Functional Single-ventricle Physiology Research Articles

Experience of Performing Systemic-to-Pulmonary Artery Shunt in Patients with Univentricular Heart Physiology and Depleted Pulmonary Blood Flow

Among patients with congenital heart disease diagnosed in infancy, 7.7% of infants have anatomical variants with functional single ventricle physiology which is often accompanied by depleted pulmonary blood flow. The type of these defects is clinically associated with cyanosis, in most cases caused not by mixing of blood at the level of the heart chambers, but by the presence of ductal-dependent pulmonary blood flow, which requires urgent surgical intervention. The aim. To evaluate the immediate and long-term outcomes of hemodynamic correction in patients with single-ventricle heart physiology with depleted pulmonary blood flow. Materials and methods. In the period from 2010 to 2022, 114 patients with reduced pulmonary blood flow underwent systemic-pulmonary anastomosis at the National Amosov Institute of Cardiovascular Surgery of the National Academy of Medical Sciences of Ukraine. Among these, 64 patients had biventricular circulation and subsequently underwent radical correction. The other 50 patients had single-ventricular heart physiology and underwent placement of systemic-pulmonary anastomosis as the first stage of the hemodynamic strategy according to Fontaine, so their data became the main material of this study. Results. Hospital mortality after systemic-pulmonary anastomosis was 8% (4 patients). An uncomplicated course of the early postoperative period was observed in 38 (76%) patients, and 16 complications were observed in the remaining 12 (24%) patients. The median follow-up period was 40 [3; 160] months. During the follow-up period, 2 (4.3%) patients died due to anastomosis thrombosis as a result of self-discontinuation of anticoagulant therapy, 3 (6.5%) patients were lost to follow-up and did not come for examination. The second stage of hemodynamic correction in the form of bidirectional cavopulmonary anastomosis was performed in 41 (82%) patients of the study group. Conclusions. Patients with single-ventricular heart physiology with depleted pulmonary blood flow are a group of extremely complex children who require an individual approach at all stages of hemodynamic correction, and early diagnosis and palliative systemic-pulmonary anastomosis continues to be a reliable alternative for these children, despite the fact that mortality after the first stage remains quite high.

Anesthesia in A Patient with Pulmonary Atresia with Intact Ventricular Septum (PA IVS) Underwent Bidirectional Cavo-Pulmonary Shunt (BCPS)

Background: Pulmonary atresia with intact ventricular septum (PA-IVS) is a rare condition, encompassing approximately 1%–3% of congenital heart diseases. Patients with PA-IVS have functional single-ventricle physiology. The ultimate possible outcomes for patients with PA-IVS are biventricular circulation, 1.5-ventricle or single-ventricle palliation, or cardiac transplantation. The bidirectional cavopulmonary shunt (BCPS) procedure directs flow from the superior vena cava into both the right and left pulmonary arteries, permitting flow to both lungs. The shunt is considered to be the second stage of palliation and is generally preparative for the third-stage Fontan procedure. The BCPS improves systemic arterial oxygen saturation without increasing ventricular work or pulmonary vascular resistance.Case: A 10-month-old, 25-day-old boy, weight 9.93 kg, body length 72 cm, diagnosed with PA-IVS, restricted persistent foramen ovale (PFO), right ventricle hypoplastic, and turtuous patent ductus arteriosus (PDA), underwent BCPS, atrial septectomy, and PDA stent evacuation surgery. The patient underwent a PDA stenting and ballooning atrial septectomy (BAS) at 17 days of age at the cathlab. The patient was cyanotic with stable hemodynamics and a saturation of 72% preoperatively.Discussion: Preoperative fasting must be observed to maintain the patient's hydration state. Pulmonary blood flow and systemic blood flow must be balanced. An adequate analgetic can prevent pain stimuli that increase pulmonary vascular resistance. Drugs to reduce the afterload, such as milrinone, are needed. Mechanical ventilation was set to get PaCO2 between 40 and 45 mmHg. Maintain the normal heart beat, preload, and contractility to maintain cardiac output (CO) with saturation 80–85%. Wean from mechanical ventilation as soon as possible.Conclusion: Anesthetic management for BCPS in patients with single ventricles from the preoperative period, intraoperative period, and postoperative period. Understanding single ventricle phsiology is important in order to treat the patient.

Partial anomalous venous connection with intrapulmonary dual drainage: Transcatheter treatment of a rare entity.

Partial anomalous pulmonary venous return (PAPVR) is a rare congenital condition, and dual-drainage connection PAPVR to the left atrium has been reported in a few cases in the literature; in which cases, percutaneous catheterization was successfully used in lieu of surgery. We, hereby, describe a 7-month-old boy with a functional single-ventricle physiology with dual drainage of the left upper pulmonary vein to the left atrium and the innominate vein. Appropriate recognition of this entity allowed safe occlusion of the anomalous draining vein.

Long-term survival in patients with univentricular heart: a nationwide, register-based cohort study

Abstract Background Univentricular heart (UVH) is a broad term that covers various cardiac structural abnormalities in which one ventricle is severely underdeveloped, or a ventricular septal wall did not form, leading to a functional single-ventricle physiology. Patients with UVH have a very limited life expectancy if not surgically treated. While the outcome in children with UVH have been extensively studied, data regarding the long-term outcomes in an unselected, nationwide cohort is still lacking. Purpose The aim of the present study was to determine long-term survival in patients with UVH compared to an age- and sex-matched control population without congenital heart disease in Sweden. Methods We linked data from the Swedish Patient and Cause of Death Register to identify patients with UVH that were born between 1970 and 2017. Each patient with UVH was matched with ten individuals without congenital heart disease for year of birth and sex. The mortality risk in patients with UVH compared with matched controls was analyzed using Cox proportional regression models and Kaplan-Meier survival analysis. Results Of a total of 5,075 patients with UVH and 50,620 matched controls, 1,992 (37.9%) and 485 (1.0%) died, respectively. The mean follow-up (standard deviation) was 15.7 (± 14.2) years. A total of 758 patients (14.9%) of the UVH population were diagnosed with hypoplastic left heart syndrome (HLHS). The mortality risk was 53.01 (95% CI, 48.0–58.6) times higher in UVH and 163.5 (95% CI, 124.3–215.2) times higher in HLHS compared to controls. According to birth period, highest mortality was found at the earliest UVH cohort (1970–1981) 59.8%, and decreased by later birth periods. The lowest mortality was in the latest birth period, 2006–2017 (16.3%). Conclusions In this nationwide, register-based cohort study, the overall risk of mortality was more than 50 times higher in patients with UVH compared to matched controls. However, an increased survival was observed over time and by later birth periods. Quadragenarians with UVH is still a rare group but are expected to increase during the next decades. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Swedish heart lung foundation

Considerations in Critical-Care and Anesthetic Management of Adult Patients Living With Fontan Circulation

The Fontan procedure is a staged palliation for various complex congenital cardiac lesions, including tricuspid atresia, pulmonary atresia, hypoplastic left heart syndrome, and double-inlet left ventricle, all of which involve a functional single-ventricle physiology. The complexity of the patients' original anatomy combined with the anatomic and physiologic consequences of the Fontan circulation creates challenges. Teens and adults living with Fontan palliation will need perioperative support for noncardiac surgery, peripartum management for labour and delivery, interventions related to their structural heart disease, electrophysiology procedures, pacemakers, cardioversions, cardiac surgery, transplantation, and advanced mechanical support. This review focuses on the anesthetic and intensive care unit (ICU) management of these patients during their perioperative journey, with an emphasis on the continuity of preintervention planning, referral pathways, and postintervention ICU management. Requests for recipes and doses of medications are frequent; however, as in normal anesthesia and ICU practice, the method of anesthesia and dosing are dependent on the presenting medical/surgical conditions and the underlying anatomy and physiologic reserve. A patient with Fontan palliation in their early 20s attending school full-time with a cavopulmonary connection is likely to have more reserve than a patient in their late 40s with an atriopulmonary Fontan at home waiting for a heart transplant. Each case will require an anesthetic and critical care plan tailored to the situation. The critical care environment is a natural extension of the anesthetic management of a patient, with complex considerations for a patient with Fontan palliation.

Fontan-associated liver disease.

Fontan-associated liver disease.

The Tricuspid Valve in Single-Ventricle Patients: Forgotten, Unforgivable, and Indispensable

The Tricuspid Valve in Single-Ventricle Patients: Forgotten, Unforgivable, and Indispensable

Improved outcomes in neonates who require venoarterial extracorporeal membrane oxygenation after the Norwood procedure.

Extracorporeal membrane oxygenation after the Norwood procedure has historically been associated with poor outcomes, with reported hospital survival rates of 13%-48%. We hypothesized that contemporary outcomes in this population have improved. We aimed to compare clinical outcomes of contemporary cohorts of patients with functional single ventricle physiology who did and did not receive extracorporeal membrane oxygenation after the Norwood procedure. Single-center retrospective cohort study of patients with single ventricle anatomy who underwent the Norwood procedure between 2009 and 2017 was performed. Kaplan-Meier survival curves were constructed, and Cox proportional hazard regression analyses were performed to compare transplant-free survival in patients who did and did not receive venoarterial extracorporeal membrane oxygenation. In total, 85 patients met inclusion criteria. Venoarterial extracorporeal membrane oxygenation was utilized in 25 patients (29%). A total of 18 patients (72%) who received venoarterial extracorporeal membrane oxygenation survived to hospital discharge, compared to 54 patients (92%) who did not receive venoarterial extracorporeal membrane oxygenation (p = 0.013). Post-discharge transplant-free survival was not significantly different between patients who did and did not receive venoarterial extracorporeal membrane oxygenation (log-rank p value = 0.28). Cox proportional hazard regression analysis revealed that the occurrence of cardiac arrest requiring cardiopulmonary resuscitation (hazard ratio = 4.5; 95% confidence interval = 2.0-10.1) during the perioperative period was independently associated with death or transplantation, whereas venoarterial extracorporeal membrane oxygenation was not an independent risk factor for death or transplantation (hazard ratio = 2.0; 95% confidence interval = 0.8-4.9). In our cohort of children who received venoarterial extracorporeal membrane oxygenation after the Norwood procedure, hospital survival was improved compared to historical data. In addition, venoarterial extracorporeal membrane oxygenation utilization was not independently associated with worse outcomes.

CRT Implantation in a Patient with Congenital Heart Malformation

Abstract Treatment of patients with functional single-ventricle physiology is achieved using surgical corrections known as the “Fontan Procedure”. Two separate blood circulations are created from the single-ventricle function. These are non-cyanogenic patients, but at high risk of developing HF. CRT implantation is an option to improve the functional class and EF.

The Superior Cavopulmonary Connection: History and Current Perspectives.

The development of the superior cavopulmonary connection is a rich illustration of international influences in congenital cardiac surgery. The bidirectional Glenn and hemi-Fontan procedures have improved survival as both definitive and staged functional single ventricle palliation. The optimal timing of the second-stage superior cavopulmonary procedures varies by center but for low- and intermediate-risk patients, this may be within three to six months after the Norwood procedure. The list of risk factors continues to grow but the most frequently cited factors include atrioventricular valve regurgitation, decreased ventricular function, need for reintervention, and failure to attain nutritional and growth goals. Ongoing prospective, multi-institutional studies, particularly those fostered internationally by the World Society for Pediatric and Congenital Heart Surgery and other associations, will hopefully provide further clarification of the complex management issues related to patients with functional single ventricle physiology.

Spectrum of congenital cardiac malformations in dextrocardia: A single institute study

Introduction: Complex congenital heart malformations are associated with dextrocardia depending on the situs. The objective is to present the spectrum of cardiac malformations and the surgical interventions done in patients with dextrocardia at our tertiary care institute over 5 years. Material and Methods: A retrospective study of patients with dextrocardia undergoing some form of cardiac surgery at our institute from January 2012 to December 2016 was done. Seventeen cases were identified, and their records were reviewed. Results: Of 2231 cardiac surgeries done for congenital heart disease, there were 17 (0.76%) patients with dextrocardia with male predominance (70.58%). The mean age was 5.69 ± 6.66 years. Of 17 patients, 9 had situs inversus, 7 had situs solitus, and 1 patient had situs ambiguous. Thirteen patients (76.47%) had functional single-ventricle physiology. Six of them (46.15%) had situs solitus, 6 (46.15%) had situs inversus, and situs ambiguous in 1 (7.69%). Biventricular repair was possible in 4 patients (23.52%), of which 3 had situs inversus and 1 had situs solitus. Three patients had ventriculoarterial (VA) discordance and 2 had atrioventricular and VA discordance. There were two early mortalities and three late mortalities, all of them had single-ventricle physiology. Discussion and Conclusion: Dextrocardia is a rare congenital anomaly with wide variations of complex congenital cardiac malformations. It is associated with all forms of spatial relationships of visceral organs with situs inversus being the most common.

The Fontan Procedure for Single-Ventricle Physiology.

The Fontan procedure is the final procedure in staged palliation for patients with functional single-ventricle physiology. The goal of the procedure is to separate systemic and pulmonary blood flow by directing systemic venous return through the Fontan connection to the pulmonary arteries and the lungs without ventricular contribution. Following the procedure, pulmonary blood flow is completely passive and dependent on pressure gradients, resulting in complex postoperative cardiopulmonary interactions. Understanding the physiology is essential to effectively manage these patients. Critical care nurses caring for patients after a Fontan procedure must understand preoperative data, risk factors, and unique postoperative physiology so they can anticipate specific postoperative problems, recognize trends in clinical status, and develop an appropriate plan of care. This paper reviews the first 2 stages of single-ventricle palliation, relevant modifications to the Fontan procedure, important preoperative cardiac catheterization data, common postoperative problems, and outcomes after the Fontan procedure.

Outcomes of Extracorporeal Membrane Oxygenation in Children: An 11-Year Single-Center Experience in Korea.

BackgroundExtracorporeal membrane oxygenation (ECMO) has become an important treatment modality in pediatric patients with cardiopulmonary failure, but few studies have been conducted in Korea.MethodsWe conducted a retrospective review of pediatric patients younger than 18 years who were placed on ECMO between January 2004 and December 2014 at Samsung Medical Center.ResultsWe identified 116 children on ECMO support. The overall rate of successful weaning was 51.7%, and the survival to discharge rate was 37.1%. There were 39, 61, and 16 patients on ECMO for respiratory, cardiac, and extracorporeal cardiopulmonary resuscitation, respectively. The weaning rate in each group was 48.7%, 55.7%, and 43.8%, respectively. The survival rate was 43.6%, 36.1%, and 25.0%, respectively. Sixteen patients on ECMO had functional single ventricle physiology; in this group, the weaning rate was 43.8% and the survival rate was 31.3%. Ten patients were on ECMO as a bridge to transplantation (8 for heart and 2 for lung). In patients with heart transplantation, the rate of survival to transplantation was 50.0%, and the overall rate of survival to discharge was 37.5%.ConclusionAn increasing trend in pediatric ECMO utilization was observed. The outcomes were favorable considering the early experiences that were included in this study and the limited supply of specialized equipment for pediatric patients.

Mechanical Circulatory Support as Bridge to Transplantation for the Failing Single Ventricle

Circulatory failure necessitating cardiac transplantation will ultimately develop in many patients with functional single-ventricle physiology. Interest in the use of mechanical circulatory support (MCS) in this population is growing. This was a retrospective case series of patients with functional single-ventricle physiology who underwent MCS with a ventricular assist device or a totalartificial heart as a bridge to cardiac transplantation between January 2006 and December 2014. Baseline demographics, intraoperative data, postoperative complications, and outcome data were collected from the medical record. MCS was used in 5 patients: HeartWare ventricular assist device (HeartWare International, Framingham, MA) in 1 patient, SynCardia total artificial heart (SynCardia Systems, Tucson, AZ) in 1, Thoratec Paracorporeal ventricular assist device (Thoratec Corp, Pleasanton, CA) in 1, and the Berlin Heart EXCOR (Berlin Heart Inc, The Woodlands, TX) in 2. The mean age at MCS was 12 ± 8 years. There were 2 early deaths at 12 and 28 days after MCS: 1 patient died of multiorgan system failure and 1 of neurologic injury. Overall, neurologic complications occurred in 3 patients (60%), and 1 patient (20%) required renal replacement therapy. Three patients (60%) underwent successful cardiac transplantation. The median time on the waiting list was 59 days (interquartile range, 18 to 126 days), and the median duration of MCS was 60 days (interquartile range, 28 to 93 days). At the time of transplant, all 3 patients were ambulatory, without the need for mechanical ventilation, and end-organ dysfunction had resolved. The 3 patients who received transplants were discharged from the hospital and were alive at an average follow-up of 9 ± 14 months. MCS can be successfully used as a bridge to transplantation in patients with a failing single-ventricle circulation. Use of MCS can allow for resolution of end-organ dysfunction and rehabilitation, leading to improved outcomes in this difficult population.

Circulation: Heart Failure Editors’ Picks

<i>Circulation: Heart Failure</i> Editors’ Picks

Impact of Sildenafil on Echocardiographic Indices of Myocardial Performance After the Fontan Operation

The objective of this study was describe the impact of sildenafil on echocardiographic measures of myocardial performance in children and young adults with a functional single-ventricle physiology late after Fontan surgery. A double-blind, placebo-controlled, crossover trial was conducted in children and young adults after the Fontan operation at a single pediatric center. Subjects were randomized to receive placebo or sildenafil (20 mg tid) for 6 weeks. After a 6-week washout period, subjects were crossed for an additional 6 weeks. Each subject underwent an echocardiogram at the start and finish of each phase. A total of 27 subjects completed study testing at a mean age of 14.9 years and a mean time from Fontan surgery of 11.3 years. After sildenafil, subjects demonstrated improvement in their myocardial performance index (MPI; -0.051; 95% CI -0.095, -0.0077; p 0.02) and in the product of the velocity time integral (VTI) of the dominant outflow tract and the heart rate (HR; 110 cm × bpm; 95% CI 7.5, 220; p = 0.04). Measures of diastolic performance, including inflow velocities, myocardial velocities, and the ratio of blood pool velocity to myocardial velocity during passive inflow, did not change. In this cohort, there were significant improvements in both the MPI and the product of the VTI × HR after 6 weeks of treatment with sildenafil. These findings suggest that sildenafil may be a useful therapy to improve or maintain ventricular performance in select patients after the Fontan operation.

Atrioventricular valve repair in patients with functional single-ventricle physiology: Impact of ventricular and valve function and morphology on survival and reintervention

This study was to determine whether atrioventricular valve repair modifies natural history of single-ventricle patients with atrioventricular valve insufficiency and to identify factors predicting survival and reintervention. Fifty-seven (13.5%) of 422 single-ventricle patients underwent atrioventricular valve repair. Valve morphology, regurgitation mechanism, and ventricular morphology and function were analyzed for effect on survival, transplant, and reintervention with multivariate logistic and Cox regression models. Comparative analysis used case-matched controls. Atrioventricular valve was tricuspid in 67% and common in 28%. Ventricular morphology was right in 83%. Regurgitation mechanisms were prolapse (n=24, 46%), dysplasia (n=18, 35%), annular dilatation (n=8, 15%), and restriction or cleft (n=2, 4%). Postrepair insufficiency was none or trivial in 14 (26%), mild in 33 (61%), and moderate in 7 (13%). Survival in repair group was lower than in matched controls (78.9% vs 92.7% at 1 year, 68.7% vs 90.6% at 3 years, P=.015). Patients with successful repair and normal ventricular function had equivalent survival to matched controls (P=.36). Independent predictors for death or transplant included increased indexed annular size (P=.05), increased cardiopulmonary bypass time (P=.04), and decreased postrepair ventricular function (P=.01). Ventricular dilation was a time-related factor for all events, including failed repair. Survival was lower in single-ventricle patients operated on for atrioventricular valve insufficiency than in case-matched controls. Patients with little postoperative residual regurgitation and preserved ventricular function had equivalent survival to controls. Lower grade ventricular function and ventricular dilation correlated with death and repair failure, suggesting that timing of intervention may affect outcome.

Nonfenestrated Extracardiac Total Cavopulmonary Connection in 132 Consecutive Patients

The study was conducted to assess the need for fenestration for completion of a total cavopulmonary connection (TCPC) with the most recent modification of an extracardiac conduit. The extracardiac approach was introduced to our institution in January 1999. Between June 2000 and June 2006, 132 consecutive patients were treated without a fenestration. At the time of TCPC, the median age was 31 months (range, 16 251), with 93 patients (70%) being younger than 48 months. Median patient weight was 12.5 kg (range, 9 to 66 kg). A previous partial cavopulmonary connection (PCPC) was accomplished in 117 patients (88.6%), without additional pulmonary blood flow. Thirty-day-mortality was 1.5%. Median time to extubation was 14 hours (range, 3 hours to 126 days). Initial pulmonary artery pressure value was 16.5 +/- 2.2 mm Hg, and 13.1 +/- 1.8 after extubation. Median drainage requirement was 4 days (range, 1 to 45), and median duration of hospitalization was 20 days (range, 5 to 128). Thirty-one (24%) required repeat drainage insertion. No subsequent fenestration was performed, and at hospital discharge no significant repeat effusions were observed. Multiple covariate logistic regression revealed longer time interval from PCPC to extracardiac TCPC (p = 0.006) as a significant predictor of pleural drainage lasting longer than 4 days, and older age at the time of extracardiac TCPC (p = 0.040) as a risk factor for hospitalization more than 20 days. Higher pulmonary artery pressure 3 hours postoperatively was a significant predictor for both outcome variables in the multivariate model (p = 0.013, p = 0.001). In general, an extracardiac TCPC can be performed without fenestration. Early staging of patients with functional single ventricle physiology may be one of the keys for these findings.

Three-Dimensional Electroanatomic Voltage Map-Guided Treatment of a Patient with a Failing Atriopulmonary Fontan Circulation

A three-dimensional electroanatomic bipolar voltage map of the right atrium was performed in a 20-year-old patient with functional single-ventricle physiology after a classic Fontan-type operation who presented with clinical signs of heart failure, a dilated right atrium, protein-losing enteropathy, and sinus node dysfunction. Previous pacemaker upgrading to a DDD system using a transvenous right atrial lead had failed due to insufficient sensing and pacing function. The voltage map showed large zones of scarring and low-amplitude signals. Consecutively, conversion to an extracardiac total cavopulmonary connection (TCPC) together with a pacing lead insertion into the left atrium was performed successfully.

Extracardiac Conduit Total Cavopulmonary Anastomosis

Since the introduction of a physiologically corrective procedure for patients with tricuspid atresia,' the concept of total right-heart bypass has been applied to a wide range of complex congenital heart defects. Over the years, a number of modifications of the original Fontan operation have been proposed in an effort to improve outcomes .2-6 Although an extracardiac variation of the Fontan concept was originally described by Humes et a1 and Nawa et a1 in 1988,7.8 its routine application for all forms of single ventricle hearts was first adopted by Marcelletti et al.9 For the past 5 years, we have used extracardiac conduit total cavopulmonary anastomosis as definitive palliation for almost all patients with functional single ventricle physiology.