilized to quantify systolic function. The shortening and ejection fraction remain the most commonly used and accepted methods. However, these measures are affected by altered loading conditions, and are not applicable when ventricular geometry differs from the prolate ellipsoid typical of a left ventricle. Mitral valve annular acceleration during isovolumic contraction (IVA) has been proposed as a load independent index of left ventricular contractility. However, published values for IVA demonstrating normal function vary. In addition, the value of IVA which may discern impaired systolic function has not been established. The purpose of this study is to determine a threshold IVA value for abnormal left ventricular function in the pediatric population. Structurally/functionally normal control (n = 90) and dilated cardiomyopathy (study = 64) patients were compared for differences in left ventricular: wall stress (WS), velocity of circumferential fiber shortening (VCFc), ejection fraction (EF), ejection force, and pulsed wave-derived medial and lateral wall IVA. No difference in body surface area (p = 0.61) or gender (p = 0.53) was noted. Left ventricular ejection fraction, ejection force, VCFc, and IVA were significantly lower and WS was significantly higher in the study group (p < 0.01). The medial IVA was 1.71 ± 0.89 m/s(2) for an EF <40%, 1.74 ± 0.70 m/s(2) for an EF = 40-50%, 2.46 ± 0.89 m/s(2) for an EF >50%. The lateral IVA was 1.81 ± 1.03 m/s(2) for an EF <40%, 2.07 ± 0.78 m/s(2) for an EF = 40-50%, 2.54 ± 0.99 m/s(2) for an EF >50%. ROC analysis demonstrated a medial IVA of 1.97 m/s(2) as the cut-off for predicting an EF <50% with a 77% sensitivity of and specificity of 66% (AUC = 0.75, CI = 0.67-0.83, p < 0.01). ROC analysis demonstrated a lateral IVA of 2.31 m/s(2) as the cut-off for predicting an EF <50% with a 73% sensitivity of and specificity of 63% (AUC = 0.72, CI = 0.63-0.82, p < 0.01). IVA lateral of 1.93 m/s(2) or less was associated with heart transplant and death. ICC analysis demonstrated some interobserver variability in IVA measurement (0.57-0.65). The normal IVA of the medial and lateral mitral valve annulus measure over 1.97 m/s(2) and 2.31 m/s(2), respectively; values less than this cut-off are associated with EF <50%. Despite some problems with reproducibility IVA remains a promising method of screening for diminished ventricular contractility in the setting of abnormal geometry.

Decremental left ventricular deformation after pulmonary artery band training and subsequent repair in ventriculoarterial discordance.

BACKGROUND: Patients with ventriculoarterial discordance, such as congenitally corrected and d-transposition of the great arteries, may undergo a morphologic left ventricular (LV) training strategy consisting of surgical pulmonary artery band (PAB) placement and subsequent anatomic repair to establish ventriculoarterial concordance. The purpose of this study was to characterize morphologic LV function and deformation longitudinally using speckle-tracking strain analysis in patients with ventriculoarterial discordance who underwent LV training. METHODS: Twenty-nine patients (12 with d-transposition of the great arteries and 17 with congenitally corrected transposition of the great arteries) who underwent LV training with PAB placement were evaluated retrospectively. LV ejection fraction and global and regional longitudinal strain and strain rate were measured before and 7 ± 5 days after PAB placement and subsequent anatomic repair. RESULTS: PAB placement caused reductions in the mean LV ejection fraction from 76.1 ± 10.2% to 66.7 ± 7.8% (P < .001), in mean global strain from -17.7 ± 9% to -13.3 ± 7.5% (P = .01), and in mean lateral wall strain from -23.3 ± 12.8% to -17.5 ± 10.3% (P = .01). After anatomic repair (a median of 21 months after PAB placement; range, 0.5-104 months), mean LV ejection fraction decreased further from 63.3 ± 8.6% to 52.4 ± 14.9% (P < .05). Mean global strain declined from -17.6% ± 4.4 to -12.6 ± 4% (P = .01), and mean lateral wall strain decreased from -18.2 ± 11.4% to -12.6 ± 5.3% (P = .04). CONCLUSIONS: In patients with ventriculoarterial discordance undergoing PAB placement for LV training and anatomic repair, the morphologic left ventricle demonstrated decremental systolic function and global longitudinal deformation acutely. Frequent functional assessment is warranted to understand long-term myocardial mechanics in these patients.

Annular tilt as a screening test for right ventricular enlargement in patients with tetralogy of fallot.

BACKGROUND: Right ventricular end-diastolic volume (RVEDV) greater than 150 mL/m² is a risk factor for sudden death in patients with tetralogy of Fallot (TOF) after repair. Because of its anterior placement and abnormal geometry, two-dimensional echocardiography is limited to a qualitative assessment of RVEDV. Cardiac magnetic resonance imaging (CMRI) and computed tomography angiography (CTA) are the accepted standards for quantifying RVEDV. This study evaluated the ability of a novel echocardiographic measure, the right ventricular annular tilt (RVAT), to identify patients with increased RVEDV. METHODS: All patients with repaired TOF with an echocardiogram and CMRI or CTA were included in this retrospective study. The RVAT was determined by measuring the angle of the tricuspid valve plane relative to the mitral valve plane at end-diastole in the apical 4-chamber view in study (n = 38) and age-matched control (n = 74) patients. The RVEDV measurements were obtained by CMRI (n = 32) or CTA (n = 6). The study and control patients' ages were no different (11.3 and 11.8 years, P = .73). RESULTS: The study group RVAT was significantly higher than the control group RVAT (17.4 vs. 0.1 degrees; P < .0001). RVAT values greater than 20 degrees had a mean RVEDV of 166 ± 60 mL/m², whereas RVAT less than 20 degrees had a mean RVEDV of 122 ± 25 mL/m² (P = .0370). Receiver operating characteristic analysis demonstrated an RVAT of 17.9 degrees as the cutoff for predicting a RVEDV of greater than 150 mL/m² with a sensitivity of 75% and specificity of 73% (area under the curve = 0.76; confidence interval, 0.56-0.96; P = .0063). Intraclass correlation analysis demonstrated minimal interobserver and intraobserver variability when measuring RVAT (0.99 and 0.92). CONCLUSION: An RVAT less than 20 degrees is associated with an RVEDV less than 150 mL/m². RVAT is a useful echocardiographic technique for detecting increased RVEDV in patients with TOF and may help discern which patients should undergo RVEDV quantification by CMRI or CTA.