Functional Univentricular Heart Research Articles

The Role of 3D-Printing in a Case of Complex Congenital Heart Disease Undergoing Heart Transplantation

<h3>Introduction</h3> Patients with complex congenital heart disease (CHD) who undergo orthotopic heart transplantation (OHT) present technical difficulties due to collateral vessels, unusual anatomy and adhesions. Becoming familiar with the specific anatomy of each individual case prior to surgery is therefore crucial for the surgeon, and all available diagnostic methods should be used before embarking on the procedure. 3D-printing technology may play a pivotal role, as in this case report. <h3>Case Report</h3> A 36-year-old male was listed for OHT in the context of a complex cyanotic CHD consisting of a functional univentricular heart with hypoplasia of the right chambers with tricuspid and pulmonary atresia and an intact ventricular septum, palliated by a right Blalock-Taussig (BT) shunt at the age of 2, a left BT shunt at the age of 6 which was stented in the follow-up, and a bidirectional Glenn shunt when he was 21 years old. To depict this complex anatomy and its spatial relationships, a 3D model was printed and used by the surgical team to enhance their understanding of the patient anatomy and reenact the planned surgery beforehand, enabling the team to predict and avoid possible complications during the act (Figure). In March 2021, the patient underwent elective OHT. During the surgery, multiple MAPCAs were ligated due to diffuse bleeding. The left pulmonary artery (PA) ostial stenosis was resected and then distally anastomosed. In addition, an end-to-end anastomosis of the right PA to the right AP of the recipient was performed, proximal to the Glenn anastomosis, which was repaired with a pericardial patch. Ischemia and CBP time were 245 and 253 minutes. The postoperative course was uneventful with no evidence of bleeding complications. <h3>Summary</h3> 3D-printing should be taken into consideration as a tool for planning surgical interventions in patients with complex CHD listed for OHT. The information provided may be useful to avoid improvisation during the procedure and thus, lead to a decrease in the expected ischemic times.

Risk factors for morbidity and mortality after a bidirectional Glenn shunt in Northern Thailand.

Owing to the evolution of surgical techniques, the survival rate of patients undergoing a bidirectional Glenn shunt has improved. However, the morbidity and mortality are still high. The aims of this study were to determine the survival rate and risk factors influencing the morbidity and mortality in patients with a functional univentricular heart after a bidirectional Glenn shunt. One hundred and fifty-one patients who had undergone a bidirectional Glenn operation were enrolled. Early worse outcomes were defined as postoperative death within 30days and a hospital stay ≥ 30days. The median age was 7.1years (range 0.3-26years). The median age at the time of the Glenn operation was 2.2years (range 0.2-15.9years). The survival rates of patients at 1-, 5-, 10- and 15-year after the Glenn operation were 89%, 79%, 75%, and 72%, respectively. The predictors for the mortality were preoperative mean pulmonary artery pressure ≥ 17mmHg, preoperative pulmonary vascular resistance index ≥ 3.1 Wood Units·m2 and atrioventricular valve regurgitation. In addition, the independent predictors of an early worse outcome included preoperative mean pulmonary artery pressure ≥ 17mmHg and diaphragmatic paralysis. The presence of preoperative atrioventricular valve regurgitation, preoperative mean pulmonary artery pressure ≥ 17mmHg, preoperative pulmonary vascular resistance index ≥ 3.1 Wood Units·m2, or diaphragmatic paralysis were found to be independent risk factors requiring the good patients' selection for the Glenn operation and early aggressive management of the diaphragmatic paralysis for reducing morbidity to ensure successful candidature for Fontan completion.

Cardiovascular complications in patients with total cavopulmonary connection: A nationwide cohort study

