Two-ventricle Physiology Research Articles

Restenosis Rate and Reinterventions after Aortic Arch Repair in Infants

The aim. This study aims to determine the reintervention rate in infantsundergoing aortic arch repair and to analyze risk factors and evaluate the results of reinterventions.
 Materials and methods. This retrospective study examines 445 infants with aortic arch hypoplasia who under-went aortic arch reconstruction between 2011 and 2019. The study included only patients with two-ventricle physiology and subsequent two-ventricle repair. Techniques for primary repair included extended end-to-end anastomosis (n = 348), end-to-side anastomosis (n = 611), autologous pericardial patch repair (n = 16).
 Results. The overall mortality in the entire study group was 3.3 %. Follow-up period ranged from 1 month to 9.4 years (mean 2.8 ± 2.5 years). Restenosis at the site of aortic arch repair was identiϐied in 47 (10.5 %) patients. Of these, 12 patients underwent surgical reconstruction of the aortic arch, 27 patients underwent balloon angioplasty, and in 8 patients both methods were used. Freedom from reintervention was 89.4 % at 1-year follow-up and 87.5 % at 4-year follow-up. The most determining factorsfor restenosis were related to hypoplastic proximal aortic arch and body weight less than 2.5 kg.
 Conclusions. Surgical treatment of aortic arch hypoplasia in newborns and infants is effective and shows good immediate and long-term results. Anatomical correction of reobstruction at the level of the aortic arch is safe with both endovacular and surgical methods with low mortality and incidence of repeated interventions. Identified risk factors for mortality and recurrent aortic arch interventions help to improve the treatment of aortic arch hypoplasia in patients under 1 year of age.

Clinical progress note: Noncardiac complications in adults with congenital heart disease.

Clinical progress note: Noncardiac complications in adults with congenital heart disease.

Sedation versus General Anesthesia for Cardiac Catheterization in Infants: A Retrospective, Monocentric, Cohort Evaluation.

Background: Children with congenital heart disease require repeated catheterization. Anesthetic management influences the procedure and may influence outcome; however, data and recommendations are lacking for infants. We studied the influence of sedation versus general anesthesia (GA) on adverse events during catheterization for children <2 years old. Methods: We conducted a monocentric, retrospective study of all catheterization procedures (2008–2013). High-severity adverse event (HSAE) rates were compared using propensity-score-adjusted models, including pre- and intra-procedural variables. Results: 803 cases (619 patients) (368 (46%) GA, 435 (54%) sedation) with a mean age of 6.9 ± 6.1 months were studied. The conversion rate (GA after sedation) was 18 (4%). Hospital stay was 4.9 ± 4.0 and 4.1 ± 2.5 (p = 0.01) after GA or sedation, respectively. HSAE occurred in 75 (20%) versus 40 (9%) (p < 0.01) in GA versus sedation procedures, respectively. Risk factors (multivariable analysis) were older patients (p = 0.05), smaller weights (p < 0.01), palliated status (OR 3.2 [1.2–8.9], p = 0.02), two-ventricle physiology (OR 7.3 [2.7–20.2], p < 0.01), cyanosis (OR 4.6 [2.2–9.8], p < 0.01), pulmonary hypertension (OR 5.6 [2.0–15.5], p < 0.01), interventional catheterization (OR 1.8 [1.1–3.2], p = 0.02) and procedure-type risk category 4 (OR 28.9 [1.8–455.1], p = 0.02). Sedation did not increase the events rate and decreased the requirement for hemodynamic support (OR 5.2 [2.2–12.0], p < 0.01). Conclusion: Sedation versus GA for cardiac catheterization in children <2 years old is safe and effective with regard to HSAE. Sedation also decreases the requirement for hemodynamic support. Paradoxical effects (older age and two-ventricle physiology) on risk have been found for this specific age cluster.

Application of moderate hypothermia while performance of the aortal arch reconstruction in new-born babies in conditions of selective antegrade cerebral perfusion

Objective. To estimate a security of application of moderate hypothermia while performing the aortal arch reconstruction in new-born babies in conditions of selective antegrade cerebral perfusion.&#x0D; Materials and methods. In 2010-2019 yrs period in Amosov National Institute of Cardiovascular Surgery and Scientific-Practical Medical Centre of Pediatric Cardiology and Cardio-Surgery in 64 new-born babies the aortal arch reconstruction was performed in conditions of selective antegrade cerebral perfusion in moderate hypothermia. In the investigation only patients with a two-ventricle physiology, in whom further two-ventricular correction was conducted, were included. There were 48 (75%) boys and 16 (25%) girls. Median age of the patients was (1.6 ± 0.8) mo, median body mass - (3.8 ± 1.1) kg, median square of the body surface - (0.24 ± 0.04) m². Echocardiographic investigation and neurosonography were the main diagnostic procedures.&#x0D; Results. Hospital mortality have constituted 4.7% (3 patients died). The death cases were not connected with the brain protection procedure. Duration of artificial blood circulation period have had constituted (138.4 ± 58.8) min at average, aortal clamping - (83.1 ± 40 min), selective antegrade cerebral perfusion - (24.4 ± 8.8) min. In 10 (15,6%) patients in early postoperative period the sternum persisted open. In 4 (6.2%) patients in early postoperative period convulsions were noted, which were treated successfully medicinally. Median stay in the Department of Reanimation and Intensive Therapy have constituted (7.1 ± 4.1) days. In late follow-up period the patients were seen from 1 mo till 8.5 yrs. No one patient died. While elective neurosonography conduction the brain pathological changes were absent. The neurological complications symptoms were absent as well.&#x0D; Conclusion. Selective antegrade cerebral perfusion with moderate hypothermia constitutes effective and secure method of the brain protection while performance of the aortal arch reconstruction in new-born babies, using median surgical approach in conditions of artificial blood circulation.

Post-operative discharge education for parent caregivers of children with congenital heart disease: a needs assessment.

Children with congenital heart disease (CHD) have complex unique post-operative care needs. Limited data assess parents' hospital discharge preparedness and education quality following cardiac surgery. The goals were to identify knowledge gaps in discharge preparedness after congenital heart surgery and to assess the acceptability of an educational mobile application to improve discharge preparedness. Telephonic interviews with parents of children with two-ventricle physiology who underwent cardiac surgery 5-7 days post-discharge and in-person interviews with clinicians were conducted. We collected parent and clinician demographics, parent health literacy information and patient clinical data. We analysed interview transcripts using summative content analysis. We interviewed 26 parents and 6 clinicians. Twenty-two of the 26 (85%) parents felt ready for discharge; 4 of the 6 (67%) clinicians did not feel most parents were ready for discharge. Fifteen of the 26 parents (58%) reported receiving the majority of discharge teaching on the day of discharge. Eight parents did not feel like all of their questions were answered. Most parents (14/26, 54%) preferred visual educational learning aids and could accurately describe important aspects of care. Most parents (23/26, 88%) and all 6 clinicians felt a mobile application for post-operative care education would be helpful. Most parents received education on the day of discharge and could describe the information they received prior to discharge, although there were some preparedness gaps identified after discharge. Clinicians and parents varied in their perceptions of the readiness for discharge. Most responses suggest that a mobile application for discharge education may be helpful for transition to home.

Reconstruction of aortal arch in patients with transposition of the main arteries: results of a one-stage correction

Objective. To analyze immediate and late results of a one-stage surgical treatment of the main arteries transposition in conjunction with obstruction on the level of aortal arch.&#x0D; Materials and metods. For the period 2010 - 2019 yrs in Amosov National Institute of Cardiovascular Surgery and Scientific-Practical Medical Centre of Pediatric Cardiology and Cardio-Surgery in 52 newborn babies a one-stage correction of the main arteries transposition with obstruction on the level of aortal arch was conducted. In the investigation were included only the patients with a two-ventricle physiology and further two-ventricle correction. There were 35 (67.3%) boys and 17 (32.7%) girls. Average age of the patients was (0.6 ± 0.3) mo, average body mass - (3.6 ± 0.8) kg. The main method of diagnosis in determination of the failure and estimation of immediate and late results was echocardiographic examination. In 24 (46.2%) of the patients while doing reconstruction of the aortal arch a selective antegrade cerebral perfusion was conducted.&#x0D; Results. Hospital mortality have constituted 3.8% (n=2). Duration of artificial blood circulation have constituted (194.3 ± 73.1) min, aortal clamping - (108.5 ± 35.6) min, selective cerebral perfusion - (19.6 ± 7.2) min. In early postoperative period 6 (11.5%) patients have been with desintegrated sternum. Average duration of observation have constituted (3.7 ± 2.8) yr (from 1 no to 9.yrs). In late period one child died. In 5 (9.6%) patients in postoperative period restenosis in aortal arch have developed, who was successfully curated endovascularly, using balloon dilatation in 3 patients, In two secondary plasty of aortal arch was done surgically. Tracheal or the main bronchi compression, neurologic complications were not observed in remote period.&#x0D; Conclusion. One-stage correction of the main arteries transposition together with the aortal arch hypoplasia - an effective and secure method of treatment of a newborn children with good immediate and late results. The investigation conducted gives a background to conclude, that this surgical strategy constitutes the affordable alternative to two-staged surgical treatment of this complex pathology.

Impact of a Multi-Interventional Nutrition Program on the Outcomes of Newborns Requiring Surgery for Congenital Heart Disease

Purpose: Up to 65% of children with congenital heart disease (CHD) suffer from malnutrition. The goal of our study was to evaluate how health and nutrition outcomes changed in newborns undergoing surgery for CHD at our institution after implementation of our “Pediatric Heart Institute Nutrition Program,” which included pre-operative and post-operative feeding algorithms to standardize nutritional management. Methods: This was a single-center cohort study in 3 phases that included newborns with single-ventricle physiology, two-ventricle physiology, and two-ventricle physiology with shunt-dependent pulmonary blood flow who underwent cardiac surgery between September 2008 and July 2015. We evaluated outcomes in the 2 years of pre-program time (Phase 0), in the 2 years after initiation of a standardized post-operative …

Pulmonary Dead Space Fraction and Extubation Success in Children After Cardiac Surgery.

1) Determine the correlation between pulmonary dead space fraction and extubation success in postoperative pediatric cardiac patients; and 2) document the natural history of pulmonary dead space fractions, dynamic compliance, and airway resistance during the first 72 hours postoperatively in postoperative pediatric cardiac patients. A retrospective chart review. Cardiac ICU in a quaternary care free-standing children's hospital. Twenty-nine with balanced single ventricle physiology, 61 with two ventricle physiology. None. We collected data for all pediatric patients undergoing congenital cardiac surgery over a 14-month period during the first 72 hours postoperatively as well as prior to extubation. Overall, patients with successful extubations had lower preextubation dead space fractions and shorter lengths of stay. Single ventricle patients had higher initial postoperative and preextubation dead space fractions. Two-ventricle physiology patients had higher extubation failure rates if the preextubation dead space fraction was greater than 0.5, whereas single ventricle patients had similar extubation failure rates whether preextubation dead space fractions were less than or equal to 0.5 or greater than 0.5. Additionally, increasing initial dead space fraction values predicted prolonged mechanical ventilation times. Airway resistance and dynamic compliance were similar between those with successful extubations and those who failed. Initial postoperative dead space fraction correlates with the length of mechanical ventilation in two ventricle patients but not in single ventricle patients. Lower preextubation dead space fractions are a strong predictor of successful extubation in two ventricle patients after cardiac surgery, but may not be as useful in single ventricle patients.

Telemedicine in Pediatric Critical Care: A Retrospective Study in an International Extracorporeal Membrane Oxygenation Program.

Extracorporeal membrane oxygenation (ECMO) is an invaluable rescue technique for critically ill children with imminent or present cardiopulmonary collapse. However, medical team expertise to optimize results and decrease complications is scarce. Telemedicine can be used to enhance the delivery of quality interventions. This is a retrospective review of pediatric patients assisted with ECMO in the cardiac intensive care unit (CICU) at Fundación Cardiovascular de Colombia from July 2011 to June 2015 (telemedicine) compared with similar patients from a previous period (pretelemedicine). Collected information included demographic data, cardiac diagnosis, risk adjustment for congenital heart surgery (RACHS-1), hospital mortality, CICU and hospital length of stay (LOS), ECMO type, and ECMO run hours as well as specific telemedicine information. Fifty-seven patients in the pretelemedicine and 109 in the telemedicine periods were included in the analysis. Forty-nine teleconsulted patients received 218 teleconsultations, with a recommendation for diagnostic or interventional catheterization in 38 patients (77.5%). A surgical procedure for significant residual lesions was recommended in 30 patients (61.2%). Patients in the telemedicine period were older (4.7 months vs. 1.6 months, p = 0.006), more likely to receive operating room ECMO (43.1% vs. 24.6%, p = 0.02), and had a higher proportion of patients with two-ventricle physiology (73.4% vs. 54.4%, p = 0.013). Hospital survival was higher during the telemedicine period (54.1% vs. 29.8%, p = 0.002), with a longer hospital LOS (67 days vs. 28 days, p < 0.001). The implementation of telemedicine-assisted interventions in a pediatric ECMO program delivered valuable diagnostic and therapeutic advice, was associated with significant changes in selection criteria and model of care, and an increased hospital survival.

Echocardiographic right ventricular function correlations with cardiac catheterisation data in biventricular congenital heart patients.

Newer echocardiographic techniques may allow for more accurate assessment of right ventricular function. Adult studies have correlated these echocardiographic measurements with invasive data, but minimal data exist in the paediatric congenital heart population. The purpose of this study was to evaluate echocardiographic measurements that correlate best with right ventricular systolic and diastolic catheterisation parameters. Patients with two-ventricle physiology who underwent simultaneous echocardiogram and cardiac catheterisation were included in this study. Right ventricular systolic echocardiographic data included fractional area change, displacement, tissue Doppler imaging s' wave, global longitudinal strain, and strain rate s' wave. Diastolic echocardiographic data included tricuspid E and A waves, tissue Doppler imaging e' and a' waves, and strain rate e' and a' waves. E/tissue Doppler imaging e', tissue Doppler imaging e'/tissue Doppler imaging a', E/strain rate e', and strain rate e'/strain rate a' ratios were also calculated. Catheterisation dP/dt was used as a marker for systolic function and right ventricular end-diastolic pressure for diastolic function. A total of 32 patients were included in this study. The median age at catheterisation was 3.1 years (0.3-17.6 years). The DP/dt was 493±327 mmHg/second, and the right ventricular end-diastolic pressure was 7.7±2.4 mmHg. There were no significant correlations between catheterisation dP/dt and systolic echocardiographic parameters. Right ventricular end-diastolic pressure correlated significantly with strain rate e' (r=-0.4, p=0.02), strain rate a' (r=-0.5, p=0.03), and E/tissue Doppler imaging e' (r=0.4, p=0.04). Catheterisation dP/dt did not correlate with echocardiographic measurements of right ventricular systolic function. Strain rate and tissue Doppler imaging analysis significantly correlated with right ventricular end-diastolic pressure. These values should be further studied to determine whether they may be used as an alternative method to estimate right ventricular end-diastolic pressure in this patient population.

Bad Oeynhausen Experience with Berlin Heart EXCOR in Children with Single- and Two-Ventricle Physiology

Bad Oeynhausen Experience with Berlin Heart EXCOR in Children with Single- and Two-Ventricle Physiology

Fontan Conversion: Literature Review and Lessons Learned Over 20 Years.

Early survival after the Fontan operation has improved significantly leading to a lifetime of Fontan circulation for patients. There is a natural progression of pulmonary artery pressure during the human lifetime that is easily tolerated in two-ventricle physiology but is deleterious for single-ventricle physiology. Obstructions in the venous to pulmonary artery pathway and pulmonary venous return or ventricular outflow, atrioventricular valve dysfunction (regurgitation), pulmonary arteriovenous malformations, venous thrombosis, and the development of atrial arrhythmias can lead to reduced functional status. These complications have been demonstrated in older patients with largely atriopulmonary connections owing to time accrual and unfavorable flow characteristics. Various surgical and catheter interventions aimed at reducing morbidity and mortality have been attempted to treat these identifiable abnormalities. The purpose of this article is to review the extant literature on Fontan Conversion and to assess the lessons learned over 20 years.

Correlations Between Echocardiographic Systolic and Diastolic Function with Cardiac Catheterization in Biventricular Congenital Heart Patients.

Newer echocardiographic techniques may allow for more accurate assessment of left ventricular (LV) function. Adult studies have correlated these echocardiographic measurements with invasive data, but minimal data exist in the pediatric congenital heart population. Purpose of this study was to evaluate which echocardiographic measurements correlated best with LV systolic and diastolic catheterization parameters. Patients with two-ventricle physiology who underwent simultaneous echocardiogram and cardiac catheterization were included. Images were obtained in the four-chamber view. LV systolic echocardiographic data included ejection fraction, displacement, tissue Doppler imaging (TDI) s' wave, global longitudinal strain, and strain rate (SR) s' wave. Diastolic echocardiographic data included mitral E and A waves, TDI e' and a' waves, and SRe' and SRa' waves. E/TDI e', TDI e'/TDI a', E/SRe', and SRe'/SRa' ratios were also calculated. Catheterization dP/dt was used as a marker for systolic function, and LV end-diastolic pressure (EDP) was used as a marker for diastolic function. Correlations of the echocardiographic and catheterization values were performed using Pearson correlation. Twenty-nine patients were included (14 females, 15 males). Median age at catheterization was 3.4 years (0.04-17.4 years). dP/dt was 1258 ± 353 mmHg/s, and LVEDP was 10.8 ± 2.4 mmHg. There were no significant correlations between catheterization dP/dt and systolic echocardiographic parameters. LVEDP correlated significantly with SRe' (r = -0.4, p = 0.03), SRa' (r = -0.4, p = 0.03), and E/SRe' (r = 0.5, p = 0.004). In pediatric congenital heart patients, catheterization dP/dt did not correlate with echocardiographic measurements of LV systolic function. Further studies are needed to determine which echocardiographic parameter best describes LV systolic function in this population. Strain rate analysis significantly correlated with LVEDP. Strain rate analysis should be considered as an alternative method to estimate LVEDP in this patient population.

Abstract 12803: Long-term Outcomes After Surgical Pulmonary Arterioplasty: Analysis of Re-intervention Rates and Patient-specific Risk Factors

Introduction: Branch pulmonary artery stenosis (PAS) is common in congenital heart disease. Surgical patch arterioplasty is a conventional therapy, however, limited data exist on long-term outcomes. Hypothesis: We examined the incidence of and risk factors for re-intervention after surgical arterioplasty for PAS. We assessed the hypothesis that certain characteristics are associated with increased need for re-intervention. Methods: This retrospective cohort study included patients with two-ventricle physiology who underwent patch arterioplasty for PAS at a single high-volume center from 2004-2013. Freedom from surgical or percutaneous re-intervention for recurrent PAS was estimated. Univariate and multivariable Cox regression were performed to determine risk factors for re-intervention. Results: Among 116 patients undergoing patch arterioplasty at a median age of 1.2 years, hospital discharge survival was 95%. Of the survivors, 97 (88%) had a median follow-up of 3.6 years (range 15 days to 11 years). PAS re-intervention occurred in 31/97 (32%) at a median time to re-intervention of 1.6 years (range 7 days to 9.3 years). Freedom from re-intervention is shown in Figure 1. In univariate analysis, age less than 30 days at time of arterioplasty, congenital PAS (versus acquired), and bilateral PAS were significantly associated with re-intervention. In multivariate analysis, neonatal age (adjusted hazard ratio [AHR 4.4], p=0.004) and bilateral PAS (AHR 3.3, p=0.003) remained independently associated with re-intervention. Conclusions: We present the largest cohort study with the longest follow-up time evaluating outcomes after surgical pulmonary arterioplasty for PAS to date. Re-intervention for recurrent PAS following patch arterioplasty is common. In conclusion, patients at highest risk for re-intervention, such as neonates and patients with bilateral PAS, may benefit from frequent monitoring or novel approaches to repair.

Abstract 12140: Prognostic Value of Multiple Biomarkers on Mortality in Adults Congenital Heart Disease: Comparison of Single- and Two-Ventricle Physiology

Introduction: Although many biomarkers are associated with heart failure, limited data is available on their prognostic predictive value in adults with congenital heart disease (ACHD). We investigate the potential of various biomarkers to predict ACHD mortality. Methods and Results: This is a single-center, retrospective cohort study. Blood levels of neurohormones (endothelin-1 [ET1], norepinephrine [NE], aldosterone, and plasma renin activity [PRA]); inflammatory biomarkers (high sensitivity C-reactive protein [hs-CRP], high sensitivity tumor necrosis factor [hs-TNF]-α, soluble TNF receptor type I and II [sTNF-RI and sTNF-RII], and interleukin-6 [IL-6]); and brain natriuretic peptide (BNP) were measured in 115 ACHD (mean age, 30 ± 10 years). NYHA class was I/ II in 86% and III/IV in 14%. The subjects were divided into two groups: patients with single-ventricle (SV group, n = 65) and with two-ventricle physiology (TV group, n = 50). We retrospectively analyzed the relationship between levels of biomarkers and cardiovascular death. During a mean follow-up period of 4.6 years, 17 (14%) cardiovascular deaths occurred, including 7 in the SV group. Univariate cox regression analysis in all subjects showed strong association between elevated levels of ET1, NE, RPA, hs-CRP, sTNF-RI and II, IL-6, and BNP and cardiovascular death (p&lt; 0.05). In the SV group, using multivariate cox regression model, BNP and sTNF-RI were the most powerful predictors in these biomarkers (adjusted hazard ratio [aHR] of BNP: 14.84; 95%CI: 2.21-99.36 per 1 SD increase, p = 0.005) (aHR of sTNF-RI: 2.30; 95%CI: 1.91-4.55 per 1 SD increase, p = 0.017). The optimal cut-off values of BNP and sTNF-RI for mortality were 196 pg/mL and 1.26 ng/mL, respectively. Conversely, in the TV group, only IL-6 was an independent predictor of mortality (aHR: 3.24; 95%CI: 1.57-6.68 per 1 SD increase, p = 0.001), while BNP was not strongly associated with outcomes. The optimal cut-off value of IL-6 for mortality was 2.3 pg/mL. Conclusion: Various biomarkers, including sTNF-R, BNP, and IL-6, are associated with prognosis in overall ACHD. The most prominent mortality predictors might differ, due to differences in SV or TV physiology.

Tracheostomy in children with congenital heart disease: a national analysis of the Kids' Inpatient Database.

Background. While single-institution studies reported the indications and outcomes of tracheostomy in children with congenital heart disease (CHD), no national analyses have been performed. We sought to examine the indications, performance, outcomes, and resource utilization of tracheostomy in children with CHD using a nationally representative database.Methods. We identified all children undergoing tracheostomy in the Kids’ Inpatient Database 1997 through 2009, and we compared children with CHD to children without CHD. Within the CHD group, we compared children whose tracheostomy occurred in the same hospital admission as a cardiac operation to those whose tracheostomy occurred without a cardiac operation in the same admission.Results. Tracheostomy was performed in n = 2,495 children with CHD, which represents 9.6% of all tracheostomies performed in children (n = 25,928), and 3.5% of all admissions for children with CHD (n = 355,460). Over the study period, there was an increasing trend in the proportion of all tracheostomies that were done in children with CHD (p < 0.0001) and an increasing trend in the proportion of admissions for children with CHD that involved a tracheostomy (p < 0.0001). The population of children with CHD undergoing tracheostomy differed markedly in baseline characteristics, outcomes, and resource utilization. Similarly, the subgroup of children whose tracheostomy was performed in the same admission as a cardiac operation differed significantly from those whose tracheostomy was not.Conclusions. Tracheostomy is an increasingly common procedure in children with CHD despite being associated with significantly greater resource utilization and in-hospital mortality. The population of children with CHD who undergo tracheostomy differs markedly from that of children without CHD who undergo tracheostomy, and important differences are observed between children who undergo tracheostomy in the same admission as a cardiac surgical procedure and those who undergo tracheostomy in a nonsurgical admission, as well as between children with single-ventricle physiology and children with two-ventricle physiology.

Doppler Echocardiography Inaccurately Estimates Right Ventricular Pressure in Children with Elevated Right Heart Pressure

Doppler echocardiography (DE) is widely used as a surrogate for right heart catheterization (RHC), the gold standard, to assess and monitor elevated right heart pressure in children. However, its accuracy has not been prospectively validated in children. The objectives of this study were to evaluate the accuracy of DE in predicting simultaneously measured right ventricular (RV) pressure by RHC in pediatric patients and to determine if the degree of RV hypertension affects the accuracy of DE in assessing right heart pressure. Eighty children (age range, 0-17.9 years; median age, 5.5 years) with two-ventricle physiology and a wide range of right heart pressures underwent simultaneous DE and RHC. The pressure gradient between the right ventricle and the right atrium was directly measured by RHC and simultaneously estimated by DE using tricuspid regurgitation. Patients were then grouped on the basis of RHC-measured RV systolic pressure (RVSP): group 1 (n= 43), with RVSP < 1/2 systemic systolic blood pressure (SBP); group 2 (n= 37), with RVSP ≥ 1/2 SBP; group 3 (n= 56), with RVSP < 2/3 SBP; and group 4 (n= 24), with RVSP ≥ 2/3 SBP. Correlation and Bland-Altman analyses were performed on all groups. Accuracy was predefined as 95% limits of agreement within ±10 mm Hg. Despite a reasonable correlation between DE and RHC in all groups, there was poor agreement between techniques as RVSP/SBP increased. DE was inaccurate in one of 43 patients in group 1 (2%) versus nine of 37 in group 2 (24%) and was inaccurate in one of 56 patients in group 3 (2%) versus eight of 24 in group 4 (33%). Overestimation and underestimation occurred equally in all groups. DE inaccurately estimates RV pressure in children with elevated right heart pressure. It should not be relied on as the sole method of assessing right heart hemodynamics in children with RV hypertension.

Editorial Comment: Critical aortic stenosis with severe left ventricular dysfunction

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Population Pharmacokinetics of Pentobarbital in Neonates, Infants, and Children after Open Heart Surgery

To determine the pharmacokinetics of pentobarbital in neonates, infants, and young children with congenital heart disease after open-heart surgery. Thirty-five subjects (3.0 days-4.4 years) after open-heart surgery who received pentobarbital as standard of care were enrolled. Serial pharmacokinetic blood samples were obtained. A population-based, nonlinear mixed-effects modeling approach was used to characterize pentobarbital pharmacokinetics. A two-compartment model with weight as a co-variate allometrically expressed on clearance (CL), inter-compartmental clearance, central (V1) and peripheral volume of distributions, bypass grafting time as a co-variate on CL and V1, and age and ventricular physiology as co-variates on CL best described the pharmacokinetics. A typical infant (two-ventricle physiology, 6.9 kg, 5.2 months, and bypass grafting time of 60 minutes) had a CL of 0.12 L/hr/kg, V1 of 0.45 L/kg, and peripheral volume of distributions of 0.98 L/kg. The bypass grafting effect was poorly estimated. For subjects <12 months age, an age effect on CL remained after accounting for weight and was precisely estimated. Pentobarbital pharmacokinetics is influenced by age and weight. Subjects with single-ventricle physiology demonstrated a 15% decrease in clearance when compared with subjects with two-ventricle physiology.

Invited Commentary

Invited Commentary