BackgroundLong-term outcomes are not well established at the population level after completion of the total cavopulmonary connection (TCPC) among patients with functional univentricular hearts. PurposeTo evaluate the incidence of cardiovascular events after TCPC completion. MethodsFrom a validated population-based cohort, we identified 178 patients with TCPC circulation completed after January 1, 1995. We established a comparison cohort by frequency-matching patients 1:200 on sex, and month and year of birth to the general Danish population (n = 35,600 population controls). We started follow-up at date of TCPC completion for cases and, for controls, at the index date of their matched case. The risks of cardiovascular events were assessed using cumulative incidence rates and Poisson regression models adjusted for age, sex, and calendar year. ResultsThe median age at TCPC completion was 3.3 years (interquartile range 2.6 to 5.3 years). Over a median follow-up of 12.5 years, 10 (5.6%) TCPC patients died and 7 (4.5%) had a heart transplantation compared with a 0.2% mortality in the matched population. In TCPC patients, 15.7% had an arrhythmia (11.8% supraventricular tachycardia), 3.4% had a stroke (all ischemic), and 21.4% of TCPC patients initiated a combination of a diuretic and a renin-angiotensin system (RAS)-inhibitor. These rates were >50-fold higher than in the comparison cohort: 0.2% arrhythmia, 0.06% stroke, and 0.04% starting a diuretic and a RAS-inhibitor. ConclusionsPatients with TCPC circulation face a high risk of cardiovascular events during intermediate term follow-up.

Diagnostic accuracy of low-dose dual-source cardiac computed tomography as compared to surgery in univentricular heart patients

BackgroundTo evaluate the ability of low radiation dose dual-source computed tomography (DSCT) to depict the features of morphological univentricular heart and to define accuracy by comparing findings with surgery.MethodsLow radiation dose dual-source cardiac computed tomography (CCT) of 33 cases of functional univentricular heart preliminary diagnosis by echocardiography compared with the results of surgery were retrospectively analyzed (aged 1 day to 4 years, median 5 months). The appropriate dose reduction strategies and iterative reconstruction were applied.ResultsThirty three univentricular heart patients were classified into three types according to Anderson’s classification method, including 16 cases (48.5%) univentricular of right ventricular type with rudimentary chamber of left ventricle, 11 cases (33.3%) univentricular of left ventricular type with rudimentary chamber of right ventricle and 6 cases (18.2%) univentricular heart of indeterminate type without rudimentary chamber. The extracardiac malformation such as hypoplastic aortic arch, coronary artery fistula, total anomalous pulmonary venous returns or hypoplastic lung were presented frequently. The overall sensitivity and specification of cardiac CT was 100% compared to the results of surgery. The procedural dose-length product was 18 ± 5 mGy-cm, and unadjusted and adjusted radiation doses were 0.25 and 0.64 mSv, respectively.ConclusionCardiac CT can diagnose accurately and be performed with a low radiation exposure in patients with the functional univentricular heart disease. The aorta, pulmonary artery and lung can be evaluated completely and simultaneously as well. Cardiac CT is an effective advanced non-invasive imaging modality to comprehensive evaluation the functional univentricular heart patients, particularly if cardiac MRI poses a high risk or is contraindicated.

Blood-threshold CMR volume analysis of functional univentricular heart.

To validate a blood-threshold (BT) segmentation software for cardiac magnetic resonance (CMR) cine images in patients with functional univentricular heart (FUH). We evaluated retrospectively 44 FUH patients aged 25±8years (mean±standard deviation). For each patient, the epicardial contour of the single ventricle was manually segmented on cine images by two readers and an automated BT algorithm was independently applied to calculate end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), and cardiac mass (CM). Aortic flow analysis (AFA) was performed on through-plane images to obtain forward volumes and used as a benchmark. Reproducibility was tested in a subgroup of 24 randomly selected patients. Wilcoxon, Spearman, and Bland-Altman statistics were used. No significant difference was found between SV (median 57.7ml; interquartile range 47.9-75.6) and aortic forward flow (57.4ml; 48.9-80.4) (p=0.123), with a high correlation (r=0.789, p<0.001). Intra-reader reproducibility was 86% for SV segmentation, and 96% for AFA. Inter-reader reproducibility was 85 and 96%, respectively. The BT segmentation provided an accurate and reproducible assessment of heart function in FUH patients.

Risk factors for in-hospital shunt thrombosis and mortality in patients weighing less than 3 kg with functionally univentricular heart undergoing a modified Blalock-Taussig shunt.

To determine the association between several perioperative variables and in-hospital shunt thrombosis and mortality in patients weighing less than 3 kg with functional univentricular heart (UVH) who underwent modified Blalock-Taussig shunt. Between January 2006 and February 2016, 85 patients who weighed less than 3 kg with functional UVH and underwent modified Blalock-Taussig shunt were reviewed. In-hospital shunt thrombosis and mortality were the primary outcomes. The associations between perioperative variables and outcomes were assessed with univariate and multivariate analyses. In-hospital shunt thrombosis was 14% (12 of 85). Hospital mortality was 18% (15 of 85), which resulted in an 82% discharge survival rate. Shunt thrombosis was significantly associated with in-hospital mortality (odds ratio 18.9, 95% confidence interval 4.5-78.9). There were no statistically significant associations between weight, specific diagnosis of functional UVH and shunt thrombosis or mortality. Multivariate analysis identified delayed initiation of anticoagulant (P < 0.01) and postoperative cardiac arrest (P < 0.01) as risk factors of shunt thrombosis, while intraoperative bradycardia (P < 0.01), high postoperative haemoglobin (P = 0.03) and shunt thrombosis (P < 0.01) were risk factors for hospital mortality. In this high-risk group of patients who weighed less than 3 kg with functional UVH and who underwent modified Blalock-Taussig shunt, in-hospital mortality was strongly associated with the occurrence of shunt thrombosis. Our study highlighted the perioperative variables of delayed postoperative initiation of anticoagulant, cardiac arrest and the occurrence of intraoperative bradycardia that were significant risk factors for shunt thrombosis and mortality. Achieving better quality of perioperative care potentially improves outcomes.

Clinical Characteristics and Independent Factors Related to Long-Term Outcomes in Patients with Left Isomerism.

Background and ObjectivesWe studied the results of patient management for left isomerism (LI) and sought to determine factors that may influence survival and prognosis.Subjects and MethodsWe reviewed the medical records of 76 patients who were compatible with LI criteria between 1982 and 2014.ResultsOf the total study population, 29 patients (38.1%) had functional univentricular heart disease, 43 patients (56.5%) had cardiac anomalies suitable for biventricular hearts, and four patients (5.2%) had normal heart structure. Extracardiac anomalies were noted in 38.1% of the study population, including biliary atresia in 7.8% of all patients. Of the 25 patients who underwent Kawashima procedures, 24.0% developed pulmonary arteriovenous fistulas (PAVFs). During the median follow-up period of 11.4 years (range: 1 day to 32 years), 14 patients died. The 10-year, 20-year, and 30-year survival rates were 87%, 84%, and 76%, respectively. Preoperative dysrhythmia and uncorrected atrioventricular valve regurgitation were significantly associated with late death. There was no significant difference in the number of surgical procedures and in survival expectancy between patients in the functional single-ventricle group and in the biventricular group. However, late mortality was higher in functional single-ventricle patients after 18 years of age.ConclusionPatients with LI need to be carefully followed, not only for late cardiovascular problems such as dysrhythmia, valve regurgitation, and the development of PAVFs, but also for noncardiac systemic manifestations.

VIEWING ONLY POSTERS1323Evaluation of right ventricular transverse strain and strain rate in patients with acute ST-segment elevation myocardial infarction: a cardiac magnetic resonance feature tracking study1333Cardiac resynchronization in ischemic heart failure patients: a comparison between therapy guided by cardiac magnetic resonance imaging and 2D-speckle tracking echocardiography1338Cardiac magnetic resonance versus bisphosphonate scintigraphy for diagnosis of cardiac amyloidosis1341Strain relaxation index, a novel

VIEWING ONLY POSTERS1323Evaluation of right ventricular transverse strain and strain rate in patients with acute ST-segment elevation myocardial infarction: a cardiac magnetic resonance feature tracking study1333Cardiac resynchronization in ischemic heart failure patients: a comparison between therapy guided by cardiac magnetic resonance imaging and 2D-speckle tracking echocardiography1338Cardiac magnetic resonance versus bisphosphonate scintigraphy for diagnosis of cardiac amyloidosis1341Strain relaxation index, a novel

Abstract 16949: Failing Fontan: Genesis of a Subpulmonary Neo-ventricle From Engineered Heart Tissue

Introduction: Fontan palliation is the treatment of choice for patients with morphological or functional univentricular hearts. The unphysiologic and non-pulsatile pulmonary blood flow results in multiorgan complications and a poor long-term outcome. We evaluated graft survival and histomorphology of a pulsatile Fontan conduit generated from Engineered Heart Tissue (EHT) after implantation in a rat model. Hypothesis: We hypothesized that EHT matures and remains contractile in the setting of venous (Fontan-like) preload. Methods: EHT was generated from ventricular cardiomyocytes of neonatal Wistar rats, fibrinogen, thrombin and DMEM. After culture for 14 days constructs were implanted around the right superior vena cava of Wistar rats (n=12, 300-350 g). Immunosupression was achieved by daily subcutaneous injection of Cyclosporin A (25 mg/kg BW) and Methylprednisolone (2 mg/kg BW). MRI (Bruker) was used to assess condensation of EHTs in vivo. Animals were euthanized after 7, 14, 28 and 56 days postoperatively for histomorphological analysis. Transmission electron microscopy was used to evaluate sarcomeric integrity of cardiomyocytes within the construct. Results: In culture, EHTs started beating around day 8 and remained contractile in vivo throughout the experiment (d7=3/3, d14=2/3, d28=3/3, d56=2/3). All animals survived circumferential implantation of EHTs around the right SVC via a right thoracotomy. MRI (d14, n=3) revealed no constriction or stenosis of the SVC by the constructs. Hematoxylin and Eosin staining showed densely packed bundles of cardiomyocytes within the EHT conduit and intense vascularisation. Immunolabeling of actinin and connexin 43 indicated adequate maturation of cardiomyocytes after grafting around the right SVC in rats. Conclusions: EHTs placed around the superior caval vein of Wistar rats survive and contract for a considerable time after implantation. Histomorphology revealed a matured phenotype of grafted cardiomyocytes and an adequate vascularisation. The functional benefit of a contractile neo-ventricle to propel pulmonary blood flow in Fontan patients remains to be evaluated.

Fontan Circulation: Generation of a Subpulmonary Neo-Ventricle from Engineered Heart Tissue

Introduction: For patients with morphological or functional univentricular hearts Fontan palliation is the treatment of choice. The unphysiologic and non-pulsatile pulmonary blood flow results in multiorgan complications. We evaluated the histomorphology of a pulsatile Fontan conduit generated from Engineered Heart Tissue (EHT) after implantation in a rat model.

Fluoroscopy-guided Umbilical Venous Catheter Placement in Infants with Congenital Heart Disease.

The objective of this study was to (1) describe the technical aspects of fluoroscopy-guided umbilical venous catheter placement (FGUVCP); and (2) determine the procedural success rate, factors contributing to procedural failure, and risks of the procedure. Umbilical venous catheters are advantageous compared with femoral venous access, but can be difficult to place at the bedside. This was a retrospective chart review from a single tertiary care referral institution. FGUVCP was successful in 138 of 180 patients (76.7%) over a seven-year period. Patients in whom FGUVCP was successful were younger at the time of procedure compared with patients in whom FGUVCP was unsuccessful (median 18.2 vs. 22.2 hours, P = .03). The optimal age cutoff to predict FGUVCP success was 20 hours with a high positive predictive value (82.4%) but low negative predictive value (32.5%). No other variables were associated with procedural failure, though functional univentricular heart and older gestational age trended toward statistical significance. Median radiation time, contrast exposure, and blood loss were 3.2 minutes, 1 mL, and 1 mL, respectively. A total of 10 complications in 10 patients were associated with FGUVCP. FGUVCP is a safe and highly successful way to obtain central venous access in neonates with congenital heart disease. Older age at the time of procedure is associated with procedural failure, but utilization of an age cutoff may not be clinically useful.

Only hepatic venous blood closes intrapulmonary shunts after cavopulmonary connection

In patients with a functional univentricular heart good results are nowadays accomplished with a staged approach to a total cavopulmonary connection (TCPC) [ [1] d'Udekem Y. Iyengar A.J. Cochrane A.D. et al. The Fontan procedure: contemporary techniques have improved long-term outcomes. Circulation. 2007; 116: I157-I164 PubMed Google Scholar ]. However, there are certain complications leading to a diminished quality of life as well as significant morbidity and mortality [ [2] Hess J. Long-term problems after cavopulmonary anastomosis: diagnosis and management. Thorac Cardiovasc Surg. 2001; 49: 98-100 Crossref PubMed Scopus (21) Google Scholar ]. Beside protein-losing enteropathy, plastic bronchitis, dysrhythmias, ventricular dysfunction and arteriovenous fistulas or venovenous collaterals due to increased venous pressure [ 2 Hess J. Long-term problems after cavopulmonary anastomosis: diagnosis and management. Thorac Cardiovasc Surg. 2001; 49: 98-100 Crossref PubMed Scopus (21) Google Scholar , 3 Lenz D. Hambsch J. Schneider P. et al. Protein-losing enteropathy in patients with Fontan circulation: is it triggered by infection?. Crit Care. 2003; 7: 185-190 Crossref PubMed Scopus (48) Google Scholar ], microscopic intrapulmonary shunts are one of the major complications [ [4] Bernstein H.S. Brook M.M. Silverman N.H. Bristow J. Development of pulmonary arteriovenous fistulae in children after cavopulmonary shunt. Circulation. 1995; 92: II309-II314 Crossref PubMed Google Scholar ]. The incidence is reported to be up to 25% [ [5] Cloutier A. Ash J.M. Smallhorn J.F. et al. Abnormal distribution of pulmonary blood flow after the Glenn shunt or Fontan procedure: risk of development of arteriovenous fistulae. Circulation. 1985; 72: 471-479 Crossref PubMed Scopus (162) Google Scholar ]. The pathophysiology of these shunts is discussed and associated with a so-called liver factor. It has been observed, that the shunts become present in lungs without direct perfusion with hepatic venous blood, which means hepatic venous drainage has to pass another capillary bed first [ [6] Srivastava D. Preminger T. Lock J.E. et al. Hepatic venous blood and the development of pulmonary arteriovenous malformations in congenital heart disease. Circulation. 1995; 92: 1217-1222 Crossref PubMed Scopus (304) Google Scholar ]. The absence of venous hepatic blood flow into the lungs then leads to development and progression of the intrapulmonary shunts. This is the case in patients with partial cavopulmonary connection (PCPC) or after completion to TCPC with the hepatic venous drainage being directed mainly to one lung. The liver-factor-hypothesis is also supported by the fact that the shunts disappear after redirecting hepatic venous blood to the affected lung [ 7 Shah M.J. Rychik J. Fogel M.A. Murphy J.D. Jacobs M.L. Pulmonary AV malformations after superior cavopulmonary connection: resolution after inclusion of hepatic veins in the pulmonary circulation. Ann Thorac Surg. 1997; 63: 960-963 Abstract Full Text Full Text PDF PubMed Scopus (154) Google Scholar , 8 Praus A. Eicken A. Balling G. Schreiber C. Hess J. Progressive intrapulmonary shunting in a child after bidirectional Glenn operation only resolved after total cavopulmonary completion. Int J Cardiol. 2008; 128: e12-e15 Abstract Full Text Full Text PDF PubMed Scopus (5) Google Scholar ]. However, the exact pathophysiology or details about the hepatic factor are still not completely understood. In this study we analyzed the results of different therapeutic approaches in patients with severe intrapulmonary shunting and functional univentricular heart.

Upper body central venous catheters in pediatric cardiac surgery

A central venous catheter located in the jugular or subclavian vein provides rapid, reliable vascular access for pediatric heart surgery. However, intravascular catheters are associated with vessel injury. Stenosis or thrombosis of central veins in the upper body can lead to 'superior vena cava syndrome' with markedly elevated venous pressures in the head and neck, causing facial swelling and headaches. This complication may be especially serious for patients with superior cavopulmonary (Glenn) or total cavopulmonary (Fontan) circulation. The authors hypothesized that upper body central line placement would be associated with a low risk of venous thrombosis or stenosis. A three-year retrospective review of infant and univentricular cardiac procedures at a single institution was performed. Two hundred and thirty-five consecutive cardiac surgical patients <1 year of age or undergoing palliation for univentricular cardiac anatomy up to five years of age during January 2010 to December 2012 were included in this study. Upper body central lines are routinely placed by the anesthesiologist after induction of anesthesia for pediatric cardiac surgery at the study institution. The major exception is existing central venous access via an umbilical vein or femoral vein. Patients <2 years of age received a 4.0-French, 5-cm double-lumen central line [Cook Medical polyurethane, no antibiotic or heparin coating]. Those over two years of age received a 5.0-French, 8-cm triple lumen central line [Cook Medical polyurethane, no antibiotic or heparin coating]. A retrospective review of charts, hospital reports, echocardiographic studies, and cardiac catheterization studies was performed. The combined population of infants <1 year of age and patients <5 years of age with functional univentricular hearts totaled 235 patients who underwent 261 cardiac surgical operations. In this cohort of 261 cases, 171 size 4.0 or 5.0-French upper body central lines were inserted. A total of 158 right internal jugular vein catheters were placed. Two left internal jugular lines, two left subclavian lines, and nine right subclavian lines were placed in this population after failure to obtain right internal jugular access. Due to the small sample size (N = 13), the central lines not placed in the right internal jugular vein were excluded from further review. Two cases with right internal jugular venous lines were excluded due to death (without known stenosis or thrombosis) with the line in place. Twenty-three size 4.0- or 5.0-French right internal jugular central venous lines were placed in patients over one year of age (range 1.1-4.3 years) having modified Glenn- or Fontan-type surgery. The central lines were removed with a median of 1.4 days after insertion (range 0.7-8.2 days) for these older children, compared with a median of 4.2 days of age (range 0.3-19.3 days) for the 133 children <1 year of age. Retrospective chart review of nursing notes, progress notes, cardiology notes, discharge summaries, echocardiographic reports, and cardiac catheterization reports for all patients who received an upper body central venous line (internal jugular or subclavian) showed no definitive diagnosis of an upper body venous stenosis or thrombosis related to the central venous line. A further targeted review of echocardiographic and cardiac catheterization studies for univentricular cardiac patients failed to show stenosis or thrombosis of a vessel associated with upper body central line placement. This study describes one institution's experience with routine upper body central venous catheter placement for neonatal and infant cardiac surgery as well as univentricular cardiac palliation (Glenn and Fontan procedures) with minimal risk of clinically significant catheter-associated vessel thrombosis or stenosis. No upper body central venous stenosis or thrombosis was detected in association with perioperative catheter placement in the upper body central venous system, primarily the right internal jugular vein in 156 cases. Right internal jugular central line placement for infant cardiac surgery can be utilized with a low risk of direct venous thrombosis or stenosis.

Transcatheter Closure of Abnormal Vessels and Arteriovenous Fistulas With the Amplatzer Vascular Plug 4 in Patients With Congenital Heart Disease

Although vascular plugs allow the interventional closure of medium-sized to large abnormal vessels, their application is limited by the need for long sheaths or large guiding catheters. The authors report their experience with the new Amplatzer vascular plug 4 (AVP 4), a self-expanding spindle-shaped occluder made of Nitinol wire mash, which can be placed through 4-Fr catheters with an internal diameter of 0.038 in. or larger. From October 2009 until June 2012, 14 AVP 4 devices were deployed in 12 patients (ages, 0.3-48.8 years). Nine patients had venovenous or arteriovenous collaterals in functional univentricular hearts. One patient had pulmonary atresia with a ventricular septal defect and major aortopulmonary collateral arteries, and one patient had a pulmonary arteriovenous fistula. One child had a large coronary artery fistula to the right atrium. The authors used AVP 4 devices with diameters of 4-8 mm. In all the patients, the AVP 4 was implanted successfully. No occluder dislocations and no complications related to the procedure occurred. Complete vessel occlusion was achieved in seven cases. In seven additional cases, a residual shunt was present at the end of the procedure while the patients were still fully heparinized. In 2 of 14 vessels, the decision was made to place additional devices to abolish residual shunting. According to the authors' experience, the AVP 4 allows safe and effective occlusion of medium-size and large abnormal vessels. It is also well suited for tortuous high-flow vessels such as coronary or pulmonary arteriovenous fistulas. In case of a suboptimal position, it is possible to reposition the occluder with ease. Further studies are needed to determine whether initial residual shunting in heparinized patients disappears during follow-up care. The AVP 4 represents a valuable new device for the interventional treatment of complex congenital vessel malformations.

Results of Additional Pulsatile Pulmonary Blood Flow with Bidirectional Glenn Cavopulmonary Anastomosis: Positive Effect on Main Pulmonary Artery Growth and Less Need for Fontan Conversion

Additional antegrade pulsatile pulmonary blood flow obtained by leaving the main pulmonary artery patent during bidirectional cavopulmonary shunt has been shown to give additional benefits to the bidirectional Glenn cavopulmonary anastomosis. We retrospectively evaluated our 20-patient pulsatile Glenn series in order to find out whether these salutary effects were valid or not. Between June 2007 and November 2011, 20 patients (11 girls and 9 boys) with single-ventricle physiology underwent bidirectional cavopulmonary anastomosis. The additional source of blood flow was through the unligated main pulmonary artery in all patients. A retrospective review of our surgical experience was performed focusing on the role of additional pulmonary flow. Medical records and perioperational and postoperative follow-up data including clinical outcomes were retrospectively retrieved and analyzed. Two patients died in the early postoperative period. One patient died in the follow-up period. Mean follow-up time was 23.9 ± 15.7 months. No superior vena cava syndrome and no increase in pulmonary vascular resistance were observed. Improvement of partial oxygen pressure after pulsatile Glenn has been shown in all patients (P = .00). At a mean interval of 22.9 months, main pulmonary artery size continued to increase after pulsatile Glenn cavopulmonary anastomosis (P = .028). Only 1 patient was converted to Fontan type circulation after pulsatile Glenn cavopulmonary anastomosis. The pulsatile cavopulmonary shunt is a useful procedure in the early and intermediate term management of patients with a functional univentricular heart. It improves partial oxygen pressure and the impact of pulsatility on the main pulmonary artery.

Commentary on “Motor Development of Infants With Univentricular Heart at the Ages of 16 and 52 Weeks”

How could I apply this information? Infants with hypoplastic left heart syndrome (HLHS) and other types of functional univentricular heart (UVH) are at high risk for delayed motor development during the first year of life. Early therapeutic intervention may be necessary to advance motor development, particularly for those infants with HLHS and UVH who have undergone open-heart surgery. Specifically, extensive family education on the benefits of prone play may be critical once the infant is medically cleared to be positioned prone. In addition, direct intervention to promote motor development may be necessary due to the complex medical status of the infant and the family's level of comfort in progressing motor skills of an infant who has recently undergone cardiac surgery. What should I be mindful about when applying this information? It is unclear what factors were associated with the delayed motor development observed in infants with HLHS and UVH. All 23 infants with HLHS and 5 of 13 infants with UVH underwent 2 cardiac surgeries, yet Alberta Infant Motor Scale subtests were only provided for the HLHS and UVH infant groups as a whole. Therefore, it is unclear whether motor development was delayed only for the infants who underwent cardiac surgery or also for some infants who did not undergo surgical intervention. In addition, 6 infants with HLHS and 4 infants with UVH received physical therapy intervention during the course of the study; however, it is unclear whether these infants continued to demonstrate delayed development at the 12-month assessment and why a greater number of infants were not referred for therapeutic intervention. Infants with HLHS and those with UVH demonstrate delayed motor development, particularly in prone and standing skills; however, further research is necessary to clarify the factors associated with motor delay. Barbara Sargent PT, PhD, PCS University of Southern California, Los Angeles Leesha Augustine, PT, DPT Children's Hospital of Orange County, Orange, California

Quantification of Ventricular Volume Load in the Context of a Bidirectional Cavopulmonary Shunt: A Theoretical Treatise

Functional univentricular hearts are currently palliated by a staged procedure of which the bidirectional cavopulmonary shunt is usually the second stage. In addition to this stage, a calibrated amount of additional pulmonary blood flow may be preserved to promote pulmonary artery growth and increase the length of the interval preceding the total cavopulmonary connection. However, additional pulmonary blood flow can be deleterious for ventricular functioning and development as it increases functional ventricular volume load. Using the Fick principle we devised a theoretic framework to estimate the ventricular volume loading caused by additional pulmonary and collateral aortopulmonary flow. To use this framework, blood samples need to be taken intraoperatively from the aorta, pulmonary veins, and inferior caval vein to determine oxygen saturations. The oxygen saturation samples have to be taken sequentially with and without additional pulmonary blood flow. The objective of this paper is to provide a theoretic framework to estimate the ventricular volume loading caused by collateral aortopulmonary flow and additional pulmonary blood flow in the context of a bidirectional cavopulmonary shunt in the staged palliation of univentricular hemodynamics. The formulas have not yet systematically been applied in vivo. The added volume loading of the ventricle caused by additional pulmonary blood flow can theoretically be estimated using the newly devised formulas so as to calibrate ventricular volume loading to a desired level intraoperatively.

Univentricular hearts in Denmark 1977 to 2009: Incidence and survival

BackgroundThe incidence of children born with functional univentricular heart (UVH) and their prognosis presumably changed substantially in recent years. This is due to introduction of fetal echocardiography and potential termination of pregnancy (TOP) when UVH is diagnosed (UVH TOP), and to improvements in treatment. We aimed to explore changes in incidence, to estimate changes in survival, and to describe predictors of mortality in UVH patients. MethodsUsing a population-based design we identified all UVH cases in Denmark from 1977 to 2009. Results703 UVH live births and 106 UVH TOP were identified. A dramatic decrease in birth incidence of UVH patients and a corresponding increase in UVH TOP was observed in recent years. Mean incidence rate of UVH (live births and UVH TOP) was 0.39 per 1000 births. In adjusted analysis survival improved significantly from birth era 1977–1989 to 1990–1999 (HR 2.65, 95% confidence interval (CI), 2.06–3.42) but not significantly from 1990–1999 to 2000–2009 (HR 0.77, 95% CI, 0.57–1.05). In the birth era 2000–2009, the lowest five-year survival was seen with hypoplastic left heart syndrome (HLHS) (18.8%), whereas the best survival was seen with tricuspid atresia (79.8%). Adjusted risk of death was 7.3 times higher in the HLHS group compared to the tricuspid atresia group (95% CI, 3.94–13.47). ConclusionsThis study demonstrates a dramatic decrease in birth incidence of UVH patients most probably due to a corresponding increase in UVH TOP. Despite survival improved after introduction of Fontan surgery, survival has not improved significantly during the last 20years.

Surgical Results for Functional Univentricular Heart With Total Anomalous Pulmonary Venous Connection Over a 25-Year Experience

Surgical results for functional univentricular heart with total anomalous pulmonary venous connection (TAPVC) have been unsatisfactory to date. During a 25-year period until December 2009, 207 TAPVC patients underwent surgical repair at our institute, including 56 with a univentricular heart. The 10-year survival rate was 51.1% with univentricular heart and 84.7% with biventricular heart (p<0.0001; log-rank, 27.6). Surgical outcomes and risk factors for early and late death after TAPVC repair in univentricular hearts were retrospectively analyzed. Patients were aged 3.8±4.3 years and weighed 12.3±10.7 kg at operation. Preoperative diagnoses included heterotaxy syndrome in 55, asplenia in 48, preoperative pulmonary venous obstruction in 35, and pulmonary atresia in 20. TAPVC was classified as I in 22, II in 26, III in 5, and IV in 3. Concomitant procedures included Fontan procedure in 29, bidirectional Glenn procedure in 5, systemic-pulmonary shunt in 11, and pulmonary artery banding in 5. There were 17 hospital deaths and 11 late deaths. Fontan completion was undertaken in 31 (55.3%). Postoperative pulmonary venous obstruction was found in 15. Multivariate analysis identified TAPVC III and IV and pulmonary atresia as risk factors for hospital death. Univariate analysis identified postoperative pulmonary venous obstruction and concomitant systemic-pulmonary shunt as risk factors for hospital and late death. TAPVC III, IV, and pulmonary atresia are risk factors for early postoperative death. Intensive intervention, including perioperative management and operation, is required in these complex patients.

Impaired chronotropic response to exercise in children with repaired cyanotic congenital heart disease

Objective — Conventionally the heart rate response to exercise has been considered as a useful parameter for the assessment of exercise performance. However, in patients with surgical repair of congenital heart defects sino-atrial dysfunction has been observed after cardiac surgery.The purpose of this study was to assess whether the heart rate response to exercise can be used in the assessment of exercise performance.Methods — Fifty-three patients with surgical repair of congenital heart disease underwent exercise testing.The patients were 19 children with repair of tetralogy of Fallot (TOF), 17 patients with arterial switch operation for transposition of the great arteries and 17 patients with a Fontan circulation for functional univentricular heart. The patients were compared to age-matched control subjects. Exercise capacity was assessed by determination of the maximal oxygen uptake.To account for the effect of age and gender on heart rate response, values in the patients were compared to age-matched control subjects of the same age and gender and were expressed as a Z-score of the normal value.Results — In the 3 groups of patients a lower than normal heart rate response was observed during submaximal and maximal exercise, varying from -1.7 to -4.6 standard deviation scores.This was not associated with normal values for exercise capacity in patients with TOF or Fontan circulation, as should be expected.Conclusion — In patients with surgical repair of congenital heart disease, the use of heart rate response in the assessment of cardiovascular exercise performance may be seriously misleading and should be complemented with measurements of gas exchange